BUFFEL GRASS MORPHOAGRONOMIC CHARACTERIZATION FROM Cenchrus GERMPLASM ACTIVE BANK

OpenAIRE

BRUNO, LEILA REGINA GOMES PASSOS; ANTONIO, RAFAELA PRISCILA; ASSIS, JOSÉ GERALDO DE AQUINO; MOREIRA, JOSÉ NILTON; LIRA, IRLANE CRISTINE DE SOUZA ANDRADE

2017-01-01

ABSTRACT This study aimed to characterize buffel grass accessions of the Cenchrus Germplasm Active Bank (CGAB) from Embrapa Semi-Arid in a morphoagronomic way, checking the descriptors variability and efficiency in accessions on two consecutive cuts. Twenty-five accessions and five buffel grass cultivars were used in randomized complete block design with three replications. Evaluations were conducted after two consecutive cuts, each evaluation performed 90 days after each cut. Characterizatio...

Phytosterol variability in almond germplasm

OpenAIRE

Fernández Cuesta, A.; Kodad, Ossama; Socias i Company, Rafel; Velasco, L.

2012-01-01

Phytosterols are important dietary components that contribute to reducing serum cholesterol levels. The objective of this research was to assess genetic diversity for total content and profile of free and esterified phytosterols in a world germplasm collection of almond [Prunus amygdalus Batsch; syn. P. dulcis (Mill.) D.A. Webb]. Steryl glycosides and acylated steryl glycosides were not measured. Fruit from 160 almond accessions were collected in 2009 and 2010. Kernel phytosterol ...

Investigation and Analysis of Genetic Diversity of Diospyros Germplasms Using SCoT Molecular Markers in Guangxi.

Science.gov (United States)

Deng, Libao; Liang, Qingzhi; He, Xinhua; Luo, Cong; Chen, Hu; Qin, Zhenshi

2015-01-01

Knowledge about genetic diversity and relationships among germplasms could be an invaluable aid in diospyros improvement strategies. This study was designed to analyze the genetic diversity and relationship of local and natural varieties in Guangxi Zhuang Autonomous Region of China using start codon targeted polymorphism (SCoT) markers. The accessions of 95 diospyros germplasms belonging to four species Diospyros kaki Thunb, D. oleifera Cheng, D. kaki var. silverstris Mak, and D. lotus Linn were collected from different eco-climatic zones in Guangxi and were analyzed using SCoT markers. Results indicated that the accessions of 95 diospyros germplasms could be distinguished using SCoT markers, and were divided into three groups at similarity coefficient of 0.608; these germplasms that belong to the same species were clustered together; of these, the degree of genetic diversity of the natural D. kaki var. silverstris Mak population was richest among the four species; the geographical distance showed that the 12 natural populations of D. kaki var. silverstris Mak were divided into two groups at similarity coefficient of 0.19. Meanwhile, in order to further verify the stable and useful of SCoT markers in diospyros germplasms, SSR markers were also used in current research to analyze the genetic diversity and relationship in the same diospyros germplasms. Once again, majority of germplasms that belong to the same species were clustered together. Thus SCoT markers were stable and especially useful for analysis of the genetic diversity and relationship in diospyros germplasms. The molecular characterization and diversity assessment of diospyros were very important for conservation of diospyros germplasm resources, meanwhile for diospyros improvement.

Genetic diversity in wheat germplasm collections from Balochistan province of Pakistan

International Nuclear Information System (INIS)

Khan, A.A.; Iqbal, A.; Awan, F.S.; Khan, I.A.

2010-01-01

Productivity of wheat varieties being bred for the last many years is stagnant in Pakistan, apparently because of the narrowed genetic base of their parental lines. As a part of the national wheat germplasm characterization programme, we examined genetic diversity among 75 accessions of wheat using RAPD markers and assessed the relationship and genetic distance between them. The accessions surveyed were comprised of land race populations of Triticum aestivum L., collected from various districts of the Balochistan province of Pakistan, which is considered a reservoir of genetic diversity, particularly for wheat. The genetic similarity revealed by RAPD markers among the wheat accessions was medium to high. The accessions collected from Sibi and Pishin districts had the greatest similarity. The polymorphism revealed in the wheat accessions, appeared to be distributed with the location of collections. The high degree of similarity even among the presumably land race material emphasizes the need for the expansion of germplasm resources and development of wheat varieties with diverse genetic background, which could substantiate the wheat breeding programmes to increase its productivity. (author)

Genetic diversity and population structure assessed by SSR and SNP markers in a large germplasm collection of grape

Science.gov (United States)

2013-01-01

Background The economic importance of grapevine has driven significant efforts in genomics to accelerate the exploitation of Vitis resources for development of new cultivars. However, although a large number of clonally propagated accessions are maintained in grape germplasm collections worldwide, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome-wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of such core samples. Results We investigated patterns of molecular diversity at 22 common microsatellite loci and 384 single nucleotide polymorphisms (SNPs) in 2273 accessions of domesticated grapevine V. vinifera ssp. sativa, its wild relative V. vinifera ssp. sylvestris, interspecific hybrid cultivars and rootstocks. Despite the large number of putative duplicates and extensive clonal relationships among the accessions, we observed high level of genetic variation. In the total germplasm collection the average genetic diversity, as quantified by the expected heterozygosity, was higher for SSR loci (0.81) than for SNPs (0.34). The analysis of the genetic structure in the grape germplasm collection revealed several levels of stratification. The primary division was between accessions of V. vinifera and non-vinifera, followed by the distinction between wild and domesticated grapevine. Intra-specific subgroups were detected within cultivated grapevine representing different eco-geographic groups. The comparison of a phenological core collection and genetic core collections showed that the latter retained more genetic diversity, while maintaining a similar phenotypic variability. Conclusions The comprehensive molecular characterization of our grape

Establishing the Bases for Introducing the Unexplored Portuguese Common Bean Germplasm into the Breeding World

Science.gov (United States)

Leitão, Susana T.; Dinis, Marco; Veloso, Maria M.; Šatović, Zlatko; Vaz Patto, Maria C.

2017-01-01

Common bean (Phaseolus vulgaris L.) is among the most important grain legumes for human consumption worldwide. Portugal has a potentially promising common bean germplasm, resulting from more than five centuries of natural adaptation and farmers' selection. Nevertheless, limited characterization of this resource hampers its exploitation by breeding programs. To support a more efficient conservation of the national bean germplasm and promote its use in crop improvement, we performed, for the first time, a simultaneous molecular marker (21 microsatellites and a DNA marker for phaseolin-type diversity analysis) and seed and plant morphological characterization (14 traits) of 175 accessions from Portuguese mainland and islands traditional bean-growing regions. A total of 188 different alleles were identified and an average pairwise Cavalli-Sforza and Edwards' chord genetic distance of 0.193 was estimated among accessions. To relate the Portuguese germplasm with the global common bean diversity, 17 wild relatives and representative accessions from the Andean and Mesoamerican gene pools were evaluated at the molecular level. No correlation was detected between the variability found and the geographic origin of accessions. Structure analysis divided the collection into three main clusters. Most of the Portuguese accessions grouped with the race representatives and wild relatives from the Andean region. One third of the national germplasm had admixed genetic origin and might represent putative hybrids among gene pools from the two original centers of domestication in the Andes and Mesoamerica. The molecular marker-based classification was largely congruent with the three most frequent phaseolin haplotype patterns observed in the accessions analyzed. Seed and plant morphological characterization of 150 Portuguese common bean accessions revealed a clear separation among genetic structure and phaseolin haplotype groups of accessions, with seed size and shape and the number of

An empirical assessment of the effects of the 1994 In Trust Agreements on IRRI Germplasm Acquisition and Distribution

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Elisabetta Gotor

2009-12-01

Full Text Available The objective of this paper is to assess the possible influence of the 1994 In Trust Agreements (ITAs on acquisition and distribution of germplasm held by the International Research Rice Institute (IRRI genebank. The agreements, legally affirmed the ‘public good’ status of the collections that were placed ‘In Trust’ for the benefit of the world community under agreements with FAO. They initiated a formal system of multilateral access to CGIAR-held ex situ genetic resources. The hypothesis that the consequences of the ITAs lead to an enhancement of CGIAR germplasm utilization is tested here using a basic conceptual framework to infer on factors determining the distribution of germplasm. Subsequently a Bayesian empirical model is applied to IRRI accessions distribution’s time-series to provide formal evidence to the hypothesis. Results show that there is a discernible ‘change’ point that would support a significant drop in germplasm distribution followed by a new growing trend around the establishment of the ITAs. This had followed a period beginning around 1989 and leading up to the establishment of the ITAs of a large number of requests for restoration of germplasm back to countries of origin and a reduction in acquisitions. As a result the number of accessions held by IRRI reached a low point around 1994. The number of accessions might not have been built back up without the establishment of a stable policy environment that was provided by the ITAs.

Diversity of Sex Types and Seasonal Sexual Plasticity in a Cucumber Germplasm Collection

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Dou Xinxin

2015-09-01

Full Text Available The sex type of a cucumber plant is determined by the proportion of male, female and hermaphrodite flowers that it bears and is an important factor that affects fruit yield. In this paper, the sex types and seasonal sexual stabilities of 322 accessions of cucumber germplasm were identified. This germplasm collection displayed a great variety of sex types. We used an updated 10-type sex classification system based on the flower types present and the proportion of nodes with pistillate flowers (PNPF. The PNPF ranges of all the accessions were 2.12%–100% in spring and 0–100% in autumn. A total of 81.37% of the accessions had PNPFs of 10%–50% in spring, but most (84.78% accessions were reduced to 0–20% PNPF in autumn. The range of reduction of PNPF from spring to autumn was 0–67.91%. In other words, most of the germplasm was normal monoecious (31.68% or subandroecious (62.73% in spring, but 94.10% of the accessions were subandroecious in autumn. According to the statistical evaluation of the difference in PNPFs between the two seasons, each accession could be classified into one of three groups: seasonally stable, seasonally sensitive and highly seasonally sensitive, accounting for 10.56%, 20.50% and 68.94% of the accessions, respectively. With a few exceptions, the seasonal PNPF differences were positively correlated with the PNPFs in a given season for most accessions. These results provided useful information and materials for sex expression mechanism research and for breeding cucumbers with high and stable yields.

Genetic diversity and population structure of Miscanthus sinensis germplasm in China.

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Hua Zhao

Full Text Available Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38, as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei's genetic diversity index (He of 0.32 and polymorphism information content (PIC of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83% was substantially greater than the between-subpopulation variation (17%. Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.

Flowering of taro germplasm (Colocasia esculenta (L. Schott in Cuba

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Yadelys Figueroa Águila

2016-01-01

Full Text Available Research was done at the Center for Tropical Crop Research (INIVIT, to evaluate inflorescence of taro germplasm (104 accessions in Cuba´s climatic conditions. Sampling was made every 7 days in the 2013-2014 period to evaluate inflorescence; accessions were characterized according to flowering parameters. The results showed that natural flowering by the 26-accession sample (25%, was observed to early blossom from July to October in 18 accessions (69.2%. Increased temperature and relative humidity lasted until November, when inflorescence ends.

Quality and bioactive compounds in fruit of foreign accessions of mango conserved in an Active Germplasm Bank1

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Thalita Passos Ribeiro

Full Text Available The aim of this study was to characterise the quality and levels of bioactive compounds in the fruit of 22 foreign accessions of the mango belonging to the Active Germplasm Bank of Embrapa Semiárido. Sixty fruits from each of the accessions: Florigon, Haden, 65, Irwin, M 13269, Momi-K, Scuper Many, Simmonds, Tommy Atkins, Van Dyke, Winter, Zill, Amrapali, Olour, Aplle DCG 406, Mon Amon DCG 407, Black Java, Kensington, Chené, Manila, Manzanillo and Maya, were harvested upon reaching physiological maturity, one half being analysed when harvested and the other half stored at ambient temperature (25.4 ± 2.9 ºC and 41 ± 9% RH until ripe. The experimental design was completely randomised in a 22 x 2 factorial (accession x maturity stage, with three replications of ten fruits. The accessions Chene, Momi-K and Van Dyke stood out for their physical attributes: weight, length, diameter and firmness of pulp, and for their good post-harvest conservation. The accession Amrapali was different because of its high levels of soluble solids, total soluble sugars, starch, ascorbic acid and carotenoids, suggesting a high potential for insertion into a breeding program aimed at the quality of the mango.

New additions to the National Plant Germplasm System's Beta collection: Southern Morocco collection

Science.gov (United States)

The USDA Agricultural Research Service’s National Plant Germplasm System’s (NPGS) Beta collection is comprised of 2,541 accessions from 14 species. The largest number of accessions is from Beta vulgaris ssp. vulgaris, (domesticated beet crops – table, leaf (Swiss chard), fodder and, primarily, sugar...

New additions to the National Plant Germplasm System’s Beta collection: Southern Morocco expedition

Science.gov (United States)

The USDA Agricultural Research Service’s National Plant Germplasm System’s (NPGS) Beta collection is comprised of 2,541 accessions from 14 species. The largest number of accessions is from Beta vulgaris ssp. vulgaris, (domesticated beet crops – table, leaf (Swiss chard), fodder and, primarily, sugar...

RAPD analysis of the genetic diversity of mango (Mangifera indica) germplasm in Brazil.

Science.gov (United States)

Souza, I G B; Valente, S E S; Britto, F B; de Souza, V A B; Lima, P S C

2011-12-14

We evaluated genetic variability of mango (Mangifera indica) accessions maintained in the Active Germplasm Bank of Embrapa Meio-Norte in Teresina, Piauí, Brazil, using RAPDs. Among these accessions, 35 originated from plantings in Brazil, six from the USA and one from India. Genomic DNA, extracted from leaf material using a commercial purification kit, was subjected to PCR with the primers A01, A09, G03, G10, N05, and M16. Fifty-five polymorphic loci were identified, with mean of 9.16 ± 3.31 bands per primer and 100% polymorphism. Application of unweighted pair group method using arithmetic average cluster analysis demonstrated five genotypic groups among the accessions examined. The genotypes Rosa 41, Rosa 48 and Rosa 49 were highly similar (94% similarity), whereas genotypes Sensation and Rosa 18 were the most divergent (only 7% similarity). The mango accessions were found to have considerable genetic variability, demonstrating the importance of analyzing each genotype in a collection in order to efficiently maintain the germplasm collection.

Identification of elite pure-lines from local lentil germplasm using diversity index based on quantitative traits

International Nuclear Information System (INIS)

Sultana, T.; Nadeem, S.; Fatima, Z.

2010-01-01

Three hundred and seventeen accessions of lentil collected from all over the country were evaluated for six quantitative traits to investigate inter and intra-accession diversity in association with geographic pattern. Variation indicated that areas with high geographic diversity that is supposed to present high biological diversity are yet to be explored. Classification of germplasm gave rise to some elite lines for specific characters and the accessions for days to flowering (45), days to maturity (7), plant height (12), pods per cluster (17) and seed weight (27) have been selected and suggested for exploitation in breeding programme. Twelve clusters were observed with varying degrees of intercluster dissimilarity that suggested the selection of diverse superior parents for hybridization. Some of the characters associated with origin as high seed weight of germplasm collected from Baluchistan is needed to exploit for specific trait/s. Germplasm distribution revealed that Punjab and Sindh represented a high collections along with high diversity, whereas other areas are yet to be explored. Similarly zone 3a, 6, 7, 9 and 10 along with high mountains lack complete representation that indicated the importance for future collection mission to these areas. (author)

Chemical Diversity in Lippia alba (Mill.) N. E. Brown Germplasm

OpenAIRE

Arie Fitzgerald Blank; Lídia Cristina Alves Camêlo; Maria de Fátima Arrigoni-Blank; José Baldin Pinheiro; Thiago Matos Andrade; Edenilson dos Santos Niculau; Péricles Barreto Alves

2015-01-01

The aim of this study was to perform chemical characterization of Lippia alba accessions from the Active Germplasm Bank of the Federal University of Sergipe. A randomized block experimental design with two replications was applied. The analysis of the chemical composition of the essential oils was conducted using a gas chromatograph coupled to a mass spectrometer. The chemical composition of the essential oils allowed the accessions to be allocated to the following six groups: group 1: linalo...

Germplasm Management in the Post-genomics Era-a case study with lettuce

Science.gov (United States)

High-throughput genotyping platforms and next-generation sequencing technologies revolutionized our ways in germplasm characterization. In collaboration with UC Davis Genome Center, we completed a project of genotyping the entire cultivated lettuce (Lactuca sativa L.) collection of 1,066 accessions ...

SeedStor: A Germplasm Information Management System and Public Database.

Science.gov (United States)

Horler, R S P; Turner, A S; Fretter, P; Ambrose, M

2018-01-01

SeedStor (https://www.seedstor.ac.uk) acts as the publicly available database for the seed collections held by the Germplasm Resources Unit (GRU) based at the John Innes Centre, Norwich, UK. The GRU is a national capability supported by the Biotechnology and Biological Sciences Research Council (BBSRC). The GRU curates germplasm collections of a range of temperate cereal, legume and Brassica crops and their associated wild relatives, as well as precise genetic stocks, near-isogenic lines and mapping populations. With >35,000 accessions, the GRU forms part of the UK's plant conservation contribution to the Multilateral System (MLS) of the International Treaty for Plant Genetic Resources for Food and Agriculture (ITPGRFA) for wheat, barley, oat and pea. SeedStor is a fully searchable system that allows our various collections to be browsed species by species through to complicated multipart phenotype criteria-driven queries. The results from these searches can be downloaded for later analysis or used to order germplasm via our shopping cart. The user community for SeedStor is the plant science research community, plant breeders, specialist growers, hobby farmers and amateur gardeners, and educationalists. Furthermore, SeedStor is much more than a database; it has been developed to act internally as a Germplasm Information Management System that allows team members to track and process germplasm requests, determine regeneration priorities, handle cost recovery and Material Transfer Agreement paperwork, manage the Seed Store holdings and easily report on a wide range of the aforementioned tasks. © The Author(s) 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Genetic diversity and population structure analysis to construct a core collection from a large Capsicum germplasm.

Science.gov (United States)

Lee, Hea-Young; Ro, Na-Young; Jeong, Hee-Jin; Kwon, Jin-Kyung; Jo, Jinkwan; Ha, Yeaseong; Jung, Ayoung; Han, Ji-Woong; Venkatesh, Jelli; Kang, Byoung-Cheorl

2016-11-14

Conservation of genetic diversity is an essential prerequisite for developing new cultivars with desirable agronomic traits. Although a large number of germplasm collections have been established worldwide, many of them face major difficulties due to large size and a lack of adequate information about population structure and genetic diversity. Core collection with a minimum number of accessions and maximum genetic diversity of pepper species and its wild relatives will facilitate easy access to genetic material as well as the use of hidden genetic diversity in Capsicum. To explore genetic diversity and population structure, we investigated patterns of molecular diversity using a transcriptome-based 48 single nucleotide polymorphisms (SNPs) in a large germplasm collection comprising 3,821 accessions. Among the 11 species examined, Capsicum annuum showed the highest genetic diversity (H E  = 0.44, I = 0.69), whereas the wild species C. galapagoense showed the lowest genetic diversity (H E  = 0.06, I = 0.07). The Capsicum germplasm collection was divided into 10 clusters (cluster 1 to 10) based on population structure analysis, and five groups (group A to E) based on phylogenetic analysis. Capsicum accessions from the five distinct groups in an unrooted phylogenetic tree showed taxonomic distinctness and reflected their geographic origins. Most of the accessions from European countries are distributed in the A and B groups, whereas the accessions from Asian countries are mainly distributed in C and D groups. Five different sampling strategies with diverse genetic clustering methods were used to select the optimal method for constructing the core collection. Using a number of allelic variations based on 48 SNP markers and 32 different phenotypic/morphological traits, a core collection 'CC240' with a total of 240 accessions (5.2 %) was selected from within the entire Capsicum germplasm. Compared to the other core collections, CC240 displayed higher

Improving Published Descriptions of Germplasm.

Science.gov (United States)

Published descriptions of new germplasm, such as in the Journal of Plant Registrations (JPR) and, prior to mid-2007, in Crop Science, are important vehicles for allowing researchers and other interested parties to learn about such germplasm and the methods used to generate them. Launched in 2007, JP...

Genetic diversity and relationship of global faba bean (Vicia faba L.) germplasm revealed by ISSR markers.

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Wang, Hai-Fei; Zong, Xu-Xiao; Guan, Jian-Ping; Yang, Tao; Sun, Xue-Lian; Ma, Yu; Redden, Robert

2012-03-01

Genetic diversity and relationships of 802 faba bean (Vicia faba L.) landraces and varieties from different geographical locations of China and abroad were examined using ISSR markers. A total of 212 repeatable amplified bands were generated with 11 ISSR primers, of which 209 were polymorphic. Accessions from North China showed highest genetic diversity, while accessions from central China showed low level of diversity. Chinese spring faba bean germplasm was clearly separated from Chinese winter faba bean, based on principal component analysis and UPGMA clustering analysis. Winter accessions from Zhejiang (East China), Jiangxi (East China), Sichuan (Southwest China) and Guizhou (Southwest China) were quite distinct to that from other provinces in China. Great differentiation between Chinese accessions and those from rest of the world was shown with a UPGMA dendrogram. AMOVA analyses demonstrated large variation and differentiation within and among groups of accessions from China. As a continental geographic group, accessions from Europe were genetically closer to those from North Africa. Based on ISSR data, grouping results of accessions from Asia, Europe and Africa were obviously associated with their geographical origin. The overall results indicated that the genetic relationship of faba bean germplasm was closely associated with their geographical origin and their ecological habit.

Development of a core set of SSR markers for the characterization of Gossypium germplasm

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Molecular markers such as simple sequence repeats (SSR) are a useful tool for characterizing genetic diversity of Gossypium germplasm collections. Genetic profiles by DNA fingerprinting of cotton accessions can only be compared among different collections if a common set of molecular markers are us...

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

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Saba Jasim Aljumaili

2018-01-01

Full Text Available Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak with 3 released varieties as a control using the 32 simple sequence repeat (SSR markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon’s information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He of 0.60 and mean Nei’s gene diversity index of 0.36. The dendrogram based on UPGMA and Nei’s genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816 from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers.

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Jasim Aljumaili, Saba; Rafii, M Y; Latif, M A; Sakimin, Siti Zaharah; Arolu, Ibrahim Wasiu; Miah, Gous

2018-01-01

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index ( I ) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity ( H e ) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

Science.gov (United States)

Jasim Aljumaili, Saba; Sakimin, Siti Zaharah; Arolu, Ibrahim Wasiu; Miah, Gous

2018-01-01

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development. PMID:29736396

Molecular characterisation and interpretation of genetic diversity within globally distributed germplasm collections of tall fescue (Festuca arundinacea Schreb.) and meadow fescue (F. pratensis Huds.).

Science.gov (United States)

Hand, Melanie L; Cogan, Noel O I; Forster, John W

2012-04-01

Allohexaploid tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum [Schreb.] Darbysh.) is an agriculturally important grass cultivated for pasture and turf world-wide. Genetic improvement of tall fescue could benefit from the use of non-domesticated germplasm to diversify breeding populations through the incorporation of novel and superior allele content. However, such potential germplasm must first be characterised, as three major morphotypes (Continental, Mediterranean and rhizomatous) with varying degrees of hybrid interfertility are commonly described within this species. As hexaploid tall fescue is also a member of a polyploid species complex that contains tetraploid, octoploid and decaploid taxa, it is also possible that germplasm collections may have inadvertently sampled some of these sub-species. In this study, 1,040 accessions from the publicly available United States Department of Agriculture tall fescue and meadow fescue germplasm collections were investigated. Sequence of the chloroplast genome-located matK gene and the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) permitted attribution of accessions to the three previously known morphotypes and also revealed the presence of tall fescue sub-species of varying ploidy levels, as well as other closely related species. The majority of accessions were, however, identified as Continental hexaploid tall fescue. Analysis using 34 simple sequence repeat markers was able to further investigate the level of genetic diversity within each hexaploid tall fescue morphotype group. At least two genetically distinct sub-groups of Continental hexaploid tall fescue were identified which are probably associated with palaeogeographic range expansion of this morphotype. This work has comprehensively characterised a large and complex germplasm collection and has identified genetically diverse accessions which may potentially contribute valuable alleles at agronomic loci for tall fescue cultivar

Effect of growing location on seed oil composition in the cultivated peanut germplasm collection

Science.gov (United States)

A particularly important component of seed oils is the content of oleic acid as this fatty acid has several health benefits and contributes to increased oil stability, i.e. longer shelf life. We measured 8846 available accessions of the USDA peanut germplasm collection to gauge the range of variatio...

Genetic characterization of guava (psidium guajava l.) Germplasm in the United States using microsatellite markers

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Genetic diversity of thirty five Psidium guajava accessions maintained at the USDA, National Plants Germplasm System, Hilo, HI, was characterized using 20 simple sequence repeat (SSR) markers. Diversity analysis detected a total of 178 alleles ranging from four to 16. The observed mean heterozygosit...

Genetic diversity of a brazilian wine grape germplasm collection based on morphoagronomic traits

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Patrícia Coelho de S. Leão

2010-12-01

Full Text Available The objectives of this study were to evaluate the performance of cultivars, to quantify the variability and to estimate the genetic distances of 66 wine grape accessions in the Grape Germplasm Bank of the EMBRAPA Semi-Arid, in Juazeiro, BA, Brazil, through the characterization of discrete and continuous phenotypic variables. Multivariate statistics, such as, principal components, Tocher's optimization procedure, and the graphic of the distance, were efficient in grouping more similar genotypes, according to their phenotypic characteristics. There was no agreement in the formation of groups between continuous and discrete morpho-agronomic traits, when Tocher's optimization procedure was used. Discrete variables allowed the separation of Vitis vinifera and hybrids in different groups. Significant positive correlations were observed between weight, length and width of bunches, and a negative correlation between titratable acidity and TSS/TTA. The major part (84.12% of the total variation present in the original data was explained by the four principal components. The results revealed little variability between wine grape accessions in the Grape Germplasm Bank of Embrapa Semi-Arid.

Microsatellite fingerprinting in the International Cocoa Genebank, Trinidad: Accession and plot homogeneity information for germplasm management

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The International Cocoa Genebank, Trinidad (ICG,T) is the largest public domain field gene bank collection of cacao and the correct identity of each tree is crucial for germplasm movement, evaluation and phenotypic characterization. Nine microsatellite loci were used to assess the identity of 1480 t...

An innovative procedure of genome-wide association analysis fits studies on germplasm population and plant breeding.

Science.gov (United States)

He, Jianbo; Meng, Shan; Zhao, Tuanjie; Xing, Guangnan; Yang, Shouping; Li, Yan; Guan, Rongzhan; Lu, Jiangjie; Wang, Yufeng; Xia, Qiuju; Yang, Bing; Gai, Junyi

2017-11-01

The innovative RTM-GWAS procedure provides a relatively thorough detection of QTL and their multiple alleles for germplasm population characterization, gene network identification, and genomic selection strategy innovation in plant breeding. The previous genome-wide association studies (GWAS) have been concentrated on finding a handful of major quantitative trait loci (QTL), but plant breeders are interested in revealing the whole-genome QTL-allele constitution in breeding materials/germplasm (in which tremendous historical allelic variation has been accumulated) for genome-wide improvement. To match this requirement, two innovations were suggested for GWAS: first grouping tightly linked sequential SNPs into linkage disequilibrium blocks (SNPLDBs) to form markers with multi-allelic haplotypes, and second utilizing two-stage association analysis for QTL identification, where the markers were preselected by single-locus model followed by multi-locus multi-allele model stepwise regression. Our proposed GWAS procedure is characterized as a novel restricted two-stage multi-locus multi-allele GWAS (RTM-GWAS, https://github.com/njau-sri/rtm-gwas ). The Chinese soybean germplasm population (CSGP) composed of 1024 accessions with 36,952 SNPLDBs (generated from 145,558 SNPs, with reduced linkage disequilibrium decay distance) was used to demonstrate the power and efficiency of RTM-GWAS. Using the CSGP marker information, simulation studies demonstrated that RTM-GWAS achieved the highest QTL detection power and efficiency compared with the previous procedures, especially under large sample size and high trait heritability conditions. A relatively thorough detection of QTL with their multiple alleles was achieved by RTM-GWAS compared with the linear mixed model method on 100-seed weight in CSGP. A QTL-allele matrix (402 alleles of 139 QTL × 1024 accessions) was established as a compact form of the population genetic constitution. The 100-seed weight QTL-allele matrix was

High-throughput genotyping for species identification and diversity assessment in germplasm collections.

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Mason, Annaliese S; Zhang, Jing; Tollenaere, Reece; Vasquez Teuber, Paula; Dalton-Morgan, Jessica; Hu, Liyong; Yan, Guijun; Edwards, David; Redden, Robert; Batley, Jacqueline

2015-09-01

Germplasm collections provide an extremely valuable resource for breeders and researchers. However, misclassification of accessions by species often hinders the effective use of these collections. We propose that use of high-throughput genotyping tools can provide a fast, efficient and cost-effective way of confirming species in germplasm collections, as well as providing valuable genetic diversity data. We genotyped 180 Brassicaceae samples sourced from the Australian Grains Genebank across the recently released Illumina Infinium Brassica 60K SNP array. Of these, 76 were provided on the basis of suspected misclassification and another 104 were sourced independently from the germplasm collection. Presence of the A- and C-genomes combined with principle components analysis clearly separated Brassica rapa, B. oleracea, B. napus, B. carinata and B. juncea samples into distinct species groups. Several lines were further validated using chromosome counts. Overall, 18% of samples (32/180) were misclassified on the basis of species. Within these 180 samples, 23/76 (30%) supplied on the basis of suspected misclassification were misclassified, and 9/105 (9%) of the samples randomly sourced from the Australian Grains Genebank were misclassified. Surprisingly, several individuals were also found to be the product of interspecific hybridization events. The SNP (single nucleotide polymorphism) array proved effective at confirming species, and provided useful information related to genetic diversity. As similar genomic resources become available for different crops, high-throughput molecular genotyping will offer an efficient and cost-effective method to screen germplasm collections worldwide, facilitating more effective use of these valuable resources by breeders and researchers. © 2015 John Wiley & Sons Ltd.

The value of crop germplasm and value accounting system

Institute of Scientific and Technical Information of China (English)

WANG Xiaowei; DING Guangzhou; CHANG Ying

2007-01-01

The value evaluation and accounting of crop germplasm not only provides the theory and method for the price of germplasm, thus makes further lawful and fair transactions, but also ensures the benefits of crop germplasm owners and is also instructive in keeping the foodstuff safety. This paper founded a multidimensional value accounting system, which included physical accounting, value accounting and quality index accounting; individual accounting and total accounting; quantity accounting and quality accounting.

Genetic diversity of cultivated flax (Linum usitatissimum L.) germplasm assessed by retrotransposon-based markers.

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Smýkal, P; Bačová-Kerteszová, N; Kalendar, R; Corander, J; Schulman, A H; Pavelek, M

2011-05-01

Retrotransposon segments were characterized and inter-retrotransposon amplified polymorphism (IRAP) markers developed for cultivated flax (Linum usitatissimum L.) and the Linum genus. Over 75 distinct long terminal repeat retrotransposon segments were cloned, the first set for Linum, and specific primers designed for them. IRAP was then used to evaluate genetic diversity among 708 accessions of cultivated flax comprising 143 landraces, 387 varieties, and 178 breeding lines. These included both traditional and modern, oil (86), fiber (351), and combined-use (271) accessions, originating from 36 countries, and 10 wild Linum species. The set of 10 most polymorphic primers yielded 141 reproducible informative data points per accession, with 52% polymorphism and a 0.34 Shannon diversity index. The maximal genetic diversity was detected among wild Linum species (100% IRAP polymorphism and 0.57 Jaccard similarity), while diversity within cultivated germplasm decreased from landraces (58%, 0.63) to breeding lines (48%, 0.85) and cultivars (50%, 0.81). Application of Bayesian methods for clustering resulted in the robust identification of 20 clusters of accessions, which were unstratified according to origin or user type. This indicates an overlap in genetic diversity despite disruptive selection for fiber versus oil types. Nevertheless, eight clusters contained high proportions (70-100%) of commercial cultivars, whereas two clusters were rich (60%) in landraces. These findings provide a basis for better flax germplasm management, core collection establishment, and exploration of diversity in breeding, as well as for exploration of the role of retrotransposons in flax genome dynamics.

Genetic divergence among Brazilian turmeric germplasm using morpho-agronomical descriptors

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Mário Sérgio Sigrist

2011-01-01

Full Text Available Turmeric (Curcuma longa L. is a vegetatively-propagated crop which is used as a natural dye in the food industryand also presents many biological active compounds. Turmeric conventional breeding is difficult and often limited to germplasmselection. The aim of this study was to evaluate the genetic divergence among turmeric accessions available in Brazil using sevenmorpho-agronomical descriptors. Overall genetic divergence was low, although some divergent genotypes were identified. Fourmain groups of genotypes were identified and could be further used in breeding programs. Canonical variable analysis suggestedthat some descriptors were more important to discriminate accessions and also that one of the descriptors could be discarded. Theresults provided useful insights for better management of the germplasm collection, optimizing conservational and breeding efforts.

Assessment of Genetic Diversity and Structure of Large Garlic (Allium sativum Germplasm Bank, by Diversity Arrays Technology “Genotyping-by-Sequencing” Platform (DArTseq

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Leticia A. Egea

2017-07-01

Full Text Available Garlic (Allium sativum is used worldwide in cooking and industry, including pharmacology/medicine and cosmetics, for its interesting properties. Identifying redundancies in germplasm blanks to generate core collections is a major concern, mostly in large stocks, in order to reduce space and maintenance costs. Yet, similar appearance and phenotypic plasticity of garlic varieties hinder their morphological classification. Molecular studies are challenging, due to the large and expected complex genome of this species, with asexual reproduction. Classical molecular markers, like isozymes, RAPD, SSR, or AFLP, are not convenient to generate germplasm core-collections for this species. The recent emergence of high-throughput genotyping-by-sequencing (GBS approaches, like DArTseq, allow to overcome such limitations to characterize and protect genetic diversity. Therefore, such technology was used in this work to: (i assess genetic diversity and structure of a large garlic-germplasm bank (417 accessions; (ii create a core collection; (iii relate genotype to agronomical features; and (iv describe a cost-effective method to manage genetic diversity in garlic-germplasm banks. Hierarchical-cluster analysis, principal-coordinates analysis and STRUCTURE showed general consistency, generating three main garlic-groups, mostly determined by variety and geographical origin. In addition, high-resolution genotyping identified 286 unique and 131 redundant accessions, used to select a reduced size germplasm-bank core collection. This demonstrates that DArTseq is a cost-effective method to analyze species with large and expected complex genomes, like garlic. To the best of our knowledge, this is the first report of high-throughput genotyping of a large garlic germplasm. This is particularly interesting for garlic adaptation and improvement, to fight biotic and abiotic stresses, in the current context of climate change and global warming.

Screening of soybean germplasm for resistance against colletotrichum truncatum infection

International Nuclear Information System (INIS)

Hossain, I.; Islam, M.R.; Hamiduzzaman, M.M.

2001-01-01

One hundred and five soybean germplasms of exotic and national origin were evaluated for their reaction to anthracnose under field condition in Bangladesh. In the field 36 materials were found to be free from infection of C. truncatum (highly resistant) while 19, 37, 3, 5 and 5 germplasms were graded as resistant, moderately resistant, moderately susceptible, susceptible and highly susceptible, respectively. Percentage of seed-borne infection by colletotrichum truncatum varied from one germplasm to another. In total 43 germplasms were completely free from seed-borne infection, whereas up to 5% infection was recorded in 25 samples, 6-30% in 32 samples and 31-36% infection was found in five samples. (author)

Joint analysis of phenotypic and molecular diversity provides new insights on the genetic variability of the Brazilian physic nut germplasm bank.

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Alves, Alexandre Alonso; Bhering, Leonardo Lopes; Rosado, Tatiana Barbosa; Laviola, Bruno Galvêas; Formighieri, Eduardo Fernandes; Cruz, Cosme Damião

2013-09-01

The genetic variability of the Brazilian physic nut (Jatropha curcas) germplasm bank (117 accessions) was assessed using a combination of phenotypic and molecular data. The joint dissimilarity matrix showed moderate correlation with the original matrices of phenotypic and molecular data. However, the correlation between the phenotypic dissimilarity matrix and the genotypic dissimilarity matrix was low. This finding indicated that molecular markers (RAPD and SSR) did not adequately sample the genomic regions that were relevant for phenotypic differentiation of the accessions. The dissimilarity values of the joint dissimilarity matrix were used to measure phenotypic + molecular diversity. This diversity varied from 0 to 1.29 among the 117 accessions, with an average dissimilarity among genotypes of 0.51. Joint analysis of phenotypic and molecular diversity indicated that the genetic diversity of the physic nut germplasm was 156% and 64% higher than the diversity estimated from phenotypic and molecular data, respectively. These results show that Jatropha genetic variability in Brazil is not as limited as previously thought.

Colombia a Source of Cacao Genetic Diversity As Revealed by the Population Structure Analysis of Germplasm Bank of Theobroma cacao L.

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Jaime A. Osorio-Guarín

2017-11-01

Full Text Available Beans of the species Theobroma cacao L., also known as cacao, are the raw material to produce chocolate. Colombian cacao has been classified as a fine flavor cacao that represents the 5% of cacao world’s production. Colombian genetic resources from this species are conserved in ex situ and in-field germplasm banks, since T. cacao has recalcitrant seeds to desication and long-term storage. Currently, the collection of T. cacao of the Colombian Corporation of Agricultural Research (CORPOICA has approximately 700 germplasm accessions. We conducted a molecular analysis of Corpoica’s cacao collection and a morphological characterization of some accessions with the goal to study its genetic diversity and population structure and, to select interesting accessions for the cacao’s breeding program. Phenotypic evaluation was performed based on 18 morphological traits and 4 biochemical traits. PCA analysis of morphological traits explained 60.6% of the total variation in seven components and 100% of the total variation of biochemical traits in four components, grouping the collection in 4 clusters for both variables. We explored 565 accessions from Corpoica’s germplasm and 252 accessions from reference populations using 96 single nucleotide polymorphism (SNP molecular markers. Molecular patterns of cacao Corpoica’s collection were obtained amplifying specific alleles in a Fluidigm platform that used integrated circuits of fluids. Corpoica’s collection showed highest genetic diversity [Expected Heterozygosity (HE = 0.314, Observed Heterozygosity (HO = 0.353] that is reduced when reference populations were included in the dataset (HE = 0.294, HO = 0.261. The collection was divided into four clusters based on population structure analysis. Cacao accessions from distinct groups showed some taxonomic concordance and reflected their geographic origins. For instance, accessions classified as Criollo were clearly differentiated in one group and we

Chemical Diversity in Lippia alba (Mill. N. E. Brown Germplasm

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Arie Fitzgerald Blank

2015-01-01

Full Text Available The aim of this study was to perform chemical characterization of Lippia alba accessions from the Active Germplasm Bank of the Federal University of Sergipe. A randomized block experimental design with two replications was applied. The analysis of the chemical composition of the essential oils was conducted using a gas chromatograph coupled to a mass spectrometer. The chemical composition of the essential oils allowed the accessions to be allocated to the following six groups: group 1: linalool, 1,8-cineole, and caryophyllene oxide; group 2: linalool, geranial, neral, 1,8-cineol, and caryophyllene oxide; group 3: limonene, carvone, and sabinene; group 4: carvone, limonene, g-muurolene, and myrcene; group 5: neral, geranial, and caryophyllene oxide; and group 6: geranial, neral, o-cymene, limonene, and caryophyllene oxide.

The extent of variation in salinity tolerance of the minicore collection of finger millet (Eleusine coracana L. Gaertn.) germplasm.

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Krishnamurthy, Lakshmanan; Upadhyaya, Hari Deo; Purushothaman, Ramamoorthy; Gowda, Cholenahalli Lakkegowda Laxmipathi; Kashiwagi, Junichi; Dwivedi, Sangam Lal; Singh, Sube; Vadez, Vincent

2014-10-01

Finger millet (Eleusine coracana L. Gaertn.) ranks third in production among the dry land cereals. It is widely cultivated in Africa and South Asia where soil salinization is a major production constraint. It is a potential crop for salt affected soils. To identify salt tolerant germplasm, the minicore finger millet germplasm (n=80) was screened for grain yield performance in a soil saturated with NaCl solution of 100 or 125mM. Genotype effect was significant for most traits, while salinity×genotype interaction was significant only in one year. Salinity delayed phenology, marginally reduced shoot biomass and grain yield. There was a large range of genotypic variation in grain yield under salinity and other traits. The yield loss was higher in accessions with prolific growth and yield potential was associated with saline yields. Based on saline yields, accessions were grouped in to four groups and the top tolerant group had 22 accessions with IE 4797 remaining at the top. Salinity had no adverse impact on grain yield of five accessions. Root anatomy in selected genotype of pearl and finger millet showed presence of porous cortex and well fortified endodermis in finger millet that can exclude Na(+) and enhance N absorption. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Isozyme characterization of Capsicum accessions from the Amazonian Colombian collection

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Lorena Quintero Barrera

2005-01-01

Full Text Available Two hundred and sixty-one accessions of the genus Capsicum were obtained from the Colombian Amazonian germplasm bank at Amazonian Institute of Scientific Research (Sinchi and were evaluated with five polymorphic enzymatic systems, including esterase (EST, peroxidase (PRX, 6-phosphogluconate dehydrogenase (6-PGDH, aspartate amino transferase (GOT, and malic enzyme (ME. Using a cluster analysis (UPGMA the genetic variability of these accessions were characterized. Grouping of the species C. baccatum and C. pubescens were observed, while the species C. annuum, C. chinense and C. frutescens did not group independently, a result that has been previously reported in isoenzyme analyses of this genus. Several accessions were deemed of particular interest for future ecological and evolutive studies. Key words: Colombia, Capsicum, germplasm bank, isoenzymes, peppers.

Notice of release for Eagle Germplasm western yarrow (selected germplasm, natural track)

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Scott M. Lambert; Stephen B. Monsen; Nancy Shaw

2011-01-01

The United States Department of Agriculture, Forest Service, Rocky Mountain Research Station; United States Department of the Interior, Bureau of Land Management, Idaho State Office; Utah State University, Agricultural Experiment Station; and University of Idaho, Agricultural Experiment Station, announce the release of a selected germplasm (natural track) of western...

Geographical gradient of the eIF4E alleles conferring resistance to potyviruses in pea (Pisum) germplasm.

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Konečná, Eva; Šafářová, Dana; Navrátil, Milan; Hanáček, Pavel; Coyne, Clarice; Flavell, Andrew; Vishnyakova, Margarita; Ambrose, Mike; Redden, Robert; Smýkal, Petr

2014-01-01

The eukaryotic translation initiation factor 4E was shown to be involved in resistance against several potyviruses in plants, including pea. We combined our knowledge of pea germplasm diversity with that of the eIF4E gene to identify novel genetic diversity. Germplasm of 2803 pea accessions was screened for eIF4E intron 3 length polymorphism, resulting in the detection of four eIF4E(A-B-C-S) variants, whose distribution was geographically structured. The eIF4E(A) variant conferring resistance to the P1 PSbMV pathotype was found in 53 accessions (1.9%), of which 15 were landraces from India, Afghanistan, Nepal, and 7 were from Ethiopia. A newly discovered variant, eIF4E(B), was present in 328 accessions (11.7%) from Ethiopia (29%), Afghanistan (23%), India (20%), Israel (25%) and China (39%). The eIF4E(C) variant was detected in 91 accessions (3.2% of total) from India (20%), Afghanistan (33%), the Iberian Peninsula (22%) and the Balkans (9.3%). The eIF4E(S) variant for susceptibility predominated as the wild type. Sequencing of 73 samples, identified 34 alleles at the whole gene, 26 at cDNA and 19 protein variants, respectively. Fifteen alleles were virologically tested and 9 alleles (eIF4E(A-1-2-3-4-5-6-7), eIF4E(B-1), eIF4E(C-2)) conferred resistance to the P1 PSbMV pathotype. This work identified novel eIF4E alleles within geographically structured pea germplasm and indicated their independent evolution from the susceptible eIF4E(S1) allele. Despite high variation present in wild Pisum accessions, none of them possessed resistance alleles, supporting a hypothesis of distinct mode of evolution of resistance in wild as opposed to crop species. The Highlands of Central Asia, the northern regions of the Indian subcontinent, Eastern Africa and China were identified as important centers of pea diversity that correspond with the diversity of the pathogen. The series of alleles identified in this study provides the basis to study the co-evolution of potyviruses and the

In vitro conservation of Dendrobium germplasm.

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Teixeira da Silva, Jaime A; Zeng, Songjun; Galdiano, Renato Fernandes; Dobránszki, Judit; Cardoso, Jean Carlos; Vendrame, Wagner A

2014-09-01

Dendrobium is a large genus in the family Orchidaceae that exhibits vast diversity in floral characteristics, which is of considerable importance to orchid breeders, biotechnologists and collectors. Native species have high value as a result of their medicinal properties, while their hybrids are important as ornamental commodities, either as cut flowers or potted plants and are thus veritable industrial crops. Thus, preservation of Dendrobium germplasm is valuable for species conservation, breeding programs and the floriculture industry. Cryopreservation represents the only safe, efficient and cost-effective long-term storage option to facilitate the conservation of genetic resources of plant species. This review highlights 16 years of literature related to the preservation of Dendrobium germplasm and comprises the most comprehensive assessment of thorough studies performed to date, which shows reliable and reproducible results. Air-drying, encapsulation-dehydration, encapsulation-vitrification, vitrification and droplet-vitrification are the current cryopreservation methodologies that have been used to cryopreserve Dendrobium germplasm. Mature seeds, pollen, protoplasts, shoot primordia, protocorms and somatic embryos or protocorm-like bodies (PLBs) have been cryopreserved with different levels of success. Encapsulation-vitrification and encapsulation-dehydration are the most used protocol, while PLBs represent the main explant explored.

Capability of multiple selection criteria to evaluate contrasting spring wheat germplasms under arid conditions

International Nuclear Information System (INIS)

Al-Suhaibani, N. A.; SALAH, E.; El-Hendawy, S. E.; Al-Gaadi, K.; Rehman, S. U.

2015-01-01

Selection criteria that would evaluate a large number of germplasm in a rapid and non-destructive manner would be considered advantageous in plant breeding programs. Trade-off between traditional and non-destructive screening criteria in evaluating 90 wheat accessions under water shortage was tested using multivariate statistical techniques. Only three irrigations during the growing cycle of germplasm were applied with the amount of water totalling 2550 m /sup 3/ ha /sup -1/. Sequential path analysis identified one traditional trait (grain weight per plant) and two non-destructive traits (leaf area index and stomatal conductance) as important first-order traits that influenced final grain yield. The three traits, taken together, explained 96.8 percentage of the total variation in grain yield. Total dry weight per plant, green leaf area per plant, harvest index, grain number per plant, leaf water content and canopy temperature were identified as important second-order traits that influenced grain yield. Although canopy temperature was ranked as a second-order trait, it explained 64.4 percentage of the total variation in stomatal conductance. Approximately 78.0 percentage of the total variation in grain weight or leaf area index was explained by the leaf water content (66.2 percentage) and total dry weight (11.5 percentage). The 90 examined spring wheat germplasms were grouped into five clusters based on all agro-physiological traits using the centroid linkage method. The tested wheat germplasm that produce high grain yield under water shortage were characterised by good performance of certain rapid, easy and non-destructive physiological traits such as high leaf area index, high stomatal conductance and low canopy temperature. Therefore, these three traits could be used in combination as quick and easy screening criteria to select suitable genotypes for water-limiting conditions. (author)

Tapping the US sweet sorghum collection to identify biofuel germplasm

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The narrow genetic base in sweet sorghum [Sorghum bicolor (L.) Moench] breeding programs is limiting the development of new varieties for biofuel production. Therefore, the identification of genetically diverse sweet sorghum germplasm in the U.S. National Plant Germplasm System (NPGS) collection is...

Screening Prosopis (mesquite) germplasm for biomass production and nitrogen fixation

Energy Technology Data Exchange (ETDEWEB)

Felker, P.; Cannell, G.H.; Clark, P.R.; Osborn, J.F.

1980-01-01

The nitrogen-fixing trees of the genus Prosopis (mesquite or algaroba) are well adapted to the semi-arid and often saline regions of the world. These trees may produce firewood or pods for livestock food, they may stabilize sand dunes and they may enrich the soil by production of leaf litter supported by nitrogen fixation. A collection of nearly 500 Prosopis accessions representing North and South American and African germplasm has been established. Seventy of these accessions representing 14 taxa are being grown under field conditions where a 30-fold range in biomass productivity among accessions has been estimated. In a greehouse experiment, 13 Prosopis taxa grew on nitrogen-free medium nodulated, and had a 10-fold difference in nitrogen fixation (acetylene reduction). When Prosopis is propagated by seed the resulting trees are extremely variable in growth rate and presence or absence of thorns. Propagation of 6 Prosopis taxa by stem cuttings has been achieved with low success (1 to 10%) in field-grown plants and with higher success (50 to 100%) with young actively growing greenhouse plants.

Genetic relationship and diversity in a sesame (Sesamum indicum L. germplasm collection using amplified fragment length polymorphism (AFLP

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Karlovsky Petr

2006-02-01

Full Text Available Abstract Background Sesame is an important oil crop in tropical and subtropical areas. Despite its nutritional value and historic and cultural importance, the research on sesame has been scarce, particularly as far as its genetic diversity is concerned. The aims of the present study were to clarify genetic relationships among 32 sesame accessions from the Venezuelan Germplasm Collection, which represents genotypes from five diversity centres (India, Africa, China-Korea-Japan, Central Asia and Western Asia, and to determine the association between geographical origin and genetic diversity using amplified fragment length polymorphism (AFLP. Results Large genetic variability was found within the germplasm collection. A total of 457 AFLP markers were recorded, 93 % of them being polymorphic. The Jaccard similarity coefficient ranged from 0.38 to 0.85 between pairs of accessions. The UPGMA dendrogram grouped 25 of 32 accessions in two robust clusters, but it has not revealed any association between genotype and geographical origin. Indian, African and Chinese-Korean-Japanese accessions were distributed throughout the dendrogram. A similar pattern was obtained using principal coordinates analysis. Genetic diversity studies considering five groups of accessions according to the geographic origin detected that only 20 % of the total diversity was due to diversity among groups using Nei's coefficient of population differentiation. Similarly, only 5% of the total diversity was attributed to differences among groups by the analysis of molecular variance (AMOVA. This small but significant difference was explained by the fact that the Central Asia group had a lower genetic variation than the other diversity centres studied. Conclusion We found that our sesame collection was genetically very variable and did not show an association between geographical origin and AFLP patterns. This result suggests that there was considerable gene flow among diversity centres

Powdery mildew reaction of hop cultivars and USDA germplasm, 2015

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This research was conducted to identify possible sources of resistance to the disease powdery mildew in publicly-available hop germplasm and cultivars. Germplasm with the highest levels of downy mildew resistance in the USDA collection and various cultivars of interest were screened for their reac...

Assessment of genetic diversity in lettuce (Lactuca sativa L.) germplasm using RAPD markers.

Science.gov (United States)

Sharma, Shubhangi; Kumar, Pankaj; Gambhir, Geetika; Kumar, Ramesh; Srivastava, D K

2018-01-01

The importance of germplasm characterization is an important link between the conservation and utilization of plant genetic resources in various breeding programmes. In the present study, genetic variability and relationships among 25 Lactuca sativa L. genotypes were tested using random amplified polymorphic DNA (RAPD) molecular markers. A total of 45 random decamer oligonucleotide primers were examined to generate RAPD profiles, out of these reproducible patterns were obtained with 22 primers. A total of 87 amplicon were obtained, out of which all were polymorphic and 7 were unique bands. The level of polymorphism across genotypes was 100% as revealed by RAPD. Genetic similarity matrix, based on Jaccard's coefficients ranged from 13.7 to 84.10% indicating a wide genetic base. Dendrogram was constructed by unweighted pair group method with arithmetic averages method. RAPD technology could be useful for identification of different accessions as well as assessing the genetic similarity among different genotypes of lettuce. The study reveals the limited genetic base and the needs to diversify using new sources from the germplasm.

Unlocking Diversity in Germplasm Collections via Genomic Selection: A Case Study Based on Quantitative Adult Plant Resistance to Stripe Rust in Spring Wheat.

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Muleta, Kebede T; Bulli, Peter; Zhang, Zhiwu; Chen, Xianming; Pumphrey, Michael

2017-11-01

Harnessing diversity from germplasm collections is more feasible today because of the development of lower-cost and higher-throughput genotyping methods. However, the cost of phenotyping is still generally high, so efficient methods of sampling and exploiting useful diversity are needed. Genomic selection (GS) has the potential to enhance the use of desirable genetic variation in germplasm collections through predicting the genomic estimated breeding values (GEBVs) for all traits that have been measured. Here, we evaluated the effects of various scenarios of population genetic properties and marker density on the accuracy of GEBVs in the context of applying GS for wheat ( L.) germplasm use. Empirical data for adult plant resistance to stripe rust ( f. sp. ) collected on 1163 spring wheat accessions and genotypic data based on the wheat 9K single nucleotide polymorphism (SNP) iSelect assay were used for various genomic prediction tests. Unsurprisingly, the results of the cross-validation tests demonstrated that prediction accuracy increased with an increase in training population size and marker density. It was evident that using all the available markers (5619) was unnecessary for capturing the trait variation in the germplasm collection, with no further gain in prediction accuracy beyond 1 SNP per 3.2 cM (∼1850 markers), which is close to the linkage disequilibrium decay rate in this population. Collectively, our results suggest that larger germplasm collections may be efficiently sampled via lower-density genotyping methods, whereas genetic relationships between the training and validation populations remain critical when exploiting GS to select from germplasm collections. Copyright © 2017 Crop Science Society of America.

Diversity Analysis and Physico-Morphlogical Characteritics of Indigenous Germplasm of Lablab Bean

OpenAIRE

Ram Bahadur KC; Bal Krishna Joshi; Surya Prasad Dahal

2016-01-01

Germplasm characterization is an important component of crop breeding program. In characterizing indigenous beans lablab which is used for vegetables as well pulses in Nepal. Twenty three lablab beans germplasm were evaluated for different qualitative and quantitive physico-morphological charecteristics for two years during 2011 and 2012 at Horticulture Research Station, Malepatan, Pokhara. The germplasm showed considerable variations in most of the qualitative and quantitative traits. Leaf ...

Chemical and nutritional evaluation of two germplasms of the tribal pulse, Bauhinia racemosa Lamk.

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Mohan, V R; Janardhanan, K

1994-12-01

Two germplasms of the tribal pulse, Bauhinia racemosa Lamk. viz., Ayyanarkoil Forest and Mundanthurai Wildlife Sanctuary, were analysed for proximate composition, total (true) seed proteins, seed protein fractions, amino acid composition, fatty acids, minerals and antinutritional factors. Crude proteins, crude lipids, ash and nitrogen free extractives constituted 19.84%, 9.52%, 3.31% and 60.65%, respectively in Ayyanarkoil Forest germplasm; whereas, in Mundanthurai Wildlife Sanctuary germplasm they constituted 19.31%, 8.94%, 3.81% and 61.30%, respectively. The caloric values were found to be 407.64 KCal (Ayyanarkoil Forest) and 402.90 KCal (Mundanthurai Wildlife Sanctuary) germplasms. Essential amino acids like isoleucine, tyrosine, phenylalanine and lysine were found to be high in the seed proteins of both the germplasms. The fatty acids, palmitic, oleic and linoleic acids, were found to be relatively higher in the seed lipids of both the germplasms. Both the germplasms seemed to be a rich source of calcium, potassium, magnesium, zinc, manganese and iron. Antinutritional substances like total free phenols, tannins, L-DOPA and phytohaemagglutinating activity also were investigated.

Notice of release of Mountain Home germplasm Sandberg bluegrass (selected germplasm, natural track)

Science.gov (United States)

Scott M. Lambert; Stephen B. Monsen; Nancy Shaw

2011-01-01

Mountain Home germplasm Sandberg bluegrass is a small, densely tufted short-lived perennial bunchgrass adapted to low elevation, semi-arid sites with long, hot growing seasons. Mountain Home's drought tolerance, competitive nature, and ease of establishment make it an excellent choice for post-fire restoration of cheatgrass (Bromus tectorum L.) dominated...

Assessment of Sugarcane Germplasm ( Saccharum spp. complex Against Red Rot Pathogen Colletotrichum Falcatum

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Atul Singh

2017-08-01

Full Text Available ABSTRACT Red rot, caused by Colletotrichum falcatum Went is the most important disease of sugarcane in India inflicting substantial loss to both cane industry and cane growers. To keep in view the importance of red rot disease of sugarcane, 117 accession of sugarcane germplasm including different Saccharum species and Indian and foreign commercial hybrids were tested against red rot with Cf 07, Cf 08 & Cf 09 (national pathotypes by plug method of inoculation. Out of 117, 6 were found resistant and 12 were moderately resistant against red rot and rest were moderately susceptible/susceptible/highly susceptible. Theses resistance and moderately resistant accession can be further utilize to produce resistance varieties against the most devastating pathogen of sugarcane.

Diversity and population structure of red rice germplasm in Bangladesh.

Science.gov (United States)

Islam, M Z; Khalequzzaman, M; Prince, M F R K; Siddique, M A; Rashid, E S M H; Ahmed, M S U; Pittendrigh, B R; Ali, M P

2018-01-01

While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI) genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR) markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC) indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35). While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V), a similar SSR analysis yielded only three major groups (I, II, and III), and a model-based population structure analysis yielded four (A, B, C and D). Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA), as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207) among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular breeding programs.

The research progress on plant mutant germplasm resources in China

International Nuclear Information System (INIS)

He Cexi; Ji Linzhen; Zhao Shirong

1991-07-01

Mutants induced by nuclear radiation or other mutagens are new artificial germplasm resources. Some mutants have been applied in plant breeding and great achievements have been reached. The status and progress on the collection, identification and utilization of mutants in China are introduced. A proposal for developing mutant germplasm resources with good agronomic characters is suggested

Discovering the desirable alleles contributing to the lignocellulosic biomass traits in Saccharum germplasm collections for energy cane improvement

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianping [Univ. of Florida, Gainesville, FL (United States); Sandhu, Hardev [Univ. of Florida, Gainesville, FL (United States)

2017-03-23

were tested on marginal soils in Florida and showed very promising yield potential that is important for the successful use of energy cane as a dedicated feedstock for lignocellulosic ethanol production. 2) Multiple techniques at different project progress stages were utilized. For example, for the whole world germplasm accession genotyping, a cheap widely used SSR marker genotyping platform was utilized due to the large number of samples (over thousand). But the throughput of this technique is low in generating data points. However, the purpose the genotyping is to form a core collection for further high throughput genotyping. Thus the results from the SSR genotyping was quite good enough to generated the core collection. To genotype the few hundred core collection accessions, an target enrichment sequencing technology was used, which is not only high throughput in generating large number of genotyping data, but also has the candidate genes targeted to genotyping. The data generated would be sufficient in identifying the alleles contributing to the traits of interests. All the techniques used in this project are effective though extensive time was invested specifically for establish the pipeline in the experimental design, data analysis, and different approach comparison. 3) the research can benefit to the public in polyploid genotyping and new and cost efficient genotyping platform development

Genetic variability of a Brazilian Capsicum frutescens germplasm collection using morphological characteristics and SSR markers.

Science.gov (United States)

Carvalho, S I C; Bianchetti, L B; Ragassi, C F; Ribeiro, C S C; Reifschneider, F J B; Buso, G S C; Faleiro, F G

2017-07-06

Characterization studies provide essential information for the conservation and use of germplasm in plant breeding programs. In this study, 103 Capsicum frutescens L. accessions from the Active Germplasm Bank of Embrapa Hortaliças, representative of all five Brazilian geographic regions, were characterized based on morphological characteristics and microsatellite (or simple sequence repeat - SSR) molecular markers. Morphological characterization was carried out using 57 descriptors, and molecular characterization was based on 239 alleles from 24 microsatellite loci. From the estimates of genetic distances among accessions, based on molecular characterization, a cluster analysis was carried out, and a dendrogram was established. Correlations between morphological and molecular variables were also estimated. Twelve morphological descriptors were monomorphic for the set of C. frutescens accessions, and those with the highest degree of polymorphism were stem length (14.0 to 62.0 cm), stem diameter (1.0 to 4.2 cm), days to flowering (90 to 129), days to fruiting (100 to 140), fruit weight (0.1 to 1.4 g), fruit length (0.6 to 4.6 cm), and fruit wall thickness (0.25 to 1.5 mm). The polymorphism information content for the SSR loci varied from 0.36 (EPMS 417) to 0.75 (CA49), with an overall mean of 0.57. The correlation value between morphological and molecular characterization data was 0.6604, which was statistically significant. Fourteen accessions were described as belonging to the morphological type tabasco, 85 were described as malagueta, and four were malaguetinha, a morphological type confirmed in this study. The typical morphological pattern of malagueta was described. Six similarity groups were established for C. frutescens based on the dendrogram and are discussed individually. The genetic variability analyzed in the study highlights the importance of characterizing genetic resources available for the development of new C. frutescens cultivars with the potential

BUFFEL GRASS MORPHOAGRONOMIC CHARACTERIZATION FROM Cenchrus GERMPLASM ACTIVE BANK

Directory of Open Access Journals (Sweden)

LEILA REGINA GOMES PASSOS BRUNO

2017-01-01

Full Text Available his study aimed to characterize buffel grass accessions of the Cenchrus Germplasm Active Bank (CGAB from Embrapa Semi - Arid in a morphoagronomic way, checking the descriptors variability and efficiency in accessions on two consecutive cuts. Twenty - five accessions and five buffel grass cultivars were used in randomized complete block design with three replications. Evaluations were conducted after two consecutive cuts, each evaluation performed 90 days after each cut. Characterization was based on 15 quantitative and qualitative morphoagronomic descriptors. Quantitative descriptors were subjected to individual and joint univariate analysis of variance, followed by the Scott - Knott’s test at 5% significance. Yet qualitative descriptors were submitted to descriptive analysis. Both quantitative and qualitative descriptors were grouped based on the Gower algorithm for divergence analysis. A dendrogram and calculations of the characters relative importance for divergence were established. Genotype and cutting effects were significant for almost all descriptors in the joint analysis. This result indicates a genetic variability between genotypes and, regarding the cut, it indicates mainly differences in growth rate of each genotype in each cutting season. Genotypes were separated into three groups, which showed good genotype variation. The number of tillers per clump, followed by number of inflorescence and color of seeds, were the most relevant characters in genotype separation.

Diversity and population structure of red rice germplasm in Bangladesh.

Directory of Open Access Journals (Sweden)

M Z Islam

Full Text Available While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35. While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V, a similar SSR analysis yielded only three major groups (I, II, and III, and a model-based population structure analysis yielded four (A, B, C and D. Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA, as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207 among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular

Regeneration in selected Cucurbita spp. germplasm

OpenAIRE

Gisbert Domenech, Maria Carmen; Picó Sirvent, María Belén N:2949; Nuez Viñals, Fernando

2011-01-01

Gisbert Domenech, MC.; Picó Sirvent, MBN.; Nuez Viñals, F. (2011). Regeneration in selected Cucurbita spp. germplasm. Report- Cucurbit Genetics Cooperative. 33-34:53-54. http://hdl.handle.net/10251/62926 Senia 53 54 33-34

Genetic diversity of sesame (sesamum indicum L.) germplasm from Pakistan using RAPD markers

Energy Technology Data Exchange (ETDEWEB)

Akbar, F; Rabbani, M A; Masood, M S; Shinwari, Z.K., E-mail: shinwari@qau.edu.p

2011-08-15

Genetic diversity among 20 sesame (Sesamum indicum L.) accessions was examined at DNA level by means of random amplified polymorphic DNA (RAPD) analysis. Ten primers used produced a total of 93 RAPD fragments, of which 70 (75%) were polymorphic. Each primer generated 5 to 17 amplified fragments with an average of 9.3 bands per primer. Based on pair-wise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were computed to assess the associations among the accessions. Pair-wise similarity indices varied from 0.65 to 0.91. A UPGMA cluster analysis based on these genetic similarities located most of the accessions far apart from one another, showing a high level of polymorphism. Genetically, all the genotypes were classified into two major groups and six subgroups or clusters. A single accession (22243) was relatively distinct from rest of the accessions and created independent cluster. In conclusion, even with the use of a limited set of primers, RAPD technique revealed a high level of genetic variation among sesame accessions collected from diverse ecologies of Pakistan. This high level of genetic diversity among the genotypes suggested that RAPD technique is valuable for sesame systematic, and can be helpful for the upholding of germplasm banks and the competent choice of parents in breeding programs. (author)

Genetic diversity of sesame (sesamum indicum L.) germplasm from Pakistan using RAPD markers

International Nuclear Information System (INIS)

Akbar, F; Rabbani, M.A.; Masood, M.S.; Shinwari, Z.K.

2011-01-01

Genetic diversity among 20 sesame (Sesamum indicum L.) accessions was examined at DNA level by means of random amplified polymorphic DNA (RAPD) analysis. Ten primers used produced a total of 93 RAPD fragments, of which 70 (75%) were polymorphic. Each primer generated 5 to 17 amplified fragments with an average of 9.3 bands per primer. Based on pair-wise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were computed to assess the associations among the accessions. Pair-wise similarity indices varied from 0.65 to 0.91. A UPGMA cluster analysis based on these genetic similarities located most of the accessions far apart from one another, showing a high level of polymorphism. Genetically, all the genotypes were classified into two major groups and six subgroups or clusters. A single accession (22243) was relatively distinct from rest of the accessions and created independent cluster. In conclusion, even with the use of a limited set of primers, RAPD technique revealed a high level of genetic variation among sesame accessions collected from diverse ecologies of Pakistan. This high level of genetic diversity among the genotypes suggested that RAPD technique is valuable for sesame systematic, and can be helpful for the upholding of germplasm banks and the competent choice of parents in breeding programs. (author)

Methods for acquisition, storage, and evaluation of leguminous tree germplasm

Energy Technology Data Exchange (ETDEWEB)

Felker, P.

1980-01-01

Simple methods for establishing, maintaining, and planting of a small scale tree legume (Prosopis) germplasm collection by one or two people are described. Suggestions are included for: developing an understanding of the worldwide distribution of genus; becoming acquainted with basic and applied scientists working on the taxa; devising seed cleaning, fumigation, cataloging, and storage techniques; requesting seed from international seed collections; collecting seed from native populations; and for field designs for planting the germplasm collection.

