WorldWideScience

Sample records for rangeland germplasm resources

  1. 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...

  2. Rangeland and water resources

    African Journals Online (AJOL)

    Session B3 Management for sustainable use — Rangeland and water resources. ... The theme of optimsing integrated catchment management will be treated ... land system, catchment, basin), with a focus on law, policy and implementation.

  3. (Gossypium barbadense) germplasm resources

    Indian Academy of Sciences (India)

    Navya

    2017-03-28

    Mar 28, 2017 ... Running title: Marker-trait associations in sea-island cotton ... In this study, Gossypium barbadense germplasm accessions with ... origins (n = 123) were used to perform association analysis of fiber traits with 120 polymorphic simple ... Because fiber yield and quality traits are complex quantitative traits, ...

  4. Conserving rangeland resources. | Mentis | African Journal of Range ...

    African Journals Online (AJOL)

    ... goal-attainment, (5) try to correct departures, and (6) align individual and societal interests by manipulating market-forces. Keywords: altruism; conservation; Conservation implementation; Conservation properties; human activity; Human values; philosophy; Range resources; rangeland; Rangelands; Science philosophy

  5. 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

  6. Ranch business planning and resource monitoring for rangeland sustainability

    Science.gov (United States)

    Kristie A. Maczko; John A. Tanaka; Michael Smith; Cindy Garretson-Weibel; Stanley F. Hamilton; John E. Mitchell; Gene Fults; Charles Stanley; Dick Loper; Larry D. Bryant; J. K. (Rooter) Brite

    2012-01-01

    Aligning a rancher's business plan goals with the capability of the ranch's rangeland resources improves the viability and sustainability of family ranches. Strategically monitoring the condition of soil, water, vegetation, wildlife, livestock production, and economics helps inform business plan goals. Business planning and resource monitoring help keep...

  7. Review on management of horticultural plant germplasm resources and construction of related database

    Directory of Open Access Journals (Sweden)

    Pan Jingxian

    2017-02-01

    Full Text Available The advances of databases on horticulture germplasm resources from China and abroad was briefly reviewed and the key technologies were discussed in details,especially in descriptors of data collection of germplasm resources. The prospective and challenges of databases were also discussed. It was evident that there was an urgent need to develop the databases of horticulture germplasm resources,with increasing diversity of germplasm,more user friendly and systematically access to the databases.

  8. Rangeland resource trends in the United States: A technical document supporting the 2000 USDA Forest Service RPA Assessment

    Science.gov (United States)

    John E. Mitchell

    2000-01-01

    This report documents trends in America's rangelands as required by the Renewable Resources Planning Act of 1974. The Forest Service has conducted assessments of the rangeland situation for 30 years. Over this period, rangeland values and uses have gradually shifted from concentrating upon forage production and meeting increasing demand for red meat to a more...

  9. 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.

  10. Resource analysis of the Chinese society 1980-2002 based on exergy-Part 4: Fishery and rangeland

    International Nuclear Information System (INIS)

    Chen, B.; Chen, G.Q.

    2007-01-01

    This fourth part is the continuation of the third part on agricultural products. The major fishery and rangeland products entering the Chinese society from 1980 to 2002 are calculated and analyzed in detail in this paper. The aquatic production, mainly relying on freshwater and seawater breeding, Enhancement policy of fishery resources, including closed fishing season system, construction of artificial fish reefs and ecological fish breeding, etc., is discussed in detail. The degradation of the major rangeland areas, hay yields and intake rangeland resources by the livestock, are also described associated with the strategic adjustment and comprehensive program to protect rangeland resources during the study period

  11. Is "Holisitc Resource Management" the answer for African Rangelands?

    OpenAIRE

    Bayer, W.; Niamir, M.; A. Waters-Bayer

    1987-01-01

    Metadata only record In Pastoral Network Newsletter No. 23, mention was made of a workshop on Holistic Resource Management (HRM) held 15-17 December 1986 in Uppsala, Sweden. The workshop was organized on behalf of SIDA by the consulting firm Terra Nova and the Swedish University of Agricultural Sciences. Participants were mainly from Swedish universities and development agencies, but also included a few individuals form Denmark, Norway, USA and Germany. The sole lecturer was Mr. Allan Savo...