Molecular Characterization and Genetic Diversity of the Macaw Palm Ex Situ Germplasm Collection Revealed by Microsatellite Markers

Directory of Open Access Journals (Sweden)

Fekadu G. Mengistu

2016-10-01

Full Text Available Macaw palm (Acrocomia aculeata is native to tropical forests in South America and highly abundant in Brazil. It is cited as a highly productive oleaginous palm tree presenting high potential for biodiesel production. The aim of this work was to characterize and study the genetic diversity of A. aculeata ex situ collections from different geographical states in Brazil using microsatellite (Simple Sequence Repeats, SSR markers. A total of 192 accessions from 10 provenances were analyzed with 10 SSR, and variations were detected in allelic diversity, polymorphism, and heterozygosity in the collections. Three major groups of accessions were formed using PCoA—principal coordinate analysis, UPGMA—unweighted pair-group method with arithmetic mean, and Tocher. The Mantel test revealed a weak correlation (r = 0.07 between genetic and geographic distances among the provenances reaffirming the result of the grouping. Reduced average heterozygosity (Ho < 50% per locus (or provenance confirmed the predominance of endogamy (or inbreeding in the germplasm collections as evidenced by positive inbreeding coefficient (F > 0 per locus (or per provenance. AMOVA—Analysis of Molecular Variance revealed higher (48.2% genetic variation within population than among populations (36.5%. SSR are useful molecular markers in characterizing A. aculeata germplasm and could facilitate the process of identifying, grouping, and selecting genotypes. Present results could be used to formulate appropriate conservation strategies in the genebank.

Assessment of Genetic Diversity of Some Finger Millet (Eleusine coracana (L. Gaertn. Accessions Using Morphological Markers

Directory of Open Access Journals (Sweden)

D.V.S. Kaluthanthri

2017-03-01

Full Text Available AbstractGermplasm characterization is an important link between conservation and utilizationof plant genetic resources. The study was conducted to characterize randomly selected 20finger millet germplasm accessions obtained from Plant Genetic Resource Center,Gannoruwa, Sri Lanka using morphological markers. Morphological study was carried outusing Randomized Complete Block Design (RCBD and 15 morphological markers wererecorded. Analysis of variance (ANOVA results for quantitative morphological charactersrevealed that all quantitative morphological characters measured differed significantly(p˂0.05 among the accessions used for the study, indicating higher levels of morphologicaldiversity. According to the ANOVA results, days to flowering and days to maturity showhigh level of predictive capability while flag leaf length and number of productive tillersshow comparatively low level of predictive capability. Principal component analysisindicated that morphological characters such as days to flowering, finger number and yieldper plant were the important traits contributing for the overall variability implying thatbreeding effort on those traits can meet the targeted objective. The clustering pattern ofstudied finger millet accessions based on morphological markers comprised of two majorclusters. Both clusters comprised of Indian accessions those conserved at PGRC, Gannoruwaand as well as Sri Lankan accessions.Results of the study suggest a considerable morphological variability, which couldexist among the studied traits. Furthermore, this study revealed that the genetic diversityexisted irrespective to the geographical origin. This finding justifies the importance ofgermplasm characterization.Keywords: Finger Millet, Morphological Markers, Germplasm Accessions, GeneticDiversity, Crop Improvement

Using GIS to check co-ordinates of genebank accessions

NARCIS (Netherlands)

Hijmans, R.J.; Schreuder, M.; Cruz, de la J.; Guarino, L.

1999-01-01

The geographic co-ordinates of the locations where germplasm accessions have been collected are usually documented in genebank databases. However, the co-ordinate data are often incomplete and may contain errors. This paper describes procedures to check for errors, to determine the cause of these

Protein and quality analyses of accessions from the USDA soybean germplasm collection for tofu production.

Science.gov (United States)

Meng, Shi; Chang, Sam; Gillen, Anne M; Zhang, Yan

2016-12-15

Food-grade soybeans with large seed size, uniformity, clear hilum and a high 11S/7S ratio are favoured by the food industry for making tofu. In order to search for soybean lines with desirable characteristics for making foods, 22 soybean lines were selected from the USDA-Soybean Germplasm Collection, were grown in Stoneville, MS for biochemical analysis and tofu texture and sensory quality tests. Eight lines were identified, from 22 lines harvested in 2014, to be suitable for tofu making, as judged by chemical composition and sensory quality of pressed tofu. In the filled tofu making and texture analysis study, the correlation between A3 subunit content and filled tofu firmness was significant (N=22, r=0.77, Pquality information for the selection of soybean genotypes for improving food quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of Genetic Diversity and Population Structure of Sesame Accessions from Africa and Asia as Major Centers of Its Cultivation

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Komivi Dossa

2016-04-01

Full Text Available Sesame is an important oil crop widely cultivated in Africa and Asia. Understanding the genetic diversity of accessions from these continents is critical to designing breeding methods and for additional collection of sesame germplasm. To determine the genetic diversity in relation to geographical regions, 96 sesame accessions collected from 22 countries distributed over six geographic regions in Africa and Asia were genotyped using 33 polymorphic SSR markers. Large genetic variability was found within the germplasm collection. The total number of alleles was 137, averaging 4.15 alleles per locus. The accessions from Asia displayed more diversity than those from Africa. Accessions from Southern Asia (SAs, Eastern Asia (EAs, and Western Africa (WAf were highly diversified, while those from Western Asia (WAs, Northern Africa (NAf, and Southeastern Africa (SAf had the lowest diversity. The analysis of molecular variance revealed that more than 44% of the genetic variance was due to diversity among geographic regions. Five subpopulations, including three in Asia and two in Africa, were cross-identified through phylogenetic, PCA, and STRUCTURE analyses. Most accessions clustered in the same population based on their geographical origins. Our results provide technical guidance for efficient management of sesame genetic resources in breeding programs and further collection of sesame germplasm from these different regions.

Comparative mapping of Phytophthora resistance loci in pepper germplasm: evidence for conserved resistance loci across Solanaceae and for a large genetic diversity.

Science.gov (United States)

Thabuis, A; Palloix, A; Pflieger, S; Daubèze, A-M; Caranta, C; Lefebvre, V

2003-05-01

Phytophthora capsici Leonian, known as the causal agent of the stem, collar and root rot, is one of the most serious problems limiting the pepper crop in many areas in the world. Genetic resistance to the parasite displays complex inheritance. Quantitative trait locus (QTL) analysis was performed in three intraspecific pepper populations, each involving an unrelated resistant accession. Resistance was evaluated by artificial inoculations of roots and stems, allowing the measurement of four components involved in different steps of the plant-pathogen interaction. The three genetic maps were aligned using common markers, which enabled the detection of QTLs involved in each resistance component and the comparison of resistance factors existing among the three resistant accessions. The major resistance factor was found to be common to the three populations. Another resistance factor was found conserved between two populations, the others being specific to a single cross. This comparison across intraspecific germplasm revealed a large variability for quantitative resistance loci to P. capsici. It also provided insights both into the allelic relationships between QTLs across pepper germplasm and for the comparative mapping of resistance factors across the Solanaceae.

Investigation and Analysis of Crop Germplasm Resources in Coastal Areas of Shandong Province

Institute of Scientific and Technical Information of China (English)

Dong WANG; Shoujin FAN; Libin ZHANG; Hui ZHANG; Yingjie LIN; Hanfeng DING; Xiaodong ZHANG; Runfang LI; Zhan LI; Yumin MA; Yu ZHANG; Nana LI; Weijing CHEN; Zhongxue FAN

2017-01-01

This study focused on the investigation of crop germplasm resources in coastal areas of Shandong Province, including 132 villages in 82 towns of 34 counties. The survey collected local varieties and wild resources of grain crops, economic crops, vegetables and fruit trees, and a total of 848 samples were collected, belonging to 54 species of 39 genera in 15 families. In this study, the current situation and growth and decline conditions of crop germplasm resources were investigated, and their botanical classification and utilization importance were analyzed. Furthermore, the conservation, development and utilization of crop germplasm resources in coastal areas of Shandong Province were also discussed in this paper.

An empirical assessment of the effects of the 1994 In Trust Agreements on IRRI Germplasm Acquisition and Distribution

OpenAIRE

Elisabetta Gotor; Francesco Caracciolo

2009-01-01

The objective of this paper is to assess the possible influence of the 1994 In Trust Agreements (ITAs) on acquisition and distribution of germplasm held by the International Research Rice Institute (IRRI) genebank. The agreements, legally affirmed the ‘public good’ status of the collections that were placed ‘In Trust’ for the benefit of the world community under agreements with FAO. They initiated a formal system of multilateral access to CGIAR-held ex situ genetic resources. The hypothesis t...

Variation for seed phytosterols in sunflower germplasm

Science.gov (United States)

Sunflower (Helianthus annuus L.) seeds and oils are rich sources of phytosterols, which are important compounds for human nutrition. There is limited information on variability for seed phytosterols in sunflower germplasm. The objective of the present research was to evaluate kernel phytosterol cont...

Identification of intra-accession genetic diversity in selfing crops using AFLP markers: implications for collection management

NARCIS (Netherlands)

Treuren, van R.; Hintum, van Th.J.L.

2001-01-01

Germplasm conserved as seeds in genebanks requires regular regeneration. In this process, selection and genetic drift may cause loss of genetic diversity from accessions. In the case of selfing crops, separation of distinct lines into different accessions may be an efficient strategy to avoid these

Study of Genetic Diversity of grain yield-associated traits in Iranian and Exotic Safflower (Carthamus tinctorius Germplasm

Directory of Open Access Journals (Sweden)

M. M. Majidi

2015-09-01

Full Text Available Safflower (Carthamus tinctorius L. is cultivated in a wide range of geographical conditions in the world from Africa to Europe, India and China. Previous studies have shown that diversity in indigenous Iranian germplasm is limited for some traits therefore germplasm collections from other origins need to be considered. An experiment was conducted to evaluate agronomic and morphological traits of 100 Iranian and exotic safflower genotypes during 2011- 2012 at the Research Farm of Isfahan University of Technology, Isfahan, Iran, using a simple lattice design of 10 × 10. The results of analysis of variance showed that the differences among genotypes were highly significant (p < 0.01 for days to flowering, seed yield, plant height, number of heads per plant, number of seeds per head, 1000-seed weight, oil content and harvest index, indicating high variability in the studied germplasm. The highest and lowest heritabilities were observed for 1000-seed weight and seed yield, respectively, indicating that indirect improving for seed yield would be more beneficial. Genetic and phenotypic correlation coefficients showed that number of heads per plant, number of seeds per head and harvest index had significantly positive correlations with seed yield. The results of stepwise regression and path analysis showed that number of heads per plant, number of seeds per head and 1000-seed weight are the most important components of seed yield, among which, number of heads per plant had the greatest direct positive effect on seed yield. These traits could be used as criteria for indirect selection in safflower breeding programs. Factor analysis recognized three factors which explained 72.56 percent of total variations. These factors were defined as phenological, physiological source and efficiency factors. Cluster analysis based on the agronomic and morphological traits grouped the genotypes into three clusters. Iranian accessions were clearly discriminated from

Genetic diversity and population structure of Brassica oleracea germplasm in Ireland using SSR markers.

Science.gov (United States)

El-Esawi, Mohamed A; Germaine, Kieran; Bourke, Paula; Malone, Renee

2016-01-01

The most economically important Brassica oleracea species is endangered in Ireland, with no prior reported genetic characterization studies. This study assesses the genetic diversity, population structure and relationships of B. oleracea germplasm in Ireland using microsatellite (SSRs) markers. A total of 118 individuals from 25 accessions of Irish B. oleracea were genotyped. The SSR loci used revealed a total of 47 alleles. The observed heterozygosity (0.699) was higher than the expected one (0.417). Moreover, the average values of fixation indices (F) were negative, indicating excess of heterozygotes in all accessions. Polymorphic information content (PIC) values of SSR loci ranged from 0.27 to 0.66, with an average of 0.571, and classified 10 loci as informative markers (PIC>0.5) to differentiate among the accessions studied. The genetic differentiation among accessions showed that 27.1% of the total genetic variation was found among accessions, and 72.9% of the variation resided within accessions. The averages of total heterozygosity (H(T)) and intra-accession genetic diversity (H(S)) were 0.577 and 0.442, respectively. Cluster analysis of SSR data distinguished among kale and Brussels sprouts cultivars. This study provided a new insight into the exploitation of the genetically diverse spring cabbages accessions, revealing a high genetic variation, as potential resources for future breeding programs. SSR loci were effective for differentiation among the accessions studied. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

MALE F ERTILITY IN UGANDA BANANA GERMPLASM

African Journals Online (AJOL)

Uidentiflcation du niveau de fertilité mâle dans le germplasm bananier à Kabanyolo, Ouganda, a été effectuée en fendant ... characteristic sterility; most of the presently cultivated .... hybrids (AB) and pollen output values from literature are for ...

Evaluation of powdery mildew-resistance of grape germplasm and rapid amplified polymorphic DNA markers associated with the resistant trait in Chinese wild Vitis.

Science.gov (United States)

Zhang, J; Zhang, Y; Yu, H; Wang, Y

2014-05-09

The resistance of wild Vitis germplasm, including Chinese and American wild Vitis and Vitis vinifera cultivars, to powdery mildew (Uncinula necator Burr.) was evaluated for two consecutive years under natural conditions. Most of the Chinese and North American species displayed a resistant phenotype, whereas all of the European species were highly susceptible. The Alachua and Conquistador accessions of Vitis rotundifolia species, which originated in North America, were immune to the disease, while Baihe-35-1, one of the accessions of Vitis pseudoreticulata, showed the strongest resistance among all Chinese accessions evaluated. Three rapid amplified polymorphic DNA (RAPD) markers, OPW02-1756, OPO11-964, and OPY13-661, were obtained after screening 520 random primers among various germplasm, and these markers were found to be associated with powdery mildew resistance in Baihe-35-1 and in some Chinese species, but not in any European species. Analysis of F₁ and F₂ progenies of a cross between resistant Baihe-35-1 and susceptible Carignane (V. vinifera) revealed that the three RAPD markers were linked to the powdery resistant trait in Baihe-35-1 plants. Potential applications of the identified RAPD markers for gene mapping, marker-assisted selection, and breeding were investigated in 168 F₂ progenies of the same cross. Characterization of the resistant phenotype of the selected F₂ seedlings for breeding a new disease-resistant grape cultivar is in progress.

The development of a droplet-vitrification method to conserve Vitis collections in the USDA-ARS National Plant Germplasm System and UDESC-CAV Santa Catarina State University in Brazil

Science.gov (United States)

Both the United States and Brazil maintain vast collections of grape genetic resources. We share a common interest in using cryopreservation methods for the secure, long-term back-up of accessions within these field collections of the USDA-ARS National Plant Germplasm System and UDESC-CAV Santa Cata...

Prosopis pod production - comparison of North American, South American, Hawaiian, and African germplasm in young plantations

Energy Technology Data Exchange (ETDEWEB)

Felker, P.; Clark, P.R.; Osborn, J.F.; Cannell, G.H.

Prosopis pod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5/sup 0/C temperature. The most productive pod producers were P. velutina accessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e. P. velutina 32 had a mean pod production of 7.2 kg/tree with a range of 3.2-12.2 kg/tree. P. chilensis and P. alba trees of the same age were much larger but had less pod production. Pod production estimates of 3000-4000 kg/ha were obtained in the dry irrigation treatment by P. velutina 20 which received 370 mm rainfall in the year preceding harvest.

Genetic diversity in green gram accessions as revealed by STMS ...

African Journals Online (AJOL)

Molecular characterization of green gram (Vigna radiata (L.) Wilczek) germplasm is essential for scientific assessment of variability and diversity for its better utilization in breeding programs. In this study, 120 accessions of green gram were analysed for 27 Sequence Tagged Microsatellites (STMS) loci. For data analysis ...

Genetic analysis of 430 Chinese Cynodon dactylon accessions using sequence-related amplified polymorphism markers.

Science.gov (United States)

Huang, Chunqiong; Liu, Guodao; Bai, Changjun; Wang, Wenqiang

2014-10-21

Although Cynodon dactylon (C. dactylon) is widely distributed in China, information on its genetic diversity within the germplasm pool is limited. The objective of this study was to reveal the genetic variation and relationships of 430 C. dactylon accessions collected from 22 Chinese provinces using sequence-related amplified polymorphism (SRAP) markers. Fifteen primer pairs were used to amplify specific C. dactylon genomic sequences. A total of 481 SRAP fragments were generated, with fragment sizes ranging from 260-1800 base pairs (bp). Genetic similarity coefficients (GSC) among the 430 accessions averaged 0.72 and ranged from 0.53-0.96. Cluster analysis conducted by two methods, namely the unweighted pair-group method with arithmetic averages (UPGMA) and principle coordinate analysis (PCoA), separated the accessions into eight distinct groups. Our findings verify that Chinese C. dactylon germplasms have rich genetic diversity, which is an excellent basis for C. dactylon breeding for new cultivars.

Population structure of Chinese southwest wheat germplasms resistant to stripe rust and powdery mildew using the DArT-seq technique

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Tianqing Chen

2018-04-01

Full Text Available ABSTRACT: Understanding genetic variability in existing wheat accessions is critical for collection, conservation and use of wheat germplasms. In this study, 138 Chinese southwest wheat accessions were investigated by genotyping using two resistance gene makers (Pm21 and Yr26 and DArT-seq technique. Finally, about 50% cultivars (lines amplified the specific allele for the Yr26 gene (Gwm11 and 40.6% for the Pm21 gene (SCAR1265. By DArT-seq analysis, 30,485 markers (6486 SNPs and 23999 DArTs were obtained with mean polymorphic information content (PIC value 0.33 and 0.28 for DArT and SNP marker, respectively. The mean Dice genetic similarity coefficient (GS was 0.72. Two consistent groups of wheat varieties were identified using principal coordinate analysis (PCoA at the level of both the chromosome 6AS and the whole-genome, respectively. Group I was composed of non-6VS/6AL translocation lines of different origins, while Group II was composed of 6VS/6AL translocation (T6VS/6AL lines, most of which carried the Yr26 and Pm21 genes and originated from Guizhou. Besides, a model-based population structure analysis revealed extensive admixture and further divided these wheat accessions into six subgroups (SG1, SG2, SG3, SG4, SG5 and SG6, based on their origin, pedigree or disease resistance. This information is useful for wheat breeding in southwestern China and association mapping for disease resistance using these wheat germplasms in future.

Characterization of chickpea germplasm conserved in the Indian National Genebank and development of a core set using qualitative and quantitative trait data

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Sunil Archak

2016-10-01

Full Text Available Chickpea is the third most important pulse crop as a source of dietary protein. Ever-increasing demand in Asian countries calls for breeding superior desi-type varieties, in turn necessitating the availability of characterized germplasm to breeders. The Indian National Genebank, located at the National Bureau of Plant Genetic Resources, New Delhi, conserves 14,651 accessions of chickpea. The entire set was characterized in a single large-scale experiment. High variation was observed for eight quantitative and 12 qualitative agro-morphological traits. Allelic richness procedure was employed to assemble a core set comprising 1103 accessions, 70.0% of which were of Indian origin. Comparable values of total variation explained by the first three principal components in the entire collection (51.1% and the core (52.4% together with conservation of nine pairwise r values among quantitative traits in the core collection and a coincidence rate around 99.7% indicated that the chickpea core was indeed an excellent representation of the entire chickpea collection in the National Genebank. The chickpea core exhibited greater diversity than the entire collection in agro-morphological traits, as assessed by higher variance and Shannon–Weaver diversity indices, indicating that the chickpea core maximized the phenotypic diversity available in the Indian chickpea germplasm. The chickpea core, comprising mainly indigenous desi genotypes, is expected to be an excellent resource for chickpea breeders. Information on the chickpea core can be accessed at http://www.nbpgr.ernet.in/pgrportal.

Molecular Scree ning of Blast Resistance Genes in Rice Germplasms Resistant to Magnaporthe oryzae

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Liang Yan

2017-01-01

Full Text Available Molecular screening of major rice blast resistance genes was determined with molecular markers, which showed close-set linkage to 11 major rice blast resistance genes (Pi-d2, Pi-z, Piz-t, Pi-9, Pi-36, Pi-37, Pi5, Pi-b, Pik-p, Pik-h and Pi-ta2, in a collection of 32 accessions resistant to Magnaporthe oryzae. Out of the 32 accessions, the Pi-d2 and Pi-z appeared to be omnipresent and gave positive express. As the second dominant, Pi-b and Piz-t gene frequencies were 96.9% and 87.5%. And Pik-h and Pik-p gene frequencies were 43.8% and 28.1%, respectively. The molecular marker linkage to Pi-ta2 produced positive bands in eleven accessions, while the molecular marker linkage to Pi-36 and Pi-37 in only three and four accessions, respectively. The natural field evaluation analysis showed that 30 of the 32 accessions were resistant, one was moderately resistant and one was susceptible. Infection types were negatively correlated with the genotype scores of Pi-9, Pi5, Pi-b, Pi-ta2 and Pik-p, although the correlation coefficients were very little. These results are useful in identification and incorporation of functional resistance genes from these germplasms into elite cultivars through marker-assisted selection for improved blast resistance in China and worldwide.

Evaluation of Maize Germplasm for Resistance to Aflatoxin Accumulation

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Michael H. Blanco

2012-03-01

Full Text Available Aflatoxin contamination of maize grain threatens human food and animal feed safety. Breeding for reduced grain aflatoxin accumulation is one of the best strategies presently available to lower grain aflatoxin accumulation. Previously identified sources of germplasm with reduced grain aflatoxin accumulation are excessively tall and late maturing. The objective of this research was to screen germplasm and identify potential sources of aflatoxin resistance. KO679Y and CUBA117:S15-101-001-B-B-B-B inbreds were evaluated for aflatoxin accumulation alongside resistant and susceptible checks with both performing well. These two lines were also evaluated in various crosses. KO679Y performed especially well in crosses with Mp494 and Mp717, resulting in low ear rot and very low aflatoxin levels, but not well in other crosses. A breeding cross including CUBA117:S15-101-001-B-B-B-B as a parent accumulated low levels of aflatoxin both years it was evaluated. Lines resulting from these crosses are being advanced for further evaluation and improvement. KO679Y and CUBA117:S15-101-001-B-B-B-B may prove useful for breeders seeking germplasm sources for ear rot and mycotoxin reduction, especially KO679Y which matures a week earlier and is approximately 25% shorter than current lines resistant to grain aflatoxin accumulation.

Variation in cassava germplasm for tolerance to post-harvest physiological deterioration.

Science.gov (United States)

Venturini, M T; Santos, L R; Vildoso, C I A; Santos, V S; Oliveira, E J

2016-05-06

Tolerant varieties can effectively control post-harvest physiological deterioration (PPD) of cassava, although knowledge on the genetic variability and inheritance of this trait is needed. The objective of this study was to estimate genetic parameters and identify sources of tolerance to PPD and their stability in cassava accessions. Roots from 418 cassava accessions, grown in four independent experiments, were evaluated for PPD tolerance 0, 2, 5, and 10 days post-harvest. Data were transformed into area under the PPD-progress curve (AUP-PPD) to quantify tolerance. Genetic parameters, stability (Si), adaptability (Ai), and the joint analysis of stability and adaptability (Zi) were obtained via residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) methods. Variance in the genotype (G) x environment (E) interaction and genotypic variance were important for PPD tolerance. Individual broad-sense heritability (hg(2)= 0.38 ± 0.04) and average heritability in accessions (hmg(2)= 0.52) showed high genetic control of PPD tolerance. Genotypic correlation of AUP-PPD in different experiments was of medium magnitude (ȓgA = 0.42), indicating significant G x E interaction. The predicted genotypic values o f G x E free of interaction (û + ĝi) showed high variation. Of the 30 accessions with high Zi, 19 were common to û + ĝi, Si, and Ai parameters. The genetic gain with selection of these 19 cassava accessions was -55.94, -466.86, -397.72, and -444.03% for û + ĝi, Si, Ai, and Zi, respectively, compared with the overall mean for each parameter. These results demonstrate the variability and potential of cassava germplasm to introduce PPD tolerance in commercial varieties.

Screening of the entire USDA castor germplasm collection for oil content and fatty acid composition for optimum biodiesel production.

Science.gov (United States)

Wang, Ming Li; Morris, J Bradley; Tonnis, Brandon; Pinnow, David; Davis, Jerry; Raymer, Paul; Pederson, Gary A

2011-09-14

Castor has tremendous potential as a feedstock for biodiesel production. The oil content and fatty acid composition in castor seed are important factors determining the price for production and affecting the key fuel properties of biodiesel. There are 1033 available castor accessions collected or donated from 48 countries worldwide in the USDA germplasm collection. The entire castor collection was screened for oil content and fatty acid composition by nuclear magnetic resonance (NMR) and gas chromatography (GC), respectively. Castor seeds on the average contain 48.2% oil with significant variability ranging from 37.2 to 60.6%. Methyl esters were prepared from castor seed by alkaline transmethylation. GC analysis of methyl esters confirmed that castor oil was composed primarily of eight fatty acids: 1.48% palmitic (C16:0), 1.58% stearic (C18:0), 4.41% oleic (C18:1), 6.42% linoleic (C18:2), 0.68% linolenic (C18:3), 0.45% gadoleic (C20:1), 84.51% ricinoleic (C18:1-1OH), and 0.47% dihydroxystearic (C18:0-2OH) acids. Significant variability in fatty acid composition was detected among castor accessions. Ricinoleic acid (RA) was positively correlated with dihydroxystearic acid (DHSA) but highly negatively correlated with the five other fatty acids except linolenic acid. The results for oil content and fatty acid composition obtained from this study will be useful for end-users to explore castor germplasm for biodiesel production.

Use of plumules cryopreservation to save coconut germplasm in ...

African Journals Online (AJOL)

SAM

2014-04-16

Apr 16, 2014 ... (PNT/GPA), Brazilian Green Tall (BGD/NVB), Cameroon Red Dwarf (CRD/NRC), Vanuatu Tall ... erosion based on it particular germplasm conservation. Its mode of ..... Tolerance of coffee (Coffea spp) seeds to ultra-low.

Prosopis pod production: comparison of North American, South American, Hawaiin, and African germplasm in young plantations

Energy Technology Data Exchange (ETDEWEB)

Felker, P.; Clark, P.R.; Osborn, J.F.; Cannell, G.H.

Prosopis pod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5/sup 0/C temperature. The most productive pod producers were P. velutina accessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e., P. velutina 32 had a mean pod production of 7.2 kg/tree with a range of 3.2-12.2 kg/tree. P. chilensis and P. alba trees of the same age were much larger but had less pod production. Trees in the driest irrigation treatment had the greatest pod production. Pod production estimates of 3000-4000 kg/ha were obtained in the dry irrigation treatment by P. velutina 20 which received 370 mm rainfall in the year preceding harvest. 32 references, 1 figure, 6 tables.

Regeneration of Algerian germplasm by stigma/style somatic ...

African Journals Online (AJOL)

... days in most of the cultured genotypes. Formed embryos were cultured in a single tube before in vivo acclimatization. After sanitary assays, regenerated plants were shown to be free from the agents detected in the mother trees. Key words: Algeria, citrus germplasm, plant regeneration, sanitation, somatic embryogenesis.

Genetic diversity of turmeric germplasm (Curcuma longa; Zingiberaceae) identified by microsatellite markers.

Science.gov (United States)

Sigrist, M S; Pinheiro, J B; Filho, J A Azevedo; Zucchi, M I

2011-03-09

Turmeric (Curcuma longa) is a triploid, vegetatively propagated crop introduced early during the colonization of Brazil. Turmeric rhizomes are ground into a powder used as a natural dye in the food industry, although recent research suggests a greater potential for the development of drugs and cosmetics. In Brazil, little is known about the genetic variability available for crop improvement. We examined the genetic diversity among turmeric accessions from a Brazilian germplasm collection comprising 39 accessions collected from the States of Goiás, Mato Grosso do Sul, Minas Gerais, São Paulo, and Pará. For comparison, 18 additional genotypes were analyzed, including samples from India and Puerto Rico. Total DNA was extracted from lyophilized leaf tissue and genetic analysis was performed using 17 microsatellite markers (single-sequence repeats). Shannon-Weiner indexes ranged from 0.017 (Minas Gerais) to 0.316 (São Paulo). Analyses of molecular variance (AMOVA) demonstrated major differences between countries (63.4%) and that most of the genetic diversity in Brazil is found within states (75.3%). Genotypes from São Paulo State were the most divergent and potentially useful for crop improvement. Structure analysis indicated two main groups of accessions. These results can help target future collecting efforts for introduction of new materials needed to develop more productive and better adapted cultivars.

Variation for yield, water-use efficiency, and canopy morphology among nine alfalfa germplasms

International Nuclear Information System (INIS)

Ray, I.M.; Townsend, M.S.; Henning, J.A.

1998-01-01

Alfalfa (Medicago sativa L.) production under irrigated and rainfed conditions may benefit from improvements in water-use efficiency (WUE), the amount of forage and root biomass produced per unit of water transpired. If benefits from improved WUE are to be realized, correlations between important agronomic traits and key physiological traits associated with WUE must be determined. This study characterized variation for dry matter yield, forage maturity, leaf-to-stem ratio (LSR), carbon isotope discrimination (delta), canopy temperature, ash content, and specific leaf mass (SLM) in alfalfa. Associations between traits were also determined. Nine alfalfa germplasms representing eight of the nine historical genetic diversity groups, and a very fall-dormant (VFD) population, were established in seeded, irrigated plots for 2 yr near Las Cruces, NM. Significant variation (P less than or equal to 0.10) was detected for all traits and was greatest for delta and maturity, intermediate for yield, canopy temperature, ash content, and LSR, and least for SLM. The African, Peruvian, and Indian germplasms exhibited a higher delta than either the Turkistan, VFD, M. varia Martyn., or Ladak germplasms. Carbon isotope discrimination was positively correlated with forage yield (r = 0.64; P less than or equal to 0.10; n = 9) and forage maturity (r = 0.66; P less than or equal to 0.05; n = 9). No association was detected between delta and either canopy temperature, ash content, SLM, or LSR. The results indicate that differences in stomatal conductance or photosynthetic capacity exist among the nine populations, and that germplasms with low delta tended to have slower growth and development rates under irrigated conditions. Neither canopy temperature, ash content, nor SLM provided suitable alternate measurements of delta among the nine alfalfa germplasms

Molecular assessment of genetic diversity in mung bean germplasm

Indian Academy of Sciences (India)

2008-04-02

Apr 2, 2008 ... crop, because of its adaptation to short growth duration, low water requirement, soil fertility and because it can be used in ... profiles have been characterized in case of several crop plant germplasm ...... Nucleic Acids Res. 18,.

Developing single nucleotide polymorphism markers for the identification of pineapple (Ananas comosus) germplasm.

Science.gov (United States)

Zhou, Lin; Matsumoto, Tracie; Tan, Hua-Wei; Meinhardt, Lyndel W; Mischke, Sue; Wang, Boyi; Zhang, Dapeng

2015-01-01

Pineapple (Ananas comosus [L.] Merr.) is the third most important tropical fruit in the world after banana and mango. As a crop with vegetative propagation, genetic redundancy is a major challenge for efficient genebank management and in breeding. Using expressed sequence tag and nucleotide sequences from public databases, we developed 213 single nucleotide polymorphism (SNP) markers and validated 96 SNPs by genotyping the United States Department of Agriculture - Agricultural Research Service pineapple germplasm collection, maintained in Hilo, Hawaii. The validation resulted in designation of a set of 57 polymorphic SNP markers that revealed a high rate of duplicates in this pineapple collection. Twenty-four groups of duplicates were detected, encompassing 130 of the total 170 A cosmos accessions. The results show that somatic mutation has been the main source of intra-cultivar variations in pineapple. Multivariate clustering and a model-based population stratification suggest that the modern pineapple cultivars are comprised of progenies that are derived from different wild Ananas botanical varieties. Parentage analysis further revealed that both A. comosus var. bracteatus and A. comosus var. ananassoides are likely progenitors of pineapple cultivars. However, the traditional classification of cultivated pineapple into horticultural groups (e.g. 'Cayenne', 'Spanish', 'Queen') was not well supported by the present study. These SNP markers provide robust and universally comparable DNA fingerprints; thus, they can serve as an efficient genotyping tool to assist pineapple germplasm management, propagation of planting material, and pineapple cultivar protection. The high rate of genetic redundancy detected in this pineapple collection suggests the potential impact of applying this technology on other clonally propagated perennial crops.

Screening of Gladiolus germplasm for agronomic performance and ...

African Journals Online (AJOL)

A field experiment was conducted to evaluate the agronomic performance and resistance of Gladiolus germplasm against corm rot disease caused by Fusarium oxysporum Schlecht. f. sp. gladioli (L. Masey) W.C. Snyder & H.N. Hans. Among the 23 Gladiolus varieties tested, Glad Red exhibited the highest spike length of 55 ...

Diversity Analysis and Physico-Morphlogical Characteritics of Indigenous Germplasm of Lablab Bean

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Ram Bahadur KC

2016-12-01

Full Text Available Germplasm characterization is an important component of crop breeding program. In characterizing indigenous beans lablab which is used for vegetables as well pulses in Nepal. Twenty three lablab beans germplasm were evaluated for different qualitative and quantitive physico-morphological charecteristics for two years during 2011 and 2012 at Horticulture Research Station, Malepatan, Pokhara. The germplasm showed considerable variations in most of the qualitative and quantitative traits. Leaf size, vine color, flower color, pod color, pod shape, pod type and seed color varied among the genotypes. Variation was also observed in yield attributing characters eg, pod length and width, 10 fresh pod weight, seeds per pod and 100-seed weight. Days to 50% flowering ranged from 81 to 130 days indicating the presence of early varieties. Fresh pod weight of 10 pods was ranged from 45.0 g to 162.5 g. Multivariate analysis indicated four groups in these genotypes, among with ML-02 and ML-10 were distinct in comparioson with other genotypes. Simple selection may be considered to develop high yielding, early type varieties from these gentopypes.

Fingerprinting for discriminating tea germplasm using inter-simple sequence repeat (ISSR) markers

International Nuclear Information System (INIS)

Liu, B.Y.; Li, Y.Y.; Wang, P.S.; Wang, L.Y.; Wang, P.S.

2012-01-01

For the discrimination of tea germplasm at the inter-specific level, 134 tea varieties preserved in the China National Germplasm Tea Repositories (CNGTR) were analyzed using inter simple sequence repeat (ISSR) markers. Eighteen primers were chosen from 60 screened for ISSR amplification, generating 99.4% polymorphic bands. The mean Nei's gene diversity (H) and the overall mean Shannon's Information index (I) were 0.396 and 0.578, respectively, indicating a wide gene pool. Using the presence, sometimes absence of unique ISSR markers, it was possible to discriminate 32 of the genotypes tested. No single primer could discriminate all the 134 genotypes. However, UBC811 provided rich band patterns and it can discriminate 35 genotypes. The combination of two and three primers could discriminate 99 and 121 genotypes, respectively. Furthermore, the combination of band patterns or the DNA fingerprinting based on specific ISSR markers generated by UBC811, UBC835, ISSR2 and ISSR3 could discriminate all 134 genotypes tested. ISSR markers also provide a powerful tool to discriminate tea germplasm at the inter-specific level. (author)

M7 germplasm release: A tetraploid clone derived from Solanum infundibuliforme for use in expanding the germplasm base for french fry processing

Science.gov (United States)

A new source of russet germplasm has been identified as a parent for processing and fresh market breeding programs. It was derived via bilateral sexual polyploidization following a cross between a diploid cultivated potato and the diploid wild species Solanum infundibuliforme. This clone, designated...

Genetic diversity of tropical-adapted onion germplasm assessed by RAPD markers Diversidade genética em germoplasma tropical de cebola estimada via marcadores RAPD

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Maria do Desterro M dos Santos

2012-03-01

Full Text Available Onion is a crop of significant socioeconomic importance to Brazil. Onion germplasm with adaptation to tropical and sub-tropical conditions has played an important role in the development of this crop in the country. In this context, we studied the genetic diversity in a germplasm collection potentially useful for the development of cultivars for tropical and subtropical regions. The genetic variability of 21 accessions/cultivars that have been used as germplasm and/or were developed by onion breeding programs in Brazil was evaluated via RAPD markers. The following accessions were included in the study :'Red Creole', 'Roxa IPA-3', 'Valenciana 14', 'Beta Cristal', 'Diamante', 'Composto IPA-6', 'Aurora', 'Bojuda Rio Grande', 'Alfa Tropical', 'Pêra IPA-4', 'Primavera', 'Belém IPA-9', 'Crioula Alto Vale', 'Conquista', 'Pira-Ouro', 'Vale-Ouro IPA-11', 'Franciscana IPA-10', 'Serrana', 'CNPH 6400', 'Petroline', and 'Baia Periforme'. From the 520 primers used in the initial screening only 38 displayed stable polymorphisms. They produced 624 amplicons, of which 522 (83.7% were monomorphic and 102 (16.3% were polymorphic. An average similarity coefficient of 0.72 was calculated among accessions based upon this subgroup of polymorphic amplicons. This allowed the discrimination of this germplasm collection into six groups with only one of them comprising more than one accession. The main group was formed by 16 accessions ('Diamante', 'Composto IPA-6', 'Aurora', 'Bojuda Rio Grande', 'Conquista', 'Pira-Ouro', 'Serrana', 'Vale-Ouro IPA-11', 'Baia Periforme', 'Primavera', 'Franciscana IPA-10', 'Belém IPA-9', 'Crioula Alto Vale', 'Petroline', 'Pêra IPA-4' and 'Alfa Tropical', for which the genetic origin (with few exceptions can be traced back to the variety 'Baia Periforme'. The populations 'Red Creole', 'Roxa IPA-3', 'Beta Cristal', 'CNPH 6400', and 'Valenciana 14' comprised a set of five isolated groups, showing genetic divergence among them and in

Genetic diversity of wild germplasm of "yerba mate" (Ilex paraguariensis St. Hil.) from Uruguay.

Science.gov (United States)

Cascales, Jimena; Bracco, Mariana; Poggio, Lidia; Gottlieb, Alexandra Marina

2014-12-01

The "yerba mate" tree, Ilex paraguariensis St. Hil., is a crop native to subtropical South America, marketed for the elaboration of the highly popular "mate" beverage. The Uruguayan germplasm occupies the southernmost area of the species distribution range and carries adaptations to environments that considerably differ from the current production area. We characterized the genetic variability of the germplasm from this unexplored area by jointly analyzing individuals from the diversification center (ABP, Argentina, Brazil and Paraguay) with 19 nuclear and 11 plastidic microsatellite markers. For the Uruguayan germplasm, we registered 55 alleles (18 % private), and 80 genotypes (44 % exclusive), whereas 63 alleles (28.6 % private) and 81 genotypes (42 % exclusive) were recorded for individuals from ABP. Only two plastidic haplotypes were detected. Distance-based and multilocus genotype analyses showed that individuals from ABP intermingle and that the Uruguayan germplasm is differentiated in three gene-pools. Significant positive correlations between genetic and geographic distances were detected. Our results concur in that ABP individuals harbor greater genetic variation than those from the tail of the distribution, as to the number of alleles (1.15-fold), He (1.19-fold), Rs (1.39-fold), and the between-group genetic distances (1.16-fold). Also the shape of the genetic landscape interpolation analysis suggests that the genetic variation decays southward towards the Uruguayan territory. We showed that Uruguayan germplasm hosts a combination of nuclear alleles not present in the central region, constituting a valuable breeding resource. Future conservation efforts should concentrate in collecting numerous individuals of "yerba mate" per site to gather the existent variation.

Mating system and pollen dispersal in Eugenia dysenterica (Myrtaceae) germplasm collection: tools for conservation and domestication.

Science.gov (United States)

Rodrigues, Eduardo B; Collevatti, Rosane G; Chaves, Lázaro J; Moreira, Lucas R; Telles, Mariana P C

2016-04-01

Eugenia dysenterica DC. (Myrtaceae) is a perennial tree producing edible fruits and ornamental flowers of potential value widely distributed in Brazilian "Cerrados" (savannas), but available genetic resources and potential for future breeding programs must be evaluated. Here we evaluated the reproductive system and pollen-mediated gene flow in one generation of Eugenia dysenterica germplasm collection of Agronomy School, Federal University of Goiás (in Goiânia city, Central Brazil). We collected leaves from all adults from the germplasm collection (682 plants) and seeds (542) from 23 mother-trees. Genotypes were obtained for seven microsatellite loci. Genetic diversity was high and did not significantly differ between adults (H e = 0.777) and progeny arrays (H e = 0.617). Our results showed that E. dysenterica has an allogamous mating system in the germplasm collection (t m = 0.957), but with high and significant biparental inbreeding (t m - t s = 0.109). Because sibs are very close to each other, mating between closely related individuals is likely. Paternity correlation was also relatively high, indicating a 11.9 % probability that a randomly chosen pair of outcrossed progeny from the same array are full sibs. The maximum pollen dispersal distance (224 m), estimated using assignment test, corresponded to the boundaries of the orchard. We were able to assign the paternity to only 64 % of the 349 seeds analyzed, indicating potential pollen immigration to the germplasm collection. The variance effective population size estimated for one maternal family in the germplasm collection (N ev = 3.42) is very close to the theoretical maximum value for half-sibs (Nev = 4.0). Because E. dysenterica has a long life cycle and generation time, the maintenance of an effective population size of at least 100 in the germplasm collection is suggested, which can be achieved by maintaining a seed-trees number around 30 individuals.

Field Screening of Cassava (Manihot esculenta Crantz) Germplasm ...

African Journals Online (AJOL)

Fiifi Baidoo

Marmey P., Beeching J. R., Hamon S. and Charrier A. (1994). Evaluation of cassava (Manihot esculenta Crantz) germplasm collection using RAPD markers. Euphytica 74: 203–209. Roa A. C., Maya, M. M., Duque M. M., Tohme J., Allen A. C. and Bonierbale M. W. (1997). AFLP analysis of relationships among cassava and ...

A strategy for developing representative germplasm sets for systematic QTL validation, demonstrated for apple, peach, and sweet cherry

NARCIS (Netherlands)

Peace, C.P.; Luby, J.; Weg, van de W.E.; Bink, M.C.A.M.; Iezzoni, A.F.

2014-01-01

Horticultural crop improvement would benefit from a standardized, systematic, and statistically robust procedure for validating quantitative trait loci (QTLs) in germplasm relevant to breeding programs. Here, we describe and demonstrate a strategy for developing reference germplasm sets of

National Plant Germplasm System: Critical Role of Customer Service

Science.gov (United States)

The National Plant Germplasm System (NPGS) conserves plant genetic resources, not only for use by future generations, but for immediate use by scientists and educators around the world. With a great deal of interaction between genebank curators and users of plant genetic resources, customer service...

Verification of genetic identity of introduced cacao germplasm in ...

African Journals Online (AJOL)

In the present study, high-throughput genotyping with SNP markers was used to fingerprint 160 cacao trees in the germplasm collection at the Cocoa Research Institute of Ghana (CRIG). ... Keywords: Cacao, conservation, chocolate, DNA fingerprint, molecular marker, tropical plant, off-type, true-to-type, West Africa.

Emerging crops in the USDA arid lands germplasm collection

Science.gov (United States)

The USDA National Plant Germplasm System maintains collections of several emerging crops for arid lands at the National Arid Land Plant Genetic Resources Unit in Parlier, CA (NALPGRU). The guayule, jojoba, and prickly pear collections are most active in terms of current research and crop development...

Characterization and evaluation of olive germplasm in southern Italy.

Science.gov (United States)

Di Vaio, Claudio; Nocerino, Sabrina; Paduano, Antonello; Sacchi, Raffaele

2013-08-15

The southern Italian region of Campania has suitable pedo-climatic conditions and a large varietal heritage able to produce oils with high typicality. The aim of this study was to characterize 20 cultivars belonging to Campania's olive germplasm, evaluating their vegetative and production aspects and their oil quality characteristics. The study was conducted from 2003 to 2009, observing the following aspects in six plants per variety: entry into production, vigour, ripening and drupe oil content. The following analyses were carried out on monovarietal oils, obtained by microextractor: acid composition, polyphenol content and aromatic profile. The agronomic results showed early entry into production for the cultivars Racioppella, Ortolana, Biancolilla and Carpellese. However, entry into production was delayed for Ritonnella, Ortice, Cornia and Rotondella. As regards vegetative behaviour, Asprinia, from the province of Caserta and Pisciottana and Carpellese, from the province of Salerno, proved the most vigorous cultivars. Groups of similar cultivars emerged from chemical and sensory analysis of their oils, while other accessions were well characterized and separated from each other, showing a high level of diversity and specificity. © 2013 Society of Chemical Industry.

Genetic diversity in radish germplasm for morphological traits and seed storage proteins

International Nuclear Information System (INIS)

Jatoi, S.A.; Siddiqui, S.U.; Masood, M.S.; Javaid, A.; Iqbal, M.; Sayal, O.U.

2011-01-01

Genetic variation of forty-nine local and exotic radish genotypes including two checks was studied for morphological traits and seed storage protein electrophoresis using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) markers. A high variation in germplasm for root shape, root length, root colour (internal and external), flesh texture and root type was observed. Among these genotypes, the genetic variation was apparent for most of the characters like plant biomass, root weight, leaf length, root length and root diameter that indicated the potential for crop improvement in these traits through simple selection. Exotic germplasm exhibited higher variation for plant biomass, root weight and root length which could be utilized through breeding programme. Cluster analysis on the basis of genetic diversity for seven quantitative traits resulted into four clusters. No clustering was found on the basis of origin. Low level of variance was observed for SDS-PAGE electrophoresis that suggested acquisition of more germplasm. On the basis of high yield and crispy root texture some genotypes (10076, 10362, 10429, 10658, 10662 and 10667) were identified for further testing under wide range of agro-ecological conditions. (author)

Association Mapping for Fusarium Wilt Resistance in Chinese Asparagus Bean Germplasm

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Xinyi Wu

2015-07-01

Full Text Available Fusarium wilt (FW is an important vascular disease attacking asparagus bean [ (L. Walp. subsp. Sesquipedalis Group] in China. The level and genetic variability of FW resistance in the Chinese asparagus bean germplasm remains elusive. In the current study, FW resistance was assessed across a natural population consisting of 95 asparagus bean and four African cowpea [ (L. Walp. subsp. Unguiculata Group] accessions. The disease index (DI based on the severity of leaf damage (LFD and vascular discoloration (VD varied highly across the population and the highly resistant varieties used for vegetable are very limited. Genome-wide association study identified 11 and seven single nucleotide polymorphisms (SNPs that are associated with LFD and VD traits, respectively. These SNPs were distributed on nine linkage groups of the asparagus bean genome and each accounted for less than 5% of the phenotypic variation. Overall, the nonstandard vegetable (NSV subgene pool harbors favorable alleles in a higher frequency than the standard vegetable (SV subgene pool. Individual NSV-type accessions tend to possess a greater number of favorable alleles than the SV-type ones. A SNP marker 1_0981 was converted to a cleaved amplified polymorphic sequences (CAPS marker to facilitate future breeding. To our knowledge, this is the first report of an association mapping (AM study in asparagus bean. The results obtained suggests that resources for FW resistance is relatively limited in the SV subgene pool; hence, introducing resistant alleles from the NSV accessions into currently leading SV cultivars will be important to improve FW resistance of the latter.

Haplotype Analysis of the Pre-harvest Sprouting Resistance Locus Phs-A1 Reveals a Causal Role of TaMKK3-A in Global Germplasm.

Science.gov (United States)

Shorinola, Oluwaseyi; Balcárková, Barbara; Hyles, Jessica; Tibbits, Josquin F G; Hayden, Matthew J; Holušova, Katarina; Valárik, Miroslav; Distelfeld, Assaf; Torada, Atsushi; Barrero, Jose M; Uauy, Cristobal

2017-01-01

Pre-harvest sprouting (PHS) is an important cause of quality loss in many cereal crops and is particularly prevalent and damaging in wheat. Resistance to PHS is therefore a valuable target trait in many breeding programs. The Phs-A1 locus on wheat chromosome arm 4AL has been consistently shown to account for a significant proportion of natural variation to PHS in diverse mapping populations. However, the deployment of sprouting resistance is confounded by the fact that different candidate genes, including the tandem duplicated Plasma Membrane 19 ( PM19 ) genes and the mitogen-activated protein kinase kinase 3 ( TaMKK3-A) gene, have been proposed to underlie Phs-A1 . To further define the Phs-A1 locus, we constructed a physical map across this interval in hexaploid and tetraploid wheat. We established close proximity of the proposed candidate genes which are located within a 1.2 Mb interval. Genetic characterization of diverse germplasm used in previous genetic mapping studies suggests that TaMKK3-A , and not PM19 , is the major gene underlying the Phs-A1 effect in European, North American, Australian and Asian germplasm. We identified the non-dormant TaMKK3-A allele at low frequencies within the A-genome diploid progenitor Triticum urartu genepool, and show an increase in the allele frequency in modern varieties. In United Kingdom varieties, the frequency of the dormant TaMKK3-A allele was significantly higher in bread-making quality varieties compared to feed and biscuit-making cultivars. Analysis of exome capture data from 58 diverse hexaploid wheat accessions identified fourteen haplotypes across the extended Phs-A1 locus and four haplotypes for TaMKK3-A . Analysis of these haplotypes in a collection of United Kingdom and Australian cultivars revealed distinct major dormant and non-dormant Phs-A1 haplotypes in each country, which were either rare or absent in the opposing germplasm set. The diagnostic markers and haplotype information reported in the study will

Haplotype Analysis of the Pre-harvest Sprouting Resistance Locus Phs-A1 Reveals a Causal Role of TaMKK3-A in Global Germplasm

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Oluwaseyi Shorinola

2017-09-01

Full Text Available Pre-harvest sprouting (PHS is an important cause of quality loss in many cereal crops and is particularly prevalent and damaging in wheat. Resistance to PHS is therefore a valuable target trait in many breeding programs. The Phs-A1 locus on wheat chromosome arm 4AL has been consistently shown to account for a significant proportion of natural variation to PHS in diverse mapping populations. However, the deployment of sprouting resistance is confounded by the fact that different candidate genes, including the tandem duplicated Plasma Membrane 19 (PM19 genes and the mitogen-activated protein kinase kinase 3 (TaMKK3-A gene, have been proposed to underlie Phs-A1. To further define the Phs-A1 locus, we constructed a physical map across this interval in hexaploid and tetraploid wheat. We established close proximity of the proposed candidate genes which are located within a 1.2 Mb interval. Genetic characterization of diverse germplasm used in previous genetic mapping studies suggests that TaMKK3-A, and not PM19, is the major gene underlying the Phs-A1 effect in European, North American, Australian and Asian germplasm. We identified the non-dormant TaMKK3-A allele at low frequencies within the A-genome diploid progenitor Triticum urartu genepool, and show an increase in the allele frequency in modern varieties. In United Kingdom varieties, the frequency of the dormant TaMKK3-A allele was significantly higher in bread-making quality varieties compared to feed and biscuit-making cultivars. Analysis of exome capture data from 58 diverse hexaploid wheat accessions identified fourteen haplotypes across the extended Phs-A1 locus and four haplotypes for TaMKK3-A. Analysis of these haplotypes in a collection of United Kingdom and Australian cultivars revealed distinct major dormant and non-dormant Phs-A1 haplotypes in each country, which were either rare or absent in the opposing germplasm set. The diagnostic markers and haplotype information reported in the

Genetic analysis of wild and cultivated germplasm of pigeonpea ...

African Journals Online (AJOL)

To compare the efficiency of the use of single versus multiple markers, the genetic diversity was quantified among 12 diverse pigeonpea germplasm comprised of eight wild and four cultivated using both random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers, and how well these two types ...

Quantitative Determination of L-DOPA in Seeds of Mucuna Pruriens Germplasm by High Performance Thin Layer Chromatography.

Science.gov (United States)

Raina, Archana P; Khatri, Renu

2011-07-01

Mucuna pruriens Linn. is an important medicinal plant used for treatment of Parkinson's disease and many others in ancient Indian medical system. L-DOPA extracted from seeds of Mucuna is a constituent of more than 200 indigenous drug formulations and is more effective as drug than the synthetic counterpart. A densitometric high performance thin-layer chromatographic (HPTLC) method was developed for quantification of L-DOPA content present in the seeds extract. The method involves separation of L-DOPA on precoated silica gel 60 GF(254) HPTLC plates using a solvent system of n-butanol-acetic-acid-water (4:1:1, v/v) as the mobile phase. Quantification was done at 280 nm using absorbance reflectance mode. Linearity was found in the concentration range of 100 to 1000 ng/spot with the correlation coefficient value of 0.9980. The method was validated for accuracy, precision and repeatability. Mean recovery was 100.89%. The LOD and LOQ for L-DOPA determination were found to be 3.41 ng/spot and 10.35 ng/spot respectively. The proposed HPTLC method was found to be precise, specific and accurate for quantitative determination of L-DOPA. It can be used for rapid screening of large germplasm collections of Mucuna pruriens for L-DOPA content. The method was used to study variation in fifteen accessions of Mucuna germplasm collected from different geographical regions.

Morphological and physio-chemical characterization of five Canistel accessions at the subtropical horticulture research station in Miami Florida

Science.gov (United States)

Fruit of five canistel cultivars, 'Fairchild','E11', 'Keisau', 'TREC#3' and 'TREC 3680' were evaluated and characterized at the National Germplasm Repository, Subtropical horticulture Research Station (SHRS) Miami, Florida. Thirty fruits were harvested from clonal accessions during July and August, ...

Genetic Diversity of Iranian and Exotic Sainfoin Accessions (Onobrychis viciifolia Scop Based on Morphological Traits

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M. Zarabiyan

2016-12-01

Full Text Available Sainfoin (Onobrychis viciifolia Scop. is widely grown as forage and pasture legume in Iran and is tolerant to environmental stresses. To investigate the genetic diversity among 56 accessions of sainfoin germplasm (including 46 Iranian and 10 foreign based on morphological and agronomic characteristics, present experiment was conducted as randomized complete block design with three replications in Isfahan University of Technology Research Farm during 2010-2011. The results of analysis of variance indicated considerable variation between studied germplasm for all traits and the better performance for Iranian accessions. The estimation of broad sense heritability for plant height, number of stems per plant, number of stems per meter square and number of nods per stem was high suggesting contribution of the major genes for controlling these traits. On the basis of means comparison, the forage yield was greatest for the first cutting as compared to the second cutting. Also the highest yield obtained from second year. Regarding the palatability (based on leaf to stem ratio the exotic accessions had higher values. Developing of superior cultivars may be possible through combining high yield and palatability in breeding programs.

Genetic variability of garlic accessions as revealed by agro-morphological traits evaluated under different environments.

Science.gov (United States)

Hoogerheide, E S S; Azevedo Filho, J A; Vencovsky, R; Zucchi, M I; Zago, B W; Pinheiro, J B

2017-05-31

The cultivated garlic (Allium sativum L.) displays a wide phenotypic diversity, which is derived from natural mutations and phenotypic plasticity, due to dependence on soil type, moisture, latitude, altitude and cultural practices, leading to a large number of cultivars. This study aimed to evaluate the genetic variability shown by 63 garlic accessions belonging to Instituto Agronômico de Campinas and the Escola Superior de Agricultura "Luiz de Queiroz" germplasm collections. We evaluated ten quantitative characters in experimental trials conducted under two localities of the State of São Paulo: Monte Alegre do Sul and Piracicaba, during the agricultural year of 2007, in a randomized blocks design with five replications. The Mahalanobis distance was used to measure genetic dissimilarities. The UPGMA method and Tocher's method were used as clustering procedures. Results indicated significant variation among accessions (P < 0.01) for all evaluated characters, except for the percentage of secondary bulb growth in MAS, indicating the existence of genetic variation for bulb production, and germplasm evaluation considering different environments is more reliable for the characterization of the genotypic variability among garlic accessions, since it diminishes the environmental effects in the clustering of genotypes.

Assessment of genetic variability in Trigonella foenum-graecum L. germplasm by SDS-page analysis

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Qadir Abdul

2017-01-01

Full Text Available The 96 genotypes of Trigonella foenum-graecum L. (Fenugreek were estimated by using Sodium Dodecyl Sulphate Poly Acrylamide Gel Electrophoresis (SDS-PAGE. The accessions were maintained from diverse ecological areas of the world. Total seed storage proteins were electrophoresis on 12.5% polyacrylamide gels. A total of 17 protein bands were detected, of which seven were highly polymorphic and six were moderate polymorphic and four were low polymorphic with molecular weight extending from of ~15 to ~180 kDa. The dendrogram based on similarity matrix using Unweighted Pair Group Method with Arithmetic Mean (UPGMA divided all the genotypes into four major clusters i.e., I, II, III and IV comprising 51, 24, 10 and 11 accessions, respectively. Although limited genetic diversity was detected amongst known germplasm but the presence/absence of polymorphic bands revealed a significant variances among different Trigonella genotypes. The differences exposed in this project work should be oppressed for the future breeding prospective of Trigonella genotypes by using other advanced molecular techniques. The SDS-PAGE per se seems inadequate tool for such kind of analysis, and may be integrated with other genetic and sequence based approaches for more precise estimation of the genetic variability within closely related accessions. Our results provide baseline for obtaining locally adapted and improved cultivars of fenugreek in Pakistan.

Bird-resistant pollination bags for sorghum breeding and germplasm maintenance

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Bird damage is a problem in sorghum breeding and germplasm maintenance operations. Paper pollination bags are damaged by rain and provide minimal deterrent to birds. To overcome these limitations we fabricated pollination bags from spun polyethylene fiber sheeting. Seed loss by bird damage was elimi...

In vitro germination and viability of pollen grain of coconut accessions1

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Catrine Regina Feitosa Moura

Full Text Available Storage as a means of maintaining the pollen viability is important for the preservation of the genetic variability, facilitates the exchange of germplasm and greatly contributes to the generation of variability obtained from artificial crosses, increasing the efficiency of breeding programs. The objective of this study was to select different culture media for the in vitro germination of pollen grain of dwarf and tall coconut accessions, as well as to determine the viability of pollen grain at room temperature conditions. For this purpose, Brazil Green Dwarf (BGD and Brazilian Tall (BRA pollen grains derived from the Coconut Active Germplasm Bank of Embrapa Coastal Tablelands Sergipe were used. To evaluate the effect of different culture media on the in vitro germination of pollen grains of anão verde do Brasil de Jiqui (AVeBrJ and gigante do Brasil Praia do Forte (GBrPF accessions, they were inoculated on to Petri dishes containing 2 ml of culture media. The pollen viability was assessed by staining with 1% acetic carmine and in vitro germination at 0, 24, 48 and 72 hours. The culture medium of Lora is suitable to assess the in vitrogermination of pollen grain of the AVeBrJ and GBrPF accessions. The pollen grain of the AVeBrJ accession showed intermediate viability (66.87% at room temperature up to 23.14 hours by in vitro germination. The pollen grain of the GBrPF accession showed high viability, above 70%, at room temperature up to 120 hours by in vitro germination.

Population structure, genetic diversity and downy mildew resistance among Ocimum species germplasm.

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Pyne, Robert M; Honig, Josh A; Vaiciunas, Jennifer; Wyenandt, Christian A; Simon, James E

2018-04-23

The basil (Ocimum spp.) genus maintains a rich diversity of phenotypes and aromatic volatiles through natural and artificial outcrossing. Characterization of population structure and genetic diversity among a representative sample of this genus is severely lacking. Absence of such information has slowed breeding efforts and the development of sweet basil (Ocimum basilicum L.) with resistance to the worldwide downy mildew epidemic, caused by the obligate oomycete Peronospora belbahrii. In an effort to improve classification of relationships 20 EST-SSR markers with species-level transferability were developed and used to resolve relationships among a diverse panel of 180 Ocimum spp. accessions with varying response to downy mildew. Results obtained from nested Bayesian model-based clustering, analysis of molecular variance and unweighted pair group method using arithmetic average (UPGMA) analyses were synergized to provide an updated phylogeny of the Ocimum genus. Three (major) and seven (sub) population (cluster) models were identified and well-supported (P UPGMA analysis provided best resolution for the 36-accession, DM resistant k3 cluster with consistently strong bootstrap support. Although the k3 cluster is a rich source of DM resistance introgression of resistance into the commercially important k1 accessions is impeded by reproductive barriers as demonstrated by multiple sterile F1 hybrids. The k2 cluster located between k1 and k3, represents a source of transferrable tolerance evidenced by fertile backcross progeny. The 90-accession k1 cluster was largely susceptible to downy mildew with accession 'MRI' representing the only source of DM resistance. High levels of genetic diversity support the observed phenotypic diversity among Ocimum spp. accessions. EST-SSRs provided a robust evaluation of molecular diversity and can be used for additional studies to increase resolution of genetic relationships in the Ocimum genus. Elucidation of population structure

Myrciaria dubia, an Amazonian fruit: population structure and its implications for germplasm conservation and genetic improvement.

Science.gov (United States)

Nunes, C F; Setotaw, T A; Pasqual, M; Chagas, E A; Santos, E G; Santos, D N; Lima, C G B; Cançado, G M A

2017-03-22

Myrciaria dubia (camu-camu) is an Amazon tree that produces a tart fruit with high vitamin C content. It is probably the fruit with the highest vitamin C content among all Brazilian fruit crops and it can be used to supplement daily vitamin C dose. This property has attracted the attention of consumers and, consequently, encouraged fruit farmers to produce it. In order to identify and select potential accessions for commercial exploitation and breeding programs, M. dubia has received considerable research attention. The identification and characterization of genetic diversity, as well as identification of the population structure of accessions preserved in germplasm banks are fundamental for the success of any breeding program. The objective of this study was to evaluate the genetic variability of 10 M. dubia populations obtained from the shores of Reis Lake, located in the municipality of Caracaraí, Roraima, Brazil. Fourteen polymorphic inter simple sequence repeat (ISSR) markers were used to study the population genetic diversity, which resulted in 108 identified alleles. Among the 14 primers, GCV, UBC810, and UBC827 produced the highest number of alleles. The study illustrated the suitability and efficiency of ISSR markers to study the genetic diversity of M. dubia accessions. We also revealed the existence of high genetic variability among both accessions and populations that can be exploited in future breeding programs and conservation activities of this species.

Characters analysis of the Macadamia cv. Ikaika (333) germplasm ...

African Journals Online (AJOL)

ajl yemi

2011-11-30

Nov 30, 2011 ... germplasm resource. Liqing Du, Hui Zeng*, ... needed by human body, but is rich in mineral and vitamin as well. .... It was suggested that climate and orchard management are the main .... than that in South Africa at their 5th, 6th and 7th year respectively, but .... In Chan HT (Ed.), Handbook of tropical foods .

Population structure and linkage disequilibrium in Lupinus albus L. germplasm and its implication for association mapping.

Science.gov (United States)

Iqbal, Muhammad Javed; Mamidi, Sujan; Ahsan, Rubina; Kianian, Shahryar F; Coyne, Clarice J; Hamama, Anwar A; Narina, Satya S; Bhardwaj, Harbans L

2012-08-01

White lupin (Lupinus albus L.) has been around since 300 B.C. and is recognized for its ability to grow on poor soils and application as green manure in addition to seed harvest. The seed has very high levels of protein (33-47 %) and oil (6-13 %). It also has many secondary metabolites that are potentially of nutraceutical value to animals and humans. Despite such a great potential, lupins role in modern agriculture began only in the twentieth century. Although a large collection of Lupinus germplasm accessions is available worldwide, rarely have they been genetically characterized. Additionally, scarce genomic resources in terms of recombinant populations and genome information have been generated for L. albus. With the advancement in association mapping methods, the natural populations have the potential to replace the recombinant populations in gene mapping and marker-trait associations. Therefore, we studied the genetic similarity, population structure and marker-trait association in a USDA germplasm collection for their current and future application in this crop improvement. A total of 122 PI (Plant Inventory) lines were screened with 18 AFLP primer pairs that generated 2,277 fragments. A subset of 892 polymorphic markers with MAF >0.05 (minor allele frequency) were used for association mapping. The cluster analysis failed to group accessions on the basis of their passport information, and a weak structure and low linkage disequilibrium (LD) were observed indicating the usefulness of the collection for association mapping. Moreover, we were also able to identify two markers (a p value of 1.53 × 10(-4) and 2.3 × 10(-4)) that explained 22.69 and 20.5 % of seed weight variation determined using R (LR) (2) . The implications of lack of geographic clustering, population structure, low LD and the ability of AFLP to map seed weight trait using association mapping and the usefulness of the PI collections in breeding programs are discussed.

Agronomic characteristic of a dwarf germplasm sunflower line

OpenAIRE

Vassilevska-Ivanova Roumiana; Tcekova Zoja

2005-01-01

A new sunflower (Helianthus annuus L) dwarf line, HA-ARG-1, has been developed after interspecific hybridization between cultivated sunflower H. annuus and wild annual silver-leaf sunflower H. argophyllus. Plants were selected for reduced height and multiple branching characteristics. The agronomic, morphologic and oil content characteristics of the line were analyzed. Isolation of similar dwarfed lines illustrates the importance of using the wild sunflower germplasms in the development of sp...

Evaluation of potato germplasm (Population A & B) for resistance to ...

African Journals Online (AJOL)

Treatments consisted of germplasm materials introduced from International Potato Centre (CIP) headquarters in Lima, Peru from two populations arranged in a completely randomised block design with three replications. At Loreto, late blight was more severe during the long rains than in the short rains while at Kabete late ...

Genetic structure and diversity of the Neem Germplasm Bank from ...

African Journals Online (AJOL)

Particular

2013-05-15

May 15, 2013 ... ... fragment length polymorphism; AMOVA, molecular variance analysis. ... are technically simple, suitable for large-scale germplasm ... Brazil, our study aims to evaluate the genetic structure and genetic ... voltage of 100 V for 90 min. Gel was .... which does not justify an extra effort in labor (Bekessy et.

Assessment of genetic variability in rice (oryza sativa l.) germplasm from Pakistan using rapd markers

International Nuclear Information System (INIS)

Pervaiz, Z.H.; Rabbani, M.A.; Shinwar, Z.K.; Masood, M.S.; Malik, S.A.

2010-01-01

Information on genetic diversity and relationships among rice genotypes from Pakistan is currently very limited. Molecular marker analysis can truly be beneficial in analyzing the diversity of rice germplasm providing useful information to broaden the genetic base of modern rice cultivars. The objective of this study was to evaluate the genetic polymorphism of 75 rice accessions and improved cultivars using random amplified polymorphic DNA (RAPD) technique. Twenty-eight decamer-primers generated a total of 145 RAPD fragments, of which 116 (80%) were polymorphic. The number of amplification products produced by each primer varied from 3 to 9 with an average of 5.2 alleles primer-1. The size of amplified fragments ranged from 250 to 4000bp. A dendrogram was generated from minimal variance algorithm using Ward method. All the 75 genotypes were grouped into two main groups corresponding to aromatic and non-aromatic types of indica rice. Clustering of accessions did not show any significant pattern of association between the RAPD fingerprints and collection sites. This type of analysis grouping different rice accessions in relation to fragrance, a major rice quality determinant, and varietal group is extremely useful to develop a core collection and gene bank management. Further more, the information revealed by the RAPDs regarding genetic variation is helpful to the plant breeder in selecting diverse parents and for future orientation of rice breeding program. (author)

Characterization of Carambola (Averrhoa carambola L. Plant Collection of Cibinong Plant Germplasm Garden Based on Phenotypic and Genetic Characters

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Dody Priadi

2016-04-01

Full Text Available Indonesia as a rich biodiversity country has many superior fruit plant germplasms such as sweet star fruit or carambola (Averrhoa carambola L.. Some varieties of carambola which collected at the Germplasm Garden of Research Center for Biotechnology-LIPI have been used for parent trees of fruit plant production. Therefore, they have to be characterized both phenotypically and genetically. The objective of the study was to analyze the relationship between eight varieties of carambola i.e. Malaysia, Penang, Rawasari, Bangkok, Sembiring, Dewabaru, Demak and Dewimurni at the germplasm garden based on phenotypic and genetic characters. Phenotypic characters were observed directly in the field, whereas genetic characters were observed with RAPD markers using 10 primers. Phylogenetic analysis was done using NT-SYS software showed that there were three clusters of carambola varieties. Meanwhile, Malaysia and Penang varieties have closed relationships (96% compared with the other varieties. The result of the study would be dedicated to updating and completing the existing fruit plant collection database of Plants Germplasm Garden. 

Genetic Vulnerability and the Relationship of Commercial Germplasms of Maize in Brazil with the Nested Association Mapping Parents.

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Luciano Rogério Braatz de Andrade

Full Text Available A few breeding companies dominate the maize (Zea mays L. hybrid market in Brazil: Monsanto® (35%, DuPont Pioneer® (30%, Dow Agrosciences® (15%, Syngenta® (10% and Helix Sementes (4%. Therefore, it is important to monitor the genetic diversity in commercial germplasms as breeding practices, registration and marketing of new cultivars can lead to a significant reduction of the genetic diversity. Reduced genetic variation may lead to crop vulnerabilities, food insecurity and limited genetic gains following selection. The aim of this study was to evaluate the genetic vulnerability risk by examining the relationship between the commercial Brazilian maize germplasms and the Nested Association Mapping (NAM Parents. For this purpose, we used the commercial hybrids with the largest market share in Brazil and the NAM parents. The hybrids were genotyped for 768 single nucleotide polymorphisms (SNPs, using the Illumina Goldengate® platform. The NAM parent genomic data, comprising 1,536 SNPs for each line, were obtained from the Panzea data bank. The population structure, genetic diversity and the correlation between allele frequencies were analyzed. Based on the estimated effective population size and genetic variability, it was found that there is a low risk of genetic vulnerability in the commercial Brazilian maize germplasms. However, the genetic diversity is lower than those found in the NAM parents. Furthermore, the Brazilian germplasms presented no close relations with most NAM parents, except B73. This indicates that B73, or its heterotic group (Iowa Stiff Stalk Synthetic, contributed to the development of the commercial Brazilian germplasms.

Genetic Vulnerability and the Relationship of Commercial Germplasms of Maize in Brazil with the Nested Association Mapping Parents.

Science.gov (United States)

Andrade, Luciano Rogério Braatz de; Fritsche Neto, Roberto; Granato, Ítalo Stefanine Correia; Sant'Ana, Gustavo César; Morais, Pedro Patric Pinho; Borém, Aluízio

2016-01-01

A few breeding companies dominate the maize (Zea mays L.) hybrid market in Brazil: Monsanto® (35%), DuPont Pioneer® (30%), Dow Agrosciences® (15%), Syngenta® (10%) and Helix Sementes (4%). Therefore, it is important to monitor the genetic diversity in commercial germplasms as breeding practices, registration and marketing of new cultivars can lead to a significant reduction of the genetic diversity. Reduced genetic variation may lead to crop vulnerabilities, food insecurity and limited genetic gains following selection. The aim of this study was to evaluate the genetic vulnerability risk by examining the relationship between the commercial Brazilian maize germplasms and the Nested Association Mapping (NAM) Parents. For this purpose, we used the commercial hybrids with the largest market share in Brazil and the NAM parents. The hybrids were genotyped for 768 single nucleotide polymorphisms (SNPs), using the Illumina Goldengate® platform. The NAM parent genomic data, comprising 1,536 SNPs for each line, were obtained from the Panzea data bank. The population structure, genetic diversity and the correlation between allele frequencies were analyzed. Based on the estimated effective population size and genetic variability, it was found that there is a low risk of genetic vulnerability in the commercial Brazilian maize germplasms. However, the genetic diversity is lower than those found in the NAM parents. Furthermore, the Brazilian germplasms presented no close relations with most NAM parents, except B73. This indicates that B73, or its heterotic group (Iowa Stiff Stalk Synthetic), contributed to the development of the commercial Brazilian germplasms.

Genetic Vulnerability and the Relationship of Commercial Germplasms of Maize in Brazil with the Nested Association Mapping Parents

Science.gov (United States)

Fritsche Neto, Roberto; Granato, Ítalo Stefanine Correia; Sant’Ana, Gustavo César; Morais, Pedro Patric Pinho; Borém, Aluízio

2016-01-01

A few breeding companies dominate the maize (Zea mays L.) hybrid market in Brazil: Monsanto® (35%), DuPont Pioneer® (30%), Dow Agrosciences® (15%), Syngenta® (10%) and Helix Sementes (4%). Therefore, it is important to monitor the genetic diversity in commercial germplasms as breeding practices, registration and marketing of new cultivars can lead to a significant reduction of the genetic diversity. Reduced genetic variation may lead to crop vulnerabilities, food insecurity and limited genetic gains following selection. The aim of this study was to evaluate the genetic vulnerability risk by examining the relationship between the commercial Brazilian maize germplasms and the Nested Association Mapping (NAM) Parents. For this purpose, we used the commercial hybrids with the largest market share in Brazil and the NAM parents. The hybrids were genotyped for 768 single nucleotide polymorphisms (SNPs), using the Illumina Goldengate® platform. The NAM parent genomic data, comprising 1,536 SNPs for each line, were obtained from the Panzea data bank. The population structure, genetic diversity and the correlation between allele frequencies were analyzed. Based on the estimated effective population size and genetic variability, it was found that there is a low risk of genetic vulnerability in the commercial Brazilian maize germplasms. However, the genetic diversity is lower than those found in the NAM parents. Furthermore, the Brazilian germplasms presented no close relations with most NAM parents, except B73. This indicates that B73, or its heterotic group (Iowa Stiff Stalk Synthetic), contributed to the development of the commercial Brazilian germplasms. PMID:27780247

Evaluating citrus germplasm for huanglongbing (HLB) resistance: USDA-ARS Inoculation Program

Science.gov (United States)

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it vectors bacteria responsible for a serious disease of citrus known as huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program for screening citrus germplasm for resistance to the di...

Discussion of submitted posters for Section 2.3 (Rangeland Germplasm Resources)

Science.gov (United States)

As part of the IX International Rangeland Congress held in Rosario, Argentina, a total of 70 posters from 17 countries were submitted to Section 2.3 (Rangeland Germplasm Resources). These posters documented research conducted in five major regions of the world: South America, North America, Africa...

Genetic variability in common wheat germplasm based on coefficients of parentage

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Fernanda Bered

2002-01-01

Full Text Available The characterization of genetic variability and an estimate of the genetic relationship among varieties are essential to any breeding program, because artificial crosses among less similar parents allow a larger segregation and the combination of different favorable alleles. Genetic variability can be evaluated in different ways, including the Coefficient of Parentage (COP, which estimates the probability of two alleles in two different individuals being identical by descent. In this study, we evaluated the degree of genetic relationship among 53 wheat genotypes, and identified the ancestor genotypes which contributed the most to the current wheat germplasm, as a prediction of the width of the genetic base of this cereal. The results revealed a mean COP of 0.07 and the formation of 22 similarity groups. The ancestor genotypes Ciano 67 and Mentana were those which contributed the most to the current wheat germplasm. According to the COP analyses, the genetic base of wheat rests on a small number of ancestral genotypes.

Ashes to ashes: Large Fraxinus germplasm collections and their fates

Science.gov (United States)

Kim C. Steiner; Paul. Lupo

2010-01-01

As the emerald ash borer (EAB) threatens the survival of our ash species, measures should be taken to preserve their genetic variability in the event that we discover a way to restore populations destroyed by the beetle. As it happens, large germplasm collections exist for our most important and widely distributed eastern species of the genus, white ash (...

Registration of Mp718 and Mp719 germplasm lines of maize

Science.gov (United States)

Maize (Zea mays L.) germplasm lines Mp718 (Reg. No. GP-xxxx, PI 662045) and Mp719 (Reg. No. GP-xxxx, PI 662046) were developed and released by USDA-ARS in cooperation with the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Mississippi, as sources of resistance to aflat...

Ploidy level of the banana (Musa spp.) accessions at the germplasm ...

African Journals Online (AJOL)

Deborah Karamura

2016-08-03

Aug 3, 2016 ... tetraploid (4x) with its peak set at channel 100, while Enyeru, an. EAHB was used as a reference triploid (3x) with its peak set at channel 75. The peaks of the unknown samples were determined by examining the position of their peaks relative to the reference accessions. All the samples with peaks at ...

Determination of the genetic diversity among accessions of Senna spectabilis (canafístula) by using RAPD markers.

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Santos, M F; Araújo Neto, R B; Nascimento, M P S B C; Lima, P S C

2013-12-02

Senna spectabilis (DC.) H.S. Irwin & Barneby (Fabaceae; Caesalpinioideae), commonly known as "canafístula" or "cassia", is widely used in the semi-arid region of northeastern Brazil as a source of forage and timber. The plant presents a high nutritional content in comparison with other forage species that are native to the Brazilian Caatinga; thus, it represents a valuable resource during periods of drought. The aim of this study was to evaluate the genetic variability among eight accessions of S. spectabilis available in the forage germplasm collection of Embrapa Meio-Norte using the random-amplified polymorphic DNA technique. The 15 primers selected for use in the analysis produced 107 bands, including 59 (55.14%) that were polymorphic. A similarity matrix was generated on the basis of Jaccard coefficients, and a dendrogram was constructed using the unweighted pair group method with arithmetic mean clustering technique. The mean value of the similarity coefficients was 0.73, and the cophenetic correlation coefficient was 83.76%. Accessions CAN. 4 and CAN. 5 presented the greatest genetic similarity, while CAN. 6 and CAN. 8 were the most divergent. The S. spectabilis accessions were classified into two main groups with group I including accessions CAN. 1, CAN. 2, CAN. 4, CAN. 5, CAN. 7, CAN. 8, and CAN. 9, and group II comprising the single accession CAN. 6. The results presented herein revealed that, although the germplasm collection is presently limited, there is sufficient genetic variability among the accessions to permit future breeding programs.

Molecular Evidence for Occurrence of Tomato leaf curl New Delhi virus in Ash Gourd (Benincasa hispida) Germplasm Showing a Severe Yellow Stunt Disease in India.

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Roy, Anirban; Spoorthi, P; Panwar, G; Bag, Manas Kumar; Prasad, T V; Kumar, Gunjeet; Gangopadhyay, K K; Dutta, M

2013-06-01

An evaluation of 70 accessions of ash gourd germplasm grown at National Bureau of Plant Genetic Resources, New Delhi, India during Kharif season (2010) showed natural occurrence of a yellow stunt disease in three accessions (IC554690, IC036330 and Pusa Ujjwal). A set of begomovirus specific primers used in PCR gave expected amplicon from all the symptomatic plants; however no betasatellite was detected. Complete genome of the begomovirus (DNA-A and DNA-B), amplified through rolling circle amplification, was cloned and sequenced. The begomovirus under study shared high sequence identities to different isolates of Tomato leaf curl New Delhi virus (ToLCNDV) and clustered with them. Among those isolates, the DNA-A and DNA-B of the present begomovirus isolate showed highest 99.6 and 96.8 % sequence identities, respectively with an isolate reported on pumpkin from India (DNA-A: AM286433, DNA-B: AM286435). Based on the sequence analysis, the begomovirus obtained from ash gourd was considered as an isolate of ToLCNDV. Thus, the present findings constitute the first report of occurrence of a new yellow stunt disease in ash gourd from India and demonstrated the association of ToLCNDV with the symptomatic samples. Occurrence of ToLCNDV in ash gourd germplasm not only adds up a new cucurbitaceous host of this virus but also raises the concern about the perpetuation of this virus in absence of its main host tomato and thus has an epidemiological relevance for understanding the rapid spread of this virus in tomato and other hosts in Indian sub-continent.

Interspecific variation of total seed protein in wild rice germplasm using SDS-Page

International Nuclear Information System (INIS)

Shah, S.M.A.; Hidayat-ur-Rahman; Abbasi, F.M.; Ashiq, M.; Rabbani, A.M.; Khan, I.A.; Shinwari, Z.K.; Shah, Z.

2011-01-01

Variation in seed protein of 14 wild rice species (Oryza spp.) along with cultivated rice species (O. sativa) was studied using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to assess genetic diversity in the rice germplasm. SDS bands were scored as present (1) or absent (0) for protein sample of each genotype. On the basis of cluster analysis, four clusters were identified at a similarity level of 0.85. O. nivara, O. rufipogon and O. sativa with AA genomes constituted the first cluster. The second cluster comprised O. punctata of BB genome and wild rice species of CC genome i.e., O. rhizomatis and O. officinalis. However, it also contained O. barthii and O. glumaepatula of AA genome. O. australiensis with EE genome, and O. latifolia, O. alta and O. grandiglumis having CCDD genomes comprised the third cluster. The fourth cluster consisted of wild rice species, O. brachyantha with EE genome along with two other wild rice species, O. longistaminata and O. meridionalis of AA genome. Overall, on the basis of total seed protein, the grouping pattern of rice genotypes was mostly compatible with their genome status. The results of the present work depicted considerable interspecific genetic variation in the investigated germplasm for total seed protein. Moreover, the results obtained in this study also suggest that analysis of seed protein can also provide a better understanding of genetic affinity of the germplasm. (author)

Genetic divergence among Psidium accessions based on biochemical and agronomic variables

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Carlos Antonio Fernandes Santos

2011-01-01

Full Text Available Sixty-nine Psidium accessions collected in six Brazilian states were analyzed by two non-hierarchical clusteringmethods and principal components (PC, to provide orientation for breeding programs. The variables ascorbic acid, b-carotene,lycopene, total phenols, total flavonoids, antioxidant activity, titrable acidity, soluble solids, total soluble sugars, moisture content,lateral and transversal fruit diameter, fruit pulp and seed weighs, and plant fruit number and weight were analyzed. Specific groups were observed for the araçazeiros accessions, by the Tocher and the k-means methods, as well as by the three-dimensionaldispersion of the four PCs. The clustering separated accessions of araçazeiros from the guava. There was no specific grouping interms of States of origin, indicating the absence of barriers in the guava propagation accessions. Analyses suggested the collectionof a greater number of guava germplasm samples from a smaller number of regions and divergent accessions with high nutritionalcompound levels to develop new cultivars.

SSR-Based DNA Fingerprinting and Diversity Assessment Among Indian Germplasm of Euryale ferox: an Aquatic Underutilized and Neglected Food Crop.

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Kumar, Nitish; Shikha, Divya; Kumari, Swati; Choudhary, Binod Kumar; Kumar, Lokendra; Singh, Indu Shekhar

2017-10-30

Euryale ferox is native to Southeast Asia and China, and it is one of the important aquatic food crops propagated mostly in eastern part of India. The aim of the present study was to characterize and evaluate the genetic diversity of ex situ collections of E. ferox germplasm from different geographical states of India using microsatellite (simple sequence repeats (SSRs)) markers. Ten SSR markers were analyzed to assess DNA fingerprinting and genetic diversity of 16 cultivated germplasm of E. ferox. Total 37 polymorphic alleles were recorded with an average of 3.7 allele frequency per primer. The polymorphic information content value varied from 0.204 to 0.735 with mean of 0.448. A high range of heterozygosity (Ho 0.228; He 0.512) was detected in the present study. The neighbor-joining (N-J) tree and the principle coordinate analysis showed that the germplasm divided in to three main clusters. The results of the present investigation comply that SSR markers are effective for computing genetic assessment of genetic diversity and similarity with classifying cultivated varieties of E. ferox. Evaluation of genetic diversity among Indian E. ferox germplasm could provide useful information for genetic improvement.

Landscape design and allocation for demonstrating the distinctive germplasm resources of SHNU offers in 2015 Shanghai International Flower Show

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CHEN Jiaying

2015-10-01

Full Text Available Combing with its theme——″The Delicate Horticulture & The Beautiful Homeland″,the 2015 Shanghai International Flower Show offers SHNU a special outdoor stand for distinctive germplasm resources to shine in different aspects of subject creativity.Many properties of the landscaping,such as landscape arrangement,season reflection,color configuration,personal training,identification,landscaping,season reflection,afforested maintenance,were discused and analyzed in this study.A proposal on how to improve the achievements in scientific research and application of the splendid germplasm resources to a further step was provided as well.The practice of the doemonstration for SHNU′s of germplasm resources in the show gave us a lot of inspirations such as doing more study and develop more plant varieties in order to meeting the social demands,furthermore,promoting the development of the horticulture industry.

Genetic diversity analysis among collected purslane (Portulaca oleracea L.) accessions using ISSR markers.

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Alam, M Amirul; Juraimi, Abdul Shukor; Rafii, Mohd Yusop; Hamid, Azizah Abdul; Arolu, Ibrahim Wasiu; Abdul Latif, M

2015-01-01

Genetic diversity and relationships among 45 collected purslane accessions were evaluated using ISSR markers. The 28 primers gave a total of 167 bands, among which 163 were polymorphic (97.6%). The genetic diversity as estimated by Shannon's information index was 0.513, revealing a quite high level of genetic diversity in the germplasm. The average number of observed allele, effective allele, expected heterozygosity, polymorphic information content (PIC) and Nei's index were 5.96, 1.59, 0.43, 0.35 and 0.35, respectively. The UPGMA dendrogram based on Nei's genetic distance grouped the whole germplasm into 7 distinct clusters. The analysis of molecular variance (AMOVA) revealed that 89% of total variation occurred within population, while 11% were found among populations. Based on the constructed dendrogram using ISSR markers those accessions that are far from each other by virtue of genetic origin and diversity index (like Ac1 and Ac42; Ac19 and Ac45; Ac9 and Ac23; Ac18 and A25; Ac24 and Ac18) are strongly recommended to select as parent for future breeding program to develop high yielding and stress tolerant purslane variety in contribution to global food security. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Screening of Turkish Melon Accessions for Resistance to ZYMV, WMV and CMV

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Ercan EKBIC

2010-03-01

Full Text Available In the Çukurova University Department of Horticulture more than 350 melon accessions were collected from different ecological parts of Turkey which is located on the secondary genetic diversification center of this crop, and their characterization studies are near completion. Furthermore, evaluation studies of these materials have started. In the present study 67 melon accessions, sampled from this germplasm, were tested for resistance to zucchini yellow mosaic virus (ZYMV, Cucumber mosaic virus (CMV and watermelon mosaic virus (WMV. After resistance tests made by mechanical inoculation, four accessions (‘CU 100’, ‘CU 287’, ‘CU 305’ and ‘CU 328’ were found resistant to ZYMV and three accessions (‘CU 305’, ‘C 264’, and ‘C 276’ to WMV. No resistant genotype was found to CMV.

Grouping and clustering of maize Lancaster germplasm inbreds according to the results of SNP-analysis

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K. V. Derkach

2017-08-01

Full Text Available The objective of this article is the grouping and clustering of maize inbred lines based on the results of SNP-genotyping for the verification of a separate cluster of Lancaster germplasm inbred lines. As material for the study, we used 91 maize (Zea mays L. inbred lines, including 31 Lancaster germplasm lines and 60 inbred lines of other germplasms (23 Iodent inbreds, 15 Reid inbreds, 7 Lacon inbreds, 12 Mix inbreds and 3 exotic inbreds. The majority of the given inbred lines are included in the Dnipro breeding programme. The SNP-genotyping of these inbred lines was conducted using BDI-III panel of 384 SNP-markers developed by BioDiagnostics, Inc. (USA on the base of Illumina VeraCode Bead Plate. The SNP-markers of this panel are biallelic and are located on all 10 maize chromosomes. Their range of conductivity was >0.6. The SNP-analysis was made in completely automated regime on Illumina BeadStation equipment at BioDiagnostics, Inc. (USA. A principal component analysis was applied to group a general set of 91 inbreds according to allelic states of SNP-markers and to identify a cluster of Lancaster inbreds. The clustering and determining hierarchy in 31 Lancaster germplasm inbreds used quantitative cluster analysis. The share of monomorphic markers in the studied set of 91 inbred lines equaled 0.7%, and the share of dimorphic markers equaled 99.3%. Minor allele frequency (MAF > 0.2 was observed for 80.6% of dimorphic markers, the average index of shift of gene diversity equaled 0.2984, PIC on average reached 0.3144. The index of gene diversity of markers varied from 0.1701 to 0.1901, pairwise genetic distances between inbred lines ranged from 0.0316–0.8000, the frequencies of major alleles of SNP-markers were within 0.5085–0.9821, and the frequencies of minor alleles were within 0.0179–0.4915. The average homozygosity of inbred lines was 98.8%. The principal component analysis of SNP-distances confirmed the isolation of the Lancaster

Genetic diversity and population structure of Chinese natural bermudagrass [Cynodon dactylon (L.) Pers.] germplasm based on SRAP markers.

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Zheng, Yiqi; Xu, Shaojun; Liu, Jing; Zhao, Yan; Liu, Jianxiu

2017-01-01

Bermudagrass [Cynodon dactylon (L.) Pers.], an important turfgrass used in public parks, home lawns, golf courses and sports fields, is widely distributed in China. In the present study, sequence-related amplified polymorphism (SRAP) markers were used to assess genetic diversity and population structure among 157 indigenous bermudagrass genotypes from 20 provinces in China. The application of 26 SRAP primer pairs produced 340 bands, of which 328 (96.58%) were polymorphic. The polymorphic information content (PIC) ranged from 0.36 to 0.49 with a mean of 0.44. Genetic distance coefficients among accessions ranged from 0.04 to 0.61, with an average of 0.32. The results of STRUCTURE analysis suggested that 157 bermudagrass accessions can be grouped into three subpopulations. Moreover, according to clustering based on the unweighted pair-group method of arithmetic averages (UPGMA), accessions were divided into three major clusters. The UPGMA dendrogram revealed that accessions from identical or adjacent areas were generally, but not entirely, clustered into the same cluster. Comparison of the UPGMA dendrogram and the Bayesian STRUCTURE analysis showed general agreement between the population subdivisions and the genetic relationships among accessions. Principal coordinate analysis (PCoA) with SRAP markers revealed a similar grouping of accessions to the UPGMA dendrogram and STRUCTUE analysis. Analysis of molecular variance (AMOVA) indicated that 18% of total molecular variance was attributed to diversity among subpopulations, while 82% of variance was associated with differences within subpopulations. Our study represents the most comprehensive investigation of the genetic diversity and population structure of bermudagrass in China to date, and provides valuable information for the germplasm collection, genetic improvement, and systematic utilization of bermudagrass.

Evaluation of high yielding soybean germplasm under water limitation.

Science.gov (United States)

Prince, Silvas J; Murphy, Mackensie; Mutava, Raymond N; Zhang, Zhengzhi; Nguyen, Na; Kim, Yoon Ha; Pathan, Safiullah M; Shannon, Grover J; Valliyodan, Babu; Nguyen, Henry T

2016-05-01

Limited information is available for soybean root traits and their plasticity under drought stress. To date, no studies have focused on examining diverse soybean germplasm for regulation of shoot and root response under water limited conditions across varying soil types. In this study, 17 genetically diverse soybean germplasm lines were selected to study root response to water limited conditions in clay (trial 1) and sandy soil (trial 2) in two target environments. Physiological data on shoot traits was measured at multiple crop stages ranging from early vegetative to pod filling. The phenotypic root traits, and biomass accumulation data are collected at pod filling stage. In trial 1, the number of lateral roots and forks were positively correlated with plot yield under water limitation and in trial 2, lateral root thickness was positively correlated with the hill plot yield. Plant Introduction (PI) 578477A and 088444 were found to have higher later root number and forks in clay soil with higher yield under water limitation. In sandy soil, PI458020 was found to have a thicker lateral root system and higher yield under water limitation. The genotypes identified in this study could be used to enhance drought tolerance of elite soybean cultivars through improved root traits specific to target environments. © 2015 Institute of Botany, Chinese Academy of Sciences.

The phylogenetic relationships among germplasm resources of wild ramie (boehmeria nivea l. gaud) in china based on trnl-f and its sequences

International Nuclear Information System (INIS)

Runqing, Y.; Baloch, S.U.; Lijun, L.; Dingxiang, P.

2015-01-01

Ramie (Boehmeria nivea L. Gaud) is an important fiber crop in China, which also possesses many wild species in genus Boehmeria Jacq. However, the taxonomic position of these species has not been settled. To determine the evolutionary relationships among the members of the genus Boehmeria, the combination of ITS and trnL-F sequences were used for molecular phylogenetic analyses of 31 ramie accessions (28 species and three varieties) including multiple materials collected in high-altitude regions that have not been previously reported (B. clidemioides var. diffusa, B. bicuspis and B. longispica). The ITS and trnL-F trees produced showed that Boehmeria was classified into four separate clusters. The Sect. Duretia, which has a high evolutionary level, clustered with Sects Zoilingeriana and Phyllostachys. The grouping pattern of clustering differed from traditional taxonomy and indicated possible interspecific hybridization among Boehmeria. We found that B. malabarica Wedd. var. leioclada of Sect. Boehmeria clustered into a clade with Sect. Tilocnide, providing solid support for the expansion of wild ramie core germplasm resources. The molecular results did not support the intraspecific geographic migration of Boehmeria. This study, therefore, established relationships among wild species which will help in ramie crop improvement programs. The results will be important for the collection and conservation of germplasm resources of Chinese wild ramie. (author)

New carrot and garlic germplasm to advance breeding and understand crop origins

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The genetic variation provided by diverse plant germplasm is the basic building material used for crop improvement that shapes the crops we grow today. Wild carrot from the U.S. provided the cytoplasm used to develop a reliable system to produce hybrid carrots that account for most of the commercial...

Encapsulation of nodal cuttings and shoot tips for storage and exchange of cassava germplasm.

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Danso, K E; Ford-Lloyd, B V

2003-04-01

We report the encapsulation of in vitro-derived nodal cuttings or shoot tips of cassava in 3% calcium alginate for storage and germplasm exchange purposes. Shoot regrowth was not significantly affected by the concentration of sucrose in the alginate matrix while root formation was. In contrast, increasing the sucrose concentration in the calcium chloride polymerisation medium significantly reduced regrowth from encapsulated nodal cuttings of accession TME 60444. Supplementing the alginate matrix with increased concentrations of 6-benzylaminopurine and alpha-naphthaleneacetic acid enhanced complete plant regrowth within 2 weeks. Furthermore, plant regrowth by encapsulated nodal cuttings and shoot tips was significantly affected by the duration of the storage period as shoot recovery decreased from almost 100% to 73.3% for encapsulated nodal cuttings and 94.4% to 60% for shoot tips after 28 days of storage. The high frequency of plant regrowth from alginate-coated micropropagules coupled with high viability percentage after 28 days of storage is highly encouraging for the exchange of cassava genetic resources. Such encapsulated micropropagules could be used as an alternative to synthetic seeds derived from somatic embryos.

PHYTOPATHOLOGICAL ASSESMENT OF CAPSICUM ANNUUM L. (SWEET PEPPER AND CHILLI GERMPLASM FROM THE GENE POOL OF THE WORLD VEGETABLE CENTER (AVRDC UNDER THE CONDITIONS OF ARARAT VALLEY IN ARMENIA

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K. M. Sarikyan

2015-01-01

Full Text Available On an experimental basis of the Scientific Center of vegetable, melon and industrial crops (Republic of Armenia 20 accessions of the world germplasm of Capsicum annuum L. (sweet pepper, chili provided by the World Vegetable Center (AVRDC have been studied. The accessions resistant to such diseases as verticillium wilt (Verticillium albo-atrum Reincke, bacterial wilt (Ralstonia solanacearum (= Pseudomonas solanacearum, tobacco mosaic virus (TMV and cucumber mosaic virus (CMV, blossom end rot of fruit, and tip-burn have been selected. These genotypes of chili and sweet pepper are the promising initial material in breeding for resistance to common diseases. In collaboration with other breeders, five varieties of peppers were developed and released: sweet pepper cultivars Natalie, Emily, Miles, and chili cultivars Zita and Gita.

Grain quality of drought tolerant accessions within the MRI Zemun Polje maize germplasm collection

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Jelena Vančetović

2014-01-01

Full Text Available Maize Research Institute Zemun Polje (MRI gene bank created an elite drought tolerant core collection of 40 accessions, based on field trials and general combining ability with inbred lines from the main heterotic groups (Lancaster, Iowa Stiff Stalk Synthetic - BSSS and Iodent. A total of seven genetic groups were identified. Seven accessions showed good combining abilities with three testers from chosen heterotic groups, thus forming a dinstinctive genetic group (Unknown. In the present research, accessions with drought tolerance were also analyzed for grain quality, as these two traits are becoming highly important due to global warming and population growth. Kernel macronutrients contents (oil, protein and starch were determined using Near Infrared Spectroscopy (NIR. Oil, protein and starch contents were significantly higher in introduced populations than in landraces for 0.43%, 0.12% and 0.85%, respectively (p<0.01. The greatest progress from the selection based on the expected genetic gain (ΔG for 5% selection intensity would be obtained for oil (14.74% followed by protein (10.14%. Landraces showed the least potential for the grain quality improvement due to the lowest expected ΔG for the three macronutrients. The differences between macronutrient content among genetic groups defined them as potentially favourable sources for a specific trait. According to ΔG values, the greatest progress in breeding would be accomplished for increased oil content with accessions from the Unknown group. Identification of the accessions with several favorable traits is valuable for simultaneous breeding for drought tolerance and grain quality.

Grain quality of drought tolerant accessions within the MRI Zemun Polje maize germplasm collection

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Vancetovic, J.; Ignjatovic-Micic, D.; Bozinovic, S.; Babbic, M.; Filipovic, M.; Grcic, N.; Andjelkovic, V.

2014-06-01

Maize Research Institute Zemun Polje (MRI) gene bank created an elite drought tolerant core collection of 40 accessions, based on field trials and general combining ability with inbred lines from the main heterotic groups (Lancaster, Iowa Stiff Stalk Synthetic . BSSS and Iodent). A total of seven genetic groups were identified. Seven accessions showed good combining abilities with three testers from chosen heterotic groups, thus forming a distinctive genetic group (Unknown). In the present research, accessions with drought tolerance were also analyzed for grain quality, as these two traits are becoming highly important due to global warming and population growth. Kernel macronutrients contents (oil, protein and starch) were determined using Near Infrared Spectroscopy (NIR). Oil, protein and starch contents were significantly higher in introduced populations than in landraces for 0.43%, 0.12% and 0.85%, respectively (p < 0.01). The greatest progress from the selection based on the expected genetic gain ({Delta}G) for 5% selection intensity would be obtained for oil (14.74%) followed by protein (10.14%). Landraces showed the least potential for the grain quality improvement due to the lowest expected {Delta}G for the three macronutrients. The differences between macronutrient content among genetic groups defined them as potentially favourable sources for a specific trait. According to {Delta}G values, the greatest progress in breeding would be accomplished for increased oil content with accessions from the Unknown group. Identification of the accessions with several favorable traits is valuable for simultaneous breeding for drought tolerance and grain quality. (Author)

Potential of Start Codon Targeted (SCoT Markers to Estimate Genetic Diversity and Relationships among Chinese Elymus sibiricus Accessions

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Junchao Zhang

2015-04-01

Full Text Available Elymus sibiricus as an important forage grass and gene pool for improving cereal crops, that is widely distributed in West and North China. Information on its genetic diversity and relationships is limited but necessary for germplasm collection, conservation and future breeding. Start Codon Targeted (SCoT markers were used for studying the genetic diversity and relationships among 53 E. sibiricus accessions from its primary distribution area in China. A total of 173 bands were generated from 16 SCoT primers, 159 bands of which were polymorphic with the percentage of polymorphic bands (PPB of 91.91%. Based upon population structure analysis five groups were formed. The cluster analysis separated the accessions into two major clusters and three sub-clusters, similar to results of principal coordinate analysis (PCoA. The molecular variance analysis (AMOVA showed that genetic variation was greater within geographical regions (50.99% than between them (49.01%. Furthermore, the study also suggested that collecting and evaluating E. sibiricus germplasm for major geographic regions and special environments broadens the available genetic base and illustrates the range of variation. The results of the present study showed that SCoT markers were efficient in assessing the genetic diversity among E. sibiricus accessions.

Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases

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Jacob, Sherry R.; Srinivasan, Kalyani; Radhamani, J.; Parimalan, R.; Sivaswamy, M.; Tyagi, Sandhya; Yadav, Mamata; Kumari, Jyotisna; Deepali; Sharma, Sandeep; Bhagat, Indoo; Meeta, Madhu; Bains, N. S.; Chowdhury, A. K.; Saha, B. C.; Bhattacharya, P. M.; Kumari, Jyoti; Singh, M. C.; Gangwar, O. P.; Prasad, P.; Bharadwaj, S. C.; Gogoi, Robin; Sharma, J. B.; GM, Sandeep Kumar; Saharan, M. S.; Bag, Manas; Roy, Anirban; Prasad, T. V.; Sharma, R. K.; Dutta, M.; Sharma, Indu; Bansal, K. C.

2016-01-01

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat–Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011–14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels. PMID:27942031

Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases.

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Sundeep Kumar

Full Text Available A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat-Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011-14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu, a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab, a hotspot for stripe rust and at Cooch Behar (West Bengal, a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases.

Science.gov (United States)

Kumar, Sundeep; Archak, Sunil; Tyagi, R K; Kumar, Jagdish; Vk, Vikas; Jacob, Sherry R; Srinivasan, Kalyani; Radhamani, J; Parimalan, R; Sivaswamy, M; Tyagi, Sandhya; Yadav, Mamata; Kumari, Jyotisna; Deepali; Sharma, Sandeep; Bhagat, Indoo; Meeta, Madhu; Bains, N S; Chowdhury, A K; Saha, B C; Bhattacharya, P M; Kumari, Jyoti; Singh, M C; Gangwar, O P; Prasad, P; Bharadwaj, S C; Gogoi, Robin; Sharma, J B; Gm, Sandeep Kumar; Saharan, M S; Bag, Manas; Roy, Anirban; Prasad, T V; Sharma, R K; Dutta, M; Sharma, Indu; Bansal, K C

2016-01-01

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat-Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011-14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

Genetic diversity of water use efficiency in Jerusalem artichoke (Helianthus tuberosus L.) germplasm

Science.gov (United States)

Genetic diversity in crop germplasm is an important resource for crop improvement, but information on genetic diversity is rare for Jerusalem artichoke, especially for traits related to water use efficiency. The objectives of this study were to investigate genetic variations for water use and water...

Genetics of the ovule fuzzless trait in Gossypium arboreum germplasm line PI 615737

Science.gov (United States)

The diploid cotton species Gossypium arboreum possesses many favorable agronomic traits such as drought tolerance and disease resistance, which can be utilized in the development of improved upland cotton cultivars. The USDA National Plant Germplasm System maintains more than 1,600 G. arboreum acces...

Genetic diversity of sweet sorghum germplasm in Mexico using AFLP and SSR markers

Science.gov (United States)

The objective of this work was to evaluate the diversity and genetic relationships between lines and varieties of the sweet sorghum (Sorghum bicolor) germplasm bank of the National Institute for Forestry, Agriculture and Livestock Research, Mexico, using AFLP and SSR markers. The molecular markers ...

Chromosome number in Brazilian germplasm accessions of Paspalum hydrophilum, P. modestum and P. palustre (Gramineae; Paniceae

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Pozzobon Marisa T.

2003-01-01

Full Text Available This paper compiles results of chromosome counts of Paspalum hydrophilum, P. modestum and P. palustre. Four Brazilian accessions of P. modestum have shown 2n = 2x = 20 chromosomes, a number already found in one accession from Argentina and in two from Brazil. Three other Brazilian accessions showed tetraploid level (2n = 4x = 40, which was previously unknown in this species. In P. hydrophilum, only one of the accessions analyzed presented tetraploid level, initially established for the species from plants collected in Argentina. Five additional accessions from Brazil showed the diploid number, previously detected in a single Brazilian population. A tetraploid cytotype was found in P. palustre, previously known as a diploid species. In addition to confirming the occurrence of distinct ploidy levels for all three species, the results establish the predominance of the diploid level in P. hydrophilum and P. modestum accessions collected in Brazil.

Genomewide association study of ionomic traits on diverse soybean populations from germplasm collections

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The elemental content of a soybean seed is a determined by both genetic and environmental factors and is an important component of its nutritional value. The elemental content is stable, making the samples stored in germplasm repositories an intriguing source of experimental material. To test the ef...

Utilizing ‘Omic’ technologies to identify and prioritize novel sources of resistance to the oomycete pathogen Phytophthora infestans in potato germplasm collections

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Pauline Stephanie Marie Van Weymers

2016-05-01

Full Text Available The biggest threat to potato production world-wide is late blight, caused by the oomycete pathogen Phytophthora infestans. A screen of 126 wild diploid Solanum accessions from the Commonwealth Potato Collection (CPC with P. infestans isolates belonging to the genotype 13-A2 identified resistances in the species S. bulbocastanum, S. capsicibaccatum, S. microdontum, S. mochiquense, S. okadae, S. pinnatisectum, S. polyadenium, S. tarijense and S. verrucosum. Effector-omics, allele mining and diagnostic RenSeq (dRenSeq were utilized to investigate the nature of resistances in S. okadae accessions. dRenSeq in resistant S. okadae accessions 7129, 7625, 3762 and a bulk of 20 resistant progeny confirmed the presence of full-length Rpi-vnt1.1 under stringent mapping conditions and corroborated allele mining results in the accessions 7129 and 7625 as well as Avr-vnt1 recognition in transient expression assays. In contrast, susceptible S. okadae accession 3761 and a bulk of 20 susceptible progeny lacked sequence homology in the 5’ end compared to the functional Rpi-vnt1.1 gene. Further evaluation of S. okadae accessions with late blight isolates that have a broad spectrum of virulence demonstrated that, although S. okadae accessions 7129, 7625 and 7629 contain functional Rpi-vnt1.1, they also carry a novel resistance gene. We provide evidence that existing germplasm collection are important sources of novel resistances and that ‘omic’ technologies such as dRenSeq-based genomics and effector-omics are efficacious tools to rapidly explore the diversity within these collections.

A bayesian approach to inferring the genetic population structure of sugarcane accessions from INTA (Argentina

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Mariana Inés Pocovi

2015-06-01

Full Text Available Understanding the population structure and genetic diversity in sugarcane (Saccharum officinarum L. accessions from INTA germplasm bank (Argentina will be of great importance for germplasm collection and breeding improvement as it will identify diverse parental combinations to create segregating progenies with maximum genetic variability for further selection. A Bayesian approach, ordination methods (PCoA, Principal Coordinate Analysis and clustering analysis (UPGMA, Unweighted Pair Group Method with Arithmetic Mean were applied to this purpose. Sixty three INTA sugarcane hybrids were genotyped for 107 Simple Sequence Repeat (SSR and 136 Amplified Fragment Length Polymorphism (AFLP loci. Given the low probability values found with AFLP for individual assignment (4.7%, microsatellites seemed to perform better (54% for STRUCTURE analysis that revealed the germplasm to exist in five optimum groups with partly corresponding to their origin. However clusters shown high degree of admixture, F ST values confirmed the existence of differences among groups. Dissimilarity coefficients ranged from 0.079 to 0.651. PCoA separated sugarcane in groups that did not agree with those identified by STRUCTURE. The clustering including all genotypes neither showed resemblance to populations find by STRUCTURE, but clustering performed considering only individuals displaying a proportional membership > 0.6 in their primary population obtained with STRUCTURE showed close similarities. The Bayesian method indubitably brought more information on cultivar origins than classical PCoA and hierarchical clustering method.

Genetic diversity and spatial structure in cacao (Theobroma cacao L.) germplasm from Bolivia

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Cacao (Theobroma cacao L.) is an important economic crop widely cultivated in the Bolivian Amazon. The germplasm group used by the Bolivian farmers was called “Cacao Nacional Boliviano” (CNB). Wild cacao populations are also found in the Beni River and in the valleys of Andes foot hills. Using DNA...

Root distribution pattern and nitrogen uptake of some wheat and triticale germplasms in relation to rates and methods of nitrogen application

International Nuclear Information System (INIS)

Meena, N.L.; Seth, Jagdish

1975-01-01

A field experiment was conducted under irrigated conditions with four germplasms viz. Triticale(70-2), and wheat varieties HD 4502(durum), Kalyan Sona and Moti (aestivums) at the Indian Agricultural Research Institute Farm, New Delhi, during rabi season of 1972-73. The treatments comprised of three rates of nitrogen viz. 0,60 and 120 kg/ha and two methods of nitrogen application viz. (1) soil + foliar and (2) soil. The root distribution of the four germplasms, studied by 32 P injection technique was increased both vertically and horizontally with the addition of nitrogen. Root distribution of triticale was observed to be deep and spreading in habit, while durum proved to be shallow rooted and compact in nature. The total uptake of nitrogen was significantly increased with higher rates of nitrogen in all the germplasms. The maximum uptake of nitrogen was observed in the durum wheat. (author)

Mutant lines of currant tomato, valuable germplasm with multiple disease resistance

International Nuclear Information System (INIS)

Govorova, G.F.; Khrustaleva, V.V.; Shcherbakov, V.K.

1987-01-01

Studies were carried out for two years on eight mutant lines of currant tomato at the Krymsk Experimental Breeding Station of the N.I. Vavilov All-Union Scientific Research Institute of Plant-Growing (VIR). The station is situated in an area of commercial field tomato growing (Krasnodar region). The mutant lines of currant tomato (VIR specimen No. k-4053) were obtained through chronic gamma-irradiation. A disease resistance evaluation of the mutants was carried out for Verticillium wilt (Verticillium albo-atrum Rein. and Berth.), for black bacterial spotting (Xanthomonas vesicatoria Dows.), for tobacco mosaic virus Nicotiana 1 Smith), for streak virus (Nicotiana 1), for the combination TMV with X and Y potato viruses, for cucumber virus (Cucumis 1), and also for top rot. Fifty plants of each mutant line were evaluated and checks were made three times in each season. A comparison of the currant tomato mutants with the standard tomato varieties demonstrates the better resistance shown by the mutant germplasm to the main pathogens. The degree to which some currant tomato mutants were affected by Verticillium was lower than that of the most VerticiIlium-resistant samples of tomato evaluated between 1975 and 1981. The mutants of currant tomato should therefore be of interest as germplasm in breeding tomatoes for improved multiple disease resistance

Comparison of Chemical Compositions in Pseudostellariae Radix from Different Cultivated Fields and Germplasms by NMR-Based Metabolomics

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Yujiao Hua

2016-11-01

Full Text Available Pseudostellariae Radix (PR is an important traditional Chinese medicine (TCM, which is consumed commonly for its positive health effects. However, the chemical differences of PR from different cultivated fields and germplasms are still unknown. In order to comprehensively compare the chemical compositions of PR from different cultivated fields, in this study, 1H-NMR-based metabolomics coupled with high performance liquid chromatography (HPLC were used to investigate the different metabolites in PR from five germplasms (jr, zs1, zs2, sb, and xc cultivated in traditional fields (Jurong, Jiangsu, JSJR and cultivated fields (Zherong, Fujian, FJZR. A total of 34 metabolites were identified based on 1H-NMR data, and fourteen of them were found to be different in PR from JSJR and FJZR. The relative contents of alanine, lactate, lysine, taurine, sucrose, tyrosine, linolenic acid, γ-aminobutyrate, and hyperoside in PR from JSJR were higher than that in PR from FJZR, while PR from FJZR contained higher levels of glutamine, raffinose, xylose, unsaturated fatty acid, and formic acid. The contents of Heterophyllin A and Heterophyllin B were higher in PR from FJZR. This study will provide the basic information for exploring the influence law of ecological environment and germplasm genetic variation on metabolite biosynthesis of PR and its quality formation mechanism.

Genetic variability of watermelon accessions based on microsatellite markers.

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de S Gama, R N C; Santos, C A F; de C S Dias, R

2013-03-13

We analyzed the genetic variability of 40 watermelon accessions collected from 8 regions of Northeastern Brazil using microsatellite markers, in order to suggest strategies of conservation and utilization of genetic variability in this species. These accessions are not commercial cultivars. They were sampled in areas of traditional farmers that usually keep their own seeds for future plantings year after year. An UPGMA dendrogram was generated from a distance matrix of the Jaccard coefficient, based on 41 alleles of 13 microsatellite loci. Analysis of molecular variance was made by partitioning between and within geographical regions. The similarity coefficient between accessions ranged from 37 to 96%; the dendrogram gave a co-phenetic value of 0.80. The among population genetic variability was high ( (^)ϕST = 0.319). Specific clusters of accessions sampled in 3 regions of Maranhão were observed while the other 5 regions did not presented specific clusters by regions. We conclude that watermelon genetic variability is not uniformly dispersed in the regions analyzed, indicating that geographical barriers or edaphoclimatic conditions have limited open mating. We suggest sampling a greater number of populations, so regional species diversity will be better represented and preserved in the germplasm bank.

Semi-high throughput screening for potential drought-tolerance in lettuce (Lactuca sativa) germplasm collections

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This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of th...

Rebuilding Hawaii’s Anthurium germplasm collection for cultivar and species preservation, breeding, and biotechnological research

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Anthurium is the third most important floriculture crop in Hawaii, grown mainly as a cut flower. The University of Hawaii (UH) has a well-established anthurium breeding program since 1950, with a germplasm collection assembled from backyard growers, hobbyists, researchers and collection trips from c...

Genome wide linkage disequilibrium in Chinese asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm: implications for domestication history and genome wide association studies.

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Xu, P; Wu, X; Wang, B; Luo, J; Liu, Y; Ehlers, J D; Close, T J; Roberts, P A; Lu, Z; Wang, S; Li, G

2012-07-01

Association mapping of important traits of crop plants relies on first understanding the extent and patterns of linkage disequilibrium (LD) in the particular germplasm being investigated. We characterize here the genetic diversity, population structure and genome wide LD patterns in a set of asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm from China. A diverse collection of 99 asparagus bean and normal cowpea accessions were genotyped with 1127 expressed sequence tag-derived single nucleotide polymorphism markers (SNPs). The proportion of polymorphic SNPs across the collection was relatively low (39%), with an average number of SNPs per locus of 1.33. Bayesian population structure analysis indicated two subdivisions within the collection sampled that generally represented the 'standard vegetable' type (subgroup SV) and the 'non-standard vegetable' type (subgroup NSV), respectively. Level of LD (r(2)) was higher and extent of LD persisted longer in subgroup SV than in subgroup NSV, whereas LD decayed rapidly (0-2 cM) in both subgroups. LD decay distance varied among chromosomes, with the longest (≈ 5 cM) five times longer than the shortest (≈ 1 cM). Partitioning of LD variance into within- and between-subgroup components coupled with comparative LD decay analysis suggested that linkage group 5, 7 and 10 may have undergone the most intensive epistatic selection toward traits favorable for vegetable use. This work provides a first population genetic insight into domestication history of asparagus bean and demonstrates the feasibility of mapping complex traits by genome wide association study in asparagus bean using a currently available cowpea SNPs marker platform.

Maize germplasm of eastern Croatia with native resistance to western corn rootworm (Diabrotica virgifera virgifera LeConte

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Brkić Andrija

2017-01-01

Full Text Available The western corn rootworm (Diabrotica virgifera virgifera LeConte; WCR is a serious maize pest in Croatia. The species was first registered in Europe in the early 1990s and since then became one of the most dangerous maize pests, especially in parts of Central and Southeast Europe. Larvae that feed on the maize roots cause the most serious damages in maize fields. Management of this pest is difficult and expensive, with possible serious impact on the environment. Native (or host-plant resistance of maize against WCR could provide new economically and ecologically sustainable options in WCR management. Main goal of this study was to assess the variability of maize germplasm, correlations among resistance traits, and detect potential sources of resistance that could be used in breeding programs in order to develop hybrids with higher level of resistance against WCR. To our knowledge, the first native resistant hybrid is yet to be registered. Results showed great variability of estimated germplasm. Effect of the genotype was significant in all environments, as well as many interactions between genotype and the environment. Significant interactions emphasize the importance of the environment in WCR native resistance research. Significant positive correlations among all traits were detected. Several inbred lines were selected as a potentially useful germplasm for resistance breeding programs.

Association Mapping of Malting Quality Quantitative Trait Loci in Winter Barley: Positive Signals from Small Germplasm Arrays

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Lucía Gutiérrez

2011-11-01

Full Text Available Malting quality comprises one of the most economically relevant set of traits in barley ( L.. It is a complex phenotype, expensive and difficult to measure, that would benefit from a marker-assisted selection strategy. Malting quality is a target of the U.S. Barley Coordinated Agricultural Project (CAP and development of winter habit malting barley varieties is a key objective of the U.S. barley research community. The objective of this work was to detect quantitative trait loci (QTL for malting quality traits in a winter breeding program that is a component of the U.S. Barley CAP. We studied the association between five malting quality traits and 3072 single nucleotide polymorphisms (SNPs from the barley oligonucleotide pool assay (BOPA 1 and 2, assayed in advanced inbred lines from the Oregon State University (OSU breeding program from three germplasm arrays (CAP I, CAP II, and CAP III. After comparing 16 models we selected a structured association model with posterior probabilities inferred from software STRUCTURE (QK approach to use on all germplasm arrays. Most of the marker-trait associations are germplasm- and environment-specific and close to previously mapped genes and QTL relevant for malt and beer quality. We found alleles fixed by random genetic drift, novel unmasked alleles, and genetic-background interaction. In a relatively small population size study we provide strong evidence for detecting true QTL.

Adaptation to mid-season drought in a sweetpotato (Ipomoea batatas [L.] Lam germplasm collection grown in Mozambique

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Makunde Godwill S.

2017-02-01

Full Text Available Drought has negative effects on sweetpotato production. Two experiments with two watering treatments (irrigated and water-stressed were conducted at Umbeluzi Research Station in 2015. The objectives were to (i determine response of 48 sweetpotato germplasms to mid-season drought, (ii determine best traits for improvement of storage root yield under mid-season drought and (iii assess the selection criteria for identifying drought tolerance in sweetpotato germplasms. The irrigated and water- stressed trials received 640 and 400 mm of water, respectively, throughout the season. Water stress was imposed from 30 to 70 days after planting. Each treatment had two replicates arranged in a randomized complete block design. Data collected on storage root and vine yield and derived drought tolerance indices including harvest index were subjected to analysis of variance in R. Sweetpotato germplasms with high storage root yield under mid-season drought were associated with a high harvest index. Harvest index stability and the geometric mean are key to identifying cultivars with high and stable storage root yield under both treatments. MUSGP0646-126, Irene and Ivone combined both low TOL, SSI, HI and high yield storage root yield across the treatments and over seasons. The use of drought and harvest indices is encouraged for selecting improved cultivars for varied production environments and their regular use in accelerated breeding schemes is suggested.

Molecular characterisation of a germplasm bank for Theobroma genus using the RAPD technique

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Yovany Moreno

2004-07-01

Full Text Available RAPD markers (Random Amplified Polymorphic DNA were used for analysing 145 individuals (128 T. grandiflorum and 17 T. bicolor from the ex situ Theobroma genus germplasm bank at Instituto Sinchi, located at San José del Guaviare. 5 primers able to generated polymorphism were selected from an initial set of 20, generating 114 bands that enable to us to distinguish between more than 99% of individuals analysed: 57 bands for T. grandiflorum (84.2% polymorphic, 45 bands for T. bicolor (26.7% polymorphic and 12 bands shared between the two species (58.3% polymorphic. A high degree of intra-specific similarity particularly in T. bicolor was established from the similarity matrix obtained by using the Dice index and represented in a UPGMA dendrogram and the principal components analysis (PCA. The comparison of this analysis with a previous morpho-agronomic evaluation of some T. grandiflorum individuals revealed that the groups generated on the basis of its agronomic and morphological traits were heterogeneous at molecular level. The obtained information will be used as a tool in strategies regarding maintenance, enrichment and use of the germplasm bank. Key words: Theobroma grandiflorum, Theobroma bicolour, RAPD, molecular characterisation.

Genetic divergence among accessions of Axonopus jesuiticus x A. scoparius based on morphological and agronomical traits

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SIMONE M. SCHEFFER-BASSO

2014-03-01

Full Text Available This study had the objective of assessing the genetic divergence in giant missionary grass (Axonopus jesuiticus x A. scoparius germplasm based on morphological and agronomic traits. Five accessions were evaluated in the field: V14337, V14403, V14404, V14405 and V14406. Three contrasting groups were formed using the UPGMA clustering method: V14337 and V14404 formed one group, V14403 and V14405 formed another, and V14406 was isolated from the other accessions. The most striking traits for the identification of the accessions were the height of the plant and the change color of the leaf. Only V14406 accession had purplish green leaves. The other four accessions differed with regards to plant height and dry matter production, with superiority of V14337 and V14404 accessions. The high similarity, as assessed by the mean Euclidean distance, suggests that V14337 and V14404 share the same genotype. The genotypic variability among accessions indicates their potential use in breeding programs.

Genome-Wide Association Mapping of Leaf Rust Response in a Durum Wheat Worldwide Germplasm Collection.

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Aoun, Meriem; Breiland, Matthew; Kathryn Turner, M; Loladze, Alexander; Chao, Shiaoman; Xu, Steven S; Ammar, Karim; Anderson, James A; Kolmer, James A; Acevedo, Maricelis

2016-11-01

Leaf rust (caused by Erikss. []) is increasingly impacting durum wheat ( L. var. ) production with the recent appearance of races with virulence to widely grown cultivars in many durum producing areas worldwide. A highly virulent race on durum wheat was recently detected in Kansas. This race may spread to the northern Great Plains, where most of the US durum wheat is produced. The objective of this study was to identify sources of resistance to several races from the United States and Mexico at seedling stage in the greenhouse and at adult stage in field experiments. Genome-wide association study (GWAS) was used to identify single-nucleotide polymorphism (SNP) markers associated with leaf rust response in a worldwide durum wheat collection of 496 accessions. Thirteen accessions were resistant across all experiments. Association mapping revealed 88 significant SNPs associated with leaf rust response. Of these, 33 SNPs were located on chromosomes 2A and 2B, and 55 SNPs were distributed across all other chromosomes except for 1B and 7B. Twenty markers were associated with leaf rust response at seedling stage, while 68 markers were associated with leaf rust response at adult plant stage. The current study identified a total of 14 previously uncharacterized loci associated with leaf rust response in durum wheat. The discovery of these loci through association mapping (AM) is a significant step in identifying useful sources of resistance that can be used to broaden the relatively narrow leaf rust resistance spectrum in durum wheat germplasm. Copyright © 2016 Crop Science Society of America.

Molecular characterization of peach [Prunus persica (L.) Batsch] germplasm in the United States using microsatellite markers

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Peach [Prunus persica (L.) Batsch] is an important medicinal fruit with immense health benefits and antioxidant activity. In this study, microsatellite markers were used as DNA fingerprinting tools for the identification and characterization of peach germplasm in the United States. Eleven microsatel...

Resistance to Penicillium allii in accessions from a National Plant Germplasm System Allium collection.

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Accessions of Allium sativum (garlic), A. ampeloprasum (elephant garlic) and A. acuminatum, A. aflatunense, A. atroviolaceum, A. canadense, A. longicuspis, A. moly, A. ponticum, A. roseum, A. scorodoprasum, A. senescens, A. stipitatum, and Allium sp. (wild or ornamental species) were screened for re...

2D random walk representation of Begonia x tuberhybrida multiallelic loci used for germplasm identification

Czech Academy of Sciences Publication Activity Database

Wiesner, Ivo; Wiesnerová, Dana

2010-01-01

Roč. 54, č. 2 (2010), s. 353-356 ISSN 0006-3134 R&D Projects: GA AV ČR 1QS500510566 Institutional research plan: CEZ:AV0Z50510513 Keywords : begonia germplasm identification * random walk * primary sequence analysis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.582, year: 2010

Ft. Collins Sugar Beet Germplasm Evaluated for Resistance to Rhizomania and Storability in Idaho, 2010

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Sugar beet germplasm and commercial check cultivars were evaluated in a sprinkler-irrigated sugar beet field near Kimberly, ID where sugar beet was grown in 2009. The field trial relied on natural inoculum for rhizomania development. The seed was treated with clothianidin (2.1 oz a.i. per 100,000 ...

Germplasm enhancement for adaptation to climate changes

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Marcelo J Carena

2011-01-01

Full Text Available Billions of dollars and crops are being lost to drying high moisture grain; drought, cold, and salt susceptibility; andto processing poor quality grain. Maize is a model crop for adaptation to climate changes. Breeding for adaptation is best doneunder challenging environmental conditions where strengths and weaknesses are quickly identified and most stable genotypes areselected. The North Dakota State University (NDSU maize breeding program is strategically located to develop products underextreme weather. It currently exploits northern U.S. environments that allow screening for adaptation traits that are as important asyield. The program focuses on germplasm adaptation and its integration into cultivar development, particularly those carryingunique alleles not present in the B73 and NAM genomes. There is a need for projects that are vital to agricultural research and willmeet present and future demands of superior genotypes tolerant to climate changes in the U.S. and abroad.

Germplasm morgue or gold mine? Enhancing the value of plant genetic resource collections for plant breeding

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Genetic diversity is the raw material that plant breeders require to develop cultivars that are productive, nutritious, pest and stress tolerant, and water and nutrient use efficient. The USDA-ARS National Plant Germplasm System (NPGS) contains a wealth of genetic diversity, including improved varie...

Diversity in 113 cowpea [Vigna unguiculata (L) Walp] accessions assessed with 458 SNP markers.

Science.gov (United States)

Egbadzor, Kenneth F; Ofori, Kwadwo; Yeboah, Martin; Aboagye, Lawrence M; Opoku-Agyeman, Michael O; Danquah, Eric Y; Offei, Samuel K

2014-01-01

Single Nucleotide Polymorphism (SNP) markers were used in characterization of 113 cowpea accessions comprising of 108 from Ghana and 5 from abroad. Leaf tissues from plants cultivated at the University of Ghana were genotyped at KBioscience in the United Kingdom. Data was generated for 477 SNPs, out of which 458 revealed polymorphism. The results were used to analyze genetic dissimilarity among the accessions using Darwin 5 software. The markers discriminated among all of the cowpea accessions and the dissimilarity values which ranged from 0.006 to 0.63 were used for factorial plot. Unexpected high levels of heterozygosity were observed on some of the accessions. Accessions known to be closely related clustered together in a dendrogram drawn with WPGMA method. A maximum length sub-tree which comprised of 48 core accessions was constructed. The software package structure was used to separate accessions into three groups, and the programme correctly identified varieties that were known hybrids. The hybrids were those accessions with numerous heterozygous loci. The structure plot showed closely related accessions with similar genome patterns. The SNP markers were more efficient in discriminating among the cowpea germplasm than morphological, seed protein polymorphism and simple sequence repeat studies reported earlier on the same collection.

Diversity, distribution of Puroindoline genes and their effect on kernel hardness in a diverse panel of Chinese wheat germplasm.

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Ma, Xiaoling; Sajjad, Muhammad; Wang, Jing; Yang, Wenlong; Sun, Jiazhu; Li, Xin; Zhang, Aimin; Liu, Dongcheng

2017-09-20

Kernel hardness, which has great influence on the end-use properties of common wheat, is mainly controlled by Puroindoline genes, Pina and Pinb. Using EcoTILLING platform, we herein investigated the allelic variations of Pina and Pinb genes and their association with the Single Kernel Characterization System (SKCS) hardness index in a diverse panel of wheat germplasm. The kernel hardness varied from 1.4 to 102.7, displaying a wide range of hardness index. In total, six Pina and nine Pinb alleles resulting in 15 genotypes were detected in 1787 accessions. The most common alleles are the wild type Pina-D1a (90.4%) and Pina-D1b (7.4%) for Pina, and Pinb-D1b (43.6%), Pinb-D1a (41.1%) and Pinb-D1p (12.8%) for Pinb. All the genotypes have hard type kernel hardness of SKCS index (>60.0), except the wild types of Pina and Pinb combination (Pina-D1a/Pinb-D1a). The most frequent genotypes in Chinese and foreign cultivars was Pina-D1a/Pinb-D1b (46.3 and 39.0%, respectively) and in Chinese landraces was Pina-D1a/Pinb-D1a (54.2%). The frequencies of hard type accessions are increasing from 35.5% in the region IV, to 40.6 and 61.4% in the regions III and II, and then to 77.0% in the region I, while those of soft type are accordingly decreasing along with the increase of latitude. Varieties released after 2000 in Beijing, Hebei, Shandong and Henan have higher average kernel hardness index than that released before 2000. The kernel hardness in a diverse panel of Chinese wheat germplasm revealed an increasing of kernel hardness generally along with the latitude across China. The wild type Pina-D1a and Pinb-D1a, and one Pinb mutant (Pinb-D1b) are the most common alleles of six Pina and nine Pinb alleles, and a new double null genotype (Pina-D1x/Pinb-D1ah) possessed relatively high SKCS hardness index. More hard type varieties were released in recent years with different prevalence of Pin-D1 combinations in different regions. This work would benefit the understanding of the selection

El nombre 'Forastero' no más: A new protocol for meaningful cacao germplasm classification.

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The title of this article (The name ‘Forastero’ no more) is to convey an attempt in this paper to try to convince the cacao scientific community not to use the term Forastero to identify cacao germplasm of non-Criollo origin. The term Forastero originated in Latin America to differentiate the intro...

SSR-based genetic diversity and structure of garlic accessions from Brazil.

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da Cunha, Camila Pinto; Resende, Francisco Vilela; Zucchi, Maria Imaculada; Pinheiro, José Baldin

2014-10-01

Garlic is a spice and a medicinal plant; hence, there is an increasing interest in 'developing' new varieties with different culinary properties or with high content of nutraceutical compounds. Phenotypic traits and dominant molecular markers are predominantly used to evaluate the genetic diversity of garlic clones. However, 24 SSR markers (codominant) specific for garlic are available in the literature, fostering germplasm researches. In this study, we genotyped 130 garlic accessions from Brazil and abroad using 17 polymorphic SSR markers to assess the genetic diversity and structure. This is the first attempt to evaluate a large set of accessions maintained by Brazilian institutions. A high level of redundancy was detected in the collection (50 % of the accessions represented eight haplotypes). However, non-redundant accessions presented high genetic diversity. We detected on average five alleles per locus, Shannon index of 1.2, HO of 0.5, and HE of 0.6. A core collection was set with 17 accessions, covering 100 % of the alleles with minimum redundancy. Overall FST and D values indicate a strong genetic structure within accessions. Two major groups identified by both model-based (Bayesian approach) and hierarchical clustering (UPGMA dendrogram) techniques were coherent with the classification of accessions according to maturity time (growth cycle): early-late and midseason accessions. Assessing genetic diversity and structure of garlic collections is the first step towards an efficient management and conservation of accessions in genebanks, as well as to advance future genetic studies and improvement of garlic worldwide.

Potential of popcorn germplasm as a source of resistance to ear rot

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Railan do Nascimento Ferreira Kurosawa

Full Text Available ABSTRACT Because of its multi-purpose nature, popcorn has sparked the interest of the World Trade Organization as regards fungal contamination by mycotoxins. However, no investigations have been conducted on popcorn for resistance of genotypes to ear rot. The aim of this study was to evaluate the potential of popcorn genotypes as to resistance to ear rot and rotten kernels, as an initial step for the implementation of a breeding program with the popcorn crop in Northern Rio de Janeiro State, Brazil. Thirty-seven accessions from different ecogeographic regions of Latin America were evaluated in 2 cultivation periods, in a randomized block design with 4 replications. We evaluated the incidence of rotten ears, incidence of rotten ears caused by Fusarium spp., severity of ears with Fusarium spp. rot, and incidence of rotten kernels. The results were subjected to analysis of variance, and means were compared by the Scott-Knott clustering test (p < 0.05. A significant effect was observed for all evaluated variables, characterizing them as efficient in the discrimination of genotypic variability for reaction to fungal injuries in popcorn. The gene pool of the tropical and temperate Germplasm Collection evaluated here has the potential to generate superior segregants and provide hybrid combinations with alleles of resistance to diseases affecting ears and stored kernels. Based on the different variables and times, the experiment was conducted, and genotypes L65, L80, and IAC 125 showed the highest levels of resistance.

Isoenzymatic variation in the germplasm of Brazilian races of maize (Zea mays L.

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Gimenes Marcos Aparecido

2000-01-01

Full Text Available There are more than 200 races of maize (Zea mays L. divided into three groups (ancient commercial races, the recent commercial races, and indigenous races. Although the indigenous races have no commercial value, they have many important characteristics which can be incorporated into maize breeding programs. Most Brazilian indigenous germplasm race stocks were collected at least 40 years ago, and nothing is known of the genetic variability present in this germplasm. The genetic variability was assayed in 15 populations from four indigenous races of maize (Caingang, Entrelaçado, Lenha and Moroti and five indigenous cultivars, using five isoenzymatic systems encoded by 14 loci. The analysis revealed a low level of variability among the samples studied. Overall, the mean number of alleles/polymorphic locus was three, 64.3% of the loci analyzed being polymorphic and the estimated heterozygosity was 0.352. The mean number of alleles/polymorphic locus per population was 1.6. A mean of 47.5% of the loci were polymorphic. The mean expected heterozygosity was 0.195, the mean genetic identity was 0.821 and the proportion of total genetic diversity partitioned among populations (Gst was 0.156. A founder effect could explain the low variability detected.

Analysis of the Volatile Profile of Core Chinese Mango Germplasm by Headspace Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry

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Xiao-Wei Ma

2018-06-01

Full Text Available Despite abundant published research on the volatile characterization of mango germplasm, the aroma differentiation of Chinese cultivars remains unclear. Using headspace solid phase microextraction (HS-SPME coupled with gas chromatography–mass spectrometry (GC-MS, the composition and relative content of volatiles in 37 cultivars representing the diversity of Chinese mango germplasm were investigated. Results indicated that there are distinct differences in the components and content of volatile compounds among and within cultivars. In total, 114 volatile compounds, including 23 monoterpenes, 16 sesquiterpenes, 29 non-terpene hydrocarbons, 25 esters, 11 aldehydes, five alcohols and five ketones, were identified. The total volatile content among cultivars ranged from 211 to 26,022 μg/kg fresh weight (FW, with 123-fold variation. Terpene compounds were the basic background volatiles, and 34 cultivars exhibited abundant monoterpenes. On the basis of hierarchical cluster analysis (HCA and principal component analysis (PCA, terpinolene and α-pinene were important components constituting the aroma of Chinese mango cultivars. Most obviously, a number of mango cultivars with high content of various aroma components were observed, and they can serve as potential germplasms for both breeding and direct use.

The puzzle of Italian rice origin and evolution: determining genetic divergence and affinity of rice germplasm from Italy and Asia.

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Xingxing Cai

Full Text Available The characterization of genetic divergence and relationships of a set of germplasm is essential for its efficient applications in crop breeding and understanding of the origin/evolution of crop varieties from a given geographical region. As the largest rice producing country in Europe, Italy holds rice germplasm with abundant genetic diversity. Although Italian rice varieties and the traditional ones in particular have played important roles in rice production and breeding, knowledge concerning the origin and evolution of Italian traditional varieties is still limited. To solve the puzzle of Italian rice origin, we characterized genetic divergence and relationships of 348 rice varieties from Italy and Asia based on the polymorphisms of microsatellite fingerprints. We also included common wild rice O. rufipogon as a reference in the characterization. Results indicated relatively rich genetic diversity (H(e = 0.63-0.65 in Italian rice varieties. Further analyses revealed a close genetic relationship of the Italian traditional varieties with those from northern China, which provides strong genetic evidence for tracing the possible origin of early established rice varieties in Italy. These findings have significant implications for the rice breeding programs, in which appropriate germplasm can be selected from a given region and utilized for transferring unique genetic traits based on its genetic diversity and evolutionary relationships.

Establishment of the U.S. castor (Ricinus communis L.) core collection using seed chemical composition analysis and genotyping with EST-SSR markers

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Natural genetic variation exists in the plant germplasm collections. Normally the germplasm collection for a specific species encompasses many accessions. Due to its large number of accessions, the entire collection is hard to handle and can’t be easily utilized. To facilitate the end-users (such as...

Evaluation of fall armyworm resistance in maize germplasm lines using visual leaf injury rating and predator survey

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After examining ear-colonizing pest resistance, 20 maize lines from the USDA-ARS germplasm enhancement of Maize (GEM) Program were evaluated for whorl-feeding fall armyworm (FAW) (Spodoptera frugiperda) resistance using four maize inbred lines as the resistant and susceptible controls. Both FAW inju...

Characterization of Resistance to Cephus cinctus (Hymenoptera: Cephidae) in Barley Germplasm.

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Varella, Andrea C; Talbert, Luther E; Achhami, Buddhi B; Blake, Nancy K; Hofland, Megan L; Sherman, Jamie D; Lamb, Peggy F; Reddy, Gadi V P; Weaver, David K

2018-04-02

Most barley cultivars have some degree of resistance to the wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae). Damage caused by WSS is currently observed in fields of barley grown in the Northern Great Plains, but the impact of WSS damage among cultivars due to genetic differences within the barley germplasm is not known. Specifically, little is known about the mechanisms underlying WSS resistance in barley. We characterized WSS resistance in a subset of the spring barley CAP (Coordinated Agricultural Project) germplasm panel containing 193 current and historically important breeding lines from six North American breeding programs. Panel lines were grown in WSS infested fields for two consecutive years. Lines were characterized for stem solidness, stem cutting, WSS infestation (antixenosis), larval mortality (antibiosis), and parasitism (indirect plant defense). Variation in resistance to WSS in barley was compared to observations made for solid-stemmed resistant and hollow-stemmed susceptible wheat lines. Results indicate that both antibiosis and antixenosis are involved in the resistance of barley to the WSS, but antibiosis seems to be more prevalent. Almost all of the barley lines had greater larval mortality than the hollow-stemmed wheat lines, and only a few barley lines had mortality as low as that observed in the solid-stemmed wheat line. Since barley lines lack solid stems, it is apparent that barley has a different form of antibiosis. Our results provide information for use of barley in rotation to control the WSS and may provide a basis for identification of new approaches for improving WSS resistance in wheat.

Allelic database and divergence among Psidium accessions by using microsatellite markers.

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da Costa, S R; Santos, C A F

2013-12-16

This study aimed to investigate the genetic variability among guava accessions and wild Psidium species of the Embrapa Semiárido germplasm collection by using microsatellite loci to guide genetic resources and breeding programs, emphasizing crosses between guava and other Psidium species. DNA was extracted using the 2X CTAB method, and polymerase chain reaction products were analyzed on 6% denatured polyacrylamide gels stained with silver nitrate. The unweighted pair-group method using arithmetic average dendrogram generated from the distance matrix of the Jaccard coefficient for 183 alleles of 13 microsatellite loci was used for visualization of genetic similarity. The number of base pairs was estimated using inverse mobility method based on the regression of known-size products. Analysis of molecular variance was performed using total decomposition between and within guava accessions. The accessions showed similarity from 0.75 to 1.00, with the dendrogram presenting cophenetic value of 0.85. Five groups were observed: the first included guava accessions; the second, P. guineense accessions; the third, one accession of P. friedrichsthalianum; and the last 2 groups, P. cattleianum. The genetic similarity among P. guineense and some guava accessions were above 80%, suggesting greater possibility to obtain interspecies hybrids between these 2 species. The genetic variability between the accessions was considered to be high (ΦST = 0.238), indicating that guava genetic variability is not uniformly distributed among the 9 Brazilian states from where the accession were obtained. Obtaining a greater number of accessions by Brazilian states is recommended in order to have greater diversity among the species.

Mango (Mangifera indica L.) germplasm diversity based on single nucleotide polymorphisms derived from the transcriptome.

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Sherman, Amir; Rubinstein, Mor; Eshed, Ravit; Benita, Miri; Ish-Shalom, Mazal; Sharabi-Schwager, Michal; Rozen, Ada; Saada, David; Cohen, Yuval; Ophir, Ron

2015-11-14

Germplasm collections are an important source for plant breeding, especially in fruit trees which have a long duration of juvenile period. Thus, efforts have been made to study the diversity of fruit tree collections. Even though mango is an economically important crop, most of the studies on diversity in mango collections have been conducted with a small number of genetic markers. We describe a de novo transcriptome assembly from mango cultivar 'Keitt'. Variation discovery was performed using Illumina resequencing of 'Keitt' and 'Tommy Atkins' cultivars identified 332,016 single-nucleotide polymorphisms (SNPs) and 1903 simple-sequence repeats (SSRs). Most of the SSRs (70.1%) were of trinucleotide with the preponderance of motif (GGA/AAG)n and only 23.5% were di-nucleotide SSRs with the mostly of (AT/AT)n motif. Further investigation of the diversity in the Israeli mango collection was performed based on a subset of 293 SNPs. Those markers have divided the Israeli mango collection into two major groups: one group included mostly mango accessions from Southeast Asia (Malaysia, Thailand, Indonesia) and India and the other with mainly of Floridian and Israeli mango cultivars. The latter group was more polymorphic (FS=-0.1 on the average) and was more of an admixture than the former group. A slight population differentiation was detected (FST=0.03), suggesting that if the mango accessions of the western world apparently was originated from Southeast Asia, as has been previously suggested, the duration of cultivation was not long enough to develop a distinct genetic background. Whole-transcriptome reconstruction was used to significantly broaden the mango's genetic variation resources, i.e., SNPs and SSRs. The set of SNP markers described in this study is novel. A subset of SNPs was sampled to explore the Israeli mango collection and most of them were polymorphic in many mango accessions. Therefore, we believe that these SNPs will be valuable as they recapitulate and

Development of STS and CAPS markers for variety identification and genetic diversity analysis of tea germplasm in Taiwan.

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Hu, Chih-Yi; Tsai, You-Zen; Lin, Shun-Fu

2014-12-01

Tea (Camellia sinensis) is an important economic crop in Taiwan. Particularly, two major commercial types of tea (Paochong tea and Oolong tea) which are produced in Taiwan are famous around the world, and they must be manufactured with specific cultivars. Nevertheless, many elite cultivars have been illegally introduced to foreign countries. Because of the lower cost, large amount of "Taiwan-type tea" are produced and imported to Taiwan, causing a dramatic damage in the tea industry. It is very urgent to develop the stable, fast and reliable DNA markers for fingerprinting tea cultivars in Taiwan and protecting intellectual property rights for breeders. Furthermore, genetic diversity and phylogenetic relationship evaluations of tea germplasm in Taiwan are imperative for parental selection in the cross-breeding program and avoidance of genetic vulnerability. Two STS and 37 CAPS markers derived from cytoplasmic genome and ESTs of tea have been developed in this study providing a useful tool for distinguishing all investigated germplasm. For identifying 12 prevailing tea cultivars in Taiwan, five core markers, including each one of mitochondria and chloroplast, and three nuclear markers, were developed. Based on principal coordinate analysis and cluster analysis, 55 tea germplasm in Taiwan were divided into three groups: sinensis type (C. sinensis var. sinensis), assamica type (C. sinensis var. assamica) and Taiwan wild species (C. formosensis). The result of genetic diversity analysis revealed that both sinensis (0.44) and assamica (0.41) types had higher genetic diversity than wild species (0.25). The close genetic distance between the first (Chin-Shin-Oolong) and the third (Shy-Jih-Chuen) prevailing cultivars was found, and many recently released varieties are the descents of Chin-Shin-Oolong. This implies the potential risk of genetic vulnerability for tea cultivation in Taiwan. We have successfully developed a tool for tea germplasm discrimination and genetic

INVENTORY OF HERPETOFAUNA IN REGIONAL GERMPLASM PRESERVATION IN PULP AND PAPER INDUSTRY OGAN KOMERING ILIR REGENCY SOUTH SUMATRA

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Denny Noberio

2015-11-01

Full Text Available The research aims to determine of herpetofauna in Regional Germplasm Preservation, PT. Bumi Mekar Hijau, Ogan Komering Ilir Regency, South Sumatra. The research was conducted in May until June 2015, conducted on 4 transect observation purposively determined by considering the type of habitat herpetofauna and the results of a preliminary survey. The method used in this research is the Visual Encounter Survey (VES. Observations carried out in the morning and evening. The total number of herpetofauna were found during the observation as many as 15 species of 9 families. The number of amphibians was found as many as 6 species of 3 families and reptiles as many as 9 species of 6 families. There are two species categorized as Vulnerable in IUCN 2015 and Appendix II CITES which are the Siebenrockiella crassicollis and Cuora amboinensis cuoro   Keywords : Inventory, herpetofauna, regional germplasm preservation, industrial plantation forest

Selecting Lentil Accessions for Global Selenium Biofortification

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Dil Thavarajah

2017-08-01

Full Text Available The biofortification of lentil (Lens culinaris Medikus. has the potential to provide adequate daily selenium (Se to human diets. The objectives of this study were to (1 determine how low-dose Se fertilizer application at germination affects seedling biomass, antioxidant activity, and Se uptake of 26 cultivated lentil genotypes; and (2 quantify the seed Se concentration of 191 lentil wild accessions grown in Terbol, Lebanon. A germination study was conducted with two Se treatments [0 (control and 30 kg of Se/ha] with three replicates. A separate field study was conducted in Lebanon for wild accessions without Se fertilizer. Among cultivated lentil accessions, PI533690 and PI533693 showed >100% biomass increase vs. controls. Se addition significantly increased seedling Se uptake, with the greatest uptake (6.2 µg g−1 by PI320937 and the least uptake (1.1 µg g−1 by W627780. Seed Se concentrations of wild accessions ranged from 0 to 2.5 µg g−1; accessions originating from Syria (0–2.5 µg g−1 and Turkey (0–2.4 µg g−1 had the highest seed Se. Frequency distribution analysis revealed that seed Se for 63% of accessions was between 0.25 and 0.75 µg g−1, and thus a single 50 g serving of lentil has the potential to provide adequate dietary Se (20–60% of daily recommended daily allowance. As such, Se application during plant growth for certain lentil genotypes grown in low Se soils may be a sustainable Se biofortification solution to increase seed Se concentration. Incorporating a diverse panel of lentil wild germplasm into Se biofortification programs will increase genetic diversity for effective genetic mapping for increased lentil seed Se nutrition and plant productivity.

Selecting Lentil Accessions for Global Selenium Biofortification.

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Thavarajah, Dil; Abare, Alex; Mapa, Indika; Coyne, Clarice J; Thavarajah, Pushparajah; Kumar, Shiv

2017-08-26

The biofortification of lentil ( Lens culinaris Medikus.) has the potential to provide adequate daily selenium (Se) to human diets. The objectives of this study were to (1) determine how low-dose Se fertilizer application at germination affects seedling biomass, antioxidant activity, and Se uptake of 26 cultivated lentil genotypes; and (2) quantify the seed Se concentration of 191 lentil wild accessions grown in Terbol, Lebanon. A germination study was conducted with two Se treatments [0 (control) and 30 kg of Se/ha] with three replicates. A separate field study was conducted in Lebanon for wild accessions without Se fertilizer. Among cultivated lentil accessions, PI533690 and PI533693 showed >100% biomass increase vs. Se addition significantly increased seedling Se uptake, with the greatest uptake (6.2 µg g -1 ) by PI320937 and the least uptake (1.1 µg g -1 ) by W627780. Seed Se concentrations of wild accessions ranged from 0 to 2.5 µg g -1 ; accessions originating from Syria (0-2.5 µg g -1 ) and Turkey (0-2.4 µg g -1 ) had the highest seed Se. Frequency distribution analysis revealed that seed Se for 63% of accessions was between 0.25 and 0.75 µg g -1 , and thus a single 50 g serving of lentil has the potential to provide adequate dietary Se (20-60% of daily recommended daily allowance). As such, Se application during plant growth for certain lentil genotypes grown in low Se soils may be a sustainable Se biofortification solution to increase seed Se concentration. Incorporating a diverse panel of lentil wild germplasm into Se biofortification programs will increase genetic diversity for effective genetic mapping for increased lentil seed Se nutrition and plant productivity.

Phytosanitary evaluation of olive germplasm in Albania

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M. Luigi

2009-09-01

Full Text Available A survey on viruses was carried out in 2008 in the main olive-growing areas of Albania (Kruja, Sauk and Vlora. Fifty samples from 14 local and 2 exotic olive cultivars were collected from 10 commercial orchards and one collection field and inspected for Arabis mosaic virus (ArMV, Cherry leaf roll virus (CLRV, Strawberry latent ringspot virus (SLRV, Olive latent virus 1 (OLV-1, Olive leaf yellowing-associated virus (OLYaV, Cucumber mosaic virus (CMV, Olive latent virus-2 (OLV-2 and Tobacco necrosis virus strain D (TNV-D by a one-step RT-PCR assay using virus-specifi c primers. None of these viruses were found in the source plants except SLRSV and OLYaV, which were detected in a ‘K. M. Berat’ olive tree grown in the collection field. These findings are important because the incidence of olive virus diseases is low in Albania but high in other Mediterranean countries. Thus, all efforts should be to directed to maintaining the Albanian olive germplasm pathogen-free and in the best agronomical and phytosanitary condition possible.

Genetic diversity and population structure analysis of the tropical pasture grass Brachiaria humidicola based on microsatellites, cytogenetics, morphological traits, and geographical origin.

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Jungmann, L; Vigna, B B Z; Boldrini, K R; Sousa, A C B; do Valle, C B; Resende, R M S; Pagliarini, M S; Zucchi, M I; de Souza, A P

2010-09-01

Brachiaria humidicola (Rendle) Schweick. is a warm-season grass commonly used as forage in the tropics. Accessions of this species were collected in eastern Africa and massively introduced into South America in the 1980s. Several of these accessions form a germplasm collection at the Brazilian Agricultural Research Corporation. However, apomixis, ploidy, and limited knowledge of the genetic basis of this germplasm collection have constrained breeding activities. The objectives of this work were to identify genetic variability in the Brazilian B. humidicola germplasm collection using microsatellite markers and to compare the results with information on the following: (1) collection sites of the accessions; (2) reproductive mode and ploidy levels; and (3) genetic diversity revealed by morphological traits. The evaluated germplasm population is highly structured into four major groups. The sole sexual accession did not group with any of the clusters. Genetic dissimilarities did not correlate with either geographic distances or genetic distances inferred from morphological descriptors. Additionally, the genetic structure identified in this collection did not correspond to differences in ploidy level. Alleles exclusive to either sexual or apomictic accessions were identified, suggesting that further evaluation of the association of these loci with apospory should be carried out.

Incorporating different proportions of exotic maize germplasm into two adapted populations

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Manoel Xavier dos Santos

2000-06-01

Full Text Available Maize breeders frequently wish to use exotic germplasm in their breeding programs without losing specific characteristics of their adapted material. The objective of this study was to determine the optimal proportions of exotic germplasm to incorporate into adapted populations (F2 = 50% exotic, BC1 = 25% exotic, BC2 = 12.5% exotic and BC3 = 6.25% exotic to form the initial foundation population and to determine the heterosis between adapted x exotics. We used six exotic populations of different origins and two adapted populations representing a Brazilian heterotic pattern. In 1993-94 and 1994-95, the parents, F1, F2, BC1, BC2, BC3 and four checks were evaluated in six environments in central Brazil using an 8 x 9 simple rectangular lattice design. Higher mean values for yield were obtained as the proportion of exotic germplasm decreased. Some backcrosses produced more than the adapted populations BR 105 (7.59 ton/ha and BR 106 (8.43 ton/ha. The best results were obtained when incorporating 6.25 or 12.5% of exotic genes. This trend was true for root lodging, stalk lodging and ear diseases but not for plant and ear height. The midparent heterosis for yield varied from -16.1 to 40.3%. Midparent heterosis with positive and negative values were also found for the other traits. The results indicate the potential of exotic germplasm for developing good hybrids. After choosing the best exotic source, some recurrent selection might be appropriate in order to adapt and improve the exotic populations.Os melhoristas de milho que utilizam germoplasmas exóticos nos programas de melhoramento têm a preocupação de não perder as características desejáveis dos materiais adaptados. Buscando atender esta demanda, o presente trabalho teve por objetivo determinar a proporção ideal de germoplasma exótico que deve ser incorporado em populações melhoradas (F2 = 50% exótico; RC1 = 25% exótico; RC2 = 12,5% exótico; RC3 = 6,25% exótico, para formar as popula

Investigation on Genetic Variation of Iran Watermelon Accession

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majid reza kiyani

2009-06-01

Full Text Available In order to determine of genetic variation in germplasm of 120 watermelon accessions, a field trial conducted at agricultural and natural resource research center of khorasan . These Accessions with four commercial cultivars as control were planted in agnomental design with six replications. 15 quantitative morphological traits were measured and some statistical parameter and analysis include of Mean, Coefficient variance, cluster analysis, correlation regression coefficients were determine for this traits. yield, Sugar percent , time between flowering and ripping, fruit length, fruit width, fruit mass to fruit weight ratio , fruit skin to fruit weight ratio , seed weight to fruit weight ratio , 100 seed weight , seed length , seed diameter , seed width were the most useful traits for identifying of genotypes from each other. A one side analysis of variance was performed for different regions genetic diversity detection, which indicated a significant difference between regions for all traits except fruit Ph and fruit skin thickness. Cluster analysis divided genotypes into eight groups based on quantitative data. Correlation analysis between traits showed a significant relation between yield and all traits except fruit ph, time to flowering and seed fruit length.

Environmental Influences on the Growing Season Duration and Ripening of Diverse Miscanthus Germplasm Grown in Six Countries

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Christopher Nunn

2017-05-01

Full Text Available The development of models to predict yield potential and quality of a Miscanthus crop must consider climatic limitations and the duration of growing season. As a biomass crop, yield and quality are impacted by the timing of plant developmental transitions such as flowering and senescence. Growth models are available for the commercially grown clone Miscanthus x giganteus (Mxg, but breeding programs have been working to expand the germplasm available, including development of interspecies hybrids. The aim of this study was to assess the performance of diverse germplasm beyond the range of environments considered suitable for a Miscanthus crop to be grown. To achieve this, six field sites were planted as part of the EU OPTIMISC project in 2012 in a longitudinal gradient from West to East: Wales—Aberystwyth, Netherlands—Wageningen, Stuttgart—Germany, Ukraine—Potash, Turkey—Adana, and Russia—Moscow. Each field trial contained three replicated plots of the same 15 Miscanthus germplasm types. Through the 2014 growing season, phenotypic traits were measured to determine the timing of developmental stages key to ripening; the tradeoff between growth (yield and quality (biomass ash and moisture content. The hottest site (Adana showed an accelerated growing season, with emergence, flowering and senescence occurring before the other sites. However, the highest yields were produced at Potash, where emergence was delayed by frost and the growing season was shortest. Flowering triggers varied with species and only in Mxg was strongly linked to accumulated thermal time. Our results show that a prolonged growing season is not essential to achieve high yields if climatic conditions are favorable and in regions where the growing season is bordered by frost, delaying harvest can improve quality of the harvested biomass.

Genetic diversity of "Pimenta Longa" genotypes (Piper spp., Piperaceae) of the Embrapa Acre germplasm collection

OpenAIRE

Wadt, Lúcia Helena de Oliveira; Ehringhaus, Christiane; Kageyama, Paulo Yoshio

2004-01-01

The commonly known Pimenta longa is a commercially valuable natural resource found wild in Acre, Brazil. Specifically, three Piperaceae species with contested taxonomic status were studied, Piper hispidinervum, Piper aduncum, and Piper hispidum, to assesses the inter- and intra-specific genetic relationship of 49 Piper genotypes kept in the Pimenta longa germplasm collection at Embrapa Acre, using sixty six Random Amplified Polymorphic DNA (RAPD) markers. The DNA polymorphism level detected w...

Evaluation of γ-oryzanol content and composition from the grains of pigmented rice-germplasms by LC-DAD-ESI/MS.

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Kim, Heon Woong; Kim, Jung Bong; Shanmugavelan, Poovan; Kim, Se Na; Cho, Young Sook; Kim, Haeng Ran; Lee, Jeong-Tae; Jeon, Weon-Tai; Lee, Dong Jin

2013-04-15

Rice is the staple food and one of the world’s three major grain crops. Rice contains more than 100 bioactive substances including phytic acid, isovitexin, γ-oryzanol, phytosterols, octacosanol, squalene, γ-aminobutyric acid (GABA), tocopherol, tocotrienol derivatives, etc. Out of them, γ-oryzanol is known to have important biological profile such as anti-oxidants, inhibitor of cholesterol oxidation, reduce serum cholesterol levels in animals, effective in the treatment of inflammatory diseases, inhibit tumor growth, reduce blood pressure and promotes food storage stability when used as a food additive, etc. Hence in the present investigation, we aimed to evaluate the content and composition of γ-oryzanol from pigmented rice germplasms using a liquid chromatography with diode array detection and electrospray ionization-mass spectrometry (LC-DAD-ESI/MS). In the present study, 33 exotic pigmented rice accessions (red, white and purple) have been evaluated. Among them, the contents of γ-oryzanol varied from 3.5 to 21.0 mg/100 g with a mean of 11.2 mg/100 g. A total of ten components of γ-oryzanol including Δ⁷-stigmastenyl ferulate were identified of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components. The mean proportions of steryl ferulates were in the descending order of 24-methylenecycloartanyl ferulate > cycloartenyl ferulate > campesteryl ferulate > sitosteryl ferulate > Δ⁷-campestenyl ferulate > campestanyl ferulate > sitostanyl ferulate > Δ⁷-stigmastenyl ferulate > stigamsteryl ferulate > Δ⁷-sitostenyl ferulate. Almost 11 accessions (33%) showed higher content than the control rice Chucheongbyeo and higher proportions ranged from 10 to 15 mg/100 g. Interestingly, the red rice accession Liberian Coll. B11/B-11 (21.0 mg/100 g) showed higher content γ-oryzanol than control rice Jeokjinjubyeo (19.1 mg/100 g) and the purple rice accession Padi Adong

EcoTurf - a case study: genetic variation and agronomic potential of bermudagrass (Cynodon spp.) germplasm collected from Australian biodiversity

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Australian Cynodon germplasm has not been comprehensively exploited for bermudagrass improvement. In this paper we will describe ‘EcoTurf’ a four year (2007-2011) project to develop water and nutrient use efficient bermudagrasses from Australian biodiversity. We describe the sampling strategies of A...

Analysis of genetic diversity and population structure in upland ...

Indian Academy of Sciences (India)

Mulugeta Seyoum

2018-06-09

Jun 9, 2018 ... diversity and population structure at DNA level, 302 elite upland cotton germplasm accessions ...... conservation of cotton germplasm in China (English abstract). ... and Alishah O. 2011 Inter simple sequence repeats (ISSR).

Quantitative Characterization of Nut Yield and Fruit Components in Indigenous Coconut Germplasm in Sri Lanka

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S. A. C. N. Perera

2014-01-01

Full Text Available Coconut (Cocos nucifera L. is a tropical palm offering multiple uses. Conservation of coconut germplasm has been undertaken globally in view of its economic importance. This research was designed to evaluate nine Sri Lankan indigenous coconut germplasm representing the three varieties Typica, Nana, and Aurantiaca. Total annual nut yield and the weights of fresh nut, husked nut, split nut, and fresh and dry kernel were scored and analyzed with analysis of variance. The annual average number of bunches varied from 14.9 to 16.8 which is significantly higher than the generally accepted 12–14 bunches in tall coconuts. The high potential of phenotypes Ran thembili and Gon thembili for kernel production was revealed. The high potential of Gon thembili, Sri Lanka Tall, and Ran thembili to produce fibre was also identified. Phenotypes Ran thembili and Gon thembili displayed their potential as pure cultivars and as parents in hybridization. King coconut, Red dwarf, and Bodiri were shown to be suitable as beverage coconuts due to the high production of nuts, bunches, and the quantity of nut water. This study reiterated the importance of conservation and characterization of indigenous coconut varieties globally for their effective use in the genetic improvement of the coconut palm.

Revealing the Diversity of Introduced Coffea canephora Germplasm in Ecuador: Towards a National Strategy to Improve Robusta

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Rey Gastón Loor Solórzano

2017-01-01

Full Text Available Genetic resources of Coffea canephora have been introduced in several tropical countries with potential for crop development. In Ecuador, the species has been cultivated since the mid-20th century. However, little is known about the diversity and genetic structure of introduced germplasm. This paper provides an overview of the genetic and phenotypic diversity of C. canephora in Ecuador and some proposals for implementing a breeding program. Twelve SSR markers were used to analyze 1491 plants of C. canephora grown in different living collections in Ecuador, compared to 29 genotypes representing the main genetic and geographic diversity groups identified within the species. Results indicated that most of the genotypes introduced are of Congolese origin, with accessions from both main subgroups, SG1 and SG2. Some genotypes were classed as hybrids between both subgroups. Substantial phenotypic diversity was also found, and correlations were observed with genetic diversity. Ecuadorian Robusta coffee displays wide genetic diversity and we propose some ways of improving Robusta in Ecuador. A breeding program could be based on three operations: the choice of elite clones, the introduction of new material from other countries (Ivory Coast, Uganda, and the creation of new hybrid material using genotypes from the different diversity groups.

Characterization of novel SSR markers in diverse sainfoin (Onobrychis viciifolia) germplasm.

Science.gov (United States)

Kempf, Katharina; Mora-Ortiz, Marina; Smith, Lydia M J; Kölliker, Roland; Skøt, Leif

2016-08-30

Sainfoin is a perennial forage legume with beneficial properties for animal husbandry due to the presence of secondary metabolites. However, worldwide cultivation of sainfoin is marginal due to the lack of varieties with good agronomic performance, adapted to a broad range of environmental conditions. Little is known about the genetics of sainfoin and only few genetic markers are available to assist breeding and genetic investigations. The objective of this study was to develop a set of SSR markers useful for genetic studies in sainfoin and their characterization in diverse germplasm. A set of 400 SSR primer combinations were tested for amplification and their ability to detect polymorphisms in a set of 32 sainfoin individuals, representing distinct varieties or landraces. Alleles were scored for presence or absence and polymorphism information content of each SSR locus was calculated with an adapted formula taking into account the tetraploid character of sainfoin. Relationships among individuals were visualized using cluster and principle components analysis. Of the 400 primer combinations tested, 101 reliably detected polymorphisms among the 32 sainfoin individuals. Among the 1154 alleles amplified 250 private alleles were observed. The number of alleles per locus ranged from 2 to 24 with an average of 11.4 alleles. The average polymorphism information content reached values of 0.14 to 0.36. The clustering of the 32 individuals suggested a separation into two groups depending on the origin of the accessions. The SSR markers characterized and tested in this study provide a valuable tool to detect polymorphisms in sainfoin for future genetic studies and breeding programs. As a proof of concept, we showed that these markers can be used to separate sainfoin individuals based on their origin.

Vegetable Genetic Resources in China

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Haiping WANG

2018-03-01

Full Text Available China is recognized as an important region for plant biodiversity based on its vast and historical collection of vegetable germplasm. The aim of this review is to describe the exploration status of vegetable genetic resources in China, including their collection, preservation, evaluation, and utilization. China has established a number of national-level vegetable genetic resources preservation units, including the National Mid-term Genebank for Vegetable Germplasm Resources, the National Germplasm Repository for Vegetatively-Propagated Vegetables, and the National Germplasm Repository for Aquatic Vegetables. In 2015, at least 36 000 accessions were collected and preserved in these units. In the past decade, 44 descriptors and data standards for different species have been published, and most accessions have been evaluated for screening the germplasms for specific important traits such as morphological characteristics, disease resistance, pest resistance, and stress tolerance. Moreover, the genetic diversity and evolution of some vegetable germplasms have been evaluated at the molecular level. Recently, more than 1 000 accessions were distributed to researchers and breeders each year by various means for vegetable research and production. However, additional wild-relative and abroad germplasms from other regions need to be collected and preserved in the units to expand genetic diversity. Furthermore, there is a need to utilize advanced techniques to better understand the background and genetic diversity of a wide range of vegetable genetic resources. This review will provide agricultural scientists’ insights into the genetic diversity in China and provide information on the distribution and potential utilization of these valuable genetic resources. Keywords: vegetable, genetic resource, preservation, evaluation, utilization

Diversity among Cynodon accessions and taxa based on DNA amplification fingerprinting.

Science.gov (United States)

Assefa, S; Taliaferro, C M; Anderson, M P; de los Reyes, B G; Edwards, R M

1999-06-01

The genus Cynodon (Gramineae), comprised of 9 species, is geographically widely distributed and genetically diverse. Information on the amounts of molecular genetic variation among and within Cynodon taxa is needed to enhance understanding of phylogenetic relations and facilitate germplasm management and breeding improvement efforts. Genetic relatedness among 62 Cynodon accessions, representing eight species, was assessed using DNA amplification fingerprinting (DAF). Ten 8-mer oligonucleotides were used to amplify specific Cynodon genomic sequences. The DNA amplification products of individual accessions were scored for presence (1) or absence (0) of bands. Similarity matrices were developed and the accessions were grouped by cluster (UPGMA) and principal coordinate analysis. Analyses were conducted within ploidy level (2x = 18 and 4x = 36) and over ploidy levels. Each primer revealed polymorphic loci among accessions within species. Of 539 loci (bands) scored, 496 (92%) were polymorphic. Cynodon arcuatus was clearly separated from other species by numerous monomorphic bands. The strongest species similarities were between C. aethiopicus and C. arcuatus, C. transvaalensis and C. plectostachyus, and C. incompletus and C. nlemfuensis. Intraspecific variation was least for C. aethiopicus, C. arcuatus, and C. transvaalensis, and greatest for C. dactylon. Accessions of like taxonomic classification were generally clustered, except the cosmopolitan C. dactylon var. dactylon and C. dactylon var. afganicus. Within taxa, accessions differing in chromosome number clustered in all instances indicating the 2x and 4x forms to be closely related. Little, if any, relationship was found between relatedness as indicated by the DAF profiles and previous estimates of hybridization potential between the different taxa.

Recent advances in the development of quality protein maize germplasm at the Centro International de Mejoramiento de Maiz y Trigo

International Nuclear Information System (INIS)

Vasal, S.K.; Villegas, E.; Tang, C.Y.

1984-01-01

The paper reviews past difficulties in the acceptance of quality protein maize (QPM) materials by farmers because of several crucial problems plaguing these materials. The breeding strategy used at the Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) over the past several years is described in detail. The strategy is based on the combined use of two genetic systems involving the opaque-2 gene and genetic modifiers. Inheritance of modifiers, some considerations in the exploitation and their role in circumventing the problems facing QPM materials are discussed. Progress is reported in overcoming the problems of yield, seed appearance, ear rot and the dry-down ability in QPM materials. Using hard endosperm QPM donor stocks, a wide array of QPM germplasm has been developed through the conversion programme and the development of QPM gene pools. To make the best use of available QPM germplasm, the current efforts in the management and handling of the germplasm are outlined. In the back-up stages, eight tropical and six subtropical QPM pools will be handled. In addition, six tropical and four subtropical advanced QPM populations were formed. These will be subjected to a rigorous international progency testing programme for improved yield, general adaptation and the stability of modifiers. Experimental data from international tests are presented, indicating the superior performance of several QPM materials. The objectives of some exploratory projects in QPM research are explained. Renewed interest in QPM research is being shown and the outlook for commercial exploitation of QPM materials in some countries seems very promising. (author)

Molecular characterization of Iranian black cumin ( Nigella sativa L. accessions using RAPD marker

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Mahmoud Ghorbanzadeh Neghab

2017-07-01

Full Text Available Nigella sativa L. (2n = 12 is an annual flowering plant belonging to the family Ranunculaceae known for medicinal properties demonstrating valuable components that are widely used in food and pharmaceutical industries. Nine Random Amplified Polymorphic DNA markers (RAPD were used in this study, in order to characterize the genetic variation of 16 black cumin varieties collected from Iran’s different regions. The amplification reaction produced 95 bands with sizes ranging from about 100 to 500 bp. The average frequency of bands was 20 while the averages of polymorphism were about 8.11 per primer. The Jaccard similarity coefficient and the Unweighted Pair-Group Method Analysis (UPGMA clustering algorithm were applied to the RAPD data sets in order to understand the genetic relationships among the tested accessions. The accessions were categorized into three groups using cluster analysis. The results were supported by the Principal Coordinate Analysis (PCoA cluster analysis. The results showed that the tested black cumin genotypes had a high genetic diversity and could be used in black cumin germplasm conservation programs. Moreover, the RAPD is a versatile approach to the diversity analysis of native accessions of black cumin.

Molecular Diversity and Population Structure of a Worldwide Collection of Cultivated Tetraploid Alfalfa (Medicago sativa subsp. sativa L.) Germplasm as Revealed by Microsatellite Markers.

Science.gov (United States)

Qiang, Haiping; Chen, Zhihong; Zhang, Zhengli; Wang, Xuemin; Gao, Hongwen; Wang, Zan

2015-01-01

Information on genetic diversity and population structure of a tetraploid alfalfa collection might be valuable in effective use of the genetic resources. A set of 336 worldwide genotypes of tetraploid alfalfa (Medicago sativa subsp. sativa L.) was genotyped using 85 genome-wide distributed SSR markers to reveal the genetic diversity and population structure in the alfalfa. Genetic diversity analysis identified a total of 1056 alleles across 85 marker loci. The average expected heterozygosity and polymorphism information content values were 0.677 and 0.638, respectively, showing high levels of genetic diversity in the cultivated tetraploid alfalfa germplasm. Comparison of genetic characteristics across chromosomes indicated regions of chromosomes 2 and 3 had the highest genetic diversity. A higher genetic diversity was detected in alfalfa landraces than that of wild materials and cultivars. Two populations were identified by the model-based population structure, principal coordinate and neighbor-joining analyses, corresponding to China and other parts of the world. However, lack of strictly correlation between clustering and geographic origins suggested extensive germplasm exchanges of alfalfa germplasm across diverse geographic regions. The quantitative analysis of the genetic diversity and population structure in this study could be useful for genetic and genomic analysis and utilization of the genetic variation in alfalfa breeding.

Semi-High Throughput Screening for Potential Drought-tolerance in Lettuce (Lactuca sativa) Germplasm Collections.

Science.gov (United States)

Knepper, Caleb; Mou, Beiquan

2015-04-17

This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of the world. Short-term drought events along with regulatory intervention in the regulation of water availability coupled with the looming threat of long-term climate shifts that may lead to reduced precipitation in many important agricultural regions has increased the need to hasten the development of crops adapted for improved water use efficiency in order to maintain or expand production in the coming years. This protocol is not meant as a step-by-step guide to identifying at either the physiological or molecular level drought-tolerance traits in lettuce, but rather is a method developed and refined through the screening of thousands of different lettuce varieties. The nature of this screen is based in part on the streamlined measurements focusing on only three water-stress indicators: leaf relative water content, wilt, and differential plant growth following drought-stress. The purpose of rapidly screening a large germplasm collection is to narrow the candidate pool to a point in which more intensive physiological, molecular, and genetic methods can be applied to identify specific drought-tolerant traits in either the lab or field. Candidates can also be directly incorporated into breeding programs as a source of drought-tolerance traits.

Genetic diversity analysis in the section Caulorrhizae (genus Arachis using microsatellite markers

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Darío A. Palmieri

2010-01-01

Full Text Available Diversity in 26 microsatellite loci from section Caulorrhizae germplasm was evaluated by using 33 accessions of A. pintoi Krapov. & W.C. Gregory and ten accessions of Arachis repens Handro. Twenty loci proved to be polymorphic and a total of 196 alleles were detected with an average of 9.8 alleles per locus. The variability found in those loci was greater than the variability found using morphological characters, seed storage proteins and RAPD markers previously used in this germplasm. The high potential of these markers to detect species-specific alleles and discriminate among accessions was demonstrated. The set of microsatellite primer pairs developed by our group for A. pintoi are useful molecular tools for evaluating Section Caulorrhizae germplasm, as well as that of species belonging to other Arachis sections.

Genetic diversity analysis in the section Caulorrhizae (genus Arachis) using microsatellite markers.

Science.gov (United States)

Palmieri, Darío A; Bechara, Marcelo D; Curi, Rogério A; Monteiro, Jomar P; Valente, Sérgio E S; Gimenes, Marcos A; Lopes, Catalina R

2010-01-01

Diversity in 26 microsatellite loci from section Caulorrhizae germplasm was evaluated by using 33 accessions of A. pintoi Krapov. & W.C. Gregory and ten accessions of Arachis repens Handro. Twenty loci proved to be polymorphic and a total of 196 alleles were detected with an average of 9.8 alleles per locus. The variability found in those loci was greater than the variability found using morphological characters, seed storage proteins and RAPD markers previously used in this germplasm. The high potential of these markers to detect species-specific alleles and discriminate among accessions was demonstrated. The set of microsatellite primer pairs developed by our group for A. pintoi are useful molecular tools for evaluating Section Caulorrhizae germplasm, as well as that of species belonging to other Arachis sections.

Assessing and Broadening Genetic Diversity of Elymus sibiricus Germplasm for the Improvement of Seed Shattering

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Zongyu Zhang

2016-07-01

Full Text Available Siberian wild rye (Elymus sibiricus L. is an important native grass in the Qinghai-Tibet Plateau of China. It is difficult to grow for commercial seed production, since seed shattering causes yield losses during harvest. Assessing the genetic diversity and relationships among germplasm from its primary distribution area contributes to evaluating the potential for its utilization as a gene pool to improve the desired agronomic traits. In the study, 40 EST-SSR primers were used to assess the genetic diversity and population structure of 36 E. sibiricus accessions with variation of seed shattering. A total of 380 bands were generated, with an average of 9.5 bands per primer. The polymorphic information content (PIC ranged from 0.23 to 0.50. The percentage of polymorphic bands (P for the species was 87.11%, suggesting a high degree of genetic diversity. Based on population structure analysis, four groups were formed, similar to results of principal coordinate analysis (PCoA. The molecular variance analysis (AMOVA revealed the majority of genetic variation occurred within geographical regions (83.40%. Two genotypes from Y1005 and ZhN06 were used to generate seven F1 hybrids. The molecular and morphological diversity analysis of F1 population revealed rich genetic variation and high level of seed shattering variation in F1 population, resulting in significant improvement of the genetic base and desired agronomic traits.

Development of a new wheat germplasm with high anther culture ability by using a combination of gamma-ray irradiation and anther culture.

Science.gov (United States)

Zhao, Linshu; Liu, Luxiang; Wang, Jing; Guo, Huijun; Gu, Jiayu; Zhao, Shirong; Li, Junhui; Xie, Yongdun

2015-01-01

Wheat with high anther culture ability would be beneficial for breeding. We aimed to screen a wheat germplasm to with high anther culture ability as well as good agronomic characteristics. The F1 young spikes of winter wheat cross combination Yanfu188/Jimai37 were irradiated with gamma rays at a dose of 1.5 Gy to develop a new germplasm H307 with high anther culture ability. The proportion of green plantlets per 100 anthers (GP/100A) of H307 was 14.50% which was higher than other H2 lines (P green plantlet regeneration ability of H307 remained high in all 3 years. Reciprocal crosses between H307 and Nongda3308 showed no significant differences in their values for calli per 100 anthers (CA/100A), green plantlets per 100 calli (GP/100C) and GP/100A (P > 0.05). Five main wheat varieties used in production, namely Yumai68, Yanzhan4110, Bainongaikang58, Zhoumai18 and Xinmai18, were selected to cross with the new H307. CA/100A, GP/100C and GP/100A were used to assess the anther culture ability of F1 hybrids, demonstrating that the anther culture ability of H307 was heritable. H307 possessed high anther culture ability that was heritable, which would be potential germplasm for improving wheat anther breeding ability. © 2014 Society of Chemical Industry.

Pengelompokan Plasma Nutfah Rambutan Berdasarkan Karakter Morfologi

OpenAIRE

Nfn, Kuswandi

2016-01-01

Rambutan is a fruit native to Indonesia, which has a high diversity. Indonesian Tropical Fruit Research Institute has a rambutan germplasm collection. The objectives of the research were to identify and classify rambutan germplasm accessions based on morphological characteristics, in order to identify the specific characteristics important for the development of future varieties of rambutan. Collecting data on the 32 accession was conducted in Aripan Experimental Field, Indonesian Tropical Fr...

Diversity and Genome Analysis of Australian and Global Oilseed Brassica napus L. Germplasm Using Transcriptomics and Whole Genome Re-sequencing

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M. Michelle Malmberg

2018-04-01

Full Text Available Intensive breeding of Brassica napus has resulted in relatively low diversity, such that B. napus would benefit from germplasm improvement schemes that sustain diversity. As such, samples representative of global germplasm pools need to be assessed for existing population structure, diversity and linkage disequilibrium (LD. Complexity reduction genotyping-by-sequencing (GBS methods, including GBS-transcriptomics (GBS-t, enable cost-effective screening of a large number of samples, while whole genome re-sequencing (WGR delivers the ability to generate large numbers of unbiased genomic single nucleotide polymorphisms (SNPs, and identify structural variants (SVs. Furthermore, the development of genomic tools based on whole genomes representative of global oilseed diversity and orientated by the reference genome has substantial industry relevance and will be highly beneficial for canola breeding. As recent studies have focused on European and Chinese varieties, a global diversity panel as well as a substantial number of Australian spring types were included in this study. Focusing on industry relevance, 633 varieties were initially genotyped using GBS-t to examine population structure using 61,037 SNPs. Subsequently, 149 samples representative of global diversity were selected for WGR and both data sets used for a side-by-side evaluation of diversity and LD. The WGR data was further used to develop genomic resources consisting of a list of 4,029,750 high-confidence SNPs annotated using SnpEff, and SVs in the form of 10,976 deletions and 2,556 insertions. These resources form the basis of a reliable and repeatable system allowing greater integration between canola genomics studies, with a strong focus on breeding germplasm and industry applicability.

Assessment of genetic diversity on a sample of cocoa accessions resistant to witches' broom disease based on RAPD and pedigree data Avaliação da diversidade genética em uma amostra de acessos de cacau resistentes à doença vassoura-de-bruxa, com base em dados de RAPD e pedigree

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Ronaldo Carvalho dos Santos

2005-01-01

Full Text Available Genetic diversity in cocoa (Theobroma cacao L. has been assessed based on morphological and molecular markers for germplasm management and breeding purposes. Pedigree data is available in cocoa but it has not been used for assessing genetic relatedness. The geneitic diversity of 30 clonal cocoa accessions resistant to witche´ broom disease, from the CEPEC series, were studied on the basis of RAPD data and pedigree information. Twenty of these accessions descend from the TSA-644 clone, originated from a cross between the Upper Amazon germplasm called Scavina-6, the main source of resistance to witches' broom disease, and IMC-67. The ten remaining clones come from different sources including Amazon and Trinitario germplasm. RAPD data was collected using 16 primers and pedigree information was obtained from the International Cocoa Germplasm Database. Genetic similarities, genetic distances and coefficient of parentage were calculated using available software. Relatively low genetic diversity was observed in this germplasm set, probably because of great genetic relatedness amongst accessions studied and the poor representation of the germplasm. The TSA-644 descendants were more diverse than the other accessions used in the study. This might be due to the origin of the TSA clone, which was derived from highly divergent genotypes. Association between genetic similarities based on RAPD data and coefficient of parentage, based on pedigree data, was very low, probably due to the homogeneity of the breeding stocks and poor pedigree information. These findings are useful to cocoa breeders in planning crosses for the development of hybrid and clonal cultivars.A diversidade genética em cacau (Theobroma cacao L., embasada em dados morfológicos e em marcadores moleculares, tem sido avaliada com fins de manejo de germoplasma e uso no melhoramento genético. Dados de genealogia de cacau, embora disponíveis, não têm sido utilizados. Foi analisada a

Genetic diversity and population structure of castor (Ricinus communis L.) germplasm within the U.S. collection assessed with EST-SSR markers

Science.gov (United States)

Castor is an important oilseed crop and although its oil is inedible, it has multiple industrial and pharmaceutical applications. The entire U.S. castor germplasm collection was previously screened for oil content and fatty acid composition, but its genetic diversity and population structure has not...

Identification of several gy4 nulls from the USDA soybean germplasm collection provides new genetic resources for the development of high-quality tofu cultivars.

Science.gov (United States)

Kim, Won-Seok; Ho, Heo Jae; Nelson, Randall L; Krishnan, Hari B

2008-12-10

Tofu, a cheese-like food made by curdling soy milk, is a major dietary staple of Asian countries. Consumption of tofu and other soy products is steadily increasing in North America due to its well-known health benefits. Soybean A(5), A(4), and B(3) peptide null lines 'Enrei' and 'Raiden' are commonly utilized in breeding programs to develop high-quality tofu cultivars. To expand the genetic diversity it is desirable to identify and utilize other A(5), A(4), and B(3) null genotypes in the development of improved tofu cultivars that are adapted to North American conditions. In this study were screened diverse soybean accessions from the USDA Soybean Germplasm Collection to identify Gy4 mutants, the locus that controls A(5), A(4), and B(3) peptide production. Analysis of total seed proteins from 485 soybean lines by SDS-PAGE enabled the identification of 38 accessions that lacked the A(5), A(4), and B(3) peptides. These accessions showed marked differences in seed size and seed coat color and represented different maturity groups ranging from 0 to IX. To ascertain the molecular basis for the lack of A(5), A(4), and B(3) peptides in the newly identified Gy4 mutants, the nucleotide sequence of a portion of the Gy4 gene was determined from eight soybean accessions representing different maturity groups. These eight Gy4 mutants revealed a single point mutation that changed the translation initiation codon ATG to ATA, resulting in the A(5), A(4), and B(3) null phenotype. The newly identified Gy4 mutants from this study will enable plant breeders to expand the genetic diversity of North American food-quality soybeans and also aid in the development of hypoallergenic soybeans.

Genetic Diversity and Population Structure in Aromatic and Quality Rice (Oryza sativa L. Landraces from North-Eastern India.

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Somnath Roy

Full Text Available The North-eastern (NE India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, possess diverse array of locally adapted non-Basmati aromatic germplasm. The germplasm collections from this region could serve as valuable resources in breeding for abiotic stress tolerance, grain yield and cooking/eating quality. To utilize such collections, however, breeders need information about the extent and distribution of genetic diversity present within collections. In this study, we report the result of population genetic analysis of 107 aromatic and quality rice accessions collected from different parts of NE India, as well as classified these accessions in the context of a set of structured global rice cultivars. A total of 322 alleles were amplified by 40 simple sequence repeat (SSR markers with an average of 8.03 alleles per locus. Average gene diversity was 0.67. Population structure analysis revealed that NE Indian aromatic rice can be subdivided into three genetically distinct population clusters: P1, joha rice accessions from Assam, tai rices from Mizoram and those from Sikkim; P2, aromatic rice accessions from Nagaland; and P3, chakhao rice germplasm from Manipur [corrected]. Pair-wise FST between three groups varied from 0.223 (P1 vs P2 to 0.453 (P2 vs P3. With reference to the global classification of rice cultivars, two major groups (Indica and Japonica were identified in NE Indian germplasm. The aromatic accessions from Assam, Manipur and Sikkim were assigned to the Indica group, while the accessions from Nagaland exhibited close association with Japonica. The tai accessions of Mizoram along with few chakhao accessions collected from the hill districts of Manipur were identified as admixed. The results highlight the importance of regional genetic studies for understanding diversification of aromatic rice in India. The data also suggest that there is scope for exploiting the genetic diversity of

Genetic Diversity and Population Structure in Aromatic and Quality Rice (Oryza sativa L.) Landraces from North-Eastern India.

Science.gov (United States)

Roy, Somnath; Banerjee, Amrita; Mawkhlieng, Bandapkuper; Misra, A K; Pattanayak, A; Harish, G D; Singh, S K; Ngachan, S V; Bansal, K C

2015-01-01

The North-eastern (NE) India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, possess diverse array of locally adapted non-Basmati aromatic germplasm. The germplasm collections from this region could serve as valuable resources in breeding for abiotic stress tolerance, grain yield and cooking/eating quality. To utilize such collections, however, breeders need information about the extent and distribution of genetic diversity present within collections. In this study, we report the result of population genetic analysis of 107 aromatic and quality rice accessions collected from different parts of NE India, as well as classified these accessions in the context of a set of structured global rice cultivars. A total of 322 alleles were amplified by 40 simple sequence repeat (SSR) markers with an average of 8.03 alleles per locus. Average gene diversity was 0.67. Population structure analysis revealed that NE Indian aromatic rice can be subdivided into three genetically distinct population clusters: P1, joha rice accessions from Assam, tai rices from Mizoram and those from Sikkim; P2, aromatic rice accessions from Nagaland; and P3, chakhao rice germplasm from Manipur [corrected]. Pair-wise FST between three groups varied from 0.223 (P1 vs P2) to 0.453 (P2 vs P3). With reference to the global classification of rice cultivars, two major groups (Indica and Japonica) were identified in NE Indian germplasm. The aromatic accessions from Assam, Manipur and Sikkim were assigned to the Indica group, while the accessions from Nagaland exhibited close association with Japonica. The tai accessions of Mizoram along with few chakhao accessions collected from the hill districts of Manipur were identified as admixed. The results highlight the importance of regional genetic studies for understanding diversification of aromatic rice in India. The data also suggest that there is scope for exploiting the genetic diversity of aromatic and

Assessment of genetic diversity in indigenous turmeric (Curcuma longa) germplasm from India using molecular markers.

Science.gov (United States)

Verma, Sushma; Singh, Shweta; Sharma, Suresh; Tewari, S K; Roy, R K; Goel, A K; Rana, T S

2015-04-01

Curcuma longa L., commonly known as turmeric, is one of the economically and medicinally important plant species. It is predominantly cultivated in the tropical and sub tropical countries. India is the largest producer, and exporter of turmeric in the world, followed by China, Indonesia, Bangladesh and Thailand. In the present study, Directed Amplification of Minisatellite DNA (DAMD) and Inter Simple Sequence Repeats (ISSR), methods were used to estimate the genetic variability in indigenous turmeric germplasm. Cumulative data analysis for DAMD (15) and ISSR (13) markers resulted into 478 fragments, out of which 392 fragments were polymorphic, revealing 82 % polymorphism across the turmeric genotypes. Wide range of pairwise genetic distances (0.03-0.59) across the genotypes revealed that these genotypes are genetically quite diverse. The UPGMA dendrogram generated using cumulative data showed significant relationships amongst the genotypes. All 29 genotypes studied grouped into two clusters irrespective of their geographical affiliations with 100 % bootstrap value except few genotypes, suggesting considerable diversity amongst the genotypes. These results suggested that the current collection of turmeric genotypes preserve the vast majority of natural variations. The results further demonstrate the efficiency and reliability of DAMD and ISSR markers in determining the genetic diversity and relationships among the indigenous turmeric germplasm. DAMD and ISSR profiling have identified diverse turmeric genotypes, which could be further utilized in various genetic improvement programmes including conventional as well as marker assisted breeding towards development of new and desirable turmeric genotypes.

The systematic description of cacao clones and its significance for taxonomy and plant breeding

NARCIS (Netherlands)

Engels, J.M.M.

1986-01-01

The value of germplasm collections depends to a large extent on the data accompanying the individual accessions. In order to facilitate the selection of the most useful characters for the systematic description of a cacao germplasm collection methods were developed to measure and to compare

Characterization of Indian and exotic quality protein maize (QPM ...

African Journals Online (AJOL)

Polymorphism analysis and genetic diversity of normal maize and quality protein maize (QPM) inbreds among locally well adapted germplasm is a prerequisite for hybrid maize breeding program. The diversity analyses of 48 maize accessions including Indian and exotic germplasm using 75 simple sequence repeat (SSR) ...

Evaluation of Resistance to Ralstonia solanacearum in Tomato Genetic Resources at Seedling Stage

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Sang Gyu Kim

2016-02-01

Full Text Available Bacterial wilt of tomatoes caused by Ralstonia solanacearum is a devastating disease that limits the production of tomato in Korea. The best way to control this disease is using genetically resistant tomato plant. The resistance degree to R. solanacearum was evaluated for 285 tomato accessions conserved in the National Agrobiodiversity Center of Rural Development Administration. These accessions of tomato were originated from 23 countries. Disease severity of tomato accessions was investigated from 7 days to 14 days at an interval of 7 days after inoculation of R. solanacearum under greenhouse conditions. A total of 279 accessions of tomato germplasm were susceptible to R. solanacearum, resulting in wilt and death in 70 to 90% of these plants. Two tomato accessions were moderately resistant to R. solanacearum. Only four accessions showed high resistance against R. solanacearum. No distinct symptom of bacterial wilt appeared on the resistant tomato germplasms for up to 14 days after inoculation of R. solanacearum. Microscopy of resistant tomato stems infected with R. solanacearum revealed limited bacterial spread with thickening of pit membrane and gum production. Therefore, these four resistant tomato germplasms could be used in tomato breeding program against bacterial wilt.

Watermelon germplasm lines USVL246-FR2 and USVL252-FR2 tolerant to fusarium oxysporum f. sp. niveum race 2

Science.gov (United States)

Two improved germplasm lines of wild watermelon (Citrullus lanatus var. citroides) designated USVL246-FR2 and USVL252-FR2 were released in 2012 by the Agricultural Research Service of the U.S. Department of Agriculture (Wechter et al. 2012). These lines are each highly uniform for growth characteri...

Molecular Insights into the Genetic Diversity of Hemarthria compressa Germplasm Collections Native to Southwest China

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Zhi-Hui Guo

2014-12-01

Full Text Available Start codon targeted polymorphism (SCoT analysis was employed to distinguish 37 whipgrass (Hemarthria compressa L. clones and assess the genetic diversity and population structure among these genotypes. The informativeness of markers was also estimated using various parameters. Using 25 highly reproducible primer sets, 368 discernible fragments were generated. Of these, 282 (77.21% were polymorphic. The number of alleles per locus ranged from five to 21, and the genetic variation indices varied. The polymorphism information content (PIC was 0.358, the Shannon diversity index (H was 0.534, the marker index (MI was 4.040, the resolving power (RP was 6.108, and the genotype index (GI was 0.782. Genetic similarity coefficients (GS between the accessions ranged from 0.563 to 0.872, with a mean of 0.685. Their patterns observed in a dendrogram constructed using the unweighted pair group method with arithmetic mean analysis (UPGMA based on GS largely confirmed the results of principal coordinate analysis (PCoA. PCoA was further confirmed by Bayesian model-based STRUCTURE analysis, which revealed no direct association between genetic relationship and geographical origins as validated by Mantel’s test (r = 0.2268, p = 0.9999. In addition, high-level genetic variation within geographical groups was significantly greater than that between groups, as determined by Shannon diversity analysis, analysis of molecular variance (AMOVA and Bayesian analysis. Overall, SCoT analysis is a simple, effective and reliable technique for characterizing and maintaining germplasm collections of whipgrass and related species.

Analysis of the Genetic Diversity and Population Structure of Austrian and Belgian Wheat Germplasm within a Regional Context Based on DArT Markers

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Mohamed A. El-Esawi

2018-01-01

Full Text Available Analysis of crop genetic diversity and structure provides valuable information needed to broaden the narrow genetic base as well as to enhance the breeding and conservation strategies of crops. In this study, 95 Austrian and Belgian wheat cultivars maintained at the Centre for Genetic Resources (CGN in the Netherlands were characterised using 1052 diversity array technology (DArT markers to evaluate their genetic diversity, relationships and population structure. The rarefacted allelic richness recorded in the Austrian and Belgian breeding pools (A25 = 1.396 and 1.341, respectively indicated that the Austrian germplasm contained a higher genetic diversity than the Belgian pool. The expected heterozygosity (HE values of the Austrian and Belgian pools were 0.411 and 0.375, respectively. Moreover, the values of the polymorphic information content (PIC of the Austrian and Belgian pools were 0.337 and 0.298, respectively. Neighbour-joining tree divided each of the Austrian and Belgian germplasm pools into two genetically distinct groups. The structure analyses of the Austrian and Belgian pools were in a complete concordance with their neighbour-joining trees. Furthermore, the 95 cultivars were compared to 618 wheat genotypes from nine European countries based on a total of 141 common DArT markers in order to place the Austrian and Belgian wheat germplasm in a wider European context. The rarefacted allelic richness (A10 varied from 1.224 (Denmark to 1.397 (Austria. Cluster and principal coordinates (PCoA analyses divided the wheat genotypes of the nine European countries into two main clusters. The first cluster comprised the Northern and Western European wheat genotypes, whereas the second included the Central European cultivars. The structure analysis of the 618 European wheat genotypes was in a complete concordance with the results of cluster and PCoA analyses. Interestingly, a highly significant difference was recorded between regions (26.53%. In

Revealing the Diversity of Introduced Coffea canephora Germplasm in Ecuador: Towards a National Strategy to Improve Robusta

OpenAIRE

Loor Solórzano, Rey Gastón; De Bellis, Fabien; Leroy, Thierry; Plaza, Luis; Guerrero, Hilton; Subia, Cristian; Calderón, Darío; Fernández, Fabián; Garzón, Iván; Lopez, Diana; Vera, Danilo

2017-01-01

Genetic resources of Coffea canephora have been introduced in several tropical countries with potential for crop development. In Ecuador, the species has been cultivated since the mid-20th century. However, little is known about the diversity and genetic structure of introduced germplasm. This paper provides an overview of the genetic and phenotypic diversity of C. canephora in Ecuador and some proposals for implementing a breeding program. Twelve SSR markers were used to analyze 1491 plants ...

Identification of Rice Accessions Associated with K+/Na+ Ratio and Salt Tolerance Based on Physiological and Molecular Responses

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Inja Naga Bheema Lingeswara Reddy

2017-11-01

Full Text Available The key for rice plant survival under NaCl salt stress is maintaining a high K+/Na+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K+/Na+ ratios. Seventeen SSR markers reported to be associated with K+/Na+ ratio were used to screen the accessions. Five SSR markers (RM8053, RM345, RM318, RM253 and RM7075 could differentiate accessions classified based on their K+/Na+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K+/Na+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

Diversity and genetic structure of jenipapo (Genipa americana L. Brazilian accessions

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Ana Veruska Cruz da Silva

2014-10-01

Full Text Available Usually known as jenipapo, Genipa americana L. is a Rubiaceae Brazilian native species. It is an important species in the restoration of Brazilian riparian forests and is one of the most promising fruit trees for sustainable harvesting programs. In this study we provide the first data on the genetic diversity and structure of a Jenipapo Germplasm Bank using inter simple sequence repeat (ISSR markers. We evaluated 160 accessions from wild populations, and the data generated from 12 ISSR primers were used to determine genetic variability via a model-based Bayesian procedure (Structure and molecular variance analysis. In addition, Shannon index, genetic diversity and Jaccard coefficients were estimated. A total of 12 primers were used, which generated 123 polymorphic fragments. Four groups were formed from the analysis of the fragments, and the CR1-2 genotype was isolated, being more divergent than the other genotypes.

Determination of genetic diversity among some almond accessions

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Pinar Hasan

2015-01-01

Full Text Available More recently the use of different molecular markers in fruit species to determine particularly genetic diversity, genetic relationships and cultivar identification has been gained more importance. In the study, 13 randomly amplified polimorfic DNA (RAPD and 4 inter-simple sequence repeat (ISSR markers were used to evaluate genetic relationships among 95 almong accessions (26 foreign cultivars and 69 national cultivars and selections. The all plant material found in Almond Germplasm Repository in Gaziantep, Turkey. Both RAPD and ISSR markers distinguished the almond cultivars and selections in various levels. 17 RAPD and ISSR markers yielded a total of 73 scorable bands, which 51 are polymorphic. The two marker system exhibited variation with regard to average band sizes and polymorphism ratio. The average polymorphism was higher in ISSR (88% compared to RAPD (74%. RAPD and ISSR marker systems were found to be useful for determining genetic diversity among almong genotypes and cultivars. Combining of two dendrograms obtained through these markers show different clustering of 96 almond specimens without geographical isolation. These results supported that almonds in Turkey indicated considerable genetic diversity.

Introduction and Utilization of INGER Rice Germplasm in China

Institute of Scientific and Technical Information of China (English)

TANGSheng-xiang; WEIXing-hua; ELJavier

2004-01-01

The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5 million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

Introduction and Utilization of INGER Rice Germplasm in China

Institute of Scientific and Technical Information of China (English)

TANG Sheng-xiang; WEI Xing-hua; E L Javier

2004-01-01

The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

Genetic Variation of Flavonols Quercetin, Myricetin, and Kaempferol in the Sri Lankan Tea (Camellia sinensis L. and Their Health-Promoting Aspects

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Brasathe Jeganathan

2016-01-01

Full Text Available Flavonol glycosides in tea leaves have been quantified as aglycones, quercetin, myricetin, and kaempferol. Occurrence of the said compounds was reported in fruits and vegetable for a long time in association with the antioxidant potential. However, data on flavonols in tea were scanty and, hence, this study aims to envisage the flavonol content in a representative pool of accessions present in the Sri Lankan tea germplasm. Significant amounts of myricetin, quercetin, and kaempferol have been detected in the beverage type tea accessions of the Sri Lankan tea germplasm. This study also revealed that tea is a good source of flavonol glycosides. The Camellia sinensis var. sinensis showed higher content of myricetin, quercetin, and total flavonols than var. assamica and ssp. lasiocalyx. Therefore flavonols and their glycosides can potentially be used in chemotaxonomic studies of tea germplasm. The nonbeverage type cultivars, especially Camellia rosaflora and Camellia japonica Red along with the exotic accessions resembling China type, could be useful in future germplasm studies because they are rich sources of flavonols, namely, quercetin and kaempferol, which are potent antioxidants. The flavonol profiles can be effectively used in choosing parents in tea breeding programmes to generate progenies with a wide range of flavonol glycosides.

New Germplasms of the Culinary-Medicinal Button Mushroom, Agaricus bisporus (Agaricomycetes): Two Wild Strains from the Tibetan Plateau (China).

Science.gov (United States)

Li, Bin-Bin; Jiang, Si-Ping; Xu, Ai-Guo; Dorji, Phurbu; Wang, Wen-Jing; Wang, Xiao-Liang; Wei, Tie-Zheng; Zhang, Zu-Tang; Yao, Yi-Jian

2017-01-01

Agaricus bisporus is one of the most important commercially cultivated culinary-medicinal mushrooms worldwide. In China, most of the cultivated strains of the fungus were introduced from other countries and cultivated in the eastern provinces. In this study, 2 wild strains of A. bisporus, 2091 and 2094, isolated from fresh specimens collected from the Tibetan Plateau, were domesticated and cultivated alongside a commercial hybrid strain, As2796, in Lhasa, China, for comparison in order to provide new germplasms for cultivation. Basic characteristics, mushroom yield, dry weight, polysaccharide contents, and antioxidant activities of the tested strains were analyzed. Compared with strain As2796, the 2 wild strains displayed good values for mycelial growth, time to fruiting, mushroom yield, dry weight, and polysaccharide contents, and their basidiomata had distinct morphological characteristics (e.g., brown or pale brown caps with some white scales). In addition, the antioxidant activities (reducing power and DPPH radical scavenging effect) of strain 2094 were significantly higher than those of the other 2 strains. Domestication of the 2 wild strains would add more genetic variation into the germplasm of A. bisporus for cultivation, especially in China, and might help to address the problem inherent to the nearly monoculture crop lacking genetic diversity in China.

Unraveling the genetic structure of Brazilian commercial sugarcane cultivars through microsatellite markers.

Science.gov (United States)

Manechini, João Ricardo Vieira; da Costa, Juliana Borges; Pereira, Bruna Turcatto; Carlini-Garcia, Luciana Aparecida; Xavier, Mauro Alexandre; Landell, Marcos Guimarães de Andrade; Pinto, Luciana Rossini

2018-01-01

The Brazilian sugarcane industry plays an important role in the worldwide supply of sugar and ethanol. Investigation into the genetic structure of current commercial cultivars and comparisons to the main ancestor species allow sugarcane breeding programs to better manage crosses and germplasm banks as well as to promote its rational use. In the present study, the genetic structure of a group of Brazilian cultivars currently grown by commercial producers was assessed through microsatellite markers and contrasted with a group of basic germplasm mainly composed of Saccharum officinarum and S. spontaneum accessions. A total of 285 alleles was obtained by a set of 12 SSRs primer pairs that taken together were able to efficiently distinguish and capture the genetic variability of sugarcane commercial cultivars and basic germplasm accessions allowing its application in a fast and cost-effective way for routine cultivar identification and management of sugarcane germplasm banks. Allelic distribution revealed that 97.6% of the cultivar alleles were found in the basic germplasm while 42% of the basic germplasm alleles were absent in cultivars. Of the absent alleles, 3% was exclusive to S. officinarum, 33% to S. spontaneum and 19% to other species/exotic hybrids. We found strong genetic differentiation between the Brazilian commercial cultivars and the two main species (S. officinarum: [Formula: see text] = 0.211 and S. spontaneum: [Formula: see text] = 0.216, Pcommercial cultivars. Average dissimilarity within cultivars was 1.2 and 1.4 times lower than that within S. officinarum and S. spontaneum. Genetic divergence found between cultivars and S. spontaneum accessions has practical applications for energy cane breeding programs as the choice of more divergent parents will maximize the frequency of transgressive individuals in the progeny.

Caracterización mediante microsatélites de 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de Corpoica-Palmira Genetic characterization using microsatellites of 34 accessions of the orange, Citrus sinensis L. Osbeck from the Germplasm bank of Corpoica-Palmira

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Yacenia Morillo Coronado

2010-01-01

Full Text Available Se utilizaron 19 marcadores microsatélites para caracterizar 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de la Corporación Colombiana de Investigación Agropecuaria (Corpoica-Palmira. Seis marcadores fueron polimórficos, los de mayor heterocigosidad fueron CCSM- 19 (0.4097 y CCSM-3 (0.3254. Se diferenciaron 33 accesiones y al 85% de similitud, con el índice de Nei-Li y el método de agrupamiento UPGMA, se conformaron cuatro grupos. En el primero se situaron dos accesiones blancas (Lerma y Valencia Olinda 2, en el segundo la mayoría de las blancas (Indian River, Valencia Olinda, Wialua, Lima Dulce, Pera del Río, St. Michael, Enterprise, Cafetera No. 1 junto con García Valencia y Navel (Lane Late, Valle Washington, New Hall y dos sanguinas (Rudy Blood, Moro Blood, en el tercero accesiones blancas (Joppa, Salerma, Cuban Queen, Rico, Galicia, Star Calyx, Valencia Cutter, Valencia Frost, Valencia Campbell y Valencia Variegado y una sola accesión sanguina (Morocco Blood. En el cuarto grupo se situaron dos accesiones blancas, (Jaffa y Valencia 1-D-E. Finalmente, la variedad Sanguinella no hizo parte de grupos. Con los marcadores microsatélites no se encontró relación entre los grupos genéticos, formación y las características morfológicas del grupo.To characterize 34 orange accessions Citrus sinensis L. Osbeck from the Germplasm bank Corpoica- Palmira, 19 microsatellite markers were used. Six markers were polymorphic; the highest heterozygosity was obtained by CCSM-19 (0.4097 and CCSM-3 (0.3254. Thirty-three accessions were differentiated; with 85% of similarity, Nei-Li´s index and the UPGMA clustering method were formed fi ve groups. In the first one, two accessions were white (Lerma and Valencia Olinda 2, in the second one most of the white (Indian River, Valencia Olinda, Wialua, Lima Dulce, Pera del Río, St. Michael, Enterprise, Cafetera No. 1, García Valencia and Navel (Lane Late, Valle Washington

High Throughput Sequencing of Small RNAs in the Two Cucurbita Germplasm with Different Sodium Accumulation Patterns Identifies Novel MicroRNAs Involved in Salt Stress Response.

Science.gov (United States)

Xie, Junjun; Lei, Bo; Niu, Mengliang; Huang, Yuan; Kong, Qiusheng; Bie, Zhilong

2015-01-01

MicroRNAs (miRNAs), a class of small non-coding RNAs, recognize their mRNA targets based on perfect sequence complementarity. MiRNAs lead to broader changes in gene expression after plants are exposed to stress. High-throughput sequencing is an effective method to identify and profile small RNA populations in non-model plants under salt stresses, significantly improving our knowledge regarding miRNA functions in salt tolerance. Cucurbits are sensitive to soil salinity, and the Cucurbita genus is used as the rootstock of other cucurbits to enhance salt tolerance. Several cucurbit crops have been used for miRNA sequencing but salt stress-related miRNAs in cucurbit species have not been reported. In this study, we subjected two Cucurbita germplasm, namely, N12 (Cucurbita. maxima Duch.) and N15 (Cucurbita. moschata Duch.), with different sodium accumulation patterns, to Illumina sequencing to determine small RNA populations in root tissues after 4 h of salt treatment and control. A total of 21,548,326 and 19,394,108 reads were generated from the control and salt-treated N12 root tissues, respectively. By contrast, 19,108,240 and 20,546,052 reads were obtained from the control and salt-treated N15 root tissues, respectively. Fifty-eight conserved miRNA families and 33 novel miRNAs were identified in the two Cucurbita germplasm. Seven miRNAs (six conserved miRNAs and one novel miRNAs) were up-regulated in salt-treated N12 and N15 samples. Most target genes of differentially expressed novel miRNAs were transcription factors and salt stress-responsive proteins, including dehydration-induced protein, cation/H+ antiporter 18, and CBL-interacting serine/threonine-protein kinase. The differential expression of miRNAs between the two Cucurbita germplasm under salt stress conditions and their target genes demonstrated that novel miRNAs play an important role in the response of the two Cucurbita germplasm to salt stress. The present study initially explored small RNAs in the

High Throughput Sequencing of Small RNAs in the Two Cucurbita Germplasm with Different Sodium Accumulation Patterns Identifies Novel MicroRNAs Involved in Salt Stress Response.

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Junjun Xie

Full Text Available MicroRNAs (miRNAs, a class of small non-coding RNAs, recognize their mRNA targets based on perfect sequence complementarity. MiRNAs lead to broader changes in gene expression after plants are exposed to stress. High-throughput sequencing is an effective method to identify and profile small RNA populations in non-model plants under salt stresses, significantly improving our knowledge regarding miRNA functions in salt tolerance. Cucurbits are sensitive to soil salinity, and the Cucurbita genus is used as the rootstock of other cucurbits to enhance salt tolerance. Several cucurbit crops have been used for miRNA sequencing but salt stress-related miRNAs in cucurbit species have not been reported. In this study, we subjected two Cucurbita germplasm, namely, N12 (Cucurbita. maxima Duch. and N15 (Cucurbita. moschata Duch., with different sodium accumulation patterns, to Illumina sequencing to determine small RNA populations in root tissues after 4 h of salt treatment and control. A total of 21,548,326 and 19,394,108 reads were generated from the control and salt-treated N12 root tissues, respectively. By contrast, 19,108,240 and 20,546,052 reads were obtained from the control and salt-treated N15 root tissues, respectively. Fifty-eight conserved miRNA families and 33 novel miRNAs were identified in the two Cucurbita germplasm. Seven miRNAs (six conserved miRNAs and one novel miRNAs were up-regulated in salt-treated N12 and N15 samples. Most target genes of differentially expressed novel miRNAs were transcription factors and salt stress-responsive proteins, including dehydration-induced protein, cation/H+ antiporter 18, and CBL-interacting serine/threonine-protein kinase. The differential expression of miRNAs between the two Cucurbita germplasm under salt stress conditions and their target genes demonstrated that novel miRNAs play an important role in the response of the two Cucurbita germplasm to salt stress. The present study initially explored small

Genetic diversity in a collection of ornamental squash (Cucurbita pepo L.

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Mladenović Emina

2014-01-01

Full Text Available The aim of this study is collecting and preserving of unique Cucurbita pepo germplasm in Serbia. This study also describes the intraspecific variation of C. pepo within twenty germplasm accessions. Conservation work aimed to develop a representative core collection of C. pepo germplasm, to guide future studies and breeding of its ornamental use. A wide range of C. pepo germplasm was collected from diferent parts of the world. Nineteen variables were recorded in 20 varieties to determine the overall degree of polymorphism and to detect similarities among them. Qualitative traits of fruit such is shape, color and texture, showed immense variation. Coefficient of variation were highest for fruit length, fruit weight and number of fruits per plant (CV=56.69161.32%, while they were the lowest for leaf length (CV=20.65%. Morphological characterization is need to facilitate the use of C. pepo varieties in breeding work. Based on the PCA results, 20 accessions of squash are separate in five groups. Those groups are unique in qualitative and quantitative traits. Knowledge of genetic divergence among varieties is essential for breeding.

Estimation of genetic divergence in rice (oryza sativa l) germplasms on the basis of paddy yield and rice stem borer's (pyralidae: lepidoptera) resistance

International Nuclear Information System (INIS)

Sarwar, M.

2013-01-01

Field trials were carried out to estimate resistance along with paddy yield in 55 rice germplasm lines (35 aromatic and 20 non-aromatic genotypes) for rice stem borers (Pyralidae: Lepidoptera) to expose their potential in pest management approach. The results expressed significant differences for pest damage build-up and paddy yield among the rice germplasm lines. The findings clearly portrayed that based upon the percentage of pest invasions (dead hearts and white heads damage), no genotype was exclusively resistant to stem borers damage under field conditions. Two aromatic genotypes, Jajai-15A/97 and Basmati-Cr-34, exhibited least borers prevalence and amplified paddy yield while Sonehri Sugdasi (P) and Sada Gulab (P) pointed out a peak pest invasion and declined paddy yield. The estimation of pest incidence build-up and paddy productivity within non-aromatic genotypes confirmed that IR8 (P), IR6-15-2 and IR6 (P) were mainly proficient for bearing condensed pest invasion and augmented paddy yield. IR8-2.5-4, IR6-15-10 and IR6-20-9 demonstrated elevated pest susceptibility and gave poor yield. Rest of the germplasms appeared to be least tolerant or vulnerable to pest build-up and reduced paddy production. The tolerant and high yielding genotypes should be popularised in rice borers endemic areas and can be used in varietals resistance breeding strategy. The outcome of current studies necessitates the integration of existing host plant tolerance along with other management strategies to accomplish a suitable control of rice stem borers and enhance paddy yield. (author)

Characterizing the population structure and genetic diversity of maize breeding germplasm in Southwest China using genome-wide SNP markers.

Science.gov (United States)

Zhang, Xiao; Zhang, Hua; Li, Lujiang; Lan, Hai; Ren, Zhiyong; Liu, Dan; Wu, Ling; Liu, Hailan; Jaqueth, Jennifer; Li, Bailin; Pan, Guangtang; Gao, Shibin

2016-08-31

Maize breeding germplasm used in Southwest China has high complexity because of the diverse ecological features of this area. In this study, the population structure, genetic diversity, and linkage disequilibrium decay distance of 362 important inbred lines collected from the breeding program of Southwest China were characterized using the MaizeSNP50 BeadChip with 56,110 single nucleotide polymorphisms (SNPs). With respect to population structure, two (Tropical and Temperate), three (Tropical, Stiff Stalk and non-Stiff Stalk), four [Tropical, group A germplasm derived from modern U.S. hybrids (PA), group B germplasm derived from modern U.S. hybrids (PB) and Reid] and six (Tropical, PB, Reid, Iowa Stiff Stalk Synthetic, PA and North) subgroups were identified. With increasing K value, the Temperate group showed pronounced hierarchical structure with division into further subgroups. The Genetic Diversity of each group was also estimated, and the Tropical group was more diverse than the Temperate group. Seven low-genetic-diversity and one high-genetic-diversity regions were collectively identified in the Temperate, Tropical groups, and the entire panel. SNPs with significant variation in allele frequency between the Tropical and Temperate groups were also evaluated. Among them, a region located at 130 Mb on Chromosome 2 showed the highest genetic diversity, including both number of SNPs with significant variation and the ratio of significant SNPs to total SNPs. Linkage disequilibrium decay distance in the Temperate group was greater (2.5-3 Mb) than that in the entire panel (0.5-0.75 Mb) and the Tropical group (0.25-0.5 Mb). A large region at 30-120 Mb of Chromosome 7 was concluded to be a region conserved during the breeding process by comparison between S37, which was considered a representative tropical line in Southwest China, and its 30 most similar derived lines. For the panel covered most of widely used inbred lines in Southwest China, this work

A web accessible resource for investigating cassava phenomics and genomics information: BIOGEN BASE.

Science.gov (United States)

Jayakodi, Murukarthick; Selvan, Sreedevi Ghokhilamani; Natesan, Senthil; Muthurajan, Raveendran; Duraisamy, Raghu; Ramineni, Jana Jeevan; Rathinasamy, Sakthi Ambothi; Karuppusamy, Nageswari; Lakshmanan, Pugalenthi; Chokkappan, Mohan

2011-01-01

The goal of our research is to establish a unique portal to bring out the potential outcome of the research in the Casssava crop. The Biogen base for cassava clearly brings out the variations of different traits of the germplasms, maintained at the Tapioca and Castor Research Station, Tamil Nadu Agricultural University. Phenotypic and genotypic variations of the accessions are clearly depicted, for the users to browse and interpret the variations using the microsatellite markers. Database (BIOGEN BASE - CASSAVA) is designed using PHP and MySQL and is equipped with extensive search options. It is more user-friendly and made publicly available, to improve the research and development of cassava by making a wealth of genetics and genomics data available through open, common, and worldwide forum for all individuals interested in the field. The database is available for free at http://www.tnaugenomics.com/biogenbase/casava.php.

The draft genome of watermelon (Citrullus lanatus) and resequencing of 20 diverse accessions.

Science.gov (United States)

Guo, Shaogui; Zhang, Jianguo; Sun, Honghe; Salse, Jerome; Lucas, William J; Zhang, Haiying; Zheng, Yi; Mao, Linyong; Ren, Yi; Wang, Zhiwen; Min, Jiumeng; Guo, Xiaosen; Murat, Florent; Ham, Byung-Kook; Zhang, Zhaoliang; Gao, Shan; Huang, Mingyun; Xu, Yimin; Zhong, Silin; Bombarely, Aureliano; Mueller, Lukas A; Zhao, Hong; He, Hongju; Zhang, Yan; Zhang, Zhonghua; Huang, Sanwen; Tan, Tao; Pang, Erli; Lin, Kui; Hu, Qun; Kuang, Hanhui; Ni, Peixiang; Wang, Bo; Liu, Jingan; Kou, Qinghe; Hou, Wenju; Zou, Xiaohua; Jiang, Jiao; Gong, Guoyi; Klee, Kathrin; Schoof, Heiko; Huang, Ying; Hu, Xuesong; Dong, Shanshan; Liang, Dequan; Wang, Juan; Wu, Kui; Xia, Yang; Zhao, Xiang; Zheng, Zequn; Xing, Miao; Liang, Xinming; Huang, Bangqing; Lv, Tian; Wang, Junyi; Yin, Ye; Yi, Hongping; Li, Ruiqiang; Wu, Mingzhu; Levi, Amnon; Zhang, Xingping; Giovannoni, James J; Wang, Jun; Li, Yunfu; Fei, Zhangjun; Xu, Yong

2013-01-01

Watermelon, Citrullus lanatus, is an important cucurbit crop grown throughout the world. Here we report a high-quality draft genome sequence of the east Asia watermelon cultivar 97103 (2n = 2× = 22) containing 23,440 predicted protein-coding genes. Comparative genomics analysis provided an evolutionary scenario for the origin of the 11 watermelon chromosomes derived from a 7-chromosome paleohexaploid eudicot ancestor. Resequencing of 20 watermelon accessions representing three different C. lanatus subspecies produced numerous haplotypes and identified the extent of genetic diversity and population structure of watermelon germplasm. Genomic regions that were preferentially selected during domestication were identified. Many disease-resistance genes were also found to be lost during domestication. In addition, integrative genomic and transcriptomic analyses yielded important insights into aspects of phloem-based vascular signaling in common between watermelon and cucumber and identified genes crucial to valuable fruit-quality traits, including sugar accumulation and citrulline metabolism.

Genetic evolution and utilization of wheat germplasm resources in Huanghuai winter wheat region of China

International Nuclear Information System (INIS)

Xiyong, C.; Haixia, X.U.; Feng, C.

2011-01-01

To determine the genetic variation of wheat germplasm resources and improve their use in wheat breeding, 215 wheat cultivars and advanced lines from the Huanghuai Wheat Region of China were used to identify 14 agronomic traits and 7 quality traits, as well as the evolution and utilization of high molecular weight glutenin subunits (HMW-GS) and low molecular weight-glutenin subunits (LMW-GS). From land race cultivars to current cultivars there had been significant increases in grain numbers spike/sip -1/, grain weight spike/sup -1/, 1000-kernel weight, grain weight plant/sup -1/, spikelet number spike/sup -1/, sterile spikelet numbers spike/sup -1/, flag leaf width, and flag leaf area. There had been significant decreases in spike number plant/sup -1/, plant height, the first inter node length, flag leaf length, kernel protein content and wet gluten content. Based on Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results, a novel HMW-GS combination 20/8 was identified in 1B chromosome of Chinese landrace cultivar Heputou. Subunits 22, 20/8, 2.2+12, and GluB3a were only found in cultivars before the 1960s, and subunits 6+8, 13+16, 3+12, and 4+12 were only found in the cultivars after the 1980s. The average diversity index of 21 traits and allele variance of HMW-GS showed a decreasing-increasing-decreasing tendency. HMW-GS and LMW-GS combination-type cultivars showed an increasing-decreasing tendency. Before the 1980s, most parental strains were from foreign cultivars and landrace cultivars, while after the 1980s, most parental strains were from released cultivars and germplasm created by distant hybridization. This study provided useful information for improvement of wheat breeding in Huanghuai winter wheat region. (author)

Exploring potential of pearl millet germplasm association panel for association mapping of drought tolerance traits.

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Deepmala Sehgal

Full Text Available A pearl millet inbred germplasm association panel (PMiGAP comprising 250 inbred lines, representative of cultivated germplasm from Africa and Asia, elite improved open-pollinated cultivars, hybrid parental inbreds and inbred mapping population parents, was recently established. This study presents the first report of genetic diversity in PMiGAP and its exploitation for association mapping of drought tolerance traits. For diversity and genetic structure analysis, PMiGAP was genotyped with 37 SSR and CISP markers representing all seven linkage groups. For association analysis, it was phenotyped for yield and yield components and morpho-physiological traits under both well-watered and drought conditions, and genotyped with SNPs and InDels from seventeen genes underlying a major validated drought tolerance (DT QTL. The average gene diversity in PMiGAP was 0.54. The STRUCTURE analysis revealed six subpopulations within PMiGAP. Significant associations were obtained for 22 SNPs and 3 InDels from 13 genes under different treatments. Seven SNPs associations from 5 genes were common under irrigated and one of the drought stress treatments. Most significantly, an important SNP in putative acetyl CoA carboxylase gene showed constitutive association with grain yield, grain harvest index and panicle yield under all treatments. An InDel in putative chlorophyll a/b binding protein gene was significantly associated with both stay-green and grain yield traits under drought stress. This can be used as a functional marker for selecting high yielding genotypes with 'stay green' phenotype under drought stress. The present study identified useful marker-trait associations of important agronomics traits under irrigated and drought stress conditions with genes underlying a major validated DT-QTL in pearl millet. Results suggest that PMiGAP is a useful panel for association mapping. Expression patterns of genes also shed light on some physiological mechanisms underlying

Molecular characterization of accessions of Cratylia argentea (Camaratuba) using ISSR markers.

Science.gov (United States)

Luz, G A; Gomes, S O; Araujo Neto, R B; Nascimento, M S C B; Lima, P S C

2015-11-27

Cratylia argentea (Desv.) Kuntze (Fabaceae) is a drought-tolerant, perennial legume found primarily in Brazil, Bolivia, and Peru. The shrub is well adapted to acid soils and exhibits high productivity and nutritional value, characteristics that would favor its use as a dry season animal forage supplement in semiarid regions. In plant improvement programs, the production of elite hybrids with superior traits is generally achieved by crossing parents that exhibit the highest level of genetic divergence. Therefore, the aim of the present study was to assess genetic diversity among 13 accessions of C. argentea from the same population maintained in the active germplasm bank of Embrapa Meio-Norte using inter-simple sequence repeat (ISSR) markers. Genetic similarities between C. argentea accessions were estimated from Jaccard coefficients, and a dendrogram was constructed using the unweighted pair group method with arithmetic average (UPGMA). The set of 15 primers selected for ISSR analysis generated a total of 313 loci of which 79.23% were polymorphic. The mean number of bands per primer was 20.87, and the amplicons ranged from 280 to 3000 bp in size. Primers UBC834 and UBC827 generated the largest number of polymorphic loci and exhibited 90.91 and 100% polymorphism, respectively. The coefficients of genetic similarity among accessions varied between 0.49 and 0.73. UPGMA cluster analysis allowed the identification of four genotypic groups and demonstrated the existence of considerable variability within the collection. Potential progenitors were selected that would offer good possibilities of obtaining unusual and favorable combinations of genes in a plant breeding program.

A novel method for conserving cowpea germplasm and breeding stocks using solar disinfestation

Energy Technology Data Exchange (ETDEWEB)

Ntoukam, G.; Kitch, L.W.; Shade, R.E.; Murdock, L.L. [Purdue Univ., Entomology Dept., Lafayette, IN (United States)

1997-10-01

Experiments conducted in Maroua, Cameroon, demonstrated that a large 50-kg-capacity solar heater can be used to successfully eradicate infestations of Callosobruchus maculatus from cowpea seeds kept in small, transparent Minigrip zip lock plastic bags. Temperatures produced inside the heater were sufficient to kill all developing insects living within infested cowpea seeds. Small, transparent ziplock plastic bags are useful seed storage containers for short-term cowpea germplasm collections and are easily inspected during storage following solar disinfestation. Published reports indicate that temperatures of up to 85{sup o}C do not adversely affect seed germination, germination rates, or seeding viability. These temperature and biological experiments provide evidence that the solar heater technique can serve as an effective and practical means to improve the short-term storage of cowpea seeds in developing country national agricultural research programs. (author)

Characterization of molecular diversity and genome-wide mapping of loci associated with resistance to stripe rust and stem rust in Ethiopian bread wheat accessions.

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Muleta, Kebede T; Rouse, Matthew N; Rynearson, Sheri; Chen, Xianming; Buta, Bedada G; Pumphrey, Michael O

2017-08-04

The narrow genetic basis of resistance in modern wheat cultivars and the strong selection response of pathogen populations have been responsible for periodic and devastating epidemics of the wheat rust diseases. Characterizing new sources of resistance and incorporating multiple genes into elite cultivars is the most widely accepted current mechanism to achieve durable varietal performance against changes in pathogen virulence. Here, we report a high-density molecular characterization and genome-wide association study (GWAS) of stripe rust and stem rust resistance in 190 Ethiopian bread wheat lines based on phenotypic data from multi-environment field trials and seedling resistance screening experiments. A total of 24,281 single nucleotide polymorphism (SNP) markers filtered from the wheat 90 K iSelect genotyping assay was used to survey Ethiopian germplasm for population structure, genetic diversity and marker-trait associations. Upon screening for field resistance to stripe rust in the Pacific Northwest of the United States and Ethiopia over multiple growing seasons, and against multiple races of stripe rust and stem rust at seedling stage, eight accessions displayed resistance to all tested races of stem rust and field resistance to stripe rust in all environments. Our GWAS results show 15 loci were significantly associated with seedling and adult plant resistance to stripe rust at false discovery rate (FDR)-adjusted probability (P) rust in the Ethiopian wheat accessions. Many of the identified resistance loci were mapped close to previously identified rust resistance genes; however, three loci on the short arms of chromosomes 5A and 7B for stripe rust resistance and two on chromosomes 3B and 7B for stem rust resistance may be novel. Our results demonstrate that considerable genetic variation resides within the landrace accessions that can be utilized to broaden the genetic base of rust resistance in wheat breeding germplasm. The molecular markers identified in

Characterization for multipurpose exploitations of genetic resources from the germplasm collection of pasture species owned by the CNR-ISPAAM in Sassari, Italy

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Bullitta Simonetta

2010-01-01

Full Text Available This paper reports the results of genetic resources characterization of some pasture species from the germplasm collection held at ISPAAM-CNR in Sassari, Sardinia, Italy. According to the peculiarities of each species, some of the uses suggested by the experimental results were phytoremediation, wildfi re prevention, biomass production for bioenergy, forage production and multiple uses, bioactive compounds for health care of domestic animals.

Best practices for fungal germplasm repositories and perspectives on their implementation.

Science.gov (United States)

Wiest, Aric; Schnittker, Robert; Plamann, Mike; McCluskey, Kevin

2012-02-01

In over 50 years, the Fungal Genetics Stock Center has grown to become a world-recognized biological resource center. Along with this growth comes the development and implementation of myriad practices for the management and curation of a diverse collection of filamentous fungi, yeast, and molecular genetic tools for working with the fungi. These practices include techniques for the testing, manipulation, and preservation of individual fungal isolates as well as for processing of thousands of isolates in parallel. In addition to providing accurate record keeping, an electronic managements system allows the observation of trends in strain distribution and in sample characteristics. Because many ex situ fungal germplasm repositories around the world share similar objectives, best-practice guidelines have been developed by a number of organizations such as the Organization for Economic Cooperation and Development or the International Society for Biological and Environmental Repositories. These best-practice guidelines provide a framework for the successful operation of collections and promote the development and interactions of biological resource centers around the world.

Phenotypic flexibility in exotic quinoa (chenopodium quinoa willd.) germplasm for seedling vigor and viability

International Nuclear Information System (INIS)

Munir, H.; Basra, S.M.A.; Cheema, M.A.

2011-01-01

Exotic quinoa genotypes were evaluated for seedling vigor, viability, heritability, and genotypic and phenotypic variations under lab. conditions. A total of 25 genotypes of quinoa underwent comparison. Distinct demarcation among these genotypes was observed for final germination percentage, mean germination time, time to 50% germination, germination index, root/shoot length and root:shoot ratio. Viable, vigorous genotypes and poorly performing genotypes were identified and grouped from the available exotic germplasm. This selection was made on the assumption that resistance to climatic adversities and better sustainability under poor storage conditions are issues of immense importance in post harvest handling of quinoa seed. For selection of vigorous quinoa genotypes, final germination percentage (more than 90%) and root (more than 3.5 cm) or shoot lengths (more than 4.0 cm) presented themselves as important associated traits, in addition to germination index (22 to 33) and seedling survival percentage (between 90-100%). However, final germination percentage and root length were demonstrated to be reliable and environment-proof traits for the crop. Exotic quinoa genotypes were evaluated for seedling vigor, viability, heritability, and genotypic and phenotypic variations under lab. conditions. A total of 25 genotypes of quinoa underwent comparison. Distinct demarcation among these genotypes was observed for final germination percentage, mean germination time, time to 50% germination, germination index, root/shoot length and root:shoot ratio. Viable, vigorous genotypes and poorly performing genotypes were identified and grouped from the available exotic germplasm. This selection was made on the assumption that resistance to climatic adversities and better sustainability under poor storage conditions are issues of immense importance in post harvest handling of quinoa seed. For selection of vigorous quinoa genotypes, final germination percentage (more than 90%) and

Genetic Diversity in Various Accessions of Pineapple [Ananas comosus (L.) Merr.] Using ISSR and SSR Markers.

Science.gov (United States)

Wang, Jian-Sheng; He, Jun-Hu; Chen, Hua-Rui; Chen, Ye-Yuan; Qiao, Fei

2017-12-01

Inter simple sequence repeat (ISSR) and simple sequence repeat (SSR) markers were used to assess the genetic diversity of 36 pineapple accessions that were introduced from 10 countries/regions. Thirteen ISSR primers amplified 96 bands, of which 91 (93.65%) were polymorphic, whereas 20 SSR primers amplified 73 bands, of which 70 (96.50%) were polymorphic. Nei's gene diversity (h = 0.28), Shannon's information index (I = 0.43), and polymorphism information content (PIC = 0.29) generated using the SSR primers were higher than that with ISSR primers (h =  0.23, I = 0.37, PIC = 0.24), thereby suggesting that the SSR system is more efficient than the ISSR system in assessing genetic diversity in various pineapple accessions. Mean genetic similarities were 0.74, 0.61, and 0.69, as determined using ISSR, SSR, and combined ISSR/SSR, respectively. These results suggest that the genetic diversity among pineapple accessions is very high. We clustered the 36 pineapple accessions into three or five groups on the basis of the phylogenetic trees constructed based on the results of ISSR, SSR, and combined ISSR/SSR analyses using the unweighted pair-group with arithmetic averaging (UPGMA) method. The results of principal components analysis (PCA) also supported the UPGMA clustering. These results will be useful not only for the scientific conservation and management of pineapple germplasm but also for the improvement of the current pineapple breeding strategies.

RELATIONS AMONG WESTERN CORN ROOTWORM RESISTANCE TRAITS AND ELEMENTS CONCENTRATION IN MAIZE GERMPLASM ROOTS

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Andrija Brkić

2015-06-01

Full Text Available Western corn rootworm – WCR (Diabrotica virgifera virgifera LeConte is an important maize pest in Croatia. Using native resistance of maize germplasm could reduce chemical treatments and other costs in maize production. Objectives of this study were: i to assess variability of WCR resistance traits (root injury, regrowth and size and concentrations of nine elements in roots of 128 maize genotypes, and ii to determine correlations among the traits and ion concentrations. Results revealed high variability of maize genotypes for both WCR resistance traits and ion concentrations. Significant moderate negative correlations (>-0.4 were detected between root injury and boron as well as between root regrowth and iron, manganese and zinc concentrations in root. Consequently, ion concentration in maize roots might have an impact on WCR resistance research.

Screening of faba bean (Vicia faba L. accessions to acidity and aluminium stresses

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Kiflemariam Y. Belachew

2017-02-01

Full Text Available Background Faba bean is an important starch-based protein crop produced worldwide. Soil acidity and aluminium toxicity are major abiotic stresses affecting its production, so in regions where soil acidity is a problem, there is a gap between the potential and actual productivity of the crop. Hence, we set out to evaluate acidity and aluminium tolerance in a range of faba bean germplasm using solution culture and pot experiments. Methods A set of 30 accessions was collected from regions where acidity and aluminium are or are not problems. The accessions were grown in solution culture and a subset of 10 was grown first in peat and later in perlite potting media. In solution culture, morphological parameters including taproot length, root regrowth and root tolerance index were measured, and in the pot experiments the key measurements were taproot length, plant biomass, chlorophyll concentration and stomatal conductance. Result Responses to acidity and aluminium were apparently independent. Accessions Dosha and NC 58 were tolerant to both stress. Kassa and GLA 1103 were tolerant to acidity showing less than 3% reduction in taproot length. Aurora and Messay were tolerant to aluminium. Babylon was sensitive to both, with up to 40% reduction in taproot length from acidity and no detectable recovery from Al3+ challenge. Discussion The apparent independence of the responses to acidity and aluminium is in agreement with the previous research findings, suggesting that crop accessions separately adapt to H+ and Al3+ toxicity as a result of the difference in the nature of soil parent materials where the accession originated. Differences in rankings between experiments were minor and attributable to heterogeneity of seed materials and the specific responses of accessions to the rooting media. Use of perlite as a potting medium offers an ideal combination of throughput, inertness of support medium, access to leaves for detection of their stress responses, and

Nuclear and chloroplast diversity and phenotypic distribution of rice (Oryza sativa L.) germplasm from the democratic people’s republic of Korea (DPRK; North Korea)

Science.gov (United States)

2014-01-01

Background Rice accounts for 43% of staple food production in the Democratic People’s Republic of Korea (DPRK). The most widely planted rice varieties were developed from a limited number of ancestral lines that were repeatedly used as parents in breeding programs. However, detailed pedigrees are not publicly available and little is known about the genetic, phenotypic, and geographical variation of DPRK varieties. Results We evaluated 80 O. sativa accessions from the DPRK, consisting of 67 improved varieties and 13 landraces. Based on nuclear SSR analysis, we divide the varieties into two genetic groups: Group 1 corresponds to the temperate japonica subpopulation and represents 78.75% of the accessions, while Group 2 shares recent ancestry with indica varieties. Interestingly, members of Group 1 are less diverse than Group 2 at the nuclear level, but are more diverse at the chloroplast level. All Group 2 varieties share a single Japonica maternal-haplotype, while Group 1 varieties trace maternal ancestry to both Japonica and Indica. Phenotypically, members of Group 1 have shorter grains than Group 2, and varieties from breeding programs have thicker and wider grains than landraces. Improved varieties in Group 1 also show similar and/or better levels of cold tolerance for most traits, except for spikelet number per panicle. Finally, geographic analysis demonstrates that the majority of genetic variation is located within regions that have the most intensive rice cultivation, including the Western territories near the capital city Pyungyang. This is consistent with the conscious and highly centralized role of human selection in determining local dispersion patterns of rice in the DPRK. Conclusions Diversity studies of DPRK rice germplasm revealed two genetic groups. The most widely planted group has a narrow genetic base and would benefit from the introduction of new genetic variation from cold tolerant landraces, wild accessions, and/or cultivated gene pools to

The AVRDC - The World Vegetable Center mungbean (Vigna radiata) core and mini core collections.

Science.gov (United States)

Schafleitner, Roland; Nair, Ramakrishnan Madhavan; Rathore, Abhishek; Wang, Yen-wei; Lin, Chen-yu; Chu, Shu-hui; Lin, Pin-yun; Chang, Jian-Cheng; Ebert, Andreas W

2015-04-29

Large ex situ germplasm collections generally harbor a wide range of crop diversity. AVRDC--The World Vegetable Center is holding in trust the world's second largest mungbean (Vigna radiata) germplasm collection with more than 6,700 accessions. Screening large collections for traits of interest is laborious and expensive. To enhance the access of breeders to the diversity of the crop, mungbean core and mini core collections have been established. The core collection of 1,481 entries has been built by random selection of 20% of the accessions after geographical stratification and subsequent cluster analysis of eight phenotypic descriptors in the whole collection. Summary statistics, especially the low differences of means, equal variance of the traits in both the whole and core collection and the visual inspection of quantile-quantile plots comparing the variation of phenotypic traits present in both collections indicated that the core collection well represented the pattern of diversity of the whole collection. The core collection was genotyped with 20 simple sequence repeat markers and a mini core set of 289 accessions was selected, which depicted the allele and genotype diversity of the core collection. The mungbean core and mini core collections plus their phenotypic and genotypic data are available for distribution to breeders. It is expected that these collections will enhance the access to biodiverse mungbean germplasm for breeding.

Genetic diversity of cultivated lentil (Lens culinaris Medik. and its relation to the world’s agro-ecological zones

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Hamid Khazaei

2016-07-01

Full Text Available Assessment of genetic diversity and population structure of germplasm collections plays a critical role in supporting conservation and crop genetic enhancement strategies. We used a cultivated lentil (Lens culinaris Medik. collection consisting of 352 accessions originating from 54 diverse countries to estimate genetic diversity and genetic structure using 1194 polymorphic single nucleotide polymorphism (SNP markers which span the lentil genome. Using principal coordinate analysis, population structure analysis and UPGMA cluster analysis, the accessions were categorized into three major groups that prominently reflected geographical origin (world’s agro-ecological zones. The three clusters complemented the origins, pedigrees and breeding histories of the germplasm. The three groups were a South Asia (sub-tropical savannah, b Mediterranean and c northern temperate. Based on the results from this study, it is also clear that breeding programs still have considerable genetic diversity to mine within the cultivated lentil, however, surveyed South Asian and Canadian germplasm revealed narrow genetic diversity.

Strategic conservation of orchard germplasm based on indigenous knowledge and genetic diversity: a case study of sour orange populations in China.

Science.gov (United States)

Ming, Feng; Liu, Qi-Kun; Shi, Jin-Lei; Wang, Wei; Lu, Bao-Rong

2009-01-01

To effectively conserve sour orange (Citrus aurantium L.) germplasm on two islands at the estuary of the Yangtze River in China, we estimated genetic variation and relationships of the known parental trees and their proposed descendents (young trees) using the fingerprints of random amplified polymorphic DNA (RAPD). Results based on RAPD analyses showed considerable genetic diversity in the parental populations (H(e)=0.202). The overall populations including the parental and young trees showed slightly higher genetic diversity (H(e)=0.298) than the parents, with about 10% variation between populations. An unweighted pair group method with arithmetic mean analysis dendrogram based on cluster analysis of the Jaccard similarity among individuals demonstrated a more complicated relationship of the parental and young trees from the two islands, although the young trees showed a clear association with parental trees. This indicates a significant contribution of parental trees in establishing the sour orange populations on the two islands. According to farmers' knowledge, conservation of only one or two parental trees would be sufficient because they believed that the whole populations were generated from a single mother tree. However, this study suggests that preserving most parental trees and some selected young trees with distant genetic relationships should be an effective conservation strategy for sour orange germplasm on the two islands.

Genetic Diversity in Jatropha curcas L. Assessed with SSR and SNP Markers

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Juan M. Montes

2014-08-01

Full Text Available Jatropha curcas L. (jatropha is an undomesticated plant that has recently received great attention for its utilization in biofuel production, rehabilitation of wasteland, and rural development. Knowledge of genetic diversity and marker-trait associations is urgently needed for the design of breeding strategies. The main goal of this study was to assess the genetic structure and diversity in jatropha germplasm with co-dominant markers (Simple Sequence Repeats (SSR and Single Nucleotide Polymorphism (SNP in a diverse, worldwide, germplasm panel of 70 accessions. We found a high level of homozygosis in the germplasm that does not correspond to the purely outcrossing mating system assumed to be present in jatropha. We hypothesize that the prevalent mating system of jatropha comprise a high level of self-fertilization and that the outcrossing rate is low. Genetic diversity in accessions from Central America and Mexico was higher than in accession from Africa, Asia, and South America. We identified makers associated with the presence of phorbol esters. We think that the utilization of molecular markers in breeding of jatropha will significantly accelerate the development of improved cultivars.

Conservation of coconut (Cocos nucifera L.) germplasm at sub-zero temperature.

Science.gov (United States)

Sisunandar; Sopade, Peter A; Samosir, Yohannes M S; Rival, Alain; Adkins, Steve W

2012-01-01

Protocols are proposed for the low (-20 degree C) and ultra-low (-80 degree C) temperature storage of coconut (Cocos nucifera L.) embryos. A tissue dehydration step prior to storage, and a rapid warming step upon recovery optimized the protocol. The thermal properties of water located within embryos were monitored using differential scanning calorimetry (DSC). In the most efficient version of the protocol, embryos were dehydrated under a sterile air flow in a dehydration solution containing glucose (3.33 M) and glycerol (15 percent) for 16 hours. This protocol decreased the embryo water content from 77 to 29 percent FW and at the same time reduced the amount of freezable water down to 0.03 percent. The dehydrated embryos could be stored for up to 3 weeks at -20 degree C (12 percent producing normal plants upon recovery) or 26 weeks at -80 degree C (28 percent producing normal plants upon recovery). These results indicate that it is possible to store coconut germplasm on a medium term basis using an ultra-deep freezer unit. However for more efficient, long term storage, cryopreservation remains the preferred option.

Genetic divergence among accessions of melon from traditional agriculture of the Brazilian Northeast.

Science.gov (United States)

Aragão, F A S; Torres Filho, J; Nunes, G H S; Queiróz, M A; Bordallo, P N; Buso, G S C; Ferreira, M A; Costa, Z P; Bezerra Neto, F

2013-12-06

The genetic divergence of 38 melon accessions from traditional agriculture of the Brazilian Northeast and three commercial hybrids were evaluated using fruit descriptors and microsatellite markers. The melon germplasm belongs to the botanic varieties cantalupensis (19), momordica (7), conomon (4), and inodorus (3), and to eight genotypes that were identified only at the species level. The fruit descriptors evaluated were: number of fruits per plant (NPF), fruit mass (FM; kg), fruit longitudinal diameter (LD; cm), fruit transversal diameter (TD; cm), shape index based on the LD/TD ratio, flesh pulp thickness, cavity thickness (CT; cm), firmness fruit pulp (N), and soluble solids (SS; °Brix). The results showed high variability for all descriptors, especially for NPF, LD, and FM. The grouping analysis based on fruit descriptors produced eight groups without taxonomic criteria. The LD (22.52%), NPF (19.70%), CT (16.13%), and SS (9.57%) characteristics were the descriptors that contributed the most to genotype dissimilarity. The 17 simple sequence repeat polymorphic markers amplified 41 alleles with an average of 2.41 alleles and three genotypes per locus. Some markers presented a high frequency for the main allele. The genetic diversity ranged from 0.07 to 0.60, the observed heterozygosity had very low values, and the mean polymorphism information content was 0.32. Molecular genetic similarity analyses clustered the accessions in 13 groups, also not following taxonomic ranks. There was no association between morphoagronomic and molecular groupings. In conclusion, there was great variability among the accessions and among and within botanic groups.

Genetic variation, population structure, and linkage disequilibrium in European elite germplasm of perennial ryegrass

DEFF Research Database (Denmark)

Brazauskas, Gintaras; Lenk, Ingo; Pedersen, Morten Greve

2011-01-01

Perennial ryegrass (Lolium perenne L.) is a highly valued temperate climate grass species grown as forage crop and for amenity uses. Due to its outbreeding nature and recent domestication, a high degree of genetic diversity is expected among cultivars. The aim of this study was to assess the extent...... of linkage disequilibrium (LD) within European elite germplasm and to evaluate the appropriate methodology for genetic association mapping in perennial ryegrass. A high level of genetic diversity was observed in a set of 380 perennial ryegrass elite genotypes when genotyped with 40 SSRs and 2 STS markers...... and occurred within 0.4 cM across European varieties, when population structure was taken into consideration. However, an extended LD of up to 6.6 cM was detected within the variety Aberdart. High genetic diversity and rapid LD decay provide means for high resolution association mapping in elite materials...

Effect of two different germplasm of Mucuna pruriens seed extracts against some fish pathogens

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M. Marimuthu M

2015-07-01

Full Text Available To investigate the two different germplasm of Mucuna seeds were collected from agro geographical regions was evaluated for its antibacterial activities. Antibacterial activity of the seed extracts was studied against the fish pathogens of Aeromonas hydrophila, Pseudomonas fluorescens, Vibrio cholera and Klebsiella pneumonia using agar well diffusion method. Results showed that methanol and ethanol extracts showed more potent antibacterial activity than other solvent extracts. The results were expressed as mean ± SD. The results obtained in the study shows that velvet bean black seed extract has more antibacterial activity against fish pathogens. The antibacterial activity of all the Mucuna seed extracts are comparable ad their potential as alternative in the treatment of infectious by these microorganisms was present in the fish. Susceptibility testing is conducted on isolates using drug selected on the basis of their importance to human medicine and use I fish production.

Genetic Diversity, Population Structure and Ancestral Origin of Australian Wheat

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Reem Joukhadar

2017-12-01

Full Text Available Since the introduction of wheat into Australia by the First Fleet settlers, germplasm from different geographical origins has been used to adapt wheat to the Australian climate through selection and breeding. In this paper, we used 482 cultivars, representing the breeding history of bread wheat in Australia since 1840, to characterize their diversity and population structure and to define the geographical ancestral background of Australian wheat germplasm. This was achieved by comparing them to a global wheat collection using in-silico chromosome painting based on SNP genotyping. The global collection involved 2,335 wheat accessions which was divided into 23 different geographical subpopulations. However, the whole set was reduced to 1,544 accessions to increase the differentiation and decrease the admixture among different global subpopulations to increase the power of the painting analysis. Our analysis revealed that the structure of Australian wheat germplasm and its geographic ancestors have changed significantly through time, especially after the Green Revolution. Before 1920, breeders used cultivars from around the world, but mainly Europe and Africa, to select potential cultivars that could tolerate Australian growing conditions. Between 1921 and 1970, a dependence on African wheat germplasm became more prevalent. Since 1970, a heavy reliance on International Maize and Wheat Improvement Center (CIMMYT germplasm has persisted. Combining the results from linkage disequilibrium, population structure and in-silico painting revealed that the dependence on CIMMYT materials has varied among different Australian States, has shrunken the germplasm effective population size and produced larger linkage disequilibrium blocks. This study documents the evolutionary history of wheat breeding in Australia and provides an understanding for how the wheat genome has been adapted to local growing conditions. This information provides a guide for industry to

Genetic Diversity, Population Structure and Ancestral Origin of Australian Wheat.

Science.gov (United States)

Joukhadar, Reem; Daetwyler, Hans D; Bansal, Urmil K; Gendall, Anthony R; Hayden, Matthew J

2017-01-01

Since the introduction of wheat into Australia by the First Fleet settlers, germplasm from different geographical origins has been used to adapt wheat to the Australian climate through selection and breeding. In this paper, we used 482 cultivars, representing the breeding history of bread wheat in Australia since 1840, to characterize their diversity and population structure and to define the geographical ancestral background of Australian wheat germplasm. This was achieved by comparing them to a global wheat collection using in-silico chromosome painting based on SNP genotyping. The global collection involved 2,335 wheat accessions which was divided into 23 different geographical subpopulations. However, the whole set was reduced to 1,544 accessions to increase the differentiation and decrease the admixture among different global subpopulations to increase the power of the painting analysis. Our analysis revealed that the structure of Australian wheat germplasm and its geographic ancestors have changed significantly through time, especially after the Green Revolution. Before 1920, breeders used cultivars from around the world, but mainly Europe and Africa, to select potential cultivars that could tolerate Australian growing conditions. Between 1921 and 1970, a dependence on African wheat germplasm became more prevalent. Since 1970, a heavy reliance on International Maize and Wheat Improvement Center (CIMMYT) germplasm has persisted. Combining the results from linkage disequilibrium, population structure and in-silico painting revealed that the dependence on CIMMYT materials has varied among different Australian States, has shrunken the germplasm effective population size and produced larger linkage disequilibrium blocks. This study documents the evolutionary history of wheat breeding in Australia and provides an understanding for how the wheat genome has been adapted to local growing conditions. This information provides a guide for industry to assist with

Genetic diversity and structure of managed and semi-natural populations of cocoa (Theobroma cacao) in the Huallaga and Ucayali Valleys of Peru.

Science.gov (United States)

Zhang, Dapeng; Arevalo-Gardini, Enrique; Mischke, Sue; Zúñiga-Cernades, Luis; Barreto-Chavez, Alejandro; Del Aguila, Jorge Adriazola

2006-09-01

Cocoa (Theobroma cacao) is indigenous to the Amazon region of South America, and it is well known that the Peruvian Amazon harbours a large number of diverse cocoa populations. A small fraction of the diversity has been collected and maintained as an ex-situ germplasm repository in Peru. However, incorrect labelling of accessions and lack of information on genetic diversity have hindered efficient conservation and use of this germplasm. This study targeted assessment of genetic diversity and population structure in a managed and a semi-natural population. Using a capillary electrophoresis genotyping system, 105 cocoa accessions collected from the Huallaga and Ucayali valleys of Peru were fingerprinted. Based on 15 loci SSR profiles, genetic identity was examined for each accession and duplicates identified, population structure assessed and genetic diversity analysed in these two populations. Ten synonymous mislabelled groups were identified among the 105 accessions. The germplasm group in the Huallaga valley was clearly separated from the group in Ucayali valley by the Bayesian assignment test. The Huallaga group has lower genetic diversity, both in terms of allelic richness and of gene diversity, than the Ucayali group. Analysis of molecular variance suggested genetic substructure in the Ucayali group. Significant spatial correlation between genetic distance and geographical distances was detected in the Ucayali group by Mantel tests. These results substantiate the hypothesis that the Peruvian Amazon hosts a high level of cocoa genetic diversity, and the diversity has a spatial structure. The introduction of exotic seed populations into the Peruvian Amazon is changing the cocoa germplasm spectrum in this region. The spatial structure of cocoa diversity recorded here highlights the need for additional collecting and conservation measures for natural and semi-natural cocoa populations.

Genetic diversity and population structure of Pisum sativum accessions for marker-trait association of lipid content

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Sajjad Ahmad

2015-06-01

Full Text Available Field pea (Pisum sativum L. is an important protein-rich pulse crop produced globally. Increasing the lipid content of Pisum seeds through conventional and contemporary molecular breeding tools may bring added value to the crop. However, knowledge about genetic diversity and lipid content in field pea is limited. An understanding of genetic diversity and population structure in diverse germplasm is important and a prerequisite for genetic dissection of complex characteristics and marker-trait associations. Fifty polymorphic microsatellite markers detecting a total of 207 alleles were used to obtain information on genetic diversity, population structure and marker-trait associations. Cluster analysis was performed using UPGMA to construct a dendrogram from a pairwise similarity matrix. Pea genotypes were divided into five major clusters. A model-based population structure analysis divided the pea accessions into four groups. Percentage lipid content in 35 diverse pea accessions was used to find potential associations with the SSR markers. Markers AD73, D21, and AA5 were significantly associated with lipid content using a mixed linear model (MLM taking population structure (Q and relative kinship (K into account. The results of this preliminary study suggested that the population could be used for marker-trait association mapping studies.

Selenium accumulation in lettuce germplasm

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Selenium (Se) is an essential micronutrient for animals and humans. Increasing Se content in food crops offers an effective approach to reduce the widespread selenium deficiency problem in many parts of the world. In this study, we evaluated thirty diverse accessions of lettuce (Lactuca sativa L.) f...

Anthocyanin characteristics of wines in Vitis germplasms cultivated in southern China

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Guo CHENG

2017-10-01

Full Text Available Abstract The anthocyanin profiles and CIELAB color values of nine wines in Vitis germplasms from southern China were compared. The results showed that the anthocyanin composition of wines from one hybrid between V. vinifera and V. labrusca (‘Moldova’, two V. labrusca varieties (‘Conquistador’ and ‘Saint-Croix’, one V. quinquangularis variety (‘Yeniang No.2’, one hybrid between V. quinquangularis and V. vinifera (‘NW196’, one V. davidii variety (‘Xiangniang No.1’ and one V. rotundifolia variety (‘Noble’ were dominated by anthocyanidin 3,5-O-diglucosides. All these were quite different from V. vinifera wines (‘Cabernet Sauvignon’ and ‘Marselan’, which were characterized by the monoglucoside and pyranoanthocyanins. 3',4',5'-substituted anthocyanins were dominant in the wines of all varieties, except ‘Noble’ wine. ‘Yeniang No.2’ (V. quinquangularis had the highest acid, total anthocyanin concentration, and showed a more intense pigmentation with a higher proportion and concentration of coumaroylated anthocyanins. In the colorimetric analysis, ‘Yeniang No.2’ (V. quinquangularis wine showed the most saturated red colors, followed by ‘NW196’ (V. quinquangularis. The detected chromatic characteristics of these wines were basically in accordance with their sensory evaluation.

Sds-page based genetic divergence in safflower (carthamus tinctorius l.)

International Nuclear Information System (INIS)

Shinwari, Z.K.; Rehman, H.; Rabbani, M.A.

2014-01-01

Safflower (Carthamus tinctorius L.) germplasm, comprising of 116 accessions was characterized using Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) of seed storage proteins. The germplasm was acquired from different countries of the world. Total seed proteins were separated through electrophoresis polyacrylamide gels using standard protocols. Eighteen (60%) of the protein bands detected were polymorphic, the rest being monomorphic. Eight bands (14, 17, 18, 19, 20, 23, 24 and 25) were more than 80% common in all accessions. Similarity coefficients among the accessions ranged from 0.00 to 1.00. Accessions 16327 and 26752 were the most divergent genotypes having maximum dissimilarity with all the other accessions used. Unweighted Pair Group Method with Arithmetic averages (UPGMA) was used which is based on dissimilarity matrix. The dendrogram obtained separated all accessions into four main clusters (I, II, III and IV) and two independent individual genotypes. Four major clusters comprised of 23, 75, 8 and 8 accessions, respectively. This technique did not reveal genetic variability of significant value in safflower genotypes, hence advanced molecular and biochemical markers are recommended for further studies. This study will be helpful for the future breeding program of safflower accessions. (author)

Discovering the desirable alleles contributing to the lignocellulosic biomass traits in saccharum germplasm collections for energy cane improvement

Energy Technology Data Exchange (ETDEWEB)

Todd, James [USDA ARS Sugarcane Field Station, Canal Point, FL (United States); Comstock, Jack C. [USDA ARS Sugarcane Field Station, Canal Point, FL (United States)

2015-11-25

of the cores and the World Collection are similar to each other genotypically and phenotypically, but the core that was selected using only genotypic data was significantly different phenotypically. This indicates that there is not enough association between the genotypic and phenotypic diversity as to select using only genotypic diversity and get the full phenotypic diversity. Core Collection: Creation and Phenotyping Methods: To evaluate this germplasm for breeding purposes, a representative diversity panel selected from the WCSRG of approximately 300 accessions was planted at Canal Point, FL in three replications. These accessions were measured for stalk height and stalk number multiple times throughout the growing season and Brix and fresh biomass during harvest in 2013 and, stalk height, stalk number, stalk diameter, internode length, Brix and fresh and dry biomass was determined in the ratoon crop harvest in 2014. Results: In correlations of multiple measurements, there were higher correlations for early measurements of stalk number and stalk height with harvest traits like Brix and fresh weight. Hybrids had higher fresh mass and Brix while Saccharum spontaneum had higher stalk number and dry mass. The heritability of hybrid mass traits was lower in the ratoon crop. According to the principal component analysis, the diversity panel was divided into two groups. One group had accessions with high stalk number and high dry biomass like S. spontaneum and the other groups contained accessions with higher Brix and fresh biomass like S. officinarum. Mass traits correlated with each other as expected but hybrids had lower correlations between fresh and dry mass. Stalk number and the mass traits correlated with each other except in S. spontaneum and hybrids in the first ratoon. There were 110 accessions not significantly different in Brix from the commercial sugarcane checks including 10 S. spontaneum accessions. There were 27 dry and 6 fresh mass accessions

Ecological characteristics and in situ genetic associations for yield-component traits of wild Miscanthus from eastern Russia

DEFF Research Database (Denmark)

Clark, Lindsay V; Dzyubenko, Elena; Dzyubenko, Nikolay

2016-01-01

, a strategy is proposed to facilitate the rapid utilization of new germplasm collections: by implementing low-cost SNP genotyping to conduct GWA studies of phenotypic data obtained at collection sites, plant breeders can be provided with actionable information on which accessions have desirable traits...... that this crop is more temperate adapted than its C4 relatives maize, sorghum and sugarcane. Methods A plant exploration was conducted in eastern Russia, at the northern extreme of the native range for Miscanthus, with collections including 174 clonal germplasm accessions (160 M. sacchariflorus and 14 M....... sinensis) from 47 sites. Accessions were genotyped by restriction site-associated DNA sequencing (RAD-seq) and plastid microsatellites. Key Results Miscanthus sinensis was found in maritime climates near Vladivostok (43·6°N) and on southern Sakhalin Island (46·6°N). Miscanthus sacchariflorus was found...

Effects of alfalfa germplasm and stage of maturity on digestive process and productive response of dairy cows fed alfalfa hay-based diets

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Igino Andrighetto

2010-01-01

Full Text Available The effects on the digestive process and the productive performances of dairy cows fed diets containing alfalfa hay from  different germplasms and maturity were assessed in the present study. Three different lots of first-cut alfalfa hay were  used in the study: the improved variety “Boreal”, harvested at two consecutive maturity stages (early flowering and full  flowering and the ecotype “Vogherese”, at full flowering. Cutting the plant at an earlier stage of maturity improved hay  quality in comparison with the more mature forages (crude protein: 21.4 vs 16.5% DM; P  DM; P  er lignin content for the latter (8.6 vs 8.2% DM; P  tating cows were formulated using an equal amount of corn silage and the maximum inclusion of one of the tested hays  as forage base. The better quality of the early cut hay made it possible to increase its inclusion in the diet up to 44% of  total dietary DM, while the two more mature hays covered only 36% of total DM of the respective diets. According to a  3 x 3 Latin square design, the diets were fed to 3 Italian Brown cows (initial average days in milk 121 ± 24 and milk  yield 20 kg ± 1.3 fitted with ruminal cannula in 3 consecutive periods of 28 d each. Alfalfa stage of maturity and  germplasm did not affect dietary DM intake (average 16 kg/d. Degradability parameters of dietary DM, calculated by in  situ nylon bags technique, showed similar kinetics of rumen disappearance for all diets. No differences were noticed in  the ruminal rate of passage of the solid phase among diets, while the liquid phase showed a slower rate of passage for  the early flowering hay diet. Consistent with the degradation process, the stage of maturity or the alfalfa germplasm did  not affect the rumen fluid data or the in vivo digestibility coefficients of the diets. Milk yield did not show any change due  to either alfalfa maturity or cultivar, while milk protein was lowered when cows received the early cut hay

Development of comprehensive medium for micropropagation of cultivated Cassava accessions

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Cassava is one of the most important foods in the human diet in the tropics, where it ranks fifth as a source of energy, after rice, sugar cane, and maize. Since it is a vegetative propagated crop, the use of in vitro propagation is very important to preserve germplasm free of pest and diseases. M...

Alginate-encapsulation of shoot tips of jojoba [Simmondsia chinensis (Link) Schneider] for germplasm exchange and distribution.

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Kumar, Sunil; Rai, Manoj K; Singh, Narender; Mangal, Manisha

2010-12-01

Shoot tips excised from in vitro proliferated shoots derived from nodal explants of jojoba [Simmondsia chinensis (Link) Schneider] were encapsulated in calcium alginate beads for germplasm exchange and distribution. A gelling matrix of 3 % sodium alginate and 100 mM calcium chloride was found most suitable for formation of ideal calcium alginate beads. Best response for shoot sprouting from encapsulated shoot tips was recorded on 0.8 % agar-solidified full-strength MS medium. Rooting was induced upon transfer of sprouted shoots to 0.8 % agar-solidified MS medium containing 1 mg l(-1) IBA. About 70 % of encapsulated shoot tips were rooted and converted into plantlets. Plants regenerated from encapsulated shoot tips were acclimatized successfully. The present encapsulation approach could also be applied as an alternative method of propagation of desirable elite genotype of jojoba.

Doubled haploid production from Spanish onion (Allium cepa L.) germplasm: embryogenesis induction, plant regeneration and chromosome doubling.

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Fayos, Oreto; Vallés, María P; Garcés-Claver, Ana; Mallor, Cristina; Castillo, Ana M

2015-01-01

The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2-3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09%) and Fuentes de Ebro the lowest (0.53%). These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%), whereas the lowest percentage was observed with glass tubes in the two protocols (20-23%). Different amiprofos-methyl (APM) treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 μM APM in liquid medium. However, the application of 25 μM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the four regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their gynogenesis

Doubled haploid production from Spanish onion (Allium cepa L. germplasm: embryogenesis induction, plant regeneration and chromosome doubling

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Oreto eFayos

2015-05-01

Full Text Available The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2 to 3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09% and Fuentes de Ebro the lowest (0.53%. These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%, whereas the lowest percentage was observed with glass tubes in the two protocols (20-23%. Different amiprofos-methyl (APM treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 µM APM in liquid medium. However, the application of 25 µM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the 4 regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their

High genetic diversity of Jatropha curcas assessed by ISSR.

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Díaz, B G; Argollo, D M; Franco, M C; Nucci, S M; Siqueira, W J; de Laat, D M; Colombo, C A

2017-05-31

Jatropha curcas L. is a highly promising oilseed for sustainable production of biofuels and bio-kerosene due to its high oil content and excellent quality. However, it is a perennial and incipiently domesticated species with none stable cultivar created until now despite genetic breeding programs in progress in several countries. Knowledge of the genetic structure and diversity of the species is a necessary step for breeding programs. The molecular marker can be used as a tool for speed up the process. This study was carried out to assess genetic diversity of a germplasm bank represented by J. curcas accessions from different provenance beside interspecific hybrid and backcrosses generated by IAC breeding programs using inter-simple sequence repeat markers. The molecular study revealed 271 bands of which 98.9% were polymorphic with an average of 22.7 polymorphic bands per primer. Genetic diversity of the germplasm evaluated was slightly higher than other germplasm around the world and ranged from 0.55 to 0.86 with an average of 0.59 (Jaccard index). Cluster analysis (UPGMA) revealed no clear grouping as to the geographical origin of accessions, consistent with genetic structure analysis using the Structure software. For diversity analysis between groups, accessions were divided into eight groups by origin. Nei's genetic distance between groups was 0.14. The results showed the importance of Mexican accessions, congeneric wild species, and interspecific hybrids for conservation and development of new genotypes in breeding programs.

Assessment of genetic diversity in Vigna unguiculata L. (Walp) accessions using inter-simple sequence repeat (ISSR) and start codon targeted (SCoT) polymorphic markers.

Science.gov (United States)

Igwe, David Okeh; Afiukwa, Celestine Azubike; Ubi, Benjamin Ewa; Ogbu, Kenneth Idika; Ojuederie, Omena Bernard; Ude, George Nkem

2017-11-17

Assessment of genetic diversity of Vigna unguiculata (L.) Walp (cowpea) accessions using informative molecular markers is imperative for their genetic improvement and conservation. Use of efficacious molecular markers to obtain the required knowledge of the genetic diversity within the local and regional germplasm collections can enhance the overall effectiveness of cowpea improvement programs, hence, the comparative assessment of Inter-simple sequence repeat (ISSR) and Start codon targeted (SCoT) markers in genetic diversity of V. unguiculata accessions from different regions in Nigeria. Comparative analysis of the genetic diversity of eighteen accessions from different locations in Nigeria was investigated using ISSR and SCoT markers. DNA extraction was done using Zymogen Kit according to its manufacturer's instructions followed by amplifications with ISSR and SCoT and agarose gel electrophoresis. The reproducible bands were scored for analyses of dendrograms, principal component analysis, genetic diversity, allele frequency, polymorphic information content, and population structure. Both ISSR and SCoT markers resolved the accessions into five major clusters based on dendrogram and principal component analyses. Alleles of 32 and 52 were obtained with ISSR and SCoT, respectively. Numbers of alleles, gene diversity and polymorphic information content detected with ISSR were 9.4000, 0.7358 and 0.7192, while SCoT yielded 11.1667, 0.8158 and 0.8009, respectively. Polymorphic loci were 70 and 80 in ISSR and SCoT, respectively. Both markers produced high polymorphism (94.44-100%). The ranges of effective number of alleles (Ne) were 1.2887 ± 0.1797-1.7831 ± 0.2944 and 1.7416 ± 0.0776-1.9181 ± 0.2426 in ISSR and SCoT, respectively. The Nei's genetic diversity (H) ranged from 0.2112 ± 0.0600-0.4335 ± 0.1371 and 0.4111 ± 0.0226-0.4778 ± 0.1168 in ISSR and SCoT, respectively. Shannon's information index (I) from ISSR and SCoT were 0

Genetic Relationships among Tall Coconut Palm (Cocos nucifera L. Accessions of the International Coconut Genebank for Latin America and the Caribbean (ICG-LAC, Evaluated Using Microsatellite Markers (SSRs.

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Carina Mendes Loiola

Full Text Available The diversity and genetic relationships among two accessions of tall coconut palms collected in Brazil and seven accessions introduced from different geographic regions of the world were analyzed using 25 microsatellite primers, 19 of which were polymorphic and detected between 4 and 10 alleles per locus, with an average of 6.57. The observed and expected heterozygosity ranged from 0.25 and 0.40 in the Rennell Islands Tall (RIT accession to 0.54 and 0.62 in the Polynesian Tall (PYT accession. The analysis of genetic structure resulted in the formation of five distinct groups. The first group was formed by the accessions Brazilian Tall-Praia do Forte (BRTPF, Brazilian Tall-Merepe (BRTMe and West African Tall (WAT; the second group consisted of Malaysian Tall (MLT; the third group of RIT; the fourth group of Vanuatu Tall (VTT; and the fifth group of Rotuman Tall (RTMT, Tonga Tall (TONT and PYT. The dendrogram based on the nearest-neighbor method detected the formation of two main groups and five subgroups, indicating that the genetic relationships of the accessions are based on their geographic regions of origin. The analyses revealed genetic relationships between the accessions collected in Brazil and the accession from Africa, and among palms from South East Asia and the South Pacific, confirming the common origin of these accessions. The information obtained in this study can guide decisions on germplasm conservation activities and the efficient selection of genetically divergent parents for use in coconut breeding programs in Brazil, which are attempting to select for disease resistance, mainly to lethal yellowing, among other characteristics.

Genetic Relationships among Tall Coconut Palm (Cocos nucifera L.) Accessions of the International Coconut Genebank for Latin America and the Caribbean (ICG-LAC), Evaluated Using Microsatellite Markers (SSRs).

Science.gov (United States)

Loiola, Carina Mendes; Azevedo, Alinne Oliveira Nunes; Diniz, Leandro E C; Aragão, Wilson Menezes; Azevedo, Carlos Diego de O; Santos, Pedro Henrique A D; Ramos, Helaine Christine C; Pereira, Messias Gonzaga; Ramos, Semíramis R Ramalho

2016-01-01

The diversity and genetic relationships among two accessions of tall coconut palms collected in Brazil and seven accessions introduced from different geographic regions of the world were analyzed using 25 microsatellite primers, 19 of which were polymorphic and detected between 4 and 10 alleles per locus, with an average of 6.57. The observed and expected heterozygosity ranged from 0.25 and 0.40 in the Rennell Islands Tall (RIT) accession to 0.54 and 0.62 in the Polynesian Tall (PYT) accession. The analysis of genetic structure resulted in the formation of five distinct groups. The first group was formed by the accessions Brazilian Tall-Praia do Forte (BRTPF), Brazilian Tall-Merepe (BRTMe) and West African Tall (WAT); the second group consisted of Malaysian Tall (MLT); the third group of RIT; the fourth group of Vanuatu Tall (VTT); and the fifth group of Rotuman Tall (RTMT), Tonga Tall (TONT) and PYT. The dendrogram based on the nearest-neighbor method detected the formation of two main groups and five subgroups, indicating that the genetic relationships of the accessions are based on their geographic regions of origin. The analyses revealed genetic relationships between the accessions collected in Brazil and the accession from Africa, and among palms from South East Asia and the South Pacific, confirming the common origin of these accessions. The information obtained in this study can guide decisions on germplasm conservation activities and the efficient selection of genetically divergent parents for use in coconut breeding programs in Brazil, which are attempting to select for disease resistance, mainly to lethal yellowing, among other characteristics.

SSR and morphological trait based population structure analysis of 130 diverse flax (Linum usitatissimum L.) accessions.

Science.gov (United States)

Choudhary, Shashi Bhushan; Sharma, Hariom Kumar; Kumar, Arroju Anil; Maruthi, Rangappa Thimmaiah; Mitra, Jiban; Chowdhury, Isholeena; Singh, Binay Kumar; Karmakar, Pran Gobinda

2017-02-01

A total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST-SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers (SI=0.46; He=0.31; P=85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P=0.01. The maximum Nei's unbiased genetic distance (D=0.11) was observed between fibre type and linseed type exotic sub-populations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasm. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Agronomical and molecular characterization of banana germplasm Caracterização agronômica e molecular de germoplasma de bananeira

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Lorenna Alves Mattos

2010-02-01

Full Text Available The objective of the present work was to characterize banana accessions from the Germplasm Bank at Embrapa Mandioca e Fruticultura Tropical (Brazil, using agronomical, physical and physicochemical characteristics of fruit and simple sequence repeats (SSR markers. Twenty-six accessions were analyzed, in which high genetic variability was found, especially for the agronomical characters number of fruit and weight of bunch. Accessions with high contents of carotenoids (diploid 'Jaran', polyphenols (triploid 'Caipira' and tetraploid 'Teparod' and vitamin C (diploid 'Tuugia' and an unknown triploid AAA in the fruit were identified. Thirteen microsatellite primers revealed an average of 7.23 alleles, which showed high variability. A dendrogram was prepared using the Gower algorithm for the distance matrices obtained from the agronomical, physical and physicolchemical analysis of fruit and SSR markers. Adopting the average genetic divergence as the cut-off point, three clusters were found: G1, formed by the diploids 'Jaran', 028003-01 and M-48; G2, by the diploids 'Malbut' and 'Ido 110'; and G3, by 21 tri-and tetraploid accessions, including one diploid, 'Tuugia'. The triploids with the B genome 'Thap Maeo', 'Walha', 'Pacha Nadan' and 'Champa Madras' were grouped in G2. Results from this work can be used for breeding hybrids with good agronomical traits and fruit quality.O objetivo deste trabalho foi caracterizar acessos de bananeira do Banco de Germoplasma da Embrapa Mandioca e Fruticultura Tropical, por meio de características agronômicas, físicas e físico-químicas dos frutos e por marcadores "Simple sequence repeats" (SSR. Foram analisados 26 acessos, nos quais observou-se ampla variabilidade genética, em especial para número de frutos e peso de cacho. Foram identificados acessos com altos teores de carotenoides (diploide 'Jaran', polifenóis (tetraploide 'Teparod' e vitamina C (diploide 'Tuugia' e um triploide AAA desconhecido. Os 13

Variability among Capsicum baccatum accessions from Goiás, Brazil, assessed by morphological traits and molecular markers.

Science.gov (United States)

Martinez, A L A; Araújo, J S P; Ragassi, C F; Buso, G S C; Reifschneider, F J B

2017-07-06

Capsicum peppers are native to the Americas, with Brazil being a significant diversity center. Capsicum baccatum accessions at Instituto Federal (IF) Goiano represent a portion of the species genetic resources from central Brazil. We aimed to characterize a C. baccatum working collection comprising 27 accessions and 3 commercial cultivars using morphological traits and molecular markers to describe its genetic and morphological variability and verify the occurrence of duplicates. This set included 1 C. baccatum var. praetermissum and 29 C. baccatum var. pendulum with potential for use in breeding programs. Twenty-two morphological descriptors, 57 inter-simple sequence repeat, and 34 random amplified polymorphic DNA markers were used. Genetic distance was calculated through the Jaccard similarity index and genetic variability through cluster analysis using the unweighted pair group method with arithmetic mean, resulting in dendrograms for both morphological analysis and molecular analysis. Genetic variability was found among C. baccatum var. pendulum accessions, and the distinction between the two C. baccatum varieties was evident in both the morphological and molecular analyses. The 29 C. baccatum var. pendulum genotypes clustered in four groups according to fruit type in the morphological analysis. They formed seven groups in the molecular analysis, without a clear correspondence with morphology. No duplicates were found. The results describe the genetic and morphological variability, provide a detailed characterization of genotypes, and discard the possibility of duplicates within the IF Goiano C. baccatum L. collection. This study will foment the use of this germplasm collection in C. baccatum breeding programs.

Drought Stress Responses of Sunflower Germplasm Developed after Wide Hybridization

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Roumiana Dimova Vassilevska-Ivanova

2016-10-01

Full Text Available Response of sunflower germplasms viz. cultivated sunflower H. annuus and two breeding lines H. annuus x T. rotundifolia and H. annuus x V. encelioides developed after wide hybridization were used for identification of drought tolerant sunflower genotypes at the seedling growth stage. Three water stress levels of zero (control, -0.4, and -0.8 MPa were developed using polyethyleneglycol-6000 (PEG-6000. Physiological and biochemical stress determining parameters such as root and shoots length, fresh weight, antioxidant enzyme activities (superoxide dismutase (SOD, catalase (CAT, guaiacol peroxidase (GPO, ascorbate peroxidase (APX and antioxidant metabolite content (total antioxidant capacity, total phenols and total flavonoids content were compared between seedlings of all three genotypes. Results revealed that sunflower genotypes have similar responses at two osmotic potentials for shoot and root length and fresh weight. The data also showed that drought stresss could induce oxidative stress, as indicated by the increase level of ascorbate peroxidase and guaiacol peroxidase at -04 MPa in H. annuus cv 1114. Although the activity of ascorbate peroxidase and guaiacol peroxidase was differentially influenced by drought, the changes of antioxidant enzyme activities such as catalase, superoxide dismutase, guaiacol peroxidase, and ascorbate peroxidase subjected to drought stress follow a similar pattern in both breeding lines, indicating that similar defense systems might be involved in the oxidative stress injury in sunflowers. Increase in content of phenols and flavonoids were detected for all three genotypes under stress, which showed that these were major antioxidant metabolites in scavenging cellular H2O2.

Exploiting Genomic Resources for Efficient Conservation and Use of Chickpea, Groundnut, and Pigeonpea Collections for Crop Improvement

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C. L. Laxmipathi Gowda

2013-11-01

Full Text Available Both chickpea ( L. and pigeonpea [ (L. Millsp.] are important dietary source of protein while groundnut ( L. is one of the major oil crops. Globally, approximately 1.1 million grain legume accessions are conserved in genebanks, of which the ICRISAT genebank holds 49,485 accessions of cultivated species and wild relatives of chickpea, pigeonpea, and groundnut from 133 countries. These genetic resources are reservoirs of many useful genes for present and future crop improvement programs. Representative subsets in the form of core and mini core collections have been used to identify trait-specific genetically diverse germplasm for use in breeding and genomic studies in these crops. Chickpea, groundnut, and pigeonpea have moved from “orphan” to “genomic resources rich crops.” The chickpea and pigeonpea genomes have been decoded, and the sequences of groundnut genome will soon be available. With the availability of these genomic resources, the germplasm curators, breeders, and molecular biologists will have abundant opportunities to enhance the efficiency of genebank operations, mine allelic variations in germplasm collection, identify genetically diverse germplasm with beneficial traits, broaden the cultigen’s genepool, and accelerate the cultivar development to address new challenges to production, particularly with respect to climate change and variability. Marker-assisted breeding approaches have already been initiated for some traits in chickpea and groundnut, which should lead to enhanced efficiency and efficacy of crop improvement. Resistance to some pests and diseases has been successfully transferred from wild relatives to cultivated species.

Nwokeocha et al (14)

African Journals Online (AJOL)

Timothy Ademakinwa

germplasm of peasant farmers (land races), wild relatives of cultivated rice ... accessions (both rootstocks and seeds) were collected, planted, screened, and ..... 3: Gene Systems Controlling Pigmentation in TOS - Purple and TOS - 15223 ...

Early maturing mutations as germplasm stocks for barley breeding

International Nuclear Information System (INIS)

Ukai, Yasuo

1985-01-01

A total of 102 early maturing mutations have been isolated after various treatments of seeds or plants with ionizing radiations or chemicals from a barley cultivar 'Chikurin Ibaraki 1' or its mutants. Fifty of them were evaluated as regards responses to internal physiological factors. The mutants were found to have a mutational alteration in vernalization and/or photoperiodic response. Earliness in a narrow sense was not noticeably changed. The original genotype is a winter and long-day type. By mutation four different degrees of change in vernalization requirement i.e. complete (V 1 ) and incomplete (V 2 ) spring habit and winter habit with reduced requirement to varying degrees (V 3 , V 4 ) have been produced. Photoperiodic response was also changed into at least three types i.e. complete (P 1 ) and incomplete (P 2 ) loss of sensitivity to short photoperiod and a slight reduction in critical daylength for heading. P 1 and P 2 type mutants were all characterized by marked earliness in heading time in field. Thirty seven mutants were located in seven separate loci. Allelism test of the mutated genes to spontaneous ones revealed that the genes carried by P 1 type mutants were all allelic to an earliness gene ea sub(k) on chromosome 5 and the gene involved in P 2 type mutants to ea 7 on chromosome 6. On the contrary, the gene commonly involved in all V 1 type mutants and one V 2 type mutant was not allelic to spring habit gene Sh 2 or Sh 3 . It seemed likely that the gene was not allelic to, either, but closely linked with sh on chromosome 4. The diversity in terms of genetic and physiological properties of the early maturing mutants arising from common ancestry emphasizes the importance of induced mutation in broadening of germplasm of barley breeding. (author)

Multi-Population Selective Genotyping to Identify Soybean [Glycine max (L.) Merr.] Seed Protein and Oil QTLs.

Science.gov (United States)

Phansak, Piyaporn; Soonsuwon, Watcharin; Hyten, David L; Song, Qijian; Cregan, Perry B; Graef, George L; Specht, James E

2016-06-01

Plant breeders continually generate ever-higher yielding cultivars, but also want to improve seed constituent value, which is mainly protein and oil, in soybean [Glycine max (L.) Merr.]. Identification of genetic loci governing those two traits would facilitate that effort. Though genome-wide association offers one such approach, selective genotyping of multiple biparental populations offers a complementary alternative, and was evaluated here, using 48 F2:3 populations (n = ∼224 plants) created by mating 48 high protein germplasm accessions to cultivars of similar maturity, but with normal seed protein content. All F2:3 progeny were phenotyped for seed protein and oil, but only 22 high and 22 low extreme progeny in each F2:3 phenotypic distribution were genotyped with a 1536-SNP chip (ca 450 bimorphic SNPs detected per mating). A significant quantitative trait locus (QTL) on one or more chromosomes was detected for protein in 35 (73%), and for oil in 25 (52%), of the 48 matings, and these QTL exhibited additive effects of ≥ 4 g kg(-1) and R(2) values of 0.07 or more. These results demonstrated that a multiple-population selective genotyping strategy, when focused on matings between parental phenotype extremes, can be used successfully to identify germplasm accessions possessing large-effect QTL alleles. Such accessions would be of interest to breeders to serve as parental donors of those alleles in cultivar development programs, though 17 of the 48 accessions were not unique in terms of SNP genotype, indicating that diversity among high protein accessions in the germplasm collection is less than what might ordinarily be assumed. Copyright © 2016 Phansak et al.

Determination of genetic variability of traditional varieties of Brazilian rice using microsatellite markers

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Claudio Brondani

2006-01-01

Full Text Available The rice (Oryza sativa breeding program of the Rice and Bean research center of the Brazilian agricultural company Empresa Brasileira de Pesquisa Agropecuária (Embrapa is well established and provides new cultivars every year to attend the demand for improved high yielding varieties with tolerance to biotic and abiotic stresses. However, the elite genitors used to compose new populations for selection are closely related, contributing to the yield plateau reached in the last 20 years. To overcome this limit, it is necessary to broaden the genetic basis of the cultivars using diverse germplasm such as wild relatives or traditional varieties, with the latter being more practical because they are more easily crossed with elite germplasm to accelerate the recovery of modern plant types in the breeding lines. The objective of our study was to characterize the allelic diversity of 192 traditional varieties of Brazilian rice using 12 simple sequence repeat (SSR or microsatellite markers. The germplasm was divided into 39 groups by common name similarity. A total of 176 alleles were detected, 30 of which (from 23 accessions were exclusive. The number of alleles per marker ranged from 6 to 22, with an average of 14.6 alleles per locus. We identified 16 accessions as a mixture of pure lines or heterozygous plants. Dendrogram analysis identified six clusters of identical accessions with different common names and just one cluster with identical accessions with the same common name, indicating that SSR markers are fundamental to determining the genetic relationship between landraces. A subset of 24 landraces, representatives of the 13 similarity groups plus the 11 accessions not grouped, was the most variable set of genotypes analyzed. These accessions can be used as genitors to increase the genetic variability available to rice breeding programs.

Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (DArT

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Edson P. Amorim

2009-01-01

Full Text Available The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 µg.g-1, and ranged from 1.06 µg.g-1 for the triploid Nanica (Cavendish group to 19.24 µg.g-1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 µg.g-1. The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00. DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.

Droplet vitrification technique for cryopreservation of different pineapple (Ananas comosus L. Merrill) accessions

Science.gov (United States)

Germplasm conservation of pineapple is crucial to secure the genetic variability of the genus for breeding programs and supporting new research. Long-term conservation is done through cryopreservation, by storing cells or tissues at ultra-low temperature in liquid nitrogen (LN; -196°C) or in the LN ...

Genetic diversity of a brazilian wine grape germplasm collection based on morphoagronomic traits Diversidade Genética de uma coleção Brasileira de uvas para vinho Baseada em Caracteres Morfoagronômicos

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Patrícia Coelho de S. Leão

2010-12-01

Full Text Available The objectives of this study were to evaluate the performance of cultivars, to quantify the variability and to estimate the genetic distances of 66 wine grape accessions in the Grape Germplasm Bank of the EMBRAPA Semi-Arid, in Juazeiro, BA, Brazil, through the characterization of discrete and continuous phenotypic variables. Multivariate statistics, such as, principal components, Tocher's optimization procedure, and the graphic of the distance, were efficient in grouping more similar genotypes, according to their phenotypic characteristics. There was no agreement in the formation of groups between continuous and discrete morpho-agronomic traits, when Tocher's optimization procedure was used. Discrete variables allowed the separation of Vitis vinifera and hybrids in different groups. Significant positive correlations were observed between weight, length and width of bunches, and a negative correlation between titratable acidity and TSS/TTA. The major part (84.12% of the total variation present in the original data was explained by the four principal components. The results revealed little variability between wine grape accessions in the Grape Germplasm Bank of Embrapa Semi-Arid.Os objetivos deste trabalho foram avaliar o comportamento agronômico, quantificar a variabilidade e estimar as distâncias genéticas de 66 acessos de videira destinadas à elaboração de vinhos, presente no Banco de Germoplasma de Videira da EMBRAPA Semiárido, em Juazeiro-BA, Brasil, por meio da caracterização de descritores fenotípicos de variação contínua e discreta. As técnicas multivariadas utilizadas, componentes principais, método de otimização de Tocher e projeção gráfica das distâncias foram eficientes no agrupamento dos genótipos mais similares, de acordo com as suas características fenotípicas. Não houve concordância na formação dos grupos pelo método de otimização de Tocher, quando foram avaliadas características morfoagronômicas de

Study of total seed proteins pattern of sesame (sesamum indicum l.) landraces via sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page)

International Nuclear Information System (INIS)

Akbar, F.; Shinwari, Z.K.

2012-01-01

The sesame (Sesamum indicum L.) germplasm, comprising of 105 accessions was characterized for total seed storage proteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The germplasm was collected from diverse agro-ecological regions of Pakistan. To our information, no studies have yet been carried out in Pakistan on the genetic evaluation of sesame genotypes based on total seed protein. Total seed proteins were electrophoretically separated on 12% polyacrylamide gels by standard protocols. A total of 20 polypeptide bands were observed, of which 14 (70%) were polymorphic and 6 (30%) were monomorphic, with molecular weight ranging from 13.5 to 100 kDa. Six bands i.e., 7, 11, 12, 15, 16 and 18 were common in all genotypes. Similarity coefficients varied fro m 0.50 to 1.00. The dendrogram based on dissimilarity matrix using unweighted pair group method with arithmetic averages (UPGMA) separated all sesame accessions into three main groups i.e., A, B, C, comprising 89, 14 and 2 genotypes, respectively. Overall a low to medium level of genetic variability was observed for SDS-PAGE (single dimension). As SDS-PAGE alone did not reveal high level of genetic variability, hence 2-D gel electrophoresis along with other advanced type DNA markers and more number of sesame accessions from all over the country are recommended for the future genetic evaluation. Our investigation will significantly support the classification, development, genetic evaluation and conservation of sesame germplasm in Pakistan. (author)

Study of total seed proteins pattern of sesame (sesamum indicum l.) landraces via sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page)

Energy Technology Data Exchange (ETDEWEB)

Akbar, F; Shinwari, Z K [Quaid-e-Azam University, Islamabad (Pakistan). Dept. of Biotechnology; Yousif, N; Masood, M S [Institute of Agri-Biotechnology and Genetic Resources, Islamabad (Pakistan)

2012-11-15

The sesame (Sesamum indicum L.) germplasm, comprising of 105 accessions was characterized for total seed storage proteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The germplasm was collected from diverse agro-ecological regions of Pakistan. To our information, no studies have yet been carried out in Pakistan on the genetic evaluation of sesame genotypes based on total seed protein. Total seed proteins were electrophoretically separated on 12% polyacrylamide gels by standard protocols. A total of 20 polypeptide bands were observed, of which 14 (70%) were polymorphic and 6 (30%) were monomorphic, with molecular weight ranging from 13.5 to 100 kDa. Six bands i.e., 7, 11, 12, 15, 16 and 18 were common in all genotypes. Similarity coefficients varied fro m 0.50 to 1.00. The dendrogram based on dissimilarity matrix using unweighted pair group method with arithmetic averages (UPGMA) separated all sesame accessions into three main groups i.e., A, B, C, comprising 89, 14 and 2 genotypes, respectively. Overall a low to medium level of genetic variability was observed for SDS-PAGE (single dimension). As SDS-PAGE alone did not reveal high level of genetic variability, hence 2-D gel electrophoresis along with other advanced type DNA markers and more number of sesame accessions from all over the country are recommended for the future genetic evaluation. Our investigation will significantly support the classification, development, genetic evaluation and conservation of sesame germplasm in Pakistan. (author)

Genetic divergence in quercus suber L. based on qualitative and quantitative traits

International Nuclear Information System (INIS)

Akbar, F.; Shinwari, Z.K.; Khan, S.J.

2011-01-01

Sesame (Sesamum indicum L.) is one of the world's oldest oil crops and has been cultivated in Asia since ancient times. The breeding potential of the germplasm accessions held in PGRP gene-bank has hardly been exploited to date. This study was carried out to evaluate the phenotypic variability in the local sesame genotypes using 16 qualitative and quantitative traits. A total of 105 sesame accessions collected from diverse ecologies of Pakistan were used. A considerable level of variation was recorded for a number of morphologic and agronomic traits, while limited diversity for observed among the accessions for characters like stem hairiness, flower color (white with purple shading), seed color and to some extent phyllody disease. The correlation coefficient analysis indicated that plant height, capsules plant/sup -1/, capsule length and 1000-seed weight had the significant positive effect on seed yield. The characters related to maturity, days to flower initiation an d days to 50% flowering showed negative correlation with seed yield. Multivariate analysis was performed in order to establish similarity and dissimilarity patterns. Principal component (PC) analysis revealed that first three PC axes explained 54.21% of the total multivariate variation, while the first four PC axes explaining 63.64%. Plant height, days to maturity, capsules plant/sup -1/ and seed yield plant/sup -1/ were the major determinants of the genetic diversity in the collection. Cluster analysis places all the accessions into seven groups. Clustering was not associated with the geographical distribution instead accessions were mainly grouped due to their morphological differences. Elite sesame germplasm has been selected on the basis of best agro-morphological performance from 105 sesame collections. These results have an important suggestion for sesame germplasm agro-morphological assessment, enhancement, categorization and conservation in Pakistan. (author)

Farmers' tree planting and access to germplasm in the southern ...

African Journals Online (AJOL)

Most farmers in the southern highlands of Tanzania plant significant numbers of trees and tree planting is an integral part of farming systems. Main purposes of tree planting are fuelwood, timber in a broad sense, and fruit production. People want to plant well-known species, which in most cases are exotics, and many ...

Detection of NAM-A1 Natural Variants in Bread Wheat Reveals Differences in Haplotype Distribution between a Worldwide Core Collection and European Elite Germplasm

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Fabien Cormier

2015-04-01

Full Text Available In wheat, remobilization of nitrogen absorbed before anthesis and regulation of monocarpic senescence is a major issue in breeding for nutrient use efficiency. We identified natural variants of NAM-A1, a gene having the same role as its well-characterized homoeolog NAM-B1, a NAC transcription factor associated with senescence kinetics and nutrient remobilization to the grain. Differences in haplotype frequencies between a worldwide core collection and a panel of European elite varieties were assessed and discussed. Moreover, hypotheses for the loss of function of the most common haplotype in elite European germplasm are discussed.

Catalog of banana (Musa spp.) accessions maintained at the USDA-ARS, Tropical Agriculture Reserach Station

Science.gov (United States)

Banana genetic resources can be found in situ in native habitats in Southeast Asia and the Pacific region. Ex situ collections also exist in important tropical regions of the world as well as in vitro cultures at the Bioversity International Musa Germplasm Transit Centre. Unfortunately, readily avai...

Resveratrols in grape berry skins and leaves in vitis germplasm.

Science.gov (United States)

Wang, Lijun; Xu, Man; Liu, Chunyan; Wang, Junfang; Xi, Huifen; Wu, Benhong; Loescher, Wayne; Duan, Wei; Fan, Peige; Li, Shaohua

2013-01-01

Resveratrol is an important stilbene that benefits human health. However, it is only distributed in a few species including grape and is very expensive. At present, grape has been an important source resveratrol. However, the details are scarce on resveratrol distribution in different Vitis species or cultivars. The composition and content of resveratrols were investigated by HPLC for assessing genotypic variation in berry skins and leaves of 75 grape cultivars, belonging to 3 species and 7 interspecific hybrids. Trans-resveratrol, cis-piceid and trans-piceid were detected in berry skins and leaves, but cis-resveratrol was not. Resveratrol content largely varied with genetic background as well as usage. In most cultivars, total resveratrol including the above three compounds was higher in berry skins than leaves. In berry skins of most cultivars and leaves of almost all cultivars, cis-piceid was the most abundant resveratrol; trans-resveratrol and trans-piceid were minor components. Some specific cultivars were found with extremely high levels of trans-resveratrol, cis- piceid, trans-piceid or total resveratrols in berry skins or leaves. In skins and leaves, rootstock cultivars had a higher content of total resveratrols, and the cultivated European type cultivars and their hybrids with V. labrusca had relatively low totals. There were no significant correlations of the amounts of total resveratrols or any individual resveratrol between berry skins and leaves. All 75 cultivars can be divided into four groups based on the composition of resveratrols and their concentration by principal component analysis. Resveratrol content of grape berries and leaves varied largely with their genetic background and usage. Rootstock cultivars had a higher content of total resveratrols than the other germplasm. Total resveratrols were lower in leaves than berry skins in most cultivars. Cis-piceid was the most abundant resveratrol in most cultivars, and trans-res and trans-pd were

Development of Pineapple Microsatellite Markers and Germplasm Genetic Diversity Analysis

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Suping Feng

2013-01-01

Full Text Available Two methods were used to develop pineapple microsatellite markers. Genomic library-based SSR development: using selectively amplified microsatellite assay, 86 sequences were generated from pineapple genomic library. 91 (96.8% of the 94 Simple Sequence Repeat (SSR loci were dinucleotide repeats (39 AC/GT repeats and 52 GA/TC repeats, accounting for 42.9% and 57.1%, resp., and the other three were mononucleotide repeats. Thirty-six pairs of SSR primers were designed; 24 of them generated clear bands of expected sizes, and 13 of them showed polymorphism. EST-based SSR development: 5659 pineapple EST sequences obtained from NCBI were analyzed; among 1397 nonredundant EST sequences, 843 were found containing 1110 SSR loci (217 of them contained more than one SSR locus. Frequency of SSRs in pineapple EST sequences is 1SSR/3.73 kb, and 44 types were found. Mononucleotide, dinucleotide, and trinucleotide repeats dominate, accounting for 95.6% in total. AG/CT and AGC/GCT were the dominant type of dinucleotide and trinucleotide repeats, accounting for 83.5% and 24.1%, respectively. Thirty pairs of primers were designed for each of randomly selected 30 sequences; 26 of them generated clear and reproducible bands, and 22 of them showed polymorphism. Eighteen pairs of primers obtained by the one or the other of the two methods above that showed polymorphism were selected to carry out germplasm genetic diversity analysis for 48 breeds of pineapple; similarity coefficients of these breeds were between 0.59 and 1.00, and they can be divided into four groups accordingly. Amplification products of five SSR markers were extracted and sequenced, corresponding repeat loci were found and locus mutations are mainly in copy number of repeats and base mutations in the flanking region.

Development of Pineapple Microsatellite Markers and Germplasm Genetic Diversity Analysis

Science.gov (United States)

Tong, Helin; Chen, You; Wang, Jingyi; Chen, Yeyuan; Sun, Guangming; He, Junhu; Wu, Yaoting

2013-01-01

Two methods were used to develop pineapple microsatellite markers. Genomic library-based SSR development: using selectively amplified microsatellite assay, 86 sequences were generated from pineapple genomic library. 91 (96.8%) of the 94 Simple Sequence Repeat (SSR) loci were dinucleotide repeats (39 AC/GT repeats and 52 GA/TC repeats, accounting for 42.9% and 57.1%, resp.), and the other three were mononucleotide repeats. Thirty-six pairs of SSR primers were designed; 24 of them generated clear bands of expected sizes, and 13 of them showed polymorphism. EST-based SSR development: 5659 pineapple EST sequences obtained from NCBI were analyzed; among 1397 nonredundant EST sequences, 843 were found containing 1110 SSR loci (217 of them contained more than one SSR locus). Frequency of SSRs in pineapple EST sequences is 1SSR/3.73 kb, and 44 types were found. Mononucleotide, dinucleotide, and trinucleotide repeats dominate, accounting for 95.6% in total. AG/CT and AGC/GCT were the dominant type of dinucleotide and trinucleotide repeats, accounting for 83.5% and 24.1%, respectively. Thirty pairs of primers were designed for each of randomly selected 30 sequences; 26 of them generated clear and reproducible bands, and 22 of them showed polymorphism. Eighteen pairs of primers obtained by the one or the other of the two methods above that showed polymorphism were selected to carry out germplasm genetic diversity analysis for 48 breeds of pineapple; similarity coefficients of these breeds were between 0.59 and 1.00, and they can be divided into four groups accordingly. Amplification products of five SSR markers were extracted and sequenced, corresponding repeat loci were found and locus mutations are mainly in copy number of repeats and base mutations in the flanking region. PMID:24024187

Pathogenic variability of Colletotrichum lindemuthianum and Ecuadorian Phaseolus vulgaris L. germplasm resistance

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Diego Rodríguez-Ortega

2018-01-01

Full Text Available Anthracnose caused by Colletotrichum lindemuthianum is one of the most economically important diseases of bean (Phaseolus vulgaris L. cultivation in Ecuador. The best control alternative is the use of resistant varieties. C. lindemuthianum presents great pathogenic variability, which hinders the development of varieties with a lasting resistance, therefore, the knowledge of the presence and distribution of the physiological races of the pathogen and the identification of resistance genes are key to developing varieties with broad and lasting resistance. The objective of this research was to determine the pathogenic variability of C. lindemuthianum and to evaluate the resistance of Ecuadorian bean germplasm. The research was carried out between 2013 and 2014. Seventeen isolates of C. lindemuthianum from northern central Ecuador were characterized by the inoculation of a group of twelve standard differential bean varieties. Among the analyzed samples, thirteen races were identified; five of those races had not been previously reported in the country. The differential G2333 (Co-42, Co-52 and Co-7 presented resistance to every characterized races in Ecuador. In addition, twenty - one improved varieties and elite bean lines were evaluated with sixteen of the seventeen isolates, three genotypes were identified (TB2, TB3 and INIAP 485 Urcuquí with resistance to the mentioned isolates, which can be used as sources of resistance to Anthracnose. The identified sources of resistance in this study will allow to plan the development of bean varieties with broad and durable resistance to C. lindemuthianum.

GRIN-Global: An International Project to Develop a Global Plant Genebank and Information Management System

Science.gov (United States)

Many of the world's national genebanks, responsible for the safeguarding and availability of their country's Plant Genetic Resource (PGR) collections, have lacked access to high quality IT needed to document and manage their collections electronically. The Germplasm Resource Information System (GRI...

Development of diagnostic markers for use in breeding potatoes resistant to Globodera pallida pathotype Pa2/3 using germplasm derived from Solanum tuberosum ssp. andigena CPC 2802.

Science.gov (United States)

Moloney, Claire; Griffin, Denis; Jones, Peter W; Bryan, Glenn J; McLean, Karen; Bradshaw, John E; Milbourne, Dan

2010-02-01

Quantitative resistance to Globodera pallida pathotype Pa2/3, originally derived from Solanum tuberosum ssp. andigena Commonwealth Potato Collection (CPC) accession 2802, is present in several potato cultivars and advanced breeding lines. One genetic component of this resistance, a large effect quantitative trait locus (QTL) on linkage group IV (which we have renamed GpaIV(adg)(s)) has previously been mapped in the tetraploid breeding line 12601ab1. In this study, we show that GpaIV(adg)(s) is also present in a breeding line called C1992/31 via genetic mapping in an F(1) population produced by crossing C1992/31 with the G. pallida susceptible cultivar Record. C1992/31 is relatively divergent from 12601ab1, confirming that GpaIV(adg)(s) is an ideal target for marker-assisted selection in currently available germplasm. To generate markers exhibiting diagnostic potential for GpaIV(adg)(s), three bacterial artificial chromosome clones were isolated from the QTL region, sequenced, and used to develop 15 primer sets generating single-copy amplicons, which were examined for polymorphisms exhibiting linkage to GpaIV(adg)(s) in C1992/31. Eight such polymorphisms were found. Subsequently, one insertion/deletion polymorphism, three single nucleotide polymorphisms and a specific allele of the microsatellite marker STM3016 were shown to exhibit diagnostic potential for the QTL in a panel of 37 potato genotypes, 12 with and 25 without accession CPC2082 in their pedigrees. STM3016 and one of the SNP polymorphisms, C237(119), were assayed in 178 potato genotypes, arising from crosses between C1992/31 and 16 G. pallida susceptible genotypes, undergoing selection in a commercial breeding programme. The results suggest that the diagnostic markers would most effectively be employed in MAS-based approaches to pyramid different resistance loci to develop cultivars exhibiting strong, durable resistance to G. pallida pathotype Pa2/3.

Agrobiodiversity and ethnoknowledge in Gleba Nova Olinda I, Pará: social interactions and sharing of manioc's germplasm (Manihot Esculenta Crantz, Euphorbiaceae

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Pedro Glécio Costa Lima

2013-08-01

Full Text Available A major concern of ethnobiology is to understand the social relations that favor the occurrence and expansion of biological diversity in the Neotropic. This article evaluates the richness of ethnovarieties of cassava cultivated in communities located in public forest lands named Gleba Nova Olinda I, Pará State, Brazil. Data were obtained in workshops with 46 informants, and were analyzed by qualitative and quantitative methods. There are at least 52 manioc ethnovarieties on this site and germplasm sharing occurs both inside and outside the community. The knowledge improvement on this agrobiological resource by community members shows the important role that the inhabitants play in biological conservation of Gleba Nova Olinda I. Thus, support to local development should be grounded on ethnoknowledge.

Analysis of Genetic Diversity and Population Structure of Rice Germplasm from North-Eastern Region of India and Development of a Core Germplasm Set

Science.gov (United States)

Singh, Amit Kumar; Kumar, Sundeep; Srinivasan, Kalyani; Tyagi, R. K.; Ahmad, Altaf; Singh, N. K.; Singh, Rakesh

2014-01-01

The North-Eastern region (NER) of India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura, is a hot spot for genetic diversity and the most probable origin of rice. North-east rice collections are known to possess various agronomically important traits like biotic and abiotic stress tolerance, unique grain and cooking quality. The genetic diversity and associated population structure of 6,984 rice accessions, originating from NER, were assessed using 36 genome wide unlinked single nucleotide polymorphism (SNP) markers distributed across the 12 rice chromosomes. All of the 36 SNP loci were polymorphic and bi-allelic, contained five types of base substitutions and together produced nine types of alleles. The polymorphic information content (PIC) ranged from 0.004 for Tripura to 0.375 for Manipur and major allele frequency ranged from 0.50 for Assam to 0.99 for Tripura. Heterozygosity ranged from 0.002 in Nagaland to 0.42 in Mizoram and gene diversity ranged from 0.006 in Arunachal Pradesh to 0.50 in Manipur. The genetic relatedness among the rice accessions was evaluated using an unrooted phylogenetic tree analysis, which grouped all accessions into three major clusters. For determining population structure, populations K = 1 to K = 20 were tested and population K = 3 was present in all the states, with the exception of Meghalaya and Manipur where, K = 5 and K = 4 populations were present, respectively. Principal Coordinate Analysis (PCoA) showed that accessions were distributed according to their population structure. AMOVA analysis showed that, maximum diversity was partitioned at the individual accession level (73% for Nagaland, 58% for Arunachal Pradesh and 57% for Tripura). Using POWERCORE software, a core set of 701 accessions was obtained, which accounted for approximately 10% of the total NE India collections, representing 99.9% of the allelic diversity. The rice core set developed will be a

Analysis of genetic diversity and population structure of rice germplasm from north-eastern region of India and development of a core germplasm set.

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Debjani Roy Choudhury

Full Text Available The North-Eastern region (NER of India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura, is a hot spot for genetic diversity and the most probable origin of rice. North-east rice collections are known to possess various agronomically important traits like biotic and abiotic stress tolerance, unique grain and cooking quality. The genetic diversity and associated population structure of 6,984 rice accessions, originating from NER, were assessed using 36 genome wide unlinked single nucleotide polymorphism (SNP markers distributed across the 12 rice chromosomes. All of the 36 SNP loci were polymorphic and bi-allelic, contained five types of base substitutions and together produced nine types of alleles. The polymorphic information content (PIC ranged from 0.004 for Tripura to 0.375 for Manipur and major allele frequency ranged from 0.50 for Assam to 0.99 for Tripura. Heterozygosity ranged from 0.002 in Nagaland to 0.42 in Mizoram and gene diversity ranged from 0.006 in Arunachal Pradesh to 0.50 in Manipur. The genetic relatedness among the rice accessions was evaluated using an unrooted phylogenetic tree analysis, which grouped all accessions into three major clusters. For determining population structure, populations K = 1 to K = 20 were tested and population K = 3 was present in all the states, with the exception of Meghalaya and Manipur where, K = 5 and K = 4 populations were present, respectively. Principal Coordinate Analysis (PCoA showed that accessions were distributed according to their population structure. AMOVA analysis showed that, maximum diversity was partitioned at the individual accession level (73% for Nagaland, 58% for Arunachal Pradesh and 57% for Tripura. Using POWERCORE software, a core set of 701 accessions was obtained, which accounted for approximately 10% of the total NE India collections, representing 99.9% of the allelic diversity. The rice core set developed

Analysis of genetic diversity and population structure of rice germplasm from north-eastern region of India and development of a core germplasm set.

Science.gov (United States)

Roy Choudhury, Debjani; Singh, Nivedita; Singh, Amit Kumar; Kumar, Sundeep; Srinivasan, Kalyani; Tyagi, R K; Ahmad, Altaf; Singh, N K; Singh, Rakesh

2014-01-01

The North-Eastern region (NER) of India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura, is a hot spot for genetic diversity and the most probable origin of rice. North-east rice collections are known to possess various agronomically important traits like biotic and abiotic stress tolerance, unique grain and cooking quality. The genetic diversity and associated population structure of 6,984 rice accessions, originating from NER, were assessed using 36 genome wide unlinked single nucleotide polymorphism (SNP) markers distributed across the 12 rice chromosomes. All of the 36 SNP loci were polymorphic and bi-allelic, contained five types of base substitutions and together produced nine types of alleles. The polymorphic information content (PIC) ranged from 0.004 for Tripura to 0.375 for Manipur and major allele frequency ranged from 0.50 for Assam to 0.99 for Tripura. Heterozygosity ranged from 0.002 in Nagaland to 0.42 in Mizoram and gene diversity ranged from 0.006 in Arunachal Pradesh to 0.50 in Manipur. The genetic relatedness among the rice accessions was evaluated using an unrooted phylogenetic tree analysis, which grouped all accessions into three major clusters. For determining population structure, populations K = 1 to K = 20 were tested and population K = 3 was present in all the states, with the exception of Meghalaya and Manipur where, K = 5 and K = 4 populations were present, respectively. Principal Coordinate Analysis (PCoA) showed that accessions were distributed according to their population structure. AMOVA analysis showed that, maximum diversity was partitioned at the individual accession level (73% for Nagaland, 58% for Arunachal Pradesh and 57% for Tripura). Using POWERCORE software, a core set of 701 accessions was obtained, which accounted for approximately 10% of the total NE India collections, representing 99.9% of the allelic diversity. The rice core set developed will be a

Número cromossômico em acessos de Pennisetum spp. (Poaceae, Poales = Chromosome number in Pennisetum spp. accessions (Poaceae, Poales

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Vânia Helena Techio

2008-07-01

Full Text Available Avaliou-se o complemento cromossômico de 16 acessos de Pennisetum disponíveis na Coleção de Germoplasma da Embrapa Gado de Leite – Juiz de Fora, Estado de Minas Gerais. Para a avaliação citogenética, utilizou-se a técnica de esmagamento e coloração com Feulgen. Paraquatro acessos foram obtidas metáfases com 2n = 28 cromossomos, confirmando sua classificação como P. purpureum. A origem híbrida P. purpureum x P. glaucum foi constatada em oito acessos, os quais apresentaram 2n = 21. Em um acesso identificado como híbrido entre P.purpureum x P. glaucum, foram observadas metáfases com 2n = 54, permitindo inferir que não se trata de um híbrido interespecífico triplóide. Para outros três acessos avaliados, também foramobservadas células com 2n = 54, embora estivessem identificados como híbridos entre P. purpureum x espécie selvagem; P. glaucum policross x hexaplóide 200 e P. glaucum x [F92-161-01 (P. purpureum x P. glaucum].The chromosome complement of 16 Pennisetum accessions belonging to the Germplasm Collection of Embrapa Gado de Leite - Juiz de Fora, Minas Gerais State was evaluated. The cytogenetic analysis employed the smear technique and staining with Feulgen. In four accessions,metaphases with 2n = 28 chromosomes were obtained, confirming their classification as P. purpureum. The hybrid origin P. purpureum x P. glaucum was observed in eight accessions, which presented 2n = 21. In an accession identified as P. purpureum x P. glaucum hybrid, metaphases with 2n = 54 were observed, suggesting that it is not a triploid interspecific hybrid. For three other evaluated accessions, cells with 2n=54 were also observed, although they were identified ashybrids between P. purpureum x wild species; P. glaucum polycross x hexaploid 200 and P. glaucum x [F92-161-01 (P. purpureum x P. glaucum].

Chemical Diversity in Basil (Ocimum sp.) Germplasm

Science.gov (United States)

da Costa, Andréa Santos; Arrigoni-Blank, Maria de Fátima; de Carvalho Filho, José Luiz Sandes; de Santana, Aléa Dayane Dantas; Santos, Darlisson de Alexandria; Alves, Péricles Barreto; Blank, Arie Fitzgerald

2015-01-01

The present study aimed to chemically characterize 31 accessions and seven cultivars of basil. The percentage composition of the essential oils of the accessions and cultivars was based on the 14 most abundant constituents: 1,8-cineole, linalool, methyl chavicol, neral, nerol, geraniol, geranial, methyl cinnamate, β-bourbonene, methyl eugenol, α-trans-bergamotene, germacrene-D, epi-α-cadinol, and δ-cadinene. The genetic materials were classified into eight clusters according to the chemical composition of the essential oils: Cluster 1—mostly linalool and 1,8-cineole; Cluster 2—mostly linalool, geraniol, and α-trans-bergamotene; Cluster 3—mostly linalool, methyl chavicol, methyl cinnamate, and β-bourbonene; Cluster 4—mostly linalool, methyl chavicol, epi-α-cadinol, and α-trans-bergamotene; Cluster 5—mainly linalool, methyl eugenol, α-trans-bergamotene, and epi-α-cadinol; Cluster 6—mainly linalool, geraniol, and epi-α-cadinol; Cluster 7—mostly linalool and methyl chavicol; Cluster 8—mainly geranial and neral. PMID:25629084

Chemical Diversity in Basil (Ocimum sp. Germplasm

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Andréa Santos da Costa

2015-01-01

Full Text Available The present study aimed to chemically characterize 31 accessions and seven cultivars of basil. The percentage composition of the essential oils of the accessions and cultivars was based on the 14 most abundant constituents: 1,8-cineole, linalool, methyl chavicol, neral, nerol, geraniol, geranial, methyl cinnamate, β-bourbonene, methyl eugenol, α-trans-bergamotene, germacrene-D, epi-α-cadinol, and δ-cadinene. The genetic materials were classified into eight clusters according to the chemical composition of the essential oils: Cluster 1—mostly linalool and 1,8-cineole; Cluster 2—mostly linalool, geraniol, and α-trans-bergamotene; Cluster 3—mostly linalool, methyl chavicol, methyl cinnamate, and β-bourbonene; Cluster 4—mostly linalool, methyl chavicol, epi-α-cadinol, and α-trans-bergamotene; Cluster 5—mainly linalool, methyl eugenol, α-trans-bergamotene, and epi-α-cadinol; Cluster 6—mainly linalool, geraniol, and epi-α-cadinol; Cluster 7—mostly linalool and methyl chavicol; Cluster 8—mainly geranial and neral.

Molecular characterization and genetic diversity of Jatropha curcas L. in Costa Rica

Science.gov (United States)

Vásquez-Mayorga, Marcela; Fuchs, Eric J.; Hernández, Eduardo J.; Herrera, Franklin; Hernández, Jesús; Moreira, Ileana; Arnáez, Elizabeth

2017-01-01

We estimated the genetic diversity of 50 Jatropha curcas samples from the Costa Rican germplasm bank using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the phylogenetic relationships among samples using nuclear ribosomal ITS markers. Non-toxicity was evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ) tree and a Maximum Likelihood (ML) tree were constructed using SSR markers and ITS sequences, respectively. Heterozygosity was moderate (He = 0.346), but considerable compared to worldwide values for J. curcas. The PIC (PIC = 0.274) and inbreeding coefficient (f =  − 0.102) were both low. Clustering was not related to the geographical origin of accessions. International accessions clustered independently of collection sites, suggesting a lack of genetic structure, probably due to the wide distribution of this crop and ample gene flow. Molecular markers identified only one non-toxic accession (JCCR-24) from Mexico. This work is part of a countrywide effort to characterize the genetic diversity of the Jatropha curcas germplasm bank in Costa Rica. PMID:28289556

Molecular characterization and genetic diversity of Jatropha curcas L. in Costa Rica

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Marcela Vásquez-Mayorga

2017-02-01

Full Text Available We estimated the genetic diversity of 50 Jatropha curcas samples from the Costa Rican germplasm bank using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the phylogenetic relationships among samples using nuclear ribosomal ITS markers. Non-toxicity was evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ tree and a Maximum Likelihood (ML tree were constructed using SSR markers and ITS sequences, respectively. Heterozygosity was moderate (He = 0.346, but considerable compared to worldwide values for J. curcas. The PIC (PIC = 0.274 and inbreeding coefficient (f =  − 0.102 were both low. Clustering was not related to the geographical origin of accessions. International accessions clustered independently of collection sites, suggesting a lack of genetic structure, probably due to the wide distribution of this crop and ample gene flow. Molecular markers identified only one non-toxic accession (JCCR-24 from Mexico. This work is part of a countrywide effort to characterize the genetic diversity of the Jatropha curcas germplasm bank in Costa Rica.

South African Journal of Plant and Soil

African Journals Online (AJOL)

AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... Log in or Register to get access to full text downloads. ... Original research papers, short communications including germplasm registrations, relevant ... Botma Visser, Liezel Herselman, Zacharias A Pretorius, 161-166.

Genetic diversity of Bambara groundnut ( Vigna subterranea (L ...

African Journals Online (AJOL)

The existence of genetic diversity in germplasm collections is crucial for cultivar development. Genetic relationships among 105 Bambara groundnuts (Vigna subterranea (L) Verdc.) accessions from Kenya were evaluated using 12 microsatellite markers. The Bambara landraces were collected from farmers in the western ...

SolRgene: an online database to explore disease resistance genes in tuber-bearing Solanum species

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Vleeshouwers Vivianne GAA

2011-08-01

Full Text Available Abstract Background The cultivated potato (Solanum tuberosum L. is an important food crop, but highly susceptible to many pathogens. The major threat to potato production is the Irish famine pathogen Phytophthora infestans, which causes the devastating late blight disease. Potato breeding makes use of germplasm from wild relatives (wild germplasm to introduce resistances into cultivated potato. The Solanum section Petota comprises tuber-bearing species that are potential donors of new disease resistance genes. The aim of this study was to explore Solanum section Petota for resistance genes and generate a widely accessible resource that is useful for studying and implementing disease resistance in potato. Description The SolRgene database contains data on resistance to P. infestans and presence of R genes and R gene homologues in Solanum section Petota. We have explored Solanum section Petota for resistance to late blight in high throughput disease tests under various laboratory conditions and in field trials. From resistant wild germplasm, segregating populations were generated and assessed for the presence of resistance genes. All these data have been entered into the SolRgene database. To facilitate genetic and resistance gene evolution studies, phylogenetic data of the entire SolRgene collection are included, as well as a tool for generating phylogenetic trees of selected groups of germplasm. Data from resistance gene allele-mining studies are incorporated, which enables detection of R gene homologs in related germplasm. Using these resources, various resistance genes have been detected and some of these have been cloned, whereas others are in the cloning pipeline. All this information is stored in the online SolRgene database, which allows users to query resistance data, sequences, passport data of the accessions, and phylogenic classifications. Conclusion Solanum section Petota forms the basis of the SolRgene database, which contains a

Population structure and genetic diversity characterization of a sunflower association mapping population using SSR and SNP markers.

Science.gov (United States)

Filippi, Carla V; Aguirre, Natalia; Rivas, Juan G; Zubrzycki, Jeremias; Puebla, Andrea; Cordes, Diego; Moreno, Maria V; Fusari, Corina M; Alvarez, Daniel; Heinz, Ruth A; Hopp, Horacio E; Paniego, Norma B; Lia, Veronica V

2015-02-13

Argentina has a long tradition of sunflower breeding, and its germplasm is a valuable genetic resource worldwide. However, knowledge of the genetic constitution and variability levels of the Argentinean germplasm is still scarce, rendering the global map of cultivated sunflower diversity incomplete. In this study, 42 microsatellite loci and 384 single nucleotide polymorphisms (SNPs) were used to characterize the first association mapping population used for quantitative trait loci mapping in sunflower, along with a selection of allied open-pollinated and composite populations from the germplasm bank of the National Institute of Agricultural Technology of Argentina. The ability of different kinds of markers to assess genetic diversity and population structure was also evaluated. The analysis of polymorphism in the set of sunflower accessions studied here showed that both the microsatellites and SNP markers were informative for germplasm characterization, although to different extents. In general, the estimates of genetic variability were moderate. The average genetic diversity, as quantified by the expected heterozygosity, was 0.52 for SSR loci and 0.29 for SNPs. Within SSR markers, those derived from non-coding regions were able to capture higher levels of diversity than EST-SSR. A significant correlation was found between SSR and SNP- based genetic distances among accessions. Bayesian and multivariate methods were used to infer population structure. Evidence for the existence of three different genetic groups was found consistently across data sets (i.e., SSR, SNP and SSR + SNP), with the maintainer/restorer status being the most prevalent characteristic associated with group delimitation. The present study constitutes the first report comparing the performance of SSR and SNP markers for population genetics analysis in cultivated sunflower. We show that the SSR and SNP panels examined here, either used separately or in conjunction, allowed consistent

Behavior in yield and quality of 54 cape gooseberry (Physalis peruviana L. accessions from north-eastern Colombia

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Herrera M. Axel M.

2011-08-01

Full Text Available

This study evaluated the performance in production and fruit quality of 54 accessions of cape gooseberry collected from plants that were cultivated, feral and indeterminate from the north-east. The experiment was carried out using a completely randomized design with four replicates per accession in a greenhouse. We estimated the germination percentage (GP for 30 seeds per accession and with a random sampling of 20 fruits at 120 days after the beginning of harvest (dah, weight of the fruit with calyx (CFW, percentage of cracked fruit (CF, number of fruits per plant (NFP and yield (Y, were determined and at 105 dah total soluble solids (TSS, total titratable acidity (TTA, maturity ratio (MR = TSS/TTA, pH and ascorbic acid (AA were evaluated. Significant differences were observed in GP, Y and CFW with the highest values recorded at 91.23%, 6.17 kg/ plant and 5.68 g, respectively. For the variables TSS and CF, feral materials showed the highest values with 14.7°Brix and 23.93%, respectively. The results suggest the presence of significant variability in the Cape gooseberry germplasm analyzed that can be incorporated into future conservation and breeding programs.

Seedling Emergence and Phenotypic Response of Common Bean Germplasm to Different Temperatures under Controlled Conditions and in Open Field.

Science.gov (United States)

De Ron, Antonio M; Rodiño, Ana P; Santalla, Marta; González, Ana M; Lema, María J; Martín, Isaura; Kigel, Jaime

2016-01-01

Rapid and uniform seed germination and seedling emergence under diverse environmental conditions is a desirable characteristic for crops. Common bean genotypes (Phaseolus vulgaris L.) differ in their low temperature tolerance regarding growth and yield. Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed for the success of the bean crop. The objectives of this study were (i) to screen the seedling emergence and the phenotypic response of bean germplasm under a range of temperatures in controlled chamber and field conditions to display stress-tolerant genotypes with good agronomic performances and yield potential, and (ii) to compare the emergence of bean seedlings under controlled environment and in open field conditions to assess the efficiency of genebanks standard germination tests for predicting the performance of the seeds in the field. Three trials were conducted with 28 dry bean genotypes in open field and in growth chamber under low, moderate, and warm temperature. Morpho-agronomic data were used to evaluate the phenotypic performance of the different genotypes. Cool temperatures resulted in a reduction of the rate of emergence in the bean genotypes, however, emergence and early growth of bean could be under different genetic control and these processes need further research to be suitably modeled. Nine groups arose from the Principal Component Analysis (PCA) representing variation in emergence time and proportion of emergence in the controlled chamber and in the open field indicating a trend to lower emergence in large and extra-large seeded genotypes. Screening of seedling emergence and phenotypic response of the bean germplasm under a range of temperatures in controlled growth chambers and under field conditions showed several genotypes, as landraces 272, 501, 593, and the cultivar Borlotto, with stress-tolerance at emergence, and high yield

Seedling Emergence and Phenotypic Response of Common Bean Germplasm to Different Temperatures under Controlled Conditions and in Open Field

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Antonio M. DE RON

2016-08-01

Full Text Available Rapid and uniform seed germination and seedling emergence under diverse environmental conditions is a desirable characteristic for crops. Common bean genotypes (Phaseolus vulgaris L. differ in their low temperature tolerance regarding growth and yield. Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed for the success of the bean crop. The objectives of this study were i to screen the seedling emergence and the phenotypic response of bean germplasm under a range of temperatures in controlled chamber and field conditions to display stress-tolerant genotypes with good agronomic performances and yield potential, and ii to compare the emergence of bean seedlings under controlled environment and in open field conditions to assess the efficiency of genebanks standard germination tests for predicting the performance of the seeds in the field. Three trials were conducted with 28 dry bean genotypes in open field and in growth chamber under low, moderate and warm temperature. Morpho-agronomic data were used to evaluate the phenotypic performance of the different genotypes. Cool temperatures resulted in a reduction of the rate of emergence in the bean genotypes, however, emergence and early growth of bean could be under different genetic control and these processes need further research to be suitably modeled. Nine groups arose from the Principal Component Analysis (PCA representing variation in emergence time and proportion of emergence in the controlled chamber and in the open field indicating a trend to lower emergence in large and extra-large seeded genotypes. Screening of seedling emergence and phenotypic response of the bean germplasm under a range of temperatures in controlled growth chambers and under field conditions showed several genotypes, as landraces 272, 501, 593 and the cultivar Borlotto, with stress-tolerance at emergence and high

石斛属植物种质资源鉴定及指纹图谱应用研究进展%Progress in Application of Germplasm Identification and Fingerprinting of Dendrobium Species

Institute of Scientific and Technical Information of China (English)

李杰; 章金辉; 朱根发; 王再花

2013-01-01

In order to identify the germplasm sources, fake and inferior Dendrobium in the market, multiple methods have been applied in identification of Dendrobium germplasm. In the paper, characteristics and applications of the morphological, microstructure, cytological, palynological, chemical fingerprinting and DNA fingerprinting methods were reviewed. It was found that fingerprintings were effective for discrimination the germplasm and geo-herbalism of Dendrobium, and medicinal material quality control, while the criterions and evaluation system of fingerprintings should be further completed, and it was necessary to focus on the aspects of reasonable evaluation and utilization wild resources, combination of fingerprintings and pharmacological action, genetic improvement and gene cloning for the future research in Dendrobium.%　　为了鉴别石斛属植物不同种质，区分石斛伪品劣品，笔者综述了传统的形态学与显微鉴定、细胞学、孢粉学以及指纹图谱技术（化学指纹图谱和DNA指纹图谱）的特点，及其在石斛属植物种质资源鉴定中的应用，发现指纹图谱技术对石斛属植物的种源和道地性鉴定以及石斛类药材质量控制十分有效，但指纹图谱标准和评价体系还存在不足，今后还需在野生石斛资源的评价与合理利用、指纹图谱与药理作用相关性、遗传改良和基因克隆等方面开展深入研究。

Characterisation of quinoa (Chenopodium quinoa Willd. accessions for the saponin content in Mediterranean environment

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Giuditta De Santis

2016-08-01

Full Text Available Seeds of the Andean seed crop quinoa (Chenopodium quinoa Willd. usually contain saponins in the seed coat. Saponins give a bitter taste sensation and are a serious antinutritional factor, therefore selection of sweet genotypes with a very low saponin content in the seeds is a main breeding goal. The objective of this work was to identify, within germplasm lines of quinoa, previously selected for production and quality traits, superior genotypes low in saponins. For this purpose the total saponin content was determined in seeds of eight lines of quinoa and one variety (cv. Regalona Baer as a control, previously evaluated over a 2-year period in a Southern Italy environment. Significant variation for the saponin content was observed among the evaluated genotypes. The total saponin content ranged from 0.10 to 1.80%, with the Q12 genotype showing the lowest value, suggesting the possibility of selecting genotypes sweet to be used in subsequent genetic improvement programs. Based on these results, in fact, it was possible to identify, among the accessions previously selected, particularly suitable for growing in Mediterranean area, some genotypes with high yields of seed (2.5 tha–1, on average, high protein (17%, on average and fibres (13%, on average and low content in saponins (0.57%, on average.

Freeing Crop Genetics through the Open Source Seed Initiative.

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Claire H Luby

2016-04-01

Full Text Available For millennia, seeds have been freely available to use for farming and plant breeding without restriction. Within the past century, however, intellectual property rights (IPRs have threatened this tradition. In response, a movement has emerged to counter the trend toward increasing consolidation of control and ownership of plant germplasm. One effort, the Open Source Seed Initiative (OSSI, www.osseeds.org, aims to ensure access to crop genetic resources by embracing an open source mechanism that fosters exchange and innovation among farmers, plant breeders, and seed companies. Plant breeders across many sectors have taken the OSSI Pledge to create a protected commons of plant germplasm for future generations.

Freeing Crop Genetics through the Open Source Seed Initiative.

Science.gov (United States)

Luby, Claire H; Goldman, Irwin L

2016-04-01

For millennia, seeds have been freely available to use for farming and plant breeding without restriction. Within the past century, however, intellectual property rights (IPRs) have threatened this tradition. In response, a movement has emerged to counter the trend toward increasing consolidation of control and ownership of plant germplasm. One effort, the Open Source Seed Initiative (OSSI, www.osseeds.org), aims to ensure access to crop genetic resources by embracing an open source mechanism that fosters exchange and innovation among farmers, plant breeders, and seed companies. Plant breeders across many sectors have taken the OSSI Pledge to create a protected commons of plant germplasm for future generations.

Genome-wide association mapping of anthracnose (Collectotrichum sublineolun) resistance in U.S. sorghum association panel

Science.gov (United States)

The productivity and profitability of sorghum [Sorghum bicolor (L.) Moench] is reduced by susceptibility to fungal diseases such as anthracnose, which causes yield loss of both grain and biomass. A limited number of resistant accessions are present in temperate adapted germplasm, while resistant sou...

Characterization and diversity assessment in coconut collections of ...

African Journals Online (AJOL)

SUBDIC

conservation. Therefore, the present study was undertaken with the aim to characterize morphological, biochemical and nut component traits and to assess the diversity among 24 exotic and six indigenous in coconut accessions conserved at World Coconut Germplasm. Centre (WCGC) in Andaman and Nicobar Islands ...

Phenotypic variation in a core collection of common bean (Phaseolus vulgaris L.) in the Netherlands

NARCIS (Netherlands)

Zeven, A.C.; Waninge, J.; Hintum, van Th.J.L.; Singh, S.P.

1999-01-01

Forty accessions, forming a core collection of mainly bush type of the common bean (Phaseolus vulgaris L.) germplasm in the Netherlands, were evaluated for 14 qualitative and quantitative traits at the Agricultural University, Wageningen (WAU), the Netherlands in 1992. These and an additional 117

Browse Title Index

African Journals Online (AJOL)

Items 101 - 150 of 1010 ... Vol 26, No 1 (2018), Characterisation of Phaseolus coccineus interspecific germplasm accessions for disease resistance, grain market class and ... Vol 20, No 2 (2012), Comparative activities of phenylalanine ammonia-lyase and tyrosine ammonia-lyase and phenolic compounds accumulated in ...

DNA profiling of figs (Ficus carica L.) from Slovenia and Californian USDA collection revealed the uniqueness of some North Adriatic varieties

Science.gov (United States)

A set of 23 local varieties from Slovenia and 218 fig accessions from Californian fig germplasm collection were compared to determine the identity of genotypes and their possible genetic relationships. Figs were genotyped using twelve microsatellite loci. One hundred alleles were identified over all...

Crop Registration: The Pathway to Public Access of Plant Genetic Materials to Build Crops for the Future

Science.gov (United States)

Starting as Crop Science Registrations in the American Journal of the Society of Agronomy in 1926, and continuing 80+ years later in the Journal of Plant Registrations, 11,241 plant cultivars, germplasm, parental lines, genetic stocks and mapping populations have been registered as of December 31, 2...

Molecular diversity of α-gliadin expressed genes in genetically contrasted spelt (Triticum aestivum ssp. spelta) accessions and comparison with bread wheat (T. aestivum ssp. aestivum) and related diploid Triticum and Aegilops species.

Science.gov (United States)

Dubois, Benjamin; Bertin, Pierre; Mingeot, Dominique

2016-01-01

The gluten proteins of cereals such as bread wheat ( Triticum aestivum ssp. aestivum ) and spelt ( T. aestivum ssp. spelta ) are responsible for celiac disease (CD). The α-gliadins constitute the most immunogenic class of gluten proteins as they include four main T-cell stimulatory epitopes that affect CD patients. Spelt has been less studied than bread wheat and could constitute a source of valuable diversity. The objective of this work was to study the genetic diversity of spelt α-gliadin transcripts and to compare it with those of bread wheat. Genotyping data from 85 spelt accessions obtained with 19 simple sequence repeat (SSR) markers were used to select 11 contrasted accessions, from which 446 full open reading frame α-gliadin genes were cloned and sequenced, which revealed a high allelic diversity. High variations among the accessions were highlighted, in terms of the proportion of α-gliadin sequences from each of the three genomes (A, B and D), and their composition in the four T-cell stimulatory epitopes. An accession from Tajikistan stood out, having a particularly high proportion of α-gliadins from the B genome and a low immunogenic content. Even if no clear separation between spelt and bread wheat sequences was shown, spelt α-gliadins displayed specific features concerning e.g. the frequencies of some amino acid substitutions. Given this observation and the variations in toxicity revealed in the spelt accessions in this study, the high genetic diversity held in spelt germplasm collections could be a valuable resource in the development of safer varieties for CD patients.

Characterization of Citrus tristeza virus isolates from grapefruit (Citrus paradisi Macf. accessions of Citrus Active Germplasm Bank Caracterização de isolados do vírus da tristeza dos citros de acessos de pomelos (Citrus paradisi Macf. do Banco Ativo de Germoplasma de Citros

Directory of Open Access Journals (Sweden)

Maria Júlia Corazza-Nunes

2006-09-01

Full Text Available Citrus tristeza virus (CTV isolates from 35 grapefruit accessions belonging to Citrus Active Germplasm Bank of the "Instituto Agronômico de Campinas" located at the "Centro APTA Citros Sylvio Moreira", Cordeirópolis, São Paulo state, Brazil, were characterized and evaluated through symptoms in the trees, biological indexing, immunological diagnosis with different monoclonal antibodies and SSCP analysis (single-strand conformation polymorphism of the coat protein gene. Symptomatology indicated that, in general, the group of plants with smaller canopy volume and severe stem pitting differed significantly from the group that presented greater vegetative development and mild to moderate stem pitting. However, the isolates from most of the accessions induced mild reaction on Mexican lime. The serological evaluation through the DAS-ELISA using monoclonal antibodies did not reveal any association between virus titer in the plant tissue and symptoms. The reaction with different monoclonal antibodies and the distinct electrophoresis patterns obtained through SSCP showed that there is a high degree of diversity among the isolates that infect these grapefruit accessions. High complexity within the same isolate was also observed in the SSCP profiles. This finding indicates that the CTV isolates from these plants are a complex mixture of CTV haplotypes. Similar SSCP banding patterns were observed among some plants with strong stem pitting symptoms, and among some plants with weak or moderate stem pitting symptoms.Isolados do vírus da tristeza dos citros (CTV de 35 acessos de pomelos que fazem parte do Banco Ativo de Germoplasma de Citros, localizado no Centro APTA Citros Sylvio Moreira, Cordeirópolis, São Paulo, Brasil, pertencente ao Instituto Agronômico de Campinas (IAC, foram caracterizados através dos sintomas observados nas árvores, indexação biológica, diagnóstico imunológico e análise SSCP (polimorfismo de conformação de fita simples

Analysis of genetic diversity in Arrhenatherum elatius Germplasm ...

African Journals Online (AJOL)

Jane

2011-07-25

Jul 25, 2011 ... The genetic diversity of 19 Arrhenatherum elatius accessions was analyzed ... can be used as novel DNA markers for genomic .... phylogenies and evolutionary biology. .... struction Project of the Beijing Academy of Agriculture.

Growth and physiological responses of two phenotypically distinct accessions of centipedegrass (Eremochloa ophiuroides (Munro) Hack.) to salt stress.

Science.gov (United States)

Li, JianJian; Ma, Jingjing; Guo, Hailin; Zong, Junqin; Chen, Jingbo; Wang, Yi; Li, Dandan; Li, Ling; Wang, Jingjing; Liu, Jianxiu

2018-05-01

Salinity is one of the major abiotic environmental stress factors affecting plant growth and development. Centipedegrass (Eremochloa ophiuroides [Munro)] Hack.) is an important warm-season turfgrass species with low turf maintenance requirements, but is sensitive to salinity stress. To explore salt tolerant germplasms in centipedegrass and better understand the growth and physiological responses of centipedegrass to salinity, we conducted anatomic observation and phytochemical quantification, examined growth parameters, and investigated photosynthetic machinery and antioxidant system in two phenotypically distinct centipedegrass accessions under NaCl salt stress. The morphophenotypical difference of the stems in the two accessions mainly depends on whether or not a thickened epidermal horny layer with purple colour was formed, which was caused by anthocyanin accumulation in the tissue. Successive salinity treatment was found to result in an inhibition of leaf growth, a marked decrease in photosynthesis, chlorophyll contents, and the maximal photochemical efficiency of PSII (Fv/Fm). Under the same treatment, purple-stem accession (E092) showed a lower degree of inhibition or decrease than green-stem one (E092-1). With the exception of malondialdehyde level, both proline content and antioxidant enzymes were upregulated to a greater extent in E092 following exposure to salinity condition. Meanwhile, significant enhancements of anthocyanin accumulation and total protein synthesis were detected in E092 after salt treatment, but not in E092-1. These results demonstrated that E092 favor better accumulation of anthocyanins under salinity condition, which contribute to salt tolerance by adjusting physiological functions and osmotic balance, and better maintenance of high turf quality. Hence, genetic phenotype can be utilized as a key indicator in E. ophiuroides breeding for salt-tolerance. Copyright © 2018. Published by Elsevier Masson SAS.

Morphologic characterization and evaluation of the national collection of germoplasm of camu camu Myrciaria dubia (H.B.K Mc Vaugh, of the INIA Loreto-Peru

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Sixto Imán Correa

2011-12-01

Full Text Available The aim of this study was to characterize and evaluate morphologically the national collection of germplasm INIA camu camu made up of 43 accessions collected in the Loreto region, for conservation and use. The results show that the germplasm of camu camu has high variability and three types of plant architecture (column, intermediate and branched. The flowers are hermaphrodite or androgynous and have herkogamy empowering the outcrossing or cross-pollination. The color of the fruit depends on the state of maturation of the same, varies from green to red-violet, the number of seeds per fruit varies from 1 to 4, the number of fruits per kg is 90 to 148. Twenty one accessions were found with yields greater than 15 kg per plant and 16 accessions of over 2000 mg of ascorbic acid /100 g of pulp. In addition, we identified 10 promising accessions by fruit yield and ascorbic acid contents. Through Principal Component Analysis was determined that the variables are positively associated with the fruit yield, plant height and stem diameter. The dendrogram derived from cluster analysis allowed the identification of three groups based on fruit yield, the first group consists of 22 accessions whose fruit yields are between 2.29 and 11.97 kg / plant, the second group 16 accessions that have yields 16.97 to 30.35 kg of / plant, and the third group consists of 5 accessions from 36.52 to 39.24 yields kg/plant.

Dry matter yield and Carbon partitioning in the aboveground part of switchgrass ( panicum virgatum l.) germplasm

Energy Technology Data Exchange (ETDEWEB)

Butkutė, B.; Lemežien ė, N.; Cesevičienė, J.; Liaudanskienė, I., E-mail: brone@lzi.lt [Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kėdainiai distr. (Lithuania)

2013-07-01

Carbon (C) accumulated in biomass can be converted into usable forms of energy like methane, bioethanol or solid fuel. Understanding the partitioning of aboveground biomass and C plays an important role in optimizing its pre-treatment technologies. Our objectives were to determine dry matter yield (DMY) and C partitioning in switch grass germplasm. Plants were sampled at heading (HS) and seed filling (SFS) stages. The biomass of the SFS-sampled plants was separated into leaves (blades+sheaths), stems, and panicles. C content was determined by dry combustion. C yield per plant (CY) at HS ranged from 25.9 to 171 g (37.3 g on average for plants in the first harvest year, and 147 for those in the second harvest year), at SFS CY varied within a range of 79.8 ‒ 295g and averaged 119 and 252g depending on the year of growth. DMY was a weighted factor for such results. At SFS, DMY of stems accounted on average for 46.3%, leaves for 40.5%, and panicles for 13.2% of the aboveground biomass of whole plant with respective C concentrations of 462, 439 and 459 g kg -1 DM. (author)

Prima facie reasons to question enclosed intellectual property regimes and favor open-source regimes for germplasm.

Science.gov (United States)

Halpert, Madeleine-Thérèse; Chappell, M Jahi

2017-01-01

In principle, intellectual property protections (IPPs) promote and protect important but costly investment in research and development. However, the empirical reality of IPPs has often gone without critical evaluation, and the potential of alternative approaches to lend equal or greater support for useful innovation is rarely considered. In this paper, we review the mounting evidence that the global intellectual property regime (IPR) for germplasm has been neither necessary nor sufficient to generate socially beneficial improvements in crop plants and maintain agrobiodiversity. Instead, based on our analysis, the dominant global IPR appears to have contributed to consolidation in the seed industry while failing to genuinely engage with the potential of alternatives to support social goods such as food security, adaptability, and resilience. The dominant IPR also constrains collaborative and cumulative plant breeding processes that are built upon the work of countless farmers past and present. Given the likely limits of current IPR, we propose that social goods in agriculture may be better supported by alternative approaches, warranting a rapid move away from the dominant single-dimensional focus on encouraging innovation through ensuring monopoly profits to IPP holders.

CARACTERIZAÇÃO MORFOLÓGICA DE ACESSOS DE GERMOPLASMA DE QUATRO ESPÉCIES BRASILEIRAS DE AMENDOIM-SILVESTRE MORPHOLOGICAL CHARACTERIZATION OF GERMPLASM ACESSIONS OF FOUR BRAZILIAN SPECIES OF WILD PEANUT

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RENATO FERRAZ DE ARRUDA VEIGA

2001-01-01

Full Text Available Caracterizaram-se morfologicamente os acessos de germoplasma de espécies silvestres brasileiras de amendoim do gênero Arachis L., Sect. Arachis e analisaram-se a similaridade genética entre acessos da mesma espécie e entre as espécies. Realizou-se o experimento nos anos agrícolas de 1993 a 1996, no Núcleo Experimental de Campinas, do Instituto Agronômico (IAC. Avaliaram-se os acessos disponíveis no Banco Ativo de Germoplasma de Espécies Silvestres de Arachis, da Embrapa Recursos Genéticos e Biotecnologia (CENARGEN - Brasília, DF, das espécies A. palustris Krapov., W.C. Gregory & Valls, A. decora Krapov., W.C. Gregory & Valls, A. praecox Krapov., W.C. Gregory & Valls e A. stenosperma Krapov. & W.C. Gregory, efetuando-se anotações fenotípicas quantitativas e qualitativas, conforme lista de descritores morfológicos. Observou-se que os acessos de A. stenosperma são semelhantes, apesar da sua grande distância geográfica, e diferem das demais espécies, formando um grupo mais coeso. Caracteres como o diâmetro do eixo central e o comprimento dos frutos e das sementes serviram para distingui-la das demais espécies. Arachis decora apresentou alta variação entre acessos nos vários caracteres morfológicos estudados. A. palustris apresentou alta variação morfológica entre acessos, ainda que tenham sido analisados apenas dois, para altura da planta, largura da semente, dimensões do esporão, istmo, folíolo, raque e eixo central e quanto à presença e ausência de tricomas no folíolo. Arachis praecox, representada por um único acesso, aproximou-se mais de A. decora que das demais espécies.In this work, a morphological characterization of germplasm accessions of wild Brazilian species of peanut, section Arachis was accomplished. Also, an analysis of the genetic similarity among accessions and between species was evaluated. The experiment was undertaken from 1993 to 1996, at the Campinas Experimental Station of the Instituto

芋种质资源颜色性状多样性观察%Observation on Diversity of Color Characters of Taro Germplasm Resource

Institute of Scientific and Technical Information of China (English)

黄新芳; 李峰; 朱红莲; 黄来春; 李明华; 王芸; 钟兰; 周凯; 刘正位; 匡晶; 孙亚林; 董红霞; 刘玉平; 柯卫东; 刘义满; 李双梅; 叶元英; 彭静

2016-01-01

为了探究芋种质资源颜色性状的变化规律，以保存在国家种质武汉水生蔬菜资源圃的300多份芋种质资源为材料，按照《农作物种质资源鉴定评价技术规范芋》对芋种质资源的颜色性状进行观察和归类，并重点对芋的叶心色斑颜色、叶柄中下部颜色及母芋芽色的相关性进行总结和探讨。根据叶柄中下部颜色将滇南芋分为绿柄野芋（白芽类型）、乌绿柄野芋（红芽类型）和紫柄野芋（白芽类型）3个类型；将芋中的多子芋分为绿柄多子芋（一般为白芽类型）、乌绿柄多子芋（一般为红芽类型）和红紫柄多子芋（白芽类型）3个基本类型，将芋中的多头芋分为绿柄多头芋（白芽类型）和乌绿柄多头芋（红芽类型）2个类型。从滇南芋和芋的整体来看，只要叶柄中下部颜色含有乌绿色成分，则母芋芽色一般为红色类型。从叶心色斑颜色来看，滇南芋中的绿色者，母芋芽色为白色类型；紫红色或紫色者，母芋芽色可能为白色类型，也可能为红色类型。芋中，多子芋叶心色斑颜色为紫红色者，母芋芽色为红色类型；黄绿色或绿色者，母芋芽色为白色类型。多头芋中，叶心色斑颜色为绿色者，母芋芽色为红色类型；紫红色者，母芋芽色为白色类型。%In order to find out the changing rule of color characters of taro germplasm resource,we observed and classified the color character diversities of taro 〔Colocasia antiquorum Schott andColocasia esculenta (L.) Schott〕 germplasm resource according to the Technical Code for Evaluating Crop Germplasm Resources-Taro 〔Colocasia esculenta (L.) Schott〕,taking over 300 taro germplasm resources conserved in Wuhan National Germplasm Repository for Aquatic Vegetables. We summarized and focused on the correlation between leaf junction color,color of middle to lower part of petiole,and bud color of corm. According

In situ evaluation of the fruit and oil characteristics of the main Lebanese olive germplasm.

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Chehade, Ali; Bitar, Ahmad El; Kadri, Aline; Choueiri, Elia; Nabbout, Rania; Youssef, Hiyam; Smeha, Maha; Awada, Ali; Chami, Ziad Al; Dubla, Eustachio; Trani, Antonio; Mondelli, Donato; Famiani, Franco

2016-05-01

Very little information is available on the characteristics of the Lebanese olive germplasm. Therefore, the aim of this work was to evaluate the fruit and oil characteristics of the main Lebanese olive varieties (Aayrouni, Abou chawkeh, Baladi, Del and Soury) from two successive crop seasons (2010-2011). All of the genotypes had medium-high oil content in the fruit, indicating their suitability for oil production; Aayrouni had particularly high values. The variety Abou chawkeh also had a high pulp/pit ratio, which is a very desirable trait in table olives. For all the varieties the values of free fatty acids, peroxide values, absorbances in ultraviolet, fatty acid composition, sterol content and composition and erythrodiol + uvaol content of the oils were within the requirements of the International Olive Council's Trade Standard for extra virgin olive oil. The only exception was for the values of Δ-7-stigmastenol in 2011 in Soury and, especially, in Baladi, which were higher than 0.5%. In some cases, stearic and arachidic acids fluctuated around the maximum values allowed. The findings of this study provide a first picture of the main characteristics of olives and oils currently produced in Lebanon. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Genetic diversity of "Pimenta Longa" genotypes (Piper spp., Piperaceae of the Embrapa Acre germplasm collection

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Lúcia Helena de Oliveira Wadt

2004-01-01

Full Text Available The commonly known Pimenta longa is a commercially valuable natural resource found wild in Acre, Brazil. Specifically, three Piperaceae species with contested taxonomic status were studied, Piper hispidinervum, Piper aduncum, and Piper hispidum, to assesses the inter- and intra-specific genetic relationship of 49 Piper genotypes kept in the Pimenta longa germplasm collection at Embrapa Acre, using sixty six Random Amplified Polymorphic DNA (RAPD markers. The DNA polymorphism level detected was high (96.97%, but the marker frequencies for each species showed polymorphism levels of 79.4% for Piper hispidinervum and 5.3% for P. aduncum. The genetic similarity clustering analysis resulted in three distinct groups corresponding to Piper hispidinervum, Piper aduncum, and Piper hispidum. Four and nine characteristic RAPD markers were identified for P. hispidinervum and P. aduncum, respectively, supporting the existence of two separate species. However, six genotypes collected in Tarauacá county formed a distinct subgroup within the P. hispidinervum group and may be considered as an ecotype of this species or an intermediate between the P. hispidinervum and P. aduncum groups. More extensive sampling of both P. hispidinervum and P. aduncum populations throughout the region are needed to further establish their relation and its implication for breeding efforts.

Seed Characteristics Diversity in Sponge Gourd (Luffa aegyptiaca Mill. Germplasms from Hatay Region in Turkey

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Kazım MAVİ

2018-05-01

Full Text Available The objective of this study was to evaluate seed characteristics of sponge gourd, to establish a core collection of sponge gourd with the germplasm collected throughout the Hatay region. A mini-core collection was assessed for morphological performance and some seed traits. Substantial variations of seed characteristics: seed length, seed width, seed thickness (mm, seed index (length/width, seed size (length × width, mm2, seed colour, seed-coat surface, seed shape, seed wing, and 100-seed weight were investigated. Seed length, width and thickness were varied as 15.12-8.97 mm, 9.71-6.25 mm and 2.86-2.16 mm respectively. The seed sizes were determined from small (31 DÖ 06 to big (31 DE 04. Seed colours were ranged from black to white, even a brown colour like 07 MA 01. A hundred seed weights were observed as 16.43 g (31 AL 02 and 7.41 (31 DÖ 06. The results of dendrogram indicated that seed traits of the sponge gourd genotypes were separating in five groups. This collection of sponge gourds will be useful for the gene pools and a wide range of phenotypic variations to provide a good source of diversity for developing of sponge gourd cultivars in breeding programs.

RAPD markers associated with resistance to blackleg disease in ...

African Journals Online (AJOL)

Blackleg, caused by Leptosphaeria maculans, is a serious disease of Brassica species. Genetic analysis of resistance to L. maculans was carried out with 15 accessions from the USDA Brassica germplasm collections, representing diploids (A, C), and tetraploid (AC) genomes, respectively; and 9 cultivars from the National ...

Quantitative trait loci mapping of western corn rootworm (Coleoptera: Chrysomelidae) host plant resistance in two populations of doubled haploid lines in maize (Zea mays L.)

Science.gov (United States)

Over the last 70 years, more than 12,000 maize accessions have been screened for their level of resistance to western corn rootworm, Diabrotica virgifera virgifera LeConte, larval feeding. Less than 1% of this germplasm was selected for initiating recurrent selection or other breeding programs. Sele...

Multivariate analysis of quantitative traits can effectively classify rapeseed germplasm

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Jankulovska Mirjana

2014-01-01

Full Text Available In this study, the use of different multivariate approaches to classify rapeseed genotypes based on quantitative traits has been presented. Tree regression analysis, PCA analysis and two-way cluster analysis were applied in order todescribe and understand the extent of genetic variability in spring rapeseed genotype by trait data. The traits which highly influenced seed and oil yield in rapeseed were successfully identified by the tree regression analysis. Principal predictor for both response variables was number of pods per plant (NP. NP and 1000 seed weight could help in the selection of high yielding genotypes. High values for both traits and oil content could lead to high oil yielding genotypes. These traits may serve as indirect selection criteria and can lead to improvement of seed and oil yield in rapeseed. Quantitative traits that explained most of the variability in the studied germplasm were classified using principal component analysis. In this data set, five PCs were identified, out of which the first three PCs explained 63% of the total variance. It helped in facilitating the choice of variables based on which the genotypes’ clustering could be performed. The two-way cluster analysissimultaneously clustered genotypes and quantitative traits. The final number of clusters was determined using bootstrapping technique. This approach provided clear overview on the variability of the analyzed genotypes. The genotypes that have similar performance regarding the traits included in this study can be easily detected on the heatmap. Genotypes grouped in the clusters 1 and 8 had high values for seed and oil yield, and relatively short vegetative growth duration period and those in cluster 9, combined moderate to low values for vegetative growth duration and moderate to high seed and oil yield. These genotypes should be further exploited and implemented in the rapeseed breeding program. The combined application of these multivariate methods

Divergência genética em tomate estimada por marcadores RAPD em comparação com descritores multicategóricos Genetic divergence among tomato accessions using RAPD markers and its comparison with multicategoric descriptors

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Leandro SA Gonçalves

2008-09-01

Full Text Available A estimativa da variabilidade genética existente em um banco de germoplasma é importante não só para a conservação dos recursos genéticos, mas também para aplicações no melhoramento de plantas. O presente trabalho teve como objetivo estudar a divergência genética entre 78 acessos de uma coleção de germoplasma de tomateiro, com base em 74 marcadores RAPD e correlacionar esses resultados àqueles da caracterização morfoagronômica realizada para 27 descritores. Foi utilizado o agrupamento hierárquico UPGMA para analisar os dados, observando-se a formação de 13 grupos. Esses grupos foram correlacionados a cinco descritores (hábito de crescimento, tipo de folha, cor do fruto, número de lóculos e formato do fruto. Alguns grupos apresentaram peculiaridades, a exemplo do grupo IV, que reuniu acessos com frutos no formato de pêra; o grupo VII com acessos resistentes a murcha-bacteriana e o grupo IX, que englobou acessos com folhas do tipo batata. As análises por bootstrap revelaram poucos agrupamentos consistentes. Houve correlação positiva e altamente significativa entre as matrizes geradas pelos 27 descritores qualitativos e pelos marcadores RAPD (t = 14,02. A correlação de Mantel (r = 0,39 foi altamente significativa, porém de baixa magnitude. O baixo valor verificado para esta correlação sugere que ambas as etapas de caracterização (morfoagronômica e molecular são importantes para um conhecimento mais amplo e melhor discriminação entre os acessos de tomate.The estimation of genetic variability in a germplasm bank is important not only for the conservation of the genetic resources, but also for applications in plant breeding. The genetic divergence among 78 tomato accessions was studied, based on 74 RAPD markers. Also, a correlation between the molecular profile and 27 morphological and agronomic data was performed. Cluster analysis (UPGMA, used to study the data, resulted in 13 groups that were correlated with

Preservation of plant genetic resources in the biotechnology era.

Science.gov (United States)

Börner, Andreas

2006-12-01

Thousands of years ago humans began domesticating crops as a food source. Among the wild germplasm available, they selected those that were best adapted for cultivation and utilization. Although wild ancestors have continued to persist in regions where domestication took place, there is a permanent risk of loss of the genetic variability of cultivated plants and their wild relatives in response to changing environmental conditions and cultural practices. Recognizing this danger, plant ex situ genebank collections were created since the beginning of the last century. World-wide, more than 6 million accessions have been accumulated including the German ex situ genebank in Gatersleben, one of the four largest global collections, housing 150,000 accessions belonging to 890 genera and 3032 species. This review summarizes the ex situ plant genetic resources conservation behavior with a special emphasis on German activities. Strategies for maintenance and management of germplasm collections are reviewed, considering modern biotechnologies (in vitro and cryo preservation). General aspects on genetic diversity and integrity are discussed.

URJC GB dataset: Community-based seed bank of Mediterranean high-mountain and semi-arid plant species at Universidad Rey Juan Carlos (Spain).

Science.gov (United States)

Alonso, Patricia; Iriondo, José María

2014-01-01

The Germplasm Bank of Universidad Rey Juan Carlos was created in 2008 and currently holds 235 accessions and 96 species. This bank focuses on the conservation of wild-plant communities and aims to conserve ex situ a representative sample of the plant biodiversity present in a habitat, emphasizing priority ecosystems identified by the Habitats Directive. It is also used to store plant material for research and teaching purposes. The collection consists of three subcollections, two representative of typical habitats in the center of the Iberian Peninsula: high-mountain pastures (psicroxerophylous pastures) and semi-arid habitats (gypsophylic steppes), and a third representative of the genus Lupinus. The high-mountain subcollection currently holds 153 accessions (63 species), the semi-arid subcollection has 76 accessions (29 species,) and the Lupinus subcollection has 6 accessions (4 species). All accessions are stored in a freezer at -18 °C in Kilner jars with silica gel. The Germplasm Bank of Universidad Rey Juan Carlos follows a quality control protocol which describes the workflow performed with seeds from seed collection to storage. All collectors are members of research groups with great experience in species identification. Herbarium specimens associated with seed accessions are preserved and 63% of the records have been georreferenced with GPS and radio points. The dataset provides unique information concerning the location of populations of plant species that form part of the psicroxerophylous pastures and gypsophylic steppes of Central Spain as well as populations of genus Lupinus in the Iberian Peninsula. It also provides relevant information concerning mean seed weight and seed germination values under specific incubation conditions. This dataset has already been used by researchers of the Area of Biodiversity and Conservation of URJC as a source of information for the design and implementation of experimental designs in these plant communities. Since

URJC GB dataset: Community-based seed bank of Mediterranean high-mountain and semi-arid plant species at Universidad Rey Juan Carlos (Spain

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Patricia Alonso

2014-03-01

Full Text Available The Germplasm Bank of Universidad Rey Juan Carlos was created in 2008 and currently holds 235 accessions and 96 species. This bank focuses on the conservation of wild-plant communities and aims to conserve ex situ a representative sample of the plant biodiversity present in a habitat, emphasizing priority ecosystems identified by the Habitats Directive. It is also used to store plant material for research and teaching purposes. The collection consists of three subcollections, two representative of typical habitats in the center of the Iberian Peninsula: high-mountain pastures (psicroxerophylous pastures and semi-arid habitats (gypsophylic steppes, and a third representative of the genus Lupinus. The high-mountain subcollection currently holds 153 accessions (63 species, the semi-arid subcollection has 76 accessions (29 species, and the Lupinus subcollection has 6 accessions (4 species. All accessions are stored in a freezer at -18 °C in Kilner jars with silica gel. The Germplasm Bank of Universidad Rey Juan Carlos follows a quality control protocol which describes the workflow performed with seeds from seed collection to storage. All collectors are members of research groups with great experience in species identification. Herbarium specimens associated with seed accessions are preserved and 63% of the records have been georreferenced with GPS and radio points. The dataset provides unique information concerning the location of populations of plant species that form part of the psicroxerophylous pastures and gypsophylic steppes of Central Spain as well as populations of genus Lupinus in the Iberian Peninsula. It also provides relevant information concerning mean seed weight and seed germination values under specific incubation conditions. This dataset has already been used by researchers of the Area of Biodiversity and Conservation of URJC as a source of information for the design and implementation of experimental designs in these plant

Characterization and evaluation of five jaboticaba accessions at the subtropical horticulture research station in Miami, Florida

Science.gov (United States)

Fruit of five Jaboticaba (Myrciaria caulifloria) cultivars ‘MC-05-06’, ‘MC-05-14’, ‘MC-05-12’, ‘MC-06-15,’ and ‘MC-06-14’ were evaluated and characterized at the National Germplasm Repository, Subtropical horticulture Research Station (SHRS) Miami, Florida. Thirty fruits were harvested from clona...

Association mapping for yield and grain quality traits in rice (Oryza sativa L.)

Science.gov (United States)

2010-01-01

Association analysis was applied to a panel of accessions of Embrapa Rice Core Collection (ERiCC) with 86 SSR and field data from two experiments. A clear subdivision between lowland and upland accessions was apparent, thereby indicating the presence of population structure. Thirty-two accessions with admixed ancestry were identified through structure analysis, these being discarded from association analysis, thus leaving 210 accessions subdivided into two panels. The association of yield and grain-quality traits with SSR was undertaken with a mixed linear model, with markers and subpopulation as fixed factors, and kinship matrix as a random factor. Eight markers from the two appraised panels showed significant association with four different traits, although only one (RM190) maintained the marker-trait association across years and cultivation. The significant association detected between amylose content and RM190 was in agreement with previous QTL analyses in the literature. Herein, the feasibility of undertaking association analysis in conjunction with germplasm characterization was demonstrated, even when considering low marker density. The high linkage disequilibrium expected in rice lines and cultivars facilitates the detection of marker-trait associations for implementing marker assisted selection, and the mining of alleles related to important traits in germplasm. PMID:21637426

Classification and characterization of species within the genus lens using genotyping-by-sequencing (GBS.

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Melissa M L Wong

Full Text Available Lentil (Lens culinaris ssp. culinaris is a nutritious and affordable pulse with an ancient crop domestication history. The genus Lens consists of seven taxa, however, there are many discrepancies in the taxon and gene pool classification of lentil and its wild relatives. Due to the narrow genetic basis of cultivated lentil, there is a need towards better understanding of the relationships amongst wild germplasm to assist introgression of favourable genes into lentil breeding programs. Genotyping-by-sequencing (GBS is an easy and affordable method that allows multiplexing of up to 384 samples or more per library to generate genome-wide single nucleotide Polymorphism (SNP markers. In this study, we aimed to characterize our lentil germplasm collection using a two-enzyme GBS approach. We constructed two 96-plex GBS libraries with a total of 60 accessions where some accessions had several samples and each sample was sequenced in two technical replicates. We developed an automated GBS pipeline and detected a total of 266,356 genome-wide SNPs. After filtering low quality and redundant SNPs based on haplotype information, we constructed a maximum-likelihood tree using 5,389 SNPs. The phylogenetic tree grouped the germplasm collection into their respective taxa with strong support. Based on phylogenetic tree and STRUCTURE analysis, we identified four gene pools, namely L. culinaris/L. orientalis/L. tomentosus, L. lamottei/L. odemensis, L. ervoides and L. nigricans which form primary, secondary, tertiary and quaternary gene pools, respectively. We discovered sequencing bias problems likely due to DNA quality and observed severe run-to-run variation in the wild lentils. We examined the authenticity of the germplasm collection and identified 17% misclassified samples. Our study demonstrated that GBS is a promising and affordable tool for screening by plant breeders interested in crop wild relatives.

Genetic diversity and population structure of common bean ...

African Journals Online (AJOL)

The Ethiopian genetic center is considered to be one of the secondary centers of diversity for the common bean. This study was conducted to characterize the distribution of genetic diversity between and within ecological/geographical regions of Ethiopia. A germplasm sample of 116 landrace accessions was developed, ...

Browse Title Index

African Journals Online (AJOL)

Items 51 - 100 of 444 ... Vol 40, No 1 (2007), Blood biochemistry and haematology of weaner rabbits fed sun-dried, ensiled, and fermented cassava peel-based diets, Abstract ... Vol 31, No 1 (1998), Characterization and preliminary evaluation of some accessions of local germplasm of velvet bean (Mucuna pruriens DCvar.

Characterisation of twenty-nine (29) accessions of okra (Abelmoschus spp (L.) Moench) in Ghana

International Nuclear Information System (INIS)

Ahiakpa, J. K.

2012-01-01

A series of investigations were carried out to determine the genetic variability within 29 accessions of okra (Abelmoschus spp (L.) Moench) through characterisation using morphological, biochemical, nutritional and molecular markers. The goal was to obtain information on key traits of okra germplasm relevant to breeders and other researchers towards improvement of the crop. Twenty six (26) indigenous (landraces) and three (3) exotic accessions of okra were collected from eight regions of Ghana and their morpho-agronomic traits were evaluated under field conditions at the Biotechnology and Nuclear Agriculture Research Institute (BNARI) research fields using the International Plant Genetic Research Institute (IPGRI) descriptor list for okra. The 29 exhibited significant variation in all but two quantitative traits studied. Block coefficients of variation were extremely low, implying that results obtained are reliable and repeatable over replications. The 29 accessions were grouped into two major clusters and subsequently into five sub-clusters based on both quantitative and qualitative characters studied. The association between pairs of quantitative yield traits in the okra landraces revealed that flowering and fruiting parameters had significant (P < 0.01) positive associations. Factor scores of 12 characters contributed substantially to total genetic variation among the 29 okra accessions studied. The pattern of clustering did not show distinct association between morpho-agronomic characters and geographic origin of the collections. The output of the Principal Components Analysis (PCA) revealed that different characters contributed differently to total genetic variation. The means of maximum viscosity values for mucilage extracted from the fruits ranged from 53.0 - 366.8bu, with three accessions; DKA (366.8bu), Yeji-Local (329bu) and Amanfrom (316.8bu) recording very high values whilst Cape (53.0bu) had the least maximum viscosity value. There was low level of

Total phenolics, flavonoids, tannins and antioxidant activity of lima beans conserved in a Brazilian Genebank

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Tânia da Silveira Agostini-Costa

2015-02-01

Full Text Available The objective of this study was to characterize for the first time polyphenols and DPPH (2-diphenyl-1-picryhydrazyl radical antioxidant activity in commonly cultivated accessions of Phaseolus lunatus from an ex situ germplasm collection maintained by Embrapa, in Brazil. Furthermore, the study aimed to detect changes in total polyphenols, total flavonoids and condensed tannin for the same accessions after regeneration in a greenhouse. The results showed the diversity of the lima bean collection for phenolic compounds, which were strongly correlated with antioxidant activity. Lima beans accessions with the highest polyphenols and antioxidant activity were those with colored seeds. Conservation through cold storage of P. lunatus seeds in a cold chamber in the germplasm collection did not necessarily affect phenolic compounds. Variations observed in values after regeneration seeds may be mainly results of biotic and abiotic factors, including not only cultivar, but also environmental conditions. This study suggests that polyphenols in the lima beans present antioxidant activity, with possible beneficial effects for human health. It was expected that the potential of this tasty legume can be also used as a functional food crop and/or as a new ingredient in gastronomy.

Comparing two approaches for introgression of germplasm from Aegilops tauschii into common wheat

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Thomas S. Cox

2017-10-01

Full Text Available Allelic diversity in the wild grass Aegilops tauschii is vastly greater than that in the D genome of common wheat (Triticum aestivum, of which Ae. tauschii is the source. Since the 1980s, there have been numerous efforts to harness a much larger share of Ae. tauschii's extensive and highly variable gene pool for wheat improvement. Those efforts have followed two distinct approaches: production of amphiploids, known as “synthetic hexaploids,” between T. turgidum and Ae. tauschii, and direct hybridization between T. aestivum and Ae. tauschii; both approaches then involve backcrossing to T. aestivum. Both synthetic hexaploid production and direct hybridization have led to the transfer of numerous new genes into common wheat that confer improvements in many traits. This work has led to release of improved cultivars in China, the United States, and many other countries. Each approach to D-genome improvement has advantages and disadvantages. For example, production of synthetic hexaploids can incorporate useful germplasm from both T. turgidum and Ae. tauschii, thereby enhancing the A, B, and D genomes; on the other hand, direct hybridization rapidly restores the recurrent parent's A and B genomes and avoids incorporation of genes with adverse effects on threshability, hybrid necrosis, vernalization response, milling and baking quality, and other traits, which are often transferred when T. turgidum is used as a parent. Choice of method will depend in part on the type of wheat being developed and the target environment. However, more extensive use of the so-far underexploited direct hybridization approach is especially warranted.

Screening of diverse local germplasm of guar (cyamposis tetragonoloba (l.) taub.) for salt tolerance: A possible approach to utilize salt - affected soils

International Nuclear Information System (INIS)

Rasheed, M. J. Z.; Ahmad, K.; Qurainy, F. A.; Khan, S.; Athar, H. U. R.

2015-01-01

Lack of good quality water and soil salinity reduces crop productivity world-over. The development of salt stress tolerant cultivars/lines by screening and selection is of considerable value to enhance crop growth and yield. Though a number of breeding programs are underway to develop salt tolerant cultivars in wheat, barley, maize, and even grasses, a low amount of work done for improving salt tolerance in a potential leguminous forage crop guar widely grown in subcontinent due to rapid increase in its demand for its commercial use. Thus, the present study was focused on efforts to develop salt tolerant cultivars of guar. The growth responses of 31 accessions/lines/cultivars of a potential leguminous crop (Cyamopsis tetragonoloba) to salt stress were assessed at the vegetative growth stage. A considerable variation in salinity tolerance was found in a set of lines/cultivars of guar using agronomic traits. Under saline conditions, Khanewal Local2, Chiniot White, 27340, 24323, BWP-5589 produced the lowest shoot fresh and dry biomass in relative terms, while genotypes/lines 5597, 24288, Br 99, Khushab white, Sillanwali white and Mardan white had greater fresh and dry biomass. Klorkot white and 24323 had maximum plant height under non-saline conditions, whereas genotypes/line 5597 and 24288 was maximal in plant height under salt stress conditions. Moreover, genotypes/lines Khanewal Local2 followed by Chiniot White and 27340 were the lowest in plant height. Growth attributes and relative salt tolerance of guar genotypes were used to group genotypes/lines as salt tolerant, moderately tolerant and salt sensitive using Hierarchical Cluster method following squared Euclidean distance. It was found that genotypes/lines 41671, Khaushab White, 5597, 24320, 24288, Sillanwali White, 24321, Mardan White were the most salt tolerant, while Chiniot White, BWP-5589, Kalorkot White, Khanewal Local 2, 24323 were the most salt sensitive. The availability of considerable amount of

Characterization of Insect Resistance Loci in the USDA Soybean Germplasm Collection Using Genome-Wide Association Studies

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Hao-Xun Chang

2017-05-01

Full Text Available Management of insects that cause economic damage to yields of soybean mainly rely on insecticide applications. Sources of resistance in soybean plant introductions (PIs to different insect pests have been reported, and some of these sources, like for the soybean aphid (SBA, have been used to develop resistant soybean cultivars. With the availability of SoySNP50K and the statistical power of genome-wide association studies, we integrated phenotypic data for beet armyworm, Mexican bean beetle (MBB, potato leafhopper (PLH, SBA, soybean looper (SBL, velvetbean caterpillar (VBC, and chewing damage caused by unspecified insects for a comprehensive understanding of insect resistance in the United States Department of Agriculture Soybean Germplasm Collection. We identified significant single nucleotide (SNP polymorphic markers for MBB, PLH, SBL, and VBC, and we highlighted several leucine-rich repeat-containing genes and myeloblastosis transcription factors within the high linkage disequilibrium region surrounding significant SNP markers. Specifically for soybean resistance to PLH, we found the PLH locus is close but distinct to a locus for soybean pubescence density on chromosome 12. The results provide genetic support that pubescence density may not directly link to PLH resistance. This study offers a novel insight of soybean resistance to four insect pests and reviews resistance mapping studies for major soybean insects.

ISSR diversity and genetic differentiation of ancient tea (camellia sinensis var. assamica) plantations from China: implications for precious tea germplasm conservation

International Nuclear Information System (INIS)

Huang, X.Q.; Ji, P.Z.; Li, H.; Zhang, J.; Gao, L.Z.; Cheng, Z.Q.

2011-01-01

Over 10 centuries, ancient cultivated tea populations (Camellia sinensis var. assamica) are still planted merely in Yunnan province of China. Genetic diversity and differentiation were examined in 10 ancient tea plantations by using ISSR markers. The average genetic diversity within populations, estimated with Nei's genetic diversity (HE), was approximately 0.2809, while Shannon indices (HO) was 0.4179. The percentage of polymorphic loci (P) of the 10 populations ranged from 56.5% to 90.91%. We found a moderate level of genetic differentiation among population as evidenced by the coefficients of gene differentiation (Gst) of 0.3911 and the analysis of molecular variance (AMOVA) of 39.70%. The result could be explained by the nature of highly out crossing in the tea species as well as serious habitat fragmentation. Finally, conservation strategies were discussed to protect these ancient tea populations, including in situ reserve settings and ex situ germplasm sampling. (author)

The influence of Weismann's germ-plasm theory on the distinction between learned and innate behavior.

Science.gov (United States)

Johnston, T D

1995-04-01

Since the early twentieth century it has been common in both psychology and behavioral biology to draw a sharp distinction between learned and innate behavior, or elements of behavior. The persistence of this dichotomy may be attributed in part to the fundamental importance of the separation of inherited and acquired characters within neo-Darwinian evolutionary theory, one of the essential foundations for the modern study of behavior. A cornerstone of early neo-Darwinian thought was August Weismann's theory of the germ plasm, which proposed a segregation between germinal and somatic cells during development, thus ruling out the possibility that acquired characters could be inherited. This denial of Lamarckian hereditary mechanisms became one of the hallmarks of neo-Darwinism, as opposed to classical Darwinism. Within the neo-Darwinian framework it thus became important, as Weismann himself pointed out, to distinguish sharply between inherited and acquired characters. Although the dichotomy has frequently been criticized it remains tenacious, surfacing in different guises as older versions of it became terminologically unacceptable. The analysis offered here suggests that this tenacity may partly be explained by the implications of Weismann's germ-plasm theory, and its modern incarnation in the central dogma of molecular genetics, and by the central thematic position of those ideas in the neo-Darwinian foundations of modern behavioral biology.

Biological and molecular characterization of silkworm strains from the Brazilian germplasm bank of Bombyx mori.

Science.gov (United States)

Pereira, N C; Munhoz, R E F; Bignotto, T S; Bespalhuk, R; Garay, L B; Saez, C R N; Fassina, V A; Nembri, A; Fernandez, M A

2013-06-28

Brazil has only one public genetic pool of Bombyx mori strains, which was established in 2005 at Universidade Estadual de Maringá, Maringá, Paraná State. This genetic bank has been maintained, and the strains have been characterized using genetic and morphological tools. The quantitative and qualitative traits, directly or indirectly related to productivity, were evaluated in 14 silkworm strains. In addition to biological and productivity analyses, DNA markers related to susceptibility to the B. mori nucleopolyhedrovirus (BmNPV) were analyzed. BmNPV is a major cause of production loss and is a serious problem for Paraná sericulture. The silkworm strains from diverse geographic origins were found to have different characteristics, including body weight, larval stage duration, cocoon weight, and other biological traits. In terms of productivity, the raw silk percentages were almost uniform, with an overall average of 16.28%. Overall, the Chinese strain C37 gave the best performance in many of the quantitative traits, and it surpassed the other strains in productivity traits. Therefore, it can be used as one of the strains that compose the elite germplasm for silkworm breeding programs. Additionally, genetic molecular markers were efficient in discriminating between B. mori strains that had been identified based on their geographical origin. We found that all Japanese strains produced a 400-bp molecular marker that has been associated with susceptibility to BmNPV.

Association Analysis of Simple Sequence Repeat (SSR Markers with Agronomic Traits in Tall Fescue (Festuca arundinacea Schreb..

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Yanhong Lou

Full Text Available Tall fescue is widely used in temperate regions throughout the world as a dominant forage grass as well as a turfgrass, in pastoral and turf industry. However, the utilization of tall fescue was limited because of its leaf roughness, poor regeneration ability and poor stress resistance. New cultivars were desirable in modern pastoral industries exceed the potential of existing cultivars. Therefore, well understanding the agronomic traits and describing germplasms would help to overcome these constraints, and morphological evaluation of tall fescue germplasm is the key component in selecting rational parents for hybridization breeding. However, describing the morphological traits of tall fescue germplasm is costly and time-consuming. Fortunately, biotechnology approaches can supplement conventional breeding efforts for tall fescue improvement. Association mapping, as a powerful approach to identify association between agronomic traits and molecular markers has been widely used for enhancing the utilization, conservation and management of the tall fescue germplasms. Therefore, in the present research, 115 tall fescue accessions from different origins (25 accessions are cultivars; 31 accessions from America; 32 accessions from European; 7 accessions from Africa; 20 accessions from Asia, were evaluated for agronomic traits and genetic diversity with 90 simple sequence repeat (SSR markers. The panel displayed significant variation in spike count per plant (SCP and spike weight (SW. However, BCS performed the lowest CV among all the observed agronomic traits. Three subpopulations were identified within the collections but no obvious relative kinship (K was found. The GLM model was used to describe the association between SSR and agronomic traits. Fifty-one SSR markers associated with agronomic traits were observed. Twelve single-associated markers were associated with PH; six single-associated markers were associated with BCS; eight single

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Worldwide germplasm collections contain about 7.4 million accessions of plant genetic resources for food and agriculture. One of the 10 largest ex situ genebanks of our globe is located at the Leibniz Institute of Plant Genetics and Crop Plant Research in Gatersleben, Germany. Molecular tools have been used for various ...

Diversity of castor ( Ricinus communis L.) in Ethiopia | Alemaw ...

African Journals Online (AJOL)

An experiment was carried out to assess the diversity of castor germplasm in Ethiopia. A total of 102 accessions, one elite genotype and two standard varieties were characterized at Melkassa and Arsi Negelle, in the Central Rift Valley of Ethiopia using 12 traits for one during 2013 main season. Analysis of variance ...

Genetic Diversity of Upland Rice Germplasm in Malaysia Based on Quantitative Traits

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M. Sohrabi

2012-01-01

Full Text Available Genetic diversity is prerequisite for any crop improvement program as it helps in the development of superior recombinants. Fifty Malaysian upland rice accessions were evaluated for 12 growth traits, yield and yield components. All of the traits were significant and highly significant among the accessions. The higher magnitudes of genotypic and phenotypic coefficients of variation were recorded for flag leaf length-to-width ratio, spikelet fertility, and days to flowering. High heritability along with high genetic advance was registered for yield of plant, days to flowering, and flag leaf length-to-width ratio suggesting preponderance of additive gene action in the gene expression of these characters. Plant height showed highly significant positive correlation with most of the traits. According to UPGMA cluster analysis all accessions were clustered into six groups. Twelve morphological traits provided around 77% of total variation among the accessions.

[Genetic diversity of wild Cynodon dactylon germplasm detected by SRAP markers].

Science.gov (United States)

Yi, Yang-Jie; Zhang, Xin-Quan; Huang, Lin-Kai; Ling, Yao; Ma, Xiao; Liu, Wei

2008-01-01

Sequence-related amplified polymorphism (SRAP) molecular markers were used to detect the genetic diversity of 32 wild accessions of Cynodon dactylon collected from Sichuan, Chongqing, Guizhou and Tibet, China. The following results were obtained. (1) Fourteen primer pairs produced 132 polymorphic bands, averaged 9.4 bands per primer pair. The percentage of polymorphic bands in average was 79.8%. The Nei's genetic similarity coefficient of the tested accessions ranged from 0.591 to 0.957, and the average Nei's coefficient was 0.759. These results suggested that there was rich genetic diversity among the wild resources of Cynodon dactylon tested. (2) Thirty two wild accessions were clustered into four groups. Moreover, the accessions from the same origin frequently clustered into one group. The findings implied that a correlation among the wild resources, geographical and ecological environment. (3) Genetic differentiation between and within six eco-geographical groups of C. dactylon was estimated by Shannon's diversity index, which showed that 65.56% genetic variance existed within group, and 34.44% genetic variance was among groups. (4) Based on Nei's unbiased measures of genetic identity, UPGMA cluster analysis measures of six eco-geographical groups of Cynodon dactylon, indicated that there was a correlation between genetic differentiation and eco-geographical habits among the groups.

Genetic diversity and population structure in cultivated sunflower and a comparison to its wild progenitor, Helianthus annuus L.

Science.gov (United States)

Mandel, J R; Dechaine, J M; Marek, L F; Burke, J M

2011-09-01

Crop germplasm collections are valuable resources for ongoing plant breeding efforts. To fully utilize such collections, however, researchers need detailed information about the amount and distribution of genetic diversity present within collections. Here, we report the results of a population genetic analysis of the primary gene pool of sunflower (Helianthus annuus L.) based on a broad sampling of 433 cultivated accessions from North America and Europe, as well as a range-wide collection of 24 wild sunflower populations. Gene diversity across the cultivars was 0.47, as compared with 0.70 in the wilds, indicating that cultivated sunflower harbors roughly two-thirds of the total genetic diversity present in wild sunflower. Population structure analyses revealed that wild sunflower can be subdivided into four genetically distinct population clusters throughout its North American range, whereas the cultivated sunflower gene pool could be split into two main clusters separating restorer lines from the balance of the gene pool. Use of a maximum likelihood method to estimate the contribution of the wild gene pool to the cultivated sunflower germplasm revealed that the bulk of the cultivar diversity is derived from two wild sunflower population genetic clusters that are primarily composed of individuals from the east-central United States, the same general region in which sunflower domestication is believed to have occurred. We also identified a nested subset of accessions that capture as much of the allelic diversity present within the sampled cultivated sunflower germplasm collection as possible. At the high end, a core set of 288 captured nearly 90% of the alleles present in the full set of 433, whereas a core set of just 12 accessions was sufficient to capture nearly 50% of the total allelic diversity present within this sample of cultivated sunflower.

Germplasm Enhancement of Maize - Strategies & Synergy with Maize Curation

Science.gov (United States)

The importance of access to and utilization of genetic plant resources for improvement of modern cultivars is widely recognized. Industry recognized the challenges of incorporating diversity into their elite breeding pools because of lack of adaptation and undesirable agronomic traits associat...

Morphological diversity of mango germplasm from the upper Athi ...

African Journals Online (AJOL)

African Journal of Food, Agriculture, Nutrition and Development. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 16, No 2 (2016) >. Log in or Register to get access to full text downloads.

Genetic architecture of kernel composition in global sorghum germplasm

Science.gov (United States)

Sorghum [Sorghum bicolor (L.) Moench] is an important cereal crop for dryland areas in the United States and for small-holder farmers in Africa. Natural variation of sorghum grain composition (protein, fat, and starch) between accessions can be used for crop improvement, but the genetic controls are...

Accessible Knowledge - Knowledge on Accessibility

DEFF Research Database (Denmark)

Kirkeby, Inge Mette

2015-01-01

Although serious efforts are made internationally and nationally, it is a slow process to make our physical environment accessible. In the actual design process, architects play a major role. But what kinds of knowledge, including research-based knowledge, do practicing architects make use of when...... designing accessible environments? The answer to the question is crucially important since it affects how knowledge is distributed and how accessibility can be ensured. In order to get first-hand knowledge about the design process and the sources from which they gain knowledge, 11 qualitative interviews...... were conducted with architects with experience of designing for accessibility. The analysis draws on two theoretical distinctions. The first is research-based knowledge versus knowledge used by architects. The second is context-independent knowledge versus context-dependent knowledge. The practitioners...

Genetic Diversity of Rose germplasm based on RAPD analysis

African Journals Online (AJOL)

AHSAN IQBAL

2012-06-12

Jun 12, 2012 ... identification and analysis of genetic variation within a collection of 4 species and 30 accessions of rose using RAPD analysis technique. The results showed the molecular distinctions among the ... that range in colour from white and yellow to many shades of pink and red have been developed. Since.

Evaluación del germoplasma de Ilex paraguariensis e Ilex dumosa (Aquifoliaceae Ilex paraguariensis and Ilex dumosa (Aquifoliaceae germplasm evaluation

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Alexandra Marina Gottlieb

2011-06-01

Full Text Available Ilex paraguariensis e I. dumosa constituyen dos especies de gran relevancia económica para nuestro país. Estas comparten muchas características de su biología, aunque se diferencian en composición fitoquímica y resistencia a factores bióticos y abióticos. El objetivo del presente trabajo es evaluar la estructura de la diversidad genética de plantas mantenidas en el Banco de Germoplasma de Yerba Mate y Té de la Estación Experimental del INTA en Cerro Azul (Misiones y de materiales comerciales de yerba mate, mediante el re-análisis de datos AFLP, así como caracterizar las secuencias nucleotídicas de bandas potencialmente diagnósticas de especie. En I. dumosa se detectó, respecto de I. paraguariensis, un nivel de variación molecular dos veces mayor, aunque una menor proporción de bandas privadas. Las secuencias caracterizadas con herramientas bioinformáticas resultan ser nuevas regiones genómicas descriptas para Ilex. Los resultados indican que los materiales estudiados de I. dumosa constituyen un reservorio de variabilidad genética apropiado para el fitomejoramiento de materiales de yerba mate potencialmente comerciales. Asimismo, nuestros resultados apoyan la renovación de estrategias de conservación tendientes a ampliar el acervo genético almacenado, particularmente de yerba mate.Ilex paraguariensis and I. dumosa are species with great economic relevance in Argentina. Both species share several features of their biology, though they differ in phytochemical composition and in their resistance to biotic and abiotic factors. The aim of the present work is to evaluate the structure of the genetic diversity of the plants kept at the Germplasm Bank of Yerba Mate (EEINTACA and also of commercial materials of yerba mate, through a re-analysis of AFLP data and a characterization of the nucleotide sequences of selected AFLP bands. For I. dumosa we have detected a molecular variation level two times higher than the value obtained

Evaluation of rice germplasm under salt stress at the seedling stage through SSR markers

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M. Al-Amin

2013-06-01

Full Text Available Twenty eight rice germplasms were used for identification of salt tolerant rice genotypes at the seedling stage at the experimental farm and Biotechnology laboratory of the Bangladesh Institute of Nuclear Agriculture (BINA, Mymensingh during February 2009 to October 2009. Phenotyping for salinity screening of the rice genotypes was done using salinized (EC level 12 dS m-1 nutrient solution in hydroponic system. Genotypes were evaluated for salinity tolerance on 1-9 scale based on seedling growth parameters following modified Standard Evaluation Scoring (SES of IRRI. Phenotypically, on the basis of SES and % total dry matter (TDM reduction of the genotypes viz. PBSAL-614, PBSAL-613, PBSAL-730, Horkuch, S-478/3 Pokkali and PBSAL (STL-15 were found to be salt tolerant; on the other hand Iratom-24, S-653/32, S-612/32, S-604/32, S-633/32, Charnock (DA6, BINA Dhan-6 and S-608/32 were identified as salt susceptible. For genotyping, ten SSR markers were used for polymorphism, where 3 primers (RM127, RM443 and RM140 were selected for evaluation of salt tolerance. In respect of Primer RM127, 7 lines were found salt tolerant and 11 lines were moderately tolerant and 10 lines were susceptible. Nine tolerant, 9 moderately tolerant and 10 susceptible lines were found when the primer RM140 was used and primer RM443 identified 8 lines as tolerant, 9 lines as moderately tolerant and 11 lines as susceptible. Thus, the salt tolerant lines can be used in further evaluation for salinity tolerance and the SSR markers used in this study are proving valuable for identifying salt tolerant genes in marker assisted breeding.

Genetic Variability of 27 Traits in a Core Collection of Flax (Linum usitatissimum L.).

Science.gov (United States)

You, Frank M; Jia, Gaofeng; Xiao, Jin; Duguid, Scott D; Rashid, Khalid Y; Booker, Helen M; Cloutier, Sylvie

2017-01-01

Assessment of genetic variability of plant core germplasm is needed for efficient germplasm utilization in breeding improvement. A total of 391 accessions of a flax core collection, which preserves the variation present in the world collection of 3,378 accessions maintained by Plant Gene Resources of Canada (PGRC) and represents a broad range of geographical origins, different improvement statuses and two morphotypes, was evaluated in field trials in up to 8 year-location environments for 10 agronomic, eight seed quality, six fiber and three disease resistance traits. The large phenotypic variation in this subset was explained by morphotypes (22%), geographical origins (11%), and other variance components (67%). Both divergence and similarity between two basic morphotypes, namely oil or linseed and fiber types, were observed, whereby linseed accessions had greater thousand seed weight, seeds m -2 , oil content, branching capability and resistance to powdery mildew while fiber accessions had greater straw weight, plant height, protein content and resistance to pasmo and fusarium wilt diseases, but they had similar performance in many traits and some of them shared common characteristics of fiber and linseed types. Weak geographical patterns within either fiber or linseed accessions were confirmed, but specific trait performance was identified in East Asia for fiber type, and South Asia and North America for linseed type. Relatively high broad-sense heritability was obtained for seed quality traits, followed by agronomic traits and resistance to powdery mildew and fusarium wilt. Diverse phenotypic and genetic variability in the flax core collection constitutes a useful resource for breeding.

Single-nucleotide polymorphism discovery by high-throughput sequencing in sorghum

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White Frank F

2011-07-01

Full Text Available Abstract Background Eight diverse sorghum (Sorghum bicolor L. Moench accessions were subjected to short-read genome sequencing to characterize the distribution of single-nucleotide polymorphisms (SNPs. Two strategies were used for DNA library preparation. Missing SNP genotype data were imputed by local haplotype comparison. The effect of library type and genomic diversity on SNP discovery and imputation are evaluated. Results Alignment of eight genome equivalents (6 Gb to the public reference genome revealed 283,000 SNPs at ≥82% confirmation probability. Sequencing from libraries constructed to limit sequencing to start at defined restriction sites led to genotyping 10-fold more SNPs in all 8 accessions, and correctly imputing 11% more missing data, than from semirandom libraries. The SNP yield advantage of the reduced-representation method was less than expected, since up to one fifth of reads started at noncanonical restriction sites and up to one third of restriction sites predicted in silico to yield unique alignments were not sampled at near-saturation. For imputation accuracy, the availability of a genomically similar accession in the germplasm panel was more important than panel size or sequencing coverage. Conclusions A sequence quantity of 3 million 50-base reads per accession using a BsrFI library would conservatively provide satisfactory genotyping of 96,000 sorghum SNPs. For most reliable SNP-genotype imputation in shallowly sequenced genomes, germplasm panels should consist of pairs or groups of genomically similar entries. These results may help in designing strategies for economical genotyping-by-sequencing of large numbers of plant accessions.

Access Request Trustworthiness in Weighted Access Control Framework

Institute of Scientific and Technical Information of China (English)

WANG Lun-wei; LIAO Xiang-ke; WANG Huai-min

2005-01-01

Weighted factor is given to access control policies to express the importance of policy and its effect on access control decision. According to this weighted access control framework, a trustworthiness model for access request is also given. In this model, we give the measure of trustworthiness factor to access request, by using some idea of uncertainty reasoning of expert system, present and prove the parallel propagation formula of request trustworthiness factor among multiple policies, and get the final trustworthiness factor to decide whether authorizing. In this model, authorization decision is given according to the calculation of request trustworthiness factor, which is more understandable, more suitable for real requirement and more powerful for security enhancement than traditional methods. Meanwhile the finer access control granularity is another advantage.

Descritores quantitativos na determinação da divergência genética entre acessos de tomateiro do grupo cereja Quantitative descriptors on determining genetic divergence among cherry tomatoes accessions

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Mariella Camargo Rocha

2009-06-01

ônicas explicaram 78,58% da variação observada, com a formação de sete grupos. A variável mais importante foi a produção de frutos não-comerciais, que explicou 22,71% da variação total. A cultivar 'Perinha Água Branca' foi a que produziu menor porcentagem de frutos não-comerciais (2,0%, enquanto o híbrido Super Sweet produziu 8% de frutos não-comerciais.Cherry tomato is becoming an important crop alternative mainly for small farmers that use family hand labor and use organic management to differentiate their product. The introduction of new genotypes in this market should be supported by germplasm characterization and evaluation. This germplasm could be recommended for farmers or introduced in breeding programs. The aim of this research was to test 40 cherry tomatoes accessions from different sources, being 36 accessions from germplasm collection of Department de Fitotecnia of UFRRJ and four cultivars, namely 'Joanna', 'Perinha Água Branca', 'Samambaia' and Super Sweet. The plants were grown in field conditions, under organic management, in a randomized block design with four replications and five plants per plot, from June to December 2004. The following variables were studied: fruit total yield; commercial and non-commercial fruit yield; longitudinal and equatorial fruit diameter; pulp thickness; minimum, medium and maximum fruit mass variation per plant. The data were analyzed considering Mahalanobis distance and the cluster analysis was performed using UPGMA (Unweighted Pair-Group Method Using an Arithmetic Average and canonic variables. The adjustment between the similarity matrix and dendrograma was performed using the cophenetic correlation. The characters relative importance was determined by Singh´s method. The accessions were clustered in two groups, one of them with only one accession (ENAS 1021 and the second group, with 39 accessions, was subdivided generating seven subgroups. The cophenetic correlation was 0.9 meaning a very good adjustment between the

Web accessibility standards and disability: developing critical perspectives on accessibility.

Science.gov (United States)

Lewthwaite, Sarah

2014-01-01

Currently, dominant web accessibility standards do not respect disability as a complex and culturally contingent interaction; recognizing that disability is a variable, contrary and political power relation, rather than a biological limit. Against this background there is clear scope to broaden the ways in which accessibility standards are understood, developed and applied. Commentary. The values that shape and are shaped by legislation promote universal, statistical and automated approaches to web accessibility. This results in web accessibility standards conveying powerful norms fixing the relationship between technology and disability, irrespective of geographical, social, technological or cultural diversity. Web accessibility standards are designed to enact universal principles; however, they express partial and biopolitical understandings of the relation between disability and technology. These values can be limiting, and potentially counter-productive, for example, for the majority of disabled people in the "Global South" where different contexts constitute different disabilities and different experiences of web access. To create more robust, accessible outcomes for disabled people, research and standards practice should diversify to embrace more interactional accounts of disability in different settings. Implications for Rehabilitation Creating accessible experiences is an essential aspect of rehabilitation. Web standards promote universal accessibility as a property of an online resource or service. This undervalues the importance of the user's intentions, expertize, their context, and the complex social and cultural nature of disability. Standardized, universal approaches to web accessibility may lead to counterproductive outcomes for disabled people whose impairments and circumstances do not meet Western disability and accessibility norms. Accessible experiences for rehabilitation can be enhanced through an additional focus on holistic approaches to

Comparison of Radial Access, Guided Femoral Access, and Non-Guided Femoral Access Among Women Undergoing Percutaneous Coronary Intervention.

Science.gov (United States)

Koshy, Linda M; Aberle, Laura H; Krucoff, Mitchell W; Hess, Connie N; Mazzaferri, Ernest; Jolly, Sanjit S; Jacobs, Alice; Gibson, C Michael; Mehran, Roxana; Gilchrist, Ian C; Rao, Sunil V

2018-01-01

This study was conducted to determine the association between radial access, guided femoral access, and non-guided femoral access on postprocedural bleeding and vascular complications after percutaneous coronary intervention (PCI). Bleeding events and major vascular complications after PCI are associated with increased morbidity, mortality, and cost. While the radial approach has been shown to be superior to the femoral approach in reducing bleeding and vascular complications, whether the use of micropuncture, fluoroscopy, or ultrasound mitigates these differences is unknown. We conducted a post hoc analysis of women in the SAFE-PCI for Women trial who underwent PCI and had the access method identified (n = 643). The primary endpoint of postprocedure bleeding or vascular complications occurring within 72 hours or at discharge was adjudicated by an independent clinical events committee and was compared based on three categories of access technique: radial, guided femoral (fluoroscopy, micropuncture, ultrasound), or non-guided femoral (none of the aforementioned). Differences between the groups were determined using multivariate logistic regression using radial access as the reference. Of the PCI population, 330 underwent radial access, 228 underwent guided femoral access, and 85 underwent non-guided femoral access. There was a statistically significant lower incidence of the primary endpoint with radial access vs non-guided femoral access; however, there was no significant difference between radial approach and femoral access guided by fluoroscopy, micropuncture, or ultrasound. This post hoc analysis demonstrates that while radial access is safer than non-guided femoral access, guided femoral access appears to be associated with similar bleeding events or vascular complications as radial access.

Diversifying Sunflower Germplasm by Integration and Mapping of a Novel Male Fertility Restoration Gene

Science.gov (United States)

Liu, Zhao; Wang, Dexing; Feng, Jiuhuan; Seiler, Gerald J.; Cai, Xiwen; Jan, Chao-Chien

2013-01-01

The combination of a single cytoplasmic male-sterile (CMS) PET-1 and the corresponding fertility restoration (Rf) gene Rf1 is used for commercial hybrid sunflower (Helianthus annuus L., 2n = 34) seed production worldwide. A new CMS line 514A was recently developed with H. tuberosus cytoplasm. However, 33 maintainers and restorers for CMS PET-1 and 20 additional tester lines failed to restore the fertility of CMS 514A. Here, we report the discovery, characterization, and molecular mapping of a novel Rf gene for CMS 514A derived from an amphiploid (Amp H. angustifolius/P 21, 2n = 68). Progeny analysis of the male-fertile (MF) plants (2n = 35) suggested that this gene, designated Rf6, was located on a single alien chromosome. Genomic in situ hybridization (GISH) indicated that Rf6 was on a chromosome with a small segment translocation on the long arm in the MF progenies (2n = 34). Rf6 was mapped to linkage group (LG) 3 of the sunflower SSR map. Eight markers were identified to be linked to this gene, covering a distance of 10.8 cM. Two markers, ORS13 and ORS1114, were only 1.6 cM away from the gene. Severe segregation distortions were observed for both the fertility trait and the linked marker loci, suggesting the possibility of a low frequency of recombination or gamete selection in this region. This study discovered a new CMS/Rf gene system derived from wild species and provided significant insight into the genetic basis of this system. This will diversify the germplasm for sunflower breeding and facilitate understanding of the interaction between the cytoplasm and nuclear genes. PMID:23307903

Loci associated with resistance to stripe rust (Puccinia striiformis f. sp. tritici) in a core collection of spring wheat (Triticum aestivum)

Science.gov (United States)

Bulli, Peter; Rynearson, Sheri; Chen, Xianming; Pumphrey, Michael

2017-01-01

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst) remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the United States Department of Agriculture-Agricultural Research Service National Small Grains Collection, representing major global production environments. The panel was characterized for field resistance in multi-environment field trials and seedling resistance under greenhouse conditions. A genome-wide set of 5,619 informative SNP markers were used to examine the population structure, linkage disequilibrium and marker-trait associations in the germplasm panel. Based on model-based analysis of population structure and hierarchical Ward clustering algorithm, the accessions were clustered into two major subgroups. These subgroups were largely separated according to geographic origin and improvement status of the accessions. A significant correlation was observed between the population sub-clusters and response to stripe rust infection. We identified 11 and 7 genomic regions with significant associations with stripe rust resistance at adult plant and seedling stages, respectively, based on a false discovery rate multiple correction method. The regions harboring all, except three, of the QTL identified from the field and greenhouse studies overlap with positions of previously reported QTL. Further work should aim at validating the identified QTL using proper germplasm and populations to enhance their utility in marker assisted breeding. PMID:28591221

Genome-Wide Association Study for Traits Related to Plant and Grain Morphology, and Root Architecture in Temperate Rice Accessions.

Science.gov (United States)

Biscarini, Filippo; Cozzi, Paolo; Casella, Laura; Riccardi, Paolo; Vattari, Alessandra; Orasen, Gabriele; Perrini, Rosaria; Tacconi, Gianni; Tondelli, Alessandro; Biselli, Chiara; Cattivelli, Luigi; Spindel, Jennifer; McCouch, Susan; Abbruscato, Pamela; Valé, Giampiero; Piffanelli, Pietro; Greco, Raffaella

2016-01-01

In this study we carried out a genome-wide association analysis for plant and grain morphology and root architecture in a unique panel of temperate rice accessions adapted to European pedo-climatic conditions. This is the first study to assess the association of selected phenotypic traits to specific genomic regions in the narrow genetic pool of temperate japonica. A set of 391 rice accessions were GBS-genotyped yielding-after data editing-57000 polymorphic and informative SNPS, among which 54% were in genic regions. In total, 42 significant genotype-phenotype associations were detected: 21 for plant morphology traits, 11 for grain quality traits, 10 for root architecture traits. The FDR of detected associations ranged from 3 · 10-7 to 0.92 (median: 0.25). In most cases, the significant detected associations co-localised with QTLs and candidate genes controlling the phenotypic variation of single or multiple traits. The most significant associations were those for flag leaf width on chromosome 4 (FDR = 3 · 10-7) and for plant height on chromosome 6 (FDR = 0.011). We demonstrate the effectiveness and resolution of the developed platform for high-throughput phenotyping, genotyping and GWAS in detecting major QTLs for relevant traits in rice. We identified strong associations that may be used for selection in temperate irrigated rice breeding: e.g. associations for flag leaf width, plant height, root volume and length, grain length, grain width and their ratio. Our findings pave the way to successfully exploit the narrow genetic pool of European temperate rice and to pinpoint the most relevant genetic components contributing to the adaptability and high yield of this germplasm. The generated data could be of direct use in genomic-assisted breeding strategies.

Genome-Wide Association Study for Traits Related to Plant and Grain Morphology, and Root Architecture in Temperate Rice Accessions.

Directory of Open Access Journals (Sweden)

Filippo Biscarini

Full Text Available In this study we carried out a genome-wide association analysis for plant and grain morphology and root architecture in a unique panel of temperate rice accessions adapted to European pedo-climatic conditions. This is the first study to assess the association of selected phenotypic traits to specific genomic regions in the narrow genetic pool of temperate japonica. A set of 391 rice accessions were GBS-genotyped yielding-after data editing-57000 polymorphic and informative SNPS, among which 54% were in genic regions.In total, 42 significant genotype-phenotype associations were detected: 21 for plant morphology traits, 11 for grain quality traits, 10 for root architecture traits. The FDR of detected associations ranged from 3 · 10-7 to 0.92 (median: 0.25. In most cases, the significant detected associations co-localised with QTLs and candidate genes controlling the phenotypic variation of single or multiple traits. The most significant associations were those for flag leaf width on chromosome 4 (FDR = 3 · 10-7 and for plant height on chromosome 6 (FDR = 0.011.We demonstrate the effectiveness and resolution of the developed platform for high-throughput phenotyping, genotyping and GWAS in detecting major QTLs for relevant traits in rice. We identified strong associations that may be used for selection in temperate irrigated rice breeding: e.g. associations for flag leaf width, plant height, root volume and length, grain length, grain width and their ratio. Our findings pave the way to successfully exploit the narrow genetic pool of European temperate rice and to pinpoint the most relevant genetic components contributing to the adaptability and high yield of this germplasm. The generated data could be of direct use in genomic-assisted breeding strategies.

Population Structure and Diversity in Finger Millet (Eleusine coracana) Germplasm.

Science.gov (United States)

A genotypic analysis of 79 finger millet accessions (E. coracana subsp. coracana) from 11 African and 5 Asian countries, plus 14 wild E. coracana subsp. africana lines collected in Uganda and Kenya was conducted with 45 SSR markers distributed across the finger millet genome. Phylogenetic and popula...

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Indian Academy of Sciences (India)

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Evaluation of barley (hordeum vulgare l.) germplasm for high forage production under salt stress

International Nuclear Information System (INIS)

Saleem, A.; Qurainy, F.A.; Akram, N.A.

2014-01-01

To explore high biomass producing salt tolerant cultivars of a potential forage crop barley (Hordeum vulgare L.), 30-day old plants of 105 different accessions from different origin were subjected to saline and non-saline (control) conditions for 45 days. Salinity stress (150 mM NaCl) markedly suppressed plant growth (shoot and/or root fresh and dry weights), chlorophyll pigments (a and b), internal CO/sub 2/ concentration, stomatal conductance, rate of transpiration and photosynthesis, while a considerable salt-induced increase was observed in all fluorescence related attributes including efficiency of photosystem-II (Fv/Fm), co-efficient of non-photochemical quenching (QN), photochemical quenching (QP), and non-photochemical quenching (NPQ) in all 105 accessions of barley. The response of all 105 barley accessions to salt stress varied significantly for all the morpho-physiological attributes determined in the present study. Overall, on the basis of shoot and root dry weights, accessions, 4050, 4053, 4056, 4163, 4228, 4229, 4244, 4245, 4290, 4414, 4415, 4427, 4452, Mahali, Jesto, 4165, 4229, 4249, 4405, 4409, 4426, 4456, and Giza 123 were found superior while accessions, 4245, 4158, 4166, 4246, 4406, 4423, 4441, 4442 4447, 4453 and 4458 inferior under saline conditions. (author)

Biochemical evaluation of tomato germplasm part I: workflow and methods

Science.gov (United States)

Of the seed crop species conserved at PGRU, tomato (Solanum lycopersicum L.) is the largest in terms of numbers of accessions. Furthermore, tomato ranks very high among vegetable crops in economic importance to the US. We are characterizing a tomato core collection for traits that are of interest to...

Molecular characterization of cultivated species of the genus Pachyrhizus Rich. ex DC. by AFLP markers

DEFF Research Database (Denmark)

Santayana, Monica; Rossel, Genoveva; Núñez, Jorge

2014-01-01

) molecular markers in order to estimate genetic diversity and interspecific relationships. To complement molecular marker information, individuals from each accession were analyzed in order to confirmploidy levels. Eight AFLP primer combinations detected 136 (68.7 %) polymorphic bands. Shannon’s diversity...... indices (Hs) for each species were 1.04 (P. ahipa), 1.07 (P. tuberosus), and 2.42 (P. erosus), while the total diversity index was 2.45. Phylogenetic analysis, principal coordinate analysis and analysis of molecular variance (FST=0.796) all showed significant species differentiation. All accessions were...... diploid (2n=2x=22), which is characteristic of the tribe Phaseoleae. Finally, a misclassified accession of P. tuberosus was identified. Molecular characterization of accessions is necessary for efficient management of germplasm collections....

Identification of SNP and SSR Markers in Finger Millet Using Next Generation Sequencing Technologies.

Science.gov (United States)

Gimode, Davis; Odeny, Damaris A; de Villiers, Etienne P; Wanyonyi, Solomon; Dida, Mathews M; Mneney, Emmarold E; Muchugi, Alice; Machuka, Jesse; de Villiers, Santie M

2016-01-01

Finger millet is an important cereal crop in eastern Africa and southern India with excellent grain storage quality and unique ability to thrive in extreme environmental conditions. Since negligible attention has been paid to improving this crop to date, the current study used Next Generation Sequencing (NGS) technologies to develop both Simple Sequence Repeat (SSR) and Single Nucleotide Polymorphism (SNP) markers. Genomic DNA from cultivated finger millet genotypes KNE755 and KNE796 was sequenced using both Roche 454 and Illumina technologies. Non-organelle sequencing reads were assembled into 207 Mbp representing approximately 13% of the finger millet genome. We identified 10,327 SSRs and 23,285 non-homeologous SNPs and tested 101 of each for polymorphism across a diverse set of wild and cultivated finger millet germplasm. For the 49 polymorphic SSRs, the mean polymorphism information content (PIC) was 0.42, ranging from 0.16 to 0.77. We also validated 92 SNP markers, 80 of which were polymorphic with a mean PIC of 0.29 across 30 wild and 59 cultivated accessions. Seventy-six of the 80 SNPs were polymorphic across 30 wild germplasm with a mean PIC of 0.30 while only 22 of the SNP markers showed polymorphism among the 59 cultivated accessions with an average PIC value of 0.15. Genetic diversity analysis using the polymorphic SNP markers revealed two major clusters; one of wild and another of cultivated accessions. Detailed STRUCTURE analysis confirmed this grouping pattern and further revealed 2 sub-populations within wild E. coracana subsp. africana. Both STRUCTURE and genetic diversity analysis assisted with the correct identification of the new germplasm collections. These polymorphic SSR and SNP markers are a significant addition to the existing 82 published SSRs, especially with regard to the previously reported low polymorphism levels in finger millet. Our results also reveal an unexploited finger millet genetic resource that can be included in the regional

Identification of SNP and SSR Markers in Finger Millet Using Next Generation Sequencing Technologies.

Directory of Open Access Journals (Sweden)

Davis Gimode

Full Text Available Finger millet is an important cereal crop in eastern Africa and southern India with excellent grain storage quality and unique ability to thrive in extreme environmental conditions. Since negligible attention has been paid to improving this crop to date, the current study used Next Generation Sequencing (NGS technologies to develop both Simple Sequence Repeat (SSR and Single Nucleotide Polymorphism (SNP markers. Genomic DNA from cultivated finger millet genotypes KNE755 and KNE796 was sequenced using both Roche 454 and Illumina technologies. Non-organelle sequencing reads were assembled into 207 Mbp representing approximately 13% of the finger millet genome. We identified 10,327 SSRs and 23,285 non-homeologous SNPs and tested 101 of each for polymorphism across a diverse set of wild and cultivated finger millet germplasm. For the 49 polymorphic SSRs, the mean polymorphism information content (PIC was 0.42, ranging from 0.16 to 0.77. We also validated 92 SNP markers, 80 of which were polymorphic with a mean PIC of 0.29 across 30 wild and 59 cultivated accessions. Seventy-six of the 80 SNPs were polymorphic across 30 wild germplasm with a mean PIC of 0.30 while only 22 of the SNP markers showed polymorphism among the 59 cultivated accessions with an average PIC value of 0.15. Genetic diversity analysis using the polymorphic SNP markers revealed two major clusters; one of wild and another of cultivated accessions. Detailed STRUCTURE analysis confirmed this grouping pattern and further revealed 2 sub-populations within wild E. coracana subsp. africana. Both STRUCTURE and genetic diversity analysis assisted with the correct identification of the new germplasm collections. These polymorphic SSR and SNP markers are a significant addition to the existing 82 published SSRs, especially with regard to the previously reported low polymorphism levels in finger millet. Our results also reveal an unexploited finger millet genetic resource that can be included

Genetic dissection of Sharka disease tolerance in peach (P. persica L. Batsch).

Science.gov (United States)

Cirilli, Marco; Rossini, Laura; Geuna, Filippo; Palmisano, Francesco; Minafra, Angelantonio; Castrignanò, Tiziana; Gattolin, Stefano; Ciacciulli, Angelo; Babini, Anna Rosa; Liverani, Alessandro; Bassi, Daniele

2017-11-03

Plum pox virus (PPV), agent of Sharka disease, is the most important quarantine pathogen of peach (P. persica L. Batsch). Extensive evaluation of peach germplasm has highlighted the lack of resistant sources, while suggesting the presence of a quantitative disease resistance, expressed as reduction in the intensity of symptoms. Unravelling the genetic architecture of peach response to PPV infection is essential for pyramiding resistant genes and for developing more tolerant varieties. For this purpose, a genome-wide association (GWA) approach was applied in a panel of accessions phenotyped for virus susceptibility and genotyped with the IPSC peach 9 K SNP Array, and coupled with an high-coverage resequencing of the tolerant accession 'Kamarat'. Genome-wide association identified three highly significant associated loci on chromosome 2 and 3, accounting for most of the reduction in PPV-M susceptibility within the analysed peach population. The exploration of associated intervals through whole-genome comparison of the tolerant accession 'Kamarat' and other susceptible accessions, including the PPV-resistant wild-related species P. davidiana, allow the identification of allelic variants in promising candidate genes, including an RTM2-like gene already characterized in A. thaliana. The present study is the first effort to identify genetic factors involved in Sharka disease in peach germplasm through a GWA approach. We provide evidence of the presence of quantitative resistant loci in a collection of peach accessions, identifying major loci and highly informative SNPs that could be useful for marker assisted selection. These results could serve as reference bases for future research aimed at the comprehension of genetic mechanism regulating the complex peach-PPV interaction.

Two-port access versus four-port access laparoscopic ovarian cystectomy.

Science.gov (United States)

Choi, Won-Kyu; Kim, Jang-Kew; Yang, Jung-Bo; Ko, Young-Bok; Nam, Sang-Lyun; Lee, Ki-Hwan

2014-09-01

This study was conducted to compare the surgical outcomes between two-port access and four-port access laparoscopic ovarian cystectomy. Four hundred and eighty nine patients who had received two-port access laparoscopic ovarian cystectomy (n=175) and four-port access laparoscopic ovarian cystectomy (n=314) in Chungnam National University Hospital from January 2009 to August 2012 were analyzed retrospectively. The data were compared between the bilaterality of the cysts and cyst diameter of less than 6 cm and 6 cm or more. There were no significant differences in patient's age, parity, body weight, body mass index and history of previous surgery between the two-port and four-port access laparoscopy group. Bilaterality of ovarian cysts was more in fourport access laparoscopy group (13.7% vs. 32.5%, P=0.000). There were no significant differences in operation time, hemoglobin change, hospital stay, adhesiolysis, transfusion, and insertion of hemo-vac between the two-port and four-port access laparoscopy group for size matched compare. However additional analgesics were more in four-port access laparoscopy group for unilateral ovarian cystectomy. Two-port access laparoscopic surgery was feasible and safe for unilateral and bilateral ovarian cystectomy compare with four-port access laparoscopic surgery.

Genetic diversity analysis of common beans based on molecular markers

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Homar R. Gill-Langarica

2011-01-01

Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

Genetic diversity analysis of common beans based on molecular markers

Directory of Open Access Journals (Sweden)

Homar R. Gill-Langarica

Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

Genetic diversity analysis of common beans based on molecular markers.

Science.gov (United States)

Gill-Langarica, Homar R; Muruaga-Martínez, José S; Vargas-Vázquez, M L Patricia; Rosales-Serna, Rigoberto; Mayek-Pérez, Netzahualcoyotl

2011-10-01

A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

Open access

NARCIS (Netherlands)

Valkenburg, P.M.

2015-01-01

Open access week Van 19 tot en met 25 oktober 2015 vond wereldwijd de Open Access Week plaats. Tijdens deze week werden er over de hele wereld evenementen georganiseerd waar open access een rol speelt. Ook in Nederland zijn er diverse symposia, workshops en debatten georganiseerd zoals het debat in

Open Access @ DTU

DEFF Research Database (Denmark)

Ekstrøm, Jeannette

Open Access is high on the agenda in Denmark and internationally. Denmark has announced a national strategy for Open Access that aims to achieve Open Access to 80% in 2017 and 100% in 2022 to peer review research articles. All public Danish funders as well as H2020 requires that all peer review...... articles that is an outcome of their funding will be Open Access. Uploading your full texts (your final author manuscript after review ) to DTU Orbit is a fundamental part of providing Open Access to your research. We are here to answer all your questions with regards to Open Access and related topics...... such as copyright, DTU Orbit, Open Access journals, APCs, Vouchers etc....

Ribosomal DNA intergenic spacer sequence in foxtail millet, Setaria italica (L.) P. Beauv. and its characterization and application to typing of foxtail millet landraces.

Science.gov (United States)

Fukunaga, Kenji; Ichitani, Katsuyuki; Taura, Satoru; Sato, Muneharu; Kawase, Makoto

2005-02-01

We determined the sequence of ribosomal DNA (rDNA) intergenic spacer (IGS) of foxtail millet isolated in our previous study, and identified subrepeats in the polymorphic region. We also developed a PCR-based method for identifying rDNA types based on sequence information and assessed 153 accessions of foxtail millet. Results were congruent with our previous works. This study provides new findings regarding the geographical distribution of rDNA variants. This new method facilitates analyses of numerous foxtail millet accessions. It is helpful for typing of foxtail millet germplasms and elucidating the evolution of this millet.

AFLP and MS-AFLP analysis of the variation within saffron crocus (Crocus sativus L. germplasm.

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Matteo Busconi

Full Text Available The presence and extent of genetic variation in saffron crocus are still debated, as testified by several contradictory articles providing contrasting results about the monomorphism or less of the species. Remarkably, phenotypic variations have been frequently observed in the field, such variations are usually unstable and can change from one growing season to another. Considering that gene expression can be influenced both by genetic and epigenetic changes, epigenetics could be a plausible cause of the alternative phenotypes. In order to obtain new insights into this issue, we carried out a molecular marker analysis of 112 accessions from the World Saffron and Crocus Collection. The accessions were grown for at least three years in the same open field conditions. The same samples were analysed using Amplified Fragment Length Polymorphism (AFLP and Methyl Sensitive AFLP in order to search for variation at the genetic (DNA sequence and epigenetic (cytosine methylation level. While the genetic variability was low (4.23% polymorphic peaks and twelve (12 effective different genotypes, the methyl sensitive analysis showed the presence of high epigenetic variability (33.57% polymorphic peaks and twenty eight (28 different effective epigenotypes. The pattern obtained by Factorial Correspondence Analysis of AFLP and, in particular, of MS-AFLP data was consistent with the geographical provenance of the accessions. Very interestingly, by focusing on Spanish accessions, it was observed that the distribution of the accessions in the Factorial Correspondence Analysis is not random but tends to reflect the geographical origin. Two clearly defined clusters grouping accessions from the West (Toledo and Ciudad Real and accessions from the East (Cuenca and Teruel were clearly recognised.

Avaliação do teor de cafeína em folhas e grãos de acessos de café arábica Evaluation of the caffeine content in leaves and grains of arabica coffee accessions

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Alexsandro Lara Teixeira

2012-03-01

Full Text Available O presente trabalho teve como objetivo identificar, dentro do banco de germoplasma do estado de Minas Gerais, acessos de Coffea arabica L. com baixos teores de cafeína e verificar a existência de correlação entre o teor de cafeína dos grãos e de folhas ainda no estádio de mudas, viabilizando a prática da seleção precoce. Foram utilizados 75 acessos de café (cultivares, híbridos e alguns genótipos selvagens oriundos do banco de germoplasma de café do Estado de Minas Gerais. Para estudo da correlação foram utilizados oito cultivares no delineamento de blocos casualizados com três repetições. Avaliaram-se os teores de cafeína presentes nos grãos e no terceiro e quarto par de folhas verdadeiras. Seis acessos apresentaram teores de cafeína nos grãos menores que 0,88%. Correlações significativas para teor de cafeína foram observadas entre o terceiro (0,69 e quarto par de folhas (0,92 e os grãos. Foram identificados acessos com teores reduzidos de cafeína e boa produtividade de grãos, podendo ser utilizados como genitores em programas de melhoramento. Verificou-se que é possível realizar a seleção precoce para teor de cafeína, em plantas de cafeeiro ainda no estádio de mudas, por meio da avaliação do quarto par de folhas.The aim of this study was to identify, within the germplasm bank of the Minas Gerais state, Coffea arabica L. accessions with low levels of caffeine and check the correlation between grain and leaves in seedling stage, making possible the practice of early selection. Seventy-five coffe accessions (cultivars, hybrids and several wild genotypes were evaluated from the coffee germplasm bank of the Minas Gerais state. In the correlation study, eight cultivars were used on randomized complete block design with three replications. Were evaluated the caffeine levels in the grains and the third and fourth pair of true leaves. Six accessions had caffeine levels in grains smaller than 0.88%. Was also detected

Diversity for seedling vigor in wild barley (hordeum vulgare L. subs. simpatina) germplasm

International Nuclear Information System (INIS)

Tyagi, K.; Park, M.R.; Lee, H.J.; Lee, C.A.; Rehman, S.; Steffenson, B.; Lee, K.J.; Yun, S.J.

2011-01-01

Seedling vigor is important for improving stand establishment of barley crops, particularly in arid regions and areas where the soil temperature is low at sowing time. Three hundred and fifteen wild barley accessions from the Wild Barley Diversity Collection (WBDC) were evaluated for nine seedling vigor traits in a poly house and growth chamber under hydroponic conditions. The accessions exhibited significant differences for all traits investigated. Traits showing greatest phenotypic variation were seedling visual score, plant height, shoot fresh weight, shoot dry weight and shoot length. Seed weight exhibited the least variation. Seed weight was significantly correlated with visual seedling score and shoot and seedling fresh and dry weight. Correlation analysis showed that the visual seedling score was a reliable method for estimating seedling vigor in wild barley. The first three principal components (PC) explained 82.3% of the variation present in the WBDC with PC1(54.0%) associated with shoot fresh weight, shoot dry weight, seedling dry weight, seedling fresh weight, shoot length and seedling length. Accessions from the southwest portion of the Fertile Crescent, like WBDC020 (Turkey), WBDC238 (Jordan) and WBDC244 (Jordan) exhibited the highest positive values for most of the plant vigor traits investigated. These wild barley accessions likely carry alleles that will be useful for the improvement of plant vigor traits in cultivated barley. (author)

Access Denied! Contrasting Data Access in the United States and Ireland

Directory of Open Access Journals (Sweden)

Grogan Samuel

2016-07-01

Full Text Available The ability of an Internet user to access data collected about himself as a result of his online activity is a key privacy safeguard. Online, data access has been overshadowed by other protections such as notice and choice. This paper describes attitudes about data access. 873 US and Irish Internet users participated in a survey designed to examine views on data access to information held by online companies and data brokers. We observed low levels of awareness of access mechanisms along with a high desire for access in both participant groups. We tested three proposed access systems in keeping with industry programs and regulatory proposals. User response was positive. We conclude that access remains an important privacy protection that is inadequately manifested in practice. Our study provides insight for lawmakers and policymakers, as well as computer scientists who implement these systems.

Tree Seed and Seedling Supply Systems

DEFF Research Database (Denmark)

Nyoka, Betserai I.; Roshetko, James M.; Jamnadass, Ramni

2015-01-01

through a legal framework or voluntary. A few countries in Africa, Asia and Latin America have developed protocols for certification of tree seeds based on the OECD. Some germplasm suppliers use branding as a way of differentiating their germplasm as having superior quality. To enhance the use of high...... quality germplasm, there is a need to demonstrate the value of using such germplasm and raise awareness of germplasm quality among the farmers and policy-makers....

Divergência genética entre acessos de batata-doce utilizando caracteres fenotípicos de raiz Genetic divergence among sweet potato accessions based on root traits

Directory of Open Access Journals (Sweden)

Giovani O da Silva

2012-12-01

Full Text Available Estudos de quantificação da divergência genética entre acessos e caracterização dos recursos genéticos têm sido de grande importância em programas de melhoramento, auxiliando na identificação de genitores e no conhecimento do material genético disponível. Os objetivos do presente trabalho foram: (1 avaliar os acessos de batata-doce pertencentes ao banco de germoplasma da Embrapa com base em caracteres de raiz; (2 calcular a importância relativa dos caracteres morfo-agronômicos quantitativos na discriminação dos acessos e, (3 obter indicações das combinações híbridas mais promissoras para cruzamentos. Foi avaliada uma coleção de 11 clones pertencentes ao Banco Ativo de Germoplasma da Embrapa por meio de um experimento conduzido na Embrapa SPM/EN, em Canoinhas-SC. Os acessos foram cultivados em condições de campo no delineamento em blocos ao acaso com quatro repetições, onde a parcela experimental foi composta por 10 plantas. As plantas de cada parcela foram colhidas e avaliadas para 12 caracteres fenotípicos de raiz. O estudo indicou que os caracteres número e massa total de raízes e peso específico foram os que mais contribuíram para a divergência genética. A maioria dos acessos é bastante similar quanto aos caracteres quantitativos avaliados. Porém, há a possibilidade de ganhos com a heterose, geração de variabilidade genética e de progênies superiores cruzando-se os acessos dos diferentes grupamentos formados; pois os genótipos mais contrastantes '1228', '051-1' e '1270' foram agrupados entre os melhores para várias características como massa e número total de raízes, massa comercial de raízes; os dois primeiros apresentaram elevado peso específico e o '1270' apresentou coloração alaranjada intensa, indicativo de alto teor de β-caroteno.The estimation of the genetic divergence among accessions of a germplasm bank, as well as their characterization are very important in breeding programs in

Morphological traits based diversity in safflower (carthamus tinctorius L.)

International Nuclear Information System (INIS)

Shinwari, Z.K.; Rehman, H.

2014-01-01

Safflower (Carthamus tinctorius L.) one of the world minor oil crops originated in the Middle East. The breeding potential of the safflower genotypes held in the gene-bank of Plant Genetic Resources Institute (PGRI) has not been exploited to date. Present work was carried out to evaluate 122 genotypes collected from various eco-geographical regions/countries of the world. Observations were recorded for eleven quantitative and five qualitative characters to estimate substantial variation and relationship among the genotypes and identify promising accession(s) for traits of economic significance. A significant level of morphological diversity was noticed for a number of traits. The largest variation was recorded for capsules plant-1, seeds capsule-1, seed yield plant-1, plant height, days to flowering initiation and days to maturity. Relatively low level of variability was distinguished in 100-seed weight, capsule diameter, primary branches plant-1, days to flower completion, time of flowering, flower color, leaf shape and spininess. The correlation analysis indicated that seed diameter, capsules plant-1 and seeds capsule-1 had highly significant positive contribution to seed yield plant-1. Only one trait, time of flowering showed negative correlation with seed yield plant-1. Principal component (PC) analysis of 122 safflower germplasm displayed significant variation with PC1 having 26.02% of the total variation, 19.97% for PC2, 12.38% for PC3 and PC4 contributed 11.24% of the total variation and revealed that the characters that mainly distinguish the germplasm are: capsule diameter, capsules plant-1, seeds capsule-1, days to maturity, plant height and time of flowering. Cluster analysis recognized five major clusters. Our findings have an important application for safflower germplasm evaluation and preservation. (author)

Accessibility and sensory experiences

DEFF Research Database (Denmark)

Ryhl, Camilla

2010-01-01

and accessibility. Sensory accessibility accommodates aspects of a sensory disability and describes architectural design requirements needed to ensure access to architectural experiences. In the context of architecture accessibility has become a design concept of its own. It is generally described as ensuring...... physical access to the built environment by accommodating physical disabilities. While the existing concept of accessibility ensures the physical access of everyone to a given space, sensory accessibility ensures the choice of everyone to stay and be able to participate and experience....

Genetic diversity and structure of Brazilian ginger germplasm (Zingiber officinale) revealed by AFLP markers.

Science.gov (United States)

Blanco, Eleonora Zambrano; Bajay, Miklos Maximiliano; Siqueira, Marcos Vinícius Bohrer Monteiro; Zucchi, Maria Imaculada; Pinheiro, José Baldin

2016-12-01

Ginger is a vegetable with medicinal and culinary properties widely cultivated in the Southern and Southeastern Brazil. The knowledge of ginger species' genetic variability is essential to direct correctly future studies of conservation and genetic improvement, but in Brazil, little is known about this species' genetic variability. In this study, we analyzed the genetic diversity and structure of 55 Brazilian accessions and 6 Colombian accessions of ginger, using AFLP (Amplified Fragment Length Polymorphism) molecular markers. The molecular characterization was based on 13 primers combinations, which generated an average of 113.5 polymorphic loci. The genetic diversity estimates of Nei (Hj), Shannon-Weiner index (I) and an effective number of alleles (n e ) were greater in the Colombian accessions in relation to the Brazilian accessions. The analysis of molecular variance showed that most of the genetic variation occurred between the two countries while in the Brazilian populations there is no genetic structure and probably each region harbors 100 % of genetic variation found in the samples. The bayesian model-based clustering and the dendrogram using the dissimilarity's coefficient of Jaccard were congruent with each other and showed that the Brazilian accessions are highly similar between themselves, regardless of the geographic region of origin. We suggested that the exploration of the interspecific variability and the introduction of new varieties of Z.officinale are viable alternatives for generating diversity in breeding programs in Brazil. The introduction of new genetic materials will certainly contribute to a higher genetic basis of such crop.

Gene Pools and the Genetic Architecture of Domesticated Cowpea

Directory of Open Access Journals (Sweden)

Bao-Lam Huynh

2013-11-01

Full Text Available Cowpea [ (L. Walp.] is a major tropical legume crop grown in warm to hot areas throughout the world and especially important to the people of sub-Saharan Africa where the crop was domesticated. To date, relatively little is understood about its domestication origins and patterns of genetic variation. In this study, a worldwide collection of cowpea landraces and African ancestral wild cowpea was genotyped with more than 1200 single nucleotide polymorphism markers. Bayesian inference revealed the presence of two major gene pools in cultivated cowpea in Africa. Landraces from gene pool 1 are mostly distributed in western Africa while the majority of gene pool 2 are located in eastern Africa. Each gene pool is most closely related to wild cowpea in the same geographic region, indicating divergent domestication processes leading to the formation of two gene pools. The total genetic variation within landraces from countries outside Africa was slightly greater than within African landraces. Accessions from Asia and Europe were more related to those from western Africa while accessions from the Americas appeared more closely related to those from eastern Africa. This delineation of cowpea germplasm into groups of genetic relatedness will be valuable for guiding introgression efforts in breeding programs and for improving the efficiency of germplasm management.

Lexical semantic access and letter access are involved in different aspects of reading

DEFF Research Database (Denmark)

Poulsen, Mads

). In this subset sample, both letter access and lexical access accounted for unique variance in reading fluency. The pattern of effects for lexical access did not change by controlling for serial rapid naming (RAN). Conclusions: The results suggest that letter access and lexical access are important for different......Purpose: This study investigated the effects of lexical access speed and letter access speed on reading fluency and reading comprehension. We hypothesized that 1) letter access speed would correlate with reading fluency but not comprehension, while 2) lexical access speed would influence reading...... comprehension. For readers who are struggling with recoding, most of the reading effort is probably tied up with recoding, leaving little to be explained by lexical access. Therefore we expected that 3) lexical access speed would primarily predict reading fluency for readers who were no longer struggling...

Optical Access Networks

Science.gov (United States)

Zheng, Jun; Ansari, Nirwan

2005-06-01

Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

Public Access and Open Access: Is There a Difference? | Poster

Science.gov (United States)

By Robin Meckley, Contributing Writer, and Tracie Frederick, Guest Writer Open access and public access—are they different concepts or are they the same? What do they mean for the researchers at NCI at Frederick? “Open-access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions. What makes it possible is the Internet and the consent of the author or copyright-holder,” according to an open access website maintained by Peter Suber, director, Harvard Open Access Project.

Moving toward a universally accessible web: Web accessibility and education.

Science.gov (United States)

Kurt, Serhat

2017-12-08

The World Wide Web is an extremely powerful source of information, inspiration, ideas, and opportunities. As such, it has become an integral part of daily life for a great majority of people. Yet, for a significant number of others, the internet offers only limited value due to the existence of barriers which make accessing the Web difficult, if not impossible. This article illustrates some of the reasons that achieving equality of access to the online world of education is so critical, explores the current status of Web accessibility, discusses evaluative tools and methods that can help identify accessibility issues in educational websites, and provides practical recommendations and guidelines for resolving some of the obstacles that currently hinder the achievability of the goal of universal Web access.

Número cromossômico em acessos de Pennisetum spp. (Poaceae, Poales - DOI: 10.4025/actascibiolsci.v30i3.5016 Chromosome number in Pennisetum spp. accessions (Poaceae, Poales - DOI: 10.4025/actascibiolsci.v30i3.5016

Directory of Open Access Journals (Sweden)

Antônio Vander Pereira

2008-10-01

Full Text Available Avaliou-se o complemento cromossômico de 16 acessos de Pennisetum disponíveis na Coleção de Germoplasma da Embrapa Gado de Leite – Juiz de Fora, Estado de Minas Gerais. Para a avaliação citogenética, utilizou-se a técnica de esmagamento e coloração com Feulgen. Para quatro acessos foram obtidas metáfases com 2n = 28 cromossomos, confirmando sua classificação como P. purpureum. A origem híbrida P. purpureum x P. glaucum foi constatada em oito acessos, os quais apresentaram 2n = 21. Em um acesso identificado como híbrido entre P. purpureum x P. glaucum, foram observadas metáfases com 2n = 54, permitindo inferir que não se trata de um híbrido interespecífico triplóide. Para outros três acessos avaliados, também foram observadas células com 2n = 54, embora estivessem identificados como híbridos entre P. purpureum x espécie selvagem; P. glaucum policross x hexaplóide 200 e P. glaucum x F92-161-01 ( P. purpureum x P. glaucum .The chromosome complement of 16 Pennisetum accessions belonging to the Germplasm Collection of Embrapa Gado de Leite - Juiz de Fora, Minas Gerais State was evaluated. The cytogenetic analysis employed the smear technique and staining with Feulgen. In four accessions, metaphases with 2n = 28 chromosomes were obtained, confirming their classification as P. purpureum. The hybrid origin P. purpureum x P. glaucum was observed in eight accessions, which presented 2n = 21. In an accession identified as P. purpureum x P. glaucum hybrid, metaphases with 2n = 54 were observed, suggesting that it is not a triploid interspecific hybrid. For three other evaluated accessions, cells with 2n=54 were also observed, although they were identified as hybrids between P. purpureum x wild species; P. glaucum polycross x hexaploid 200 and P. glaucum x [F92-161-01 (P. purpureum x P. glaucum].

Access Customized Forms

OpenAIRE

Cosma Emil; Jeflea Victor

2010-01-01

By using Word, Excel or PowerPoint one can automate routine operations using the VBA language (Visual Basic for Applications). This language is also used in Access, allowing access to data stored in tables or queries. Thus, Access and VBA resources can be used together. Access is designed for programming forms and reports (among other things), so there won’t be found any of the VBA editor’s specific forms.

Evidence for a Common Origin of Homomorphic and Heteromorphic Sex Chromosomes in Distinct Spinacia Species

OpenAIRE

Fujito, Satoshi; Takahata, Satoshi; Suzuki, Reimi; Hoshino, Yoichiro; Ohmido, Nobuko; Onodera, Yasuyuki

2015-01-01

The dioecious genus Spinacia is thought to include two wild relatives (S. turkestanica Ilj. and S. tetrandra Stev.) of cultivated spinach (S. oleracea L.). In this study, nuclear and chloroplast sequences from 21 accessions of Spinacia germplasm and six spinach cultivars or lines were subjected to phylogenetic analysis to define the relationships among the three species. Maximum-likelihood sequence analysis suggested that the Spinacia plant samples could be classified into two monophyletic gr...

Open access

CERN Document Server

Suber, Peter

2012-01-01

The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder consent, and many authors, musicians, filmmakers, and other creators who depend on royalties are understandably unwilling to give their consent. But for 350 years, scholars have written peer-reviewed journal articles for impact, not for money, and are free to consent to open access without losing revenue. In this concise introduction, Peter Suber tells us what open access is and isn't, how it benefits authors and readers of research, how we pay for it, how it avoids copyright problems, how it has moved from the periphery to the mainstream, and what its future may hold. Distilling a decade of Suber's influential writing and thinking about open access, this is the indispe...

Caracterização da diversidade genética entre acessos crioulos de feijão (Phaseolus vulgaris L. coletados em Santa Catarina por marcadores RAPD Characterization of the genetic diversity of landraces of common bean (Phaseolus vulgaris L. collected in Santa Catarina State by RAPD markers

Directory of Open Access Journals (Sweden)

Márcio Fonseca de Carvalho

2008-09-01

, and of three cultivars ('Pérola', 'SCS 202-Guará' e 'BRS Valente', using RAPD markers. 21 decamer-primers that allowed the visualization of 96 bands were used, and 41 (42.7% presented polymorphism among the studied accesses, resulting in a band range of 650 to 2000pb. The dissimilarity was calculated using the Sorensen-Dice coefficient and the grouping analyses were derived from UPGMA. The accesses were separated in two main groups, with wide dissimilarity when compared with the divergence inside each group. These two groups indicate the possible center of domestication, Middle-American or Andean, of the accesses in this study. The dissimilarity among the cultivars evaluated ('SCS 202-Guará', 'BRS Valente' e 'Pérola' was small (0.15, if compared with the divergence among the accesses of the germplasm bank (0.65. The smaller dissimilarity among the studied accesses (BAF63 and BAF04 was 0.02. The results reinforce the need of new collection expeditions, which will increase the representation of the genetic variability of the remaining bean landraces in Santa Catarina State.

From spatial to social accessibility: How socio-economic factors can affect accessibility?

OpenAIRE

Mercier , Aurélie

2016-01-01

The concept of accessibility cannot only focus on " spatial accessibility " measurement but has to integer a " social accessibility " level to take into account individual inequalities and socioeconomic disparities to access to urban opportunities. In this context, this contribution focuses on socioeconomic disparities integration on accessibility measurement, considering the Lyon case study. The paper is divided into three parts The first part aims to present a method for integrating the soc...

Accessibility

DEFF Research Database (Denmark)

Brooks, Anthony Lewis

2017-01-01

This contribution is timely as it addresses accessibility in regards system hardware and software aligned with introduction of the Twenty-First Century Communications and Video Accessibility Act (CVAA) and adjoined game industry waiver that comes into force January 2017. This is an act created...... by the USA Federal Communications Commission (FCC) to increase the access of persons with disabilities to modern communications, and for other purposes. The act impacts advanced communications services and products including text messaging; e-mail; instant messaging; video communications; browsers; game...... platforms; and games software. However, the CVAA has no legal status in the EU. This text succinctly introduces and questions implications, impact, and wider adoption. By presenting the full CVAA and game industry waiver the text targets to motivate discussions and further publications on the subject...

Optical Access Networks

Science.gov (United States)

Zheng, Jun; Ansari, Nirwan

2005-01-01

Call for Papers: Optical Access Networks Guest Editors Jun Zheng, University of Ottawa Nirwan Ansari, New Jersey Institute of Technology Submission Deadline: 1 June 2005 Background With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks

Demystifying Open Access

International Nuclear Information System (INIS)

Mele, Salvatore

2007-01-01

The tenets of Open Access are to grant anyone, anywhere and anytime free access to the results of scientific research. HEP spearheaded the Open Access dissemination of scientific results with the mass mailing of preprints in the pre-WWW era and with the launch of the arXiv preprint system at the dawn of the '90s. The HEP community is now ready for a further push to Open Access while retaining all the advantages of the peer-review system and, at the same time, bring the spiralling cost of journal subscriptions under control. I will present a possible plan for the conversion to Open Access of HEP peer-reviewed journals, through a consortium of HEP funding agencies, laboratories and libraries: SCOAP3 (Sponsoring Consortium for Open Access Publishing in Particle Physics). SCOAP3 will engage with scientific publishers towards building a sustainable model for Open Access publishing, which is as transparent as possible for HEP authors. The current system in which journals income comes from subscription fees is replaced with a scheme where SCOAP3 compensates publishers for the costs incurred to organise the peer-review service and give Open Access to the final version of articles. SCOAP3 will be funded by all countries active in HEP under a 'fair share' scenario, according to their production of HEP articles. In this talk I will present a short overview of the history of Open Access in HEP, the details of the SCOAP3 model and the outlook for its implementation.

Compositional characterization of native Peruvian chili peppers (Capsicum spp.).

Science.gov (United States)

Meckelmann, Sven W; Riegel, Dieter W; van Zonneveld, Maarten J; Ríos, Llermé; Peña, Karla; Ugas, Roberto; Quinonez, Lourdes; Mueller-Seitz, Erika; Petz, Michael

2013-03-13

The national Capsicum germplasm bank of Peru at INIA holds a unique collection of more than 700 Capsicum accessions, including many landraces. These conserved accessions have never been thoroughly characterized or evaluated. Another smaller collection exists at UNALM, and CIDRA provided taxonomically characterized fruits from the Amazon region of Ucayali. Of these collections, 147 accessions have been selected to represent the biodiversity of Peruvian Capsicum annuum , Capsicum baccatum , Capsicum chinense , and Capsicum frutescens by morphological traits as well as by agronomic characteristics and regional origin. All fruits from the selected accessions have been oven-dried and ground in Peru and analyzed in Germany. Results are reported for each accession by total capsaicinoids and capsaicinoid pattern, total polyphenol content, antioxidant capacity, specific flavonoids (quercetin, kaempferol, luteolin, apigenin), fat content, vitamin C, surface color, and extractable color. A wide variability in phytochemical composition and concentration levels was found.

Overview: Routes to Open Access

OpenAIRE

Tullney, Marco; van Wezenbeek, Wilma

2017-01-01

Slides of an overview presentation given at a CESAER workshop on Open Access, February 2nd, 2017, in Brussels Cover major routes to more open access as discussed in the Task Force Open Science of CESAER: (national) open access strategies open access mandates open access incentives open access awareness open access publishing open access infrastructure

Accessing Electronic Journals.

Science.gov (United States)

McKay, Sharon Cline

1999-01-01

Discusses issues librarians need to consider when providing access to electronic journals. Topics include gateways; index and abstract services; validation and pay-per-view; title selection; integration with OPACs (online public access catalogs)or Web sites; paper availability; ownership versus access; usage restrictions; and services offered…

Accessing memory

Science.gov (United States)

Yoon, Doe Hyun; Muralimanohar, Naveen; Chang, Jichuan; Ranganthan, Parthasarathy

2017-09-26

A disclosed example method involves performing simultaneous data accesses on at least first and second independently selectable logical sub-ranks to access first data via a wide internal data bus in a memory device. The memory device includes a translation buffer chip, memory chips in independently selectable logical sub-ranks, a narrow external data bus to connect the translation buffer chip to a memory controller, and the wide internal data bus between the translation buffer chip and the memory chips. A data access is performed on only the first independently selectable logical sub-rank to access second data via the wide internal data bus. The example method also involves locating a first portion of the first data, a second portion of the first data, and the second data on the narrow external data bus during separate data transfers.

Wireless Access

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Wireless Access. Wireless connect to the Base station. Easy and Convenient access. Costlier as compared to the wired technology. Reliability challenges. We see it as a complementary technology to the DSL.

Transparency of Biobank Access in Canada: An Assessment of Industry Access and the Availability of Information on Access Policies and Resulting Research.

Science.gov (United States)

Gibson, Shannon G; Axler, Renata E; Lemmens, Trudo

2017-12-01

A key issue impacting public trust in biobanks is how these resources are utilized, including who is given access to biobank data and samples. To assess the conditions under which researchers are given access to Canadian biobanks, we reviewed websites and contacted Canadian biobanks to determine the availability of information on access policies and procedures; research resulting from access biobank data and samples; and conditions on private industry access to biobanks. We also conducted expert interviews with key Canadian stakeholders ( n = 11) to obtain their perspectives on biobank transparency and access policies. Among 21 Canadian biobanks, there was wide variation in the access information made publicly available, and the majority of these allowed access by industry applicants. Biobanks should be governed by the principles of transparency, accountability, and accessibility, and attention must be given to the conditions around the commercialization of biobank-based research.

Professional Access 2013 programming

CERN Document Server

Hennig, Teresa; Hepworth, George; Yudovich, Dagi (Doug)

2013-01-01

Authoritative and comprehensive coverage for building Access 2013 Solutions Access, the most popular database system in the world, just opened a new frontier in the Cloud. Access 2013 provides significant new features for building robust line-of-business solutions for web, client and integrated environments.  This book was written by a team of Microsoft Access MVPs, with consulting and editing by Access experts, MVPs and members of the Microsoft Access team. It gives you the information and examples to expand your areas of expertise and immediately start to develop and upgrade projects. Exp

Access 2010 Programmer's Reference

CERN Document Server

Hennig, Teresa; Griffith, Geoffrey L

2010-01-01

A comprehensive guide to programming for Access 2010 and 2007. Millions of people use the Access database applications, and hundreds of thousands of developers work with Access daily. Access 2010 brings better integration with SQL Server and enhanced XML support; this Wrox guide shows developers how to take advantage of these and other improvements. With in-depth coverage of VBA, macros, and other programming methods for building Access applications, this book also provides real-world code examples to demonstrate each topic.: Access is the leading database that is used worldwide; While VBA rem

Genome-wide SNP detection, validation, and development of an 8K SNP array for apple.

Directory of Open Access Journals (Sweden)

David Chagné

Full Text Available As high-throughput genetic marker screening systems are essential for a range of genetics studies and plant breeding applications, the International RosBREED SNP Consortium (IRSC has utilized the Illumina Infinium® II system to develop a medium- to high-throughput SNP screening tool for genome-wide evaluation of allelic variation in apple (Malus×domestica breeding germplasm. For genome-wide SNP discovery, 27 apple cultivars were chosen to represent worldwide breeding germplasm and re-sequenced at low coverage with the Illumina Genome Analyzer II. Following alignment of these sequences to the whole genome sequence of 'Golden Delicious', SNPs were identified using SoapSNP. A total of 2,113,120 SNPs were detected, corresponding to one SNP to every 288 bp of the genome. The Illumina GoldenGate® assay was then used to validate a subset of 144 SNPs with a range of characteristics, using a set of 160 apple accessions. This validation assay enabled fine-tuning of the final subset of SNPs for the Illumina Infinium® II system. The set of stringent filtering criteria developed allowed choice of a set of SNPs that not only exhibited an even distribution across the apple genome and a range of minor allele frequencies to ensure utility across germplasm, but also were located in putative exonic regions to maximize genotyping success rate. A total of 7867 apple SNPs was established for the IRSC apple 8K SNP array v1, of which 5554 were polymorphic after evaluation in segregating families and a germplasm collection. This publicly available genomics resource will provide an unprecedented resolution of SNP haplotypes, which will enable marker-locus-trait association discovery, description of the genetic architecture of quantitative traits, investigation of genetic variation (neutral and functional, and genomic selection in apple.

Genome-Wide SNP Detection, Validation, and Development of an 8K SNP Array for Apple

Science.gov (United States)

Chagné, David; Crowhurst, Ross N.; Troggio, Michela; Davey, Mark W.; Gilmore, Barbara; Lawley, Cindy; Vanderzande, Stijn; Hellens, Roger P.; Kumar, Satish; Cestaro, Alessandro; Velasco, Riccardo; Main, Dorrie; Rees, Jasper D.; Iezzoni, Amy; Mockler, Todd; Wilhelm, Larry; Van de Weg, Eric; Gardiner, Susan E.; Bassil, Nahla; Peace, Cameron

2012-01-01

As high-throughput genetic marker screening systems are essential for a range of genetics studies and plant breeding applications, the International RosBREED SNP Consortium (IRSC) has utilized the Illumina Infinium® II system to develop a medium- to high-throughput SNP screening tool for genome-wide evaluation of allelic variation in apple (Malus×domestica) breeding germplasm. For genome-wide SNP discovery, 27 apple cultivars were chosen to represent worldwide breeding germplasm and re-sequenced at low coverage with the Illumina Genome Analyzer II. Following alignment of these sequences to the whole genome sequence of ‘Golden Delicious’, SNPs were identified using SoapSNP. A total of 2,113,120 SNPs were detected, corresponding to one SNP to every 288 bp of the genome. The Illumina GoldenGate® assay was then used to validate a subset of 144 SNPs with a range of characteristics, using a set of 160 apple accessions. This validation assay enabled fine-tuning of the final subset of SNPs for the Illumina Infinium® II system. The set of stringent filtering criteria developed allowed choice of a set of SNPs that not only exhibited an even distribution across the apple genome and a range of minor allele frequencies to ensure utility across germplasm, but also were located in putative exonic regions to maximize genotyping success rate. A total of 7867 apple SNPs was established for the IRSC apple 8K SNP array v1, of which 5554 were polymorphic after evaluation in segregating families and a germplasm collection. This publicly available genomics resource will provide an unprecedented resolution of SNP haplotypes, which will enable marker-locus-trait association discovery, description of the genetic architecture of quantitative traits, investigation of genetic variation (neutral and functional), and genomic selection in apple. PMID:22363718

Construction of Core Collections Suitable for Association Mapping to Optimize Use of Mediterranean Olive (Olea europaea L.) Genetic Resources

Science.gov (United States)

El Bakkali, Ahmed; Haouane, Hicham; Moukhli, Abdelmajid; Costes, Evelyne; Van Damme, Patrick; Khadari, Bouchaib

2013-01-01

Phenotypic characterisation of germplasm collections is a decisive step towards association mapping analyses, but it is particularly expensive and tedious for woody perennial plant species. Characterisation could be more efficient if focused on a reasonably sized subset of accessions, or so-called core collection (CC), reflecting the geographic origin and variability of the germplasm. The questions that arise concern the sample size to use and genetic parameters that should be optimized in a core collection to make it suitable for association mapping. Here we investigated these questions in olive (Olea europaea L.), a perennial fruit species. By testing different sampling methods and sizes in a worldwide olive germplasm bank (OWGB Marrakech, Morocco) containing 502 unique genotypes characterized by nuclear and plastid loci, a two-step sampling method was proposed. The Shannon-Weaver diversity index was found to be the best criterion to be maximized in the first step using the Core Hunter program. A primary core collection of 50 entries (CC50) was defined that captured more than 80% of the diversity. This latter was subsequently used as a kernel with the Mstrat program to capture the remaining diversity. 200 core collections of 94 entries (CC94) were thus built for flexibility in the choice of varieties to be studied. Most entries of both core collections (CC50 and CC94) were revealed to be unrelated due to the low kinship coefficient, whereas a genetic structure spanning the eastern and western/central Mediterranean regions was noted. Linkage disequilibrium was observed in CC94 which was mainly explained by a genetic structure effect as noted for OWGB Marrakech. Since they reflect the geographic origin and diversity of olive germplasm and are of reasonable size, both core collections will be of major interest to develop long-term association studies and thus enhance genomic selection in olive species. PMID:23667437

JISC Open Access Briefing Paper

OpenAIRE

Swan, Alma

2005-01-01

What Open Access is. What Open Access is not. How is Open Access provided? Open Access archives or repositories. Open Access journals. Why should authors provide Open Access to their work? Further information and resources

Access 2013 bible

CERN Document Server

Alexander, Michael

2013-01-01

A comprehensive reference to the updated and new features of Access 2013 As the world's most popular database management tool, Access enables you to organize, present, analyze, and share data as well as build powerful database solutions. However, databases can be complex. That's why you need the expert guidance in this comprehensive reference. Access 2013 Bible helps you gain a solid understanding of database purpose, construction, and application so that whether you're new to Access or looking to upgrade to the 2013 version, this well-rounded resource provides you with a th

Pediatric vascular access

International Nuclear Information System (INIS)

Donaldson, James S.

2006-01-01

Pediatric interventional radiologists are ideally suited to provide vascular access services to children because of inherent safety advantages and higher success from using image-guided techniques. The performance of vascular access procedures has become routine at many adult interventional radiology practices, but this service is not as widely developed at pediatric institutions. Although interventional radiologists at some children's hospitals offer full-service vascular access, there is little or none at others. Developing and maintaining a pediatric vascular access service is a challenge. Interventionalists skilled in performing such procedures are limited at pediatric institutions, and institutional support from clerical staff, nursing staff, and technologists might not be sufficiently available to fulfill the needs of such a service. There must also be a strong commitment by all members of the team to support such a demanding service. There is a slippery slope of expected services that becomes steeper and steeper as the vascular access service grows. This review is intended primarily as general education for pediatric radiologists learning vascular access techniques. Additionally, the pediatric or adult interventional radiologist seeking to expand services might find helpful tips. The article also provides education for the diagnostic radiologist who routinely interprets radiographs containing vascular access devices. (orig.)

Resistance of Wheat Accessions to the English Grain Aphid Sitobion avenae

Science.gov (United States)

Hu, Xiang-Shun; Liu, Ying-Jie; Wang, Yu-Han; Wang, Zhe; Yu, Xin-lin; Wang, Bo; Zhang, Gai-Sheng; Liu, Xiao-Feng; Hu, Zu-Qing; Zhao, Hui-Yan; Liu, Tong-Xian

2016-01-01

The English grain aphid, Sitobion avenae, is a major pest species of wheat crops; however, certain varieties may have stronger resistance to infestation than others. Here, we investigated 3 classical resistance mechanisms (antixenosis, antibiosis, and tolerance) by 14 wheat varieties/lines to S. avenae under laboratory and field conditions. Under laboratory conditions, alatae given the choice between 2 wheat varieties, strongly discriminated against certain varieties. Specifically, the ‘Amigo’ variety had the lowest palatability to S. avenae alatae of all varieties. ‘Tm’ (Triticum monococcum), ‘Astron,’ ‘Xanthus,’ ‘Ww2730,’ and ‘Batis’ varieties also had lower palatability than other varieties. Thus, these accessions may use antibiosis as the resistant mechanism. In contrast, under field conditions, there were no significant differences in the number of alatae detected on the 14 wheat varieties. One synthetic line (98-10-30, a cross between of Triticum aestivum (var. Chris) and Triticum turgidum (var. durum) hybridization) had low aphid numbers but high yield loss, indicating that it has high antibiosis, but poor tolerance. In comparison, ‘Amigo,’ ‘Xiaoyan22,’ and some ‘186Tm’ samples had high aphid numbers but low yield loss rates, indicating they have low antibiosis, but good tolerance. Aphid population size and wheat yield loss rates greatly varied in different fields and years for ‘98-10-35,’ ‘Xiaoyan22,’ ‘Tp,’ ‘Tam200,’ ‘PI high,’ and other ‘186Tm’ samples, which were hybrid offspring of T. aestivum and wheat related species. Thus, these germplasm should be considered for use in future studies. Overall, S. avenae is best adapted to ‘Xinong1376,’ because it was the most palatable variety, with the greatest yield loss rates of all 14 wheat varieties. However, individual varieties/lines influenced aphid populations differently in different years. Therefore, we strongly recommend a combination of

Validation of molecular markers associated with perpetual flowering in octoploid Fragaria germplasm

Science.gov (United States)

Perpetual flowering (PF) is a highly desirable trait within cultivated strawberries (Fragaria ×ananassa) for the commercial and home garden markets. The most widely used source of the PF trait was originally introgressed from a wild Fragaria virginiana subsp. glauca accession collected in the Wasatc...

Preliminary evidence for associations between molecular markers and quantitative traits in a set of bread wheat (Triticum aestivum L.) cultivars and breeding lines.

Science.gov (United States)

Abdollahi Mandoulakani, Babak; Nasri, Shilan; Dashchi, Sahar; Arzhang, Sorour; Bernousi, Iraj; Abbasi Holasou, Hossein

The identification of polymorphic markers associated with various quantitative traits allows us to test their performance for the exploitation of the extensive quantitative variation maintained in gene banks. In the current study, a set of 97 wheat germplasm accessions including 48 cultivars and 49 breeding lines were evaluated for 18 agronomic traits. The accessions were also genotyped with 23 ISSR, nine IRAP and 20 REMAP markers, generating a total of 658 clear and scorable bands, 86% of which were polymorphic. Both neighbor-joining dendrogram and Bayesian analysis of clustering of individuals revealed that the accessions could be divided into four genetically distinct groups, indicating the presence of a population structure in current wheat germplasm. Associations between molecular markers and 18 agronomic traits were analyzed using the mixed linear model (MLM) approach. A total of 94 loci were found to be significantly associated with agronomic traits (P≤0.01). The highest number of bands significantly associated with the 18 traits varied from 11 for number of spikelets spike -1 (NSS) to two for grain yield in row (GRY). Loci ISSR16-9 and REMAP13-10 were associated with three different traits. The results of the current study provide useful information about the performance of retrotransposon-based and ISSR molecular markers that could be helpful in selecting potentially elite gene bank samples for wheat-breeding programs. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Sorghum Landrace Collections from Cooler Regions of the World Exhibit Magnificent Genetic Differentiation and Early Season Cold Tolerance

Directory of Open Access Journals (Sweden)

Frank Maulana

2017-05-01

Full Text Available Cold temperature is an important abiotic stress affecting sorghum production in temperate regions. It reduces seed germination, seedling emergence and seedling vigor thus limiting the production of the crop both temporally and spatially. The objectives of this study were (1 to assess early season cold temperature stress response of sorghum germplasm from cooler environments and identify sources of tolerance for use in breeding programs, (2 to determine population structure and marker-trait association among these germplasms for eventual development of marker tools for improving cold tolerance. A total of 136 sorghum accessions from cooler regions of the world were phenotyped for seedling growth characteristics under cold temperature imposed through early planting. The accessions were genotyped using 67 simple sequence repeats markers spanning all ten linkage groups of sorghum, of which 50 highly polymorphic markers were used in the analysis. Genetic diversity and population structure analyses sorted the population into four subpopulations. Several accessions distributed in all subpopulations showed either better or comparable level of tolerance to the standard cold tolerance source, Shan qui red. Association analysis between the markers and seedling traits identified markers Xtxp34, Xtxp88, and Xtxp319 as associated with seedling emergence, Xtxp211 and Xtxp304 with seedling dry weight, and Xtxp20 with seedling height. The markers were detected on chromosomes previously found to harbor QTLs associated with cold tolerance in sorghum. Once validated these may serve as genomic tools in marker-assisted breeding or for screening larger pool of genotypes to identify additional sources of cold tolerance.

Assessment of genetic diversity using RAPD analysis in a germplasm collection of sea buckthorn

Directory of Open Access Journals (Sweden)

G.I. BARTISH

2008-12-01

Full Text Available Random amplified polymorphic DNA (RAPD markers were used to characterize a part of a sea buckthorn gene bank collected for plant breeding purposes. Molecular markers were generated in 55 cultivars and accessions, representing five subspecies of Hippophae rhamnoides L. and intraspecific hybrids between different subspecies. Sixty-three markers were used to generate a Dice's similarity coefficient matrix of pairwise comparisons between individual RAPD profiles. Cluster (UPGMA and principal co-ordinate analyses, based on this matrix, revealed clustering of plants into groups which generally correspond to their taxonomic classification or geographic origin. The analysis of molecular variance (AMOVA was found useful for estimating components of genetic variation between and within taxonomic and geographic groups of accessions and cultivars. Whereas both alternatives for grouping the material (taxonomic or geographic origin resulted in significant between-group variation, the major part of molecular variance (approximately 75% was still attributed to variation within groups. We conclude that the RAPD analysis is useful for clarification of taxonomic and geographic origin of accessions and cultivars of sea buckthorn.

Open access

African Journals Online (AJOL)

Prof. Dennis Ocholla

The argument that access to information is an instrumental and individual as well as ... and Dean School of Information Studies, University of Wisconsin, Milwaukee, USA. ... to scholarly publications and can be in any digital format, including text, movies and ... language barriers, censorship, lack of access to the Internet and ...

Access 2013 for dummies

CERN Document Server

Ulrich Fuller, Laurie

2013-01-01

The easy guide to Microsoft Access returns with updates on the latest version! Microsoft Access allows you to store, organize, view, analyze, and share data; the new Access 2013 release enables you to build even more powerful, custom database solutions that integrate with the web and enterprise data sources. Access 2013 For Dummies covers all the new features of the latest version of Accessand serves as an ideal reference, combining the latest Access features with the basics of building usable databases. You'll learn how to create an app from the Welcome screen, get support

Pro Access 2010 Development

CERN Document Server

Collins, Mark

2011-01-01

Pro Access 2010 Development is a fundamental resource for developing business applications that take advantage of the features of Access 2010 and the many sources of data available to your business. In this book, you'll learn how to build database applications, create Web-based databases, develop macros and Visual Basic for Applications (VBA) tools for Access applications, integrate Access with SharePoint and other business systems, and much more. Using a practical, hands-on approach, this book will take you through all the facets of developing Access-based solutions, such as data modeling, co

Data access performance through parallelization and vectored access. Some results

International Nuclear Information System (INIS)

Furano, F; Hanushevsky, A

2008-01-01

High Energy Physics data processing and analysis applications typically deal with the problem of accessing and processing data at high speed. Recent studies, development and test work have shown that the latencies due to data access can often be hidden by parallelizing them with the data processing, thus giving the ability to have applications which process remote data with a high level of efficiency. Techniques and algorithms able to reach this result have been implemented in the client side of the Scalla/xrootd system, and in this contribution we describe the results of some tests done in order to compare their performance and characteristics. These techniques, if used together with multiple streams data access, can also be effective in allowing to efficiently and transparently deal with data repositories accessible via a Wide Area Network

Effector-mediated discovery of a novel resistance gene against Bremia lactucae in a nonhost lettuce species.

Science.gov (United States)

Giesbers, Anne K J; Pelgrom, Alexandra J E; Visser, Richard G F; Niks, Rients E; Van den Ackerveken, Guido; Jeuken, Marieke J W

2017-11-01

Candidate effectors from lettuce downy mildew (Bremia lactucae) enable high-throughput germplasm screening for the presence of resistance (R) genes. The nonhost species Lactuca saligna comprises a source of B. lactucae R genes that has hardly been exploited in lettuce breeding. Its cross-compatibility with the host species L. sativa enables the study of inheritance of nonhost resistance (NHR). We performed transient expression of candidate RXLR effector genes from B. lactucae in a diverse Lactuca germplasm set. Responses to two candidate effectors (BLR31 and BLN08) were genetically mapped and tested for co-segregation with disease resistance. BLN08 induced a hypersensitive response (HR) in 55% of the L. saligna accessions, but responsiveness did not co-segregate with resistance to Bl:24. BLR31 triggered an HR in 5% of the L. saligna accessions, and revealed a novel R gene providing complete B. lactucae race Bl:24 resistance. Resistant hybrid plants that were BLR31 nonresponsive indicated other unlinked R genes and/or nonhost QTLs. We have identified a candidate avirulence effector of B. lactucae (BLR31) and its cognate R gene in L. saligna. Concurrently, our results suggest that R genes are not required for NHR of L. saligna. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Genetic resources in maize breeding

Directory of Open Access Journals (Sweden)

Anđelković Violeta

2017-01-01

Full Text Available Maize, wheat and rice are the most important cereals grown in the world. It is predicted that by 2025 maize is likely to become the crop with the greatest production globally. Conservation of maize germplasm provides the main resources for increased food and feed production. Conservation in gene banks (ex-situ is dominant strategy for maize conservation. More than 130 000 maize accessions, e.g. about 40% of total number, are stored in ten largest gene banks worldwide and Maize Research Institute Zemun Polje (MRIZP gene bank, with about 6000 accessions, is among them. Organized collecting missions started in 1961. in the former Yugoslavian territory, and up today, more than 2000 local maize landraces were stored. Pre-breeding activities that refer to identification of desirable traits from unadapted germplasm within genebank, result in materials expected to be included in breeding programs. Successful examples are LAMP, GEM and GENRES projects. At the end of XX century, at MRIZP genebank two pre-breeding activities were undertaken: eco-core and elite-core collections were created and landraces fulfilled particular criteria were chosen. In the last decade, MRIZP genebank collection was used for identification of sources for drought tolerance and improved grain quality. According to agronomic traits and general combining ability, two mini-core collections were created and included in commercial breeding programs.

Two new promising cultivars of mango for Florida

Science.gov (United States)

Mango cultivars are mostly the result of random selections from open pollinated chance seedlings of indigenous or introduced germplasm. The National Germplasm Repository (genebank) at the Subtropical Horticulture Research Station (SHRS) in Miami, Florida is an important mango germplasm repository an...

Open Access

Science.gov (United States)

Suber, Peter

2012-01-01

The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder…

Migrants' access to healthcare

DEFF Research Database (Denmark)

Norredam, Marie

2011-01-01

There are strong pragmatic and moral reasons for receiving societies to address access to healthcare for migrants. Receiving societies have a pragmatic interest in sustaining migrants' health to facilitate integration; they also have a moral obligation to ensure migrants' access to healthcare...... according to international human rights principles. The intention of this thesis is to increase the understanding of migrants' access to healthcare by exploring two study aims: 1) Are there differences in migrants' access to healthcare compared to that of non-migrants? (substudy I and II); and 2) Why...... are there possible differences in migrants' access to healthcare compared to that of non-migrants? (substudy III and IV). The thesis builds on different methodological approaches using both register-based retrospective cohort design, cross-sectional design and survey methods. Two different measures of access were...

Genetic diversity in sugar apple (Annona squamosa L. by using RAPD markers

Directory of Open Access Journals (Sweden)

João Filipi Rodrigues Guimarães

2013-06-01

Full Text Available Genetic diversity in a collection of 64 sugar apple accessions collected from different municipalities in northern Minas Gerais was assessed by RAPD analysis. Using 20 selected RAPD primers 167 fragments were generated, of which 48 were polymorphic (28.7% producing an average of 2.4 polymorphic fragments per primer. Low percentage of polymorphism (< 29% was observed by using the set of primers indicating low level of genetic variation among the 64 accessions evaluated. Genetic relationships were estimated using Jaccard's coefficient of similarity. Accessions from different municipalities clustered together indicating no correlation between molecular grouping and geographical origin. The dendrogram revealed five clusters. The first cluster grouped C19 and G29 accessions collected from the municipalities of Verdelândia and Monte Azul, respectively. The second cluster grouped G16 and B11 accessions collected from the municipalities of Monte Azul and Coração de Jesus, respectively. The remaining accessions were grouped in three clusters, with 8, 15 and 37 accessions, respectively. In summary, RAPD showed a low percentage of polymorphism in the germplasm collection.

Association of State Access Standards With Accessibility to Specialists for Medicaid Managed Care Enrollees.

Science.gov (United States)

Ndumele, Chima D; Cohen, Michael S; Cleary, Paul D

2017-10-01

Medicaid recipients have consistently reported less timely access to specialists than patients with other types of coverage. By 2018, state Medicaid agencies will be required by the Center for Medicare and Medicaid Services (CMS) to enact time and distance standards for managed care organizations to ensure an adequate supply of specialist physicians for enrollees; however, there have been no published studies of whether these policies have significant effects on access to specialty care. To compare ratings of access to specialists for adult Medicaid and commercial enrollees before and after the implementation of specialty access standards. We used Consumer Assessment of Healthcare Providers and Systems survey data to conduct a quasiexperimental difference-in-differences (DID) analysis of 20 163 nonelderly adult Medicaid managed care (MMC) enrollees and 54 465 commercially insured enrollees in 5 states adopting access standards, and 37 290 MMC enrollees in 5 matched states that previously adopted access standards. Reported access to specialty care in the previous 6 months. Seven thousand six hundred ninety-eight (69%) Medicaid enrollees and 28 423 (75%) commercial enrollees reported that it was always or usually easy to get an appointment with a specialist before the policy implementation (or at baseline) compared with 11 889 (67%) of Medicaid enrollees in states that had previously implemented access standards. Overall, there was no significant improvement in timely access to specialty services for MMC enrollees in the period following implementation of standard(s) (adjusted difference-in-differences, -1.2 percentage points; 95% CI, -2.7 to 0.1), nor was there any impact of access standards on insurance-based disparities in access (0.6 percentage points; 95% CI, -4.3 to 5.4). There was heterogeneity across states, with 1 state that implemented both time and distance standards demonstrating significant improvements in access and reductions in disparities

Fishing Access Areas

Data.gov (United States)

Vermont Center for Geographic Information — The Vermont Fish & Wildlife Department maintains developed fishing access areas. These sites provide public access to waters in Vermont for shore fishing...

Variation of medicinal components in a unique geographical accession of horny goat weed Epimedium sagittatum Maxim. (Berberidaceae).

Science.gov (United States)

Liang, Qiong; Wei, Guoyan; Chen, Jianjun; Wang, Ying; Huang, Hongwen

2012-11-08

Herbal Epimedium species have been widely in Traditional Chinese Medicine for sexual enhancement, immunity improvement, anticancer and anti-aging treatment, with flavonoids and polysaccharides being the major active components. However, exhaustive depletion of wild sources warrants germplasm evaluation and quality resource exploration. A preliminarily analysis had previously indicated that a specific local geographic accession of Epimedium sagittatum found in Luotian (LT) county of Hubei Province (China) had a much higher content of total flavonoids and polysaccharides. In this study, we further investigated the medicinal component variation in the LT type under different light intensities and in different regions by the common-garden experiment. The results indicated a light intensity range of 40-160 μmol/m²/s was the most suitable for the synthesis and accumulation of total flavonoids, while polysaccharide accumulation was negatively correlated with the light intensity. Icariin was the component displaying the highest content among flavonoids, and the content of major flavonoid bioactive components was relatively stable in the third year after cultivation. There was significant correlation between the major flavonol glycoside constituents and the geographic location, and Central China followed by Northern China were the highly suitable regions for cultivation of LT type E. sagittatum. The results revealed that there was a functional balance between flavonoids and polysaccharides at different developmental stages, and the best harvesting stage should consider the primary contents of interest. This study provides important information on the exploration of quality resources, further breeding approaches and cultivation practices of E. sagittatum, and thus the important insights to enhance our understanding of quality control of traditional medicinal plants.

Variation of Medicinal Components in a Unique Geographical Accession of Horny Goat Weed Epimedium sagittatum Maxim. (Berberidaceae

Directory of Open Access Journals (Sweden)

Hongwen Huang

2012-11-01

Full Text Available Herbal Epimedium species have been widely in Traditional Chinese Medicine for sexual enhancement, immunity improvement, anticancer and anti-aging treatment, with flavonoids and polysaccharides being the major active components. However, exhaustive depletion of wild sources warrants germplasm evaluation and quality resource exploration. A preliminarily analysis had previously indicated that a specific local geographic accession of Epimedium sagittatum found in Luotian (LT county of Hubei Province (China had a much higher content of total flavonoids and polysaccharides. In this study, we further investigated the medicinal component variation in the LT type under different light intensities and in different regions by the common-garden experiment. The results indicated a light intensity range of 40–160 μmol/m2/s was the most suitable for the synthesis and accumulation of total flavonoids, while polysaccharide accumulation was negatively correlated with the light intensity. Icariin was the component displaying the highest content among flavonoids, and the content of major flavonoid bioactive components was relatively stable in the third year after cultivation. There was significant correlation between the major flavonol glycoside constituents and the geographic location, and Central China followed by Northern China were the highly suitable regions for cultivation of LT type E. sagittatum. The results revealed that there was a functional balance between flavonoids and polysaccharides at different developmental stages, and the best harvesting stage should consider the primary contents of interest. This study provides important information on the exploration of quality resources, further breeding approaches and cultivation practices of E. sagittatum, and thus the important insights to enhance our understanding of quality control of traditional medicinal plants.

Web Accessibility and Guidelines

Science.gov (United States)

Harper, Simon; Yesilada, Yeliz

Access to, and movement around, complex online environments, of which the World Wide Web (Web) is the most popular example, has long been considered an important and major issue in the Web design and usability field. The commonly used slang phrase ‘surfing the Web’ implies rapid and free access, pointing to its importance among designers and users alike. It has also been long established that this potentially complex and difficult access is further complicated, and becomes neither rapid nor free, if the user is disabled. There are millions of people who have disabilities that affect their use of the Web. Web accessibility aims to help these people to perceive, understand, navigate, and interact with, as well as contribute to, the Web, and thereby the society in general. This accessibility is, in part, facilitated by the Web Content Accessibility Guidelines (WCAG) currently moving from version one to two. These guidelines are intended to encourage designers to make sure their sites conform to specifications, and in that conformance enable the assistive technologies of disabled users to better interact with the page content. In this way, it was hoped that accessibility could be supported. While this is in part true, guidelines do not solve all problems and the new WCAG version two guidelines are surrounded by controversy and intrigue. This chapter aims to establish the published literature related to Web accessibility and Web accessibility guidelines, and discuss limitations of the current guidelines and future directions.

Android Access Control Extension

Directory of Open Access Journals (Sweden)

Anton Baláž

2015-12-01

Full Text Available The main objective of this work is to analyze and extend security model of mobile devices running on Android OS. Provided security extension is a Linux kernel security module that allows the system administrator to restrict program's capabilities with per-program profiles. Profiles can allow capabilities like network access, raw socket access, and the permission to read, write, or execute files on matching paths. Module supplements the traditional Android capability access control model by providing mandatory access control (MAC based on path. This extension increases security of access to system objects in a device and allows creating security sandboxes per application.

Notified Access: Extending Remote Memory Access Programming Models for Producer-Consumer Synchronization

KAUST Repository

Belli, Roberto; Hoefler, Torsten

2015-01-01

Remote Memory Access (RMA) programming enables direct access to low-level hardware features to achieve high performance for distributed-memory programs. However, the design of RMA programming schemes focuses on the memory access and less on the synchronization. For example, in contemporary RMA programming systems, the widely used producer-consumer pattern can only be implemented inefficiently, incurring in an overhead of an additional round-trip message. We propose Notified Access, a scheme where the target process of an access can receive a completion notification. This scheme enables direct and efficient synchronization with a minimum number of messages. We implement our scheme in an open source MPI-3 RMA library and demonstrate lower overheads (two cache misses) than other point-to-point synchronization mechanisms for each notification. We also evaluate our implementation on three real-world benchmarks, a stencil computation, a tree computation, and a Colicky factorization implemented with tasks. Our scheme always performs better than traditional message passing and other existing RMA synchronization schemes, providing up to 50% speedup on small messages. Our analysis shows that Notified Access is a valuable primitive for any RMA system. Furthermore, we provide guidance for the design of low-level network interfaces to support Notified Access efficiently.

Notified Access: Extending Remote Memory Access Programming Models for Producer-Consumer Synchronization

KAUST Repository

Belli, Roberto

2015-05-01

Remote Memory Access (RMA) programming enables direct access to low-level hardware features to achieve high performance for distributed-memory programs. However, the design of RMA programming schemes focuses on the memory access and less on the synchronization. For example, in contemporary RMA programming systems, the widely used producer-consumer pattern can only be implemented inefficiently, incurring in an overhead of an additional round-trip message. We propose Notified Access, a scheme where the target process of an access can receive a completion notification. This scheme enables direct and efficient synchronization with a minimum number of messages. We implement our scheme in an open source MPI-3 RMA library and demonstrate lower overheads (two cache misses) than other point-to-point synchronization mechanisms for each notification. We also evaluate our implementation on three real-world benchmarks, a stencil computation, a tree computation, and a Colicky factorization implemented with tasks. Our scheme always performs better than traditional message passing and other existing RMA synchronization schemes, providing up to 50% speedup on small messages. Our analysis shows that Notified Access is a valuable primitive for any RMA system. Furthermore, we provide guidance for the design of low-level network interfaces to support Notified Access efficiently.

Strategic Accessibility Competition

OpenAIRE

Bacchiega, Emanuele; Randon, Emanuela; Zirulia, Lorenzo

2010-01-01

We analyze the effect of competition in market-accessibility enhancement among quality-differentiated firms. Firms are located in regions with different ex-ante transport costs to reach the final market. We characterize the equilibrium of the two-stage game in which firms first invest to improve market accessibility and then compete in prices. Efforts in accessibility improvement crucially depend on the interplay between the willingness to pay for the quality premium of the median consumer an...

Performance analysis of quantum access network using code division multiple access model

International Nuclear Information System (INIS)

Hu Linxi; Yang Can; He Guangqiang

2017-01-01

A quantum access network has been implemented by frequency division multiple access and time division multiple access, while code division multiple access is limited for its difficulty to realize the orthogonality of the code. Recently, the chaotic phase shifters were proposed to guarantee the orthogonality by different chaotic signals and spread the spectral content of the quantum states. In this letter, we propose to implement the code division multiple access quantum network by using chaotic phase shifters and synchronization. Due to the orthogonality of the different chaotic phase shifter, every pair of users can faithfully transmit quantum information through a common channel and have little crosstalk between different users. Meanwhile, the broadband spectra of chaotic signals efficiently help the quantum states to defend against channel loss and noise. (paper)

Design for Accessibility