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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)

  14. Contrasting watershed-scale trends in runoff and sediment yield complicate rangeland water resources planning

    Science.gov (United States)

    Berg, Matthew D.; Marcantonio, Franco; Allison, Mead A.; McAlister, Jason; Wilcox, Bradford P.; Fox, William E.

    2016-06-01

    Rangelands cover a large portion of the earth's land surface and are undergoing dramatic landscape changes. At the same time, these ecosystems face increasing expectations to meet growing water supply needs. To address major gaps in our understanding of rangeland hydrologic function, we investigated historical watershed-scale runoff and sediment yield in a dynamic landscape in central Texas, USA. We quantified the relationship between precipitation and runoff and analyzed reservoir sediment cores dated using cesium-137 and lead-210 radioisotopes. Local rainfall and streamflow showed no directional trend over a period of 85 years, resulting in a rainfall-runoff ratio that has been resilient to watershed changes. Reservoir sedimentation rates generally were higher before 1963, but have been much lower and very stable since that time. Our findings suggest that (1) rangeland water yields may be stable over long periods despite dramatic landscape changes while (2) these same landscape changes influence sediment yields that impact downstream reservoir storage. Relying on rangelands to meet water needs demands an understanding of how these dynamic landscapes function and a quantification of the physical processes at work.

  15. RANGELAND SEQUESTRATION POTENTIAL ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; George F. Vance; Gerald E. Schuman; Justin D. Derner

    2012-03-31

    Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terrestrial carbon in rangelands resulting from management can account for significant carbon sequestration given the magnitude of this land resource. Despite the significance rangelands can play in carbon sequestration, our understanding remains limited. Researchers conducted a literature review to identify sustainably management practices that conserve existing rangeland carbon pools, as well as increase or restore carbon sequestration potentials for this type of ecosystem. The research team also reviewed the impact of grazing management on rangeland carbon dynamics, which are not well understood due to heterogeneity in grassland types. The literature review on the impact of grazing showed a wide variation of results, ranging from positive to negative to no response. On further review, the intensity of grazing appears to be a major factor in controlling rangeland soil organic carbon dynamics. In 2003, researchers conducted field sampling to assess the effect of several drought years during the period 1993-2002. Results suggested that drought can significantly impact rangeland soil organic carbon (SOC) levels, and therefore, carbon sequestration. Resampling was conducted in 2006; results again suggested that climatic conditions may have overridden management effects on SOC due to the ecological lag of the severe drought of 2002. Analysis of grazing practices during this research effort suggested that there are beneficial effects of light grazing compared to heavy grazing and non-grazing with respect to increased SOC and nitrogen contents. In general, carbon storage in rangelands also increases with increased precipitation, although researchers identified threshold levels of

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

    Science.gov (United States)

    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...

  17. Assessment of water resource potential for common use of cow and goat by GIS (Case study: Boroujerd Rangeland, Sarab Sefid, Iran)

    International Nuclear Information System (INIS)

    Ariapour, A; Karami, K; Sadr, A

    2014-01-01

    One of the most important factors to sustainability utilization of natural potential by rangeland grazing suitability is water resources suitability. This study is a model for quantitative, qualitative and spatial distance assessment of water resource's propriety for goat and cow grazing based on geographic information systems (GIS) in Boroujerd Sarab Sefid rangeland, Lorestan province, Iran 2013. In this research from combining three factors such as quantity, quality and water resource's distances; the final model of degree of propriety of water resources for goat and cow grazing is characterized. Results showed that slope factor was the reason of limitation, and it is considered as a limiting factor in propriety of water resources, so in terms of access to water resources for goat grazing, 4856.4 ha (100%) located in S1 classes and for cow grazing, 4023.14 ha (68.6%) located in S1(suitability) classes, 1,187 ha (20.24%) in S2 classes and 654.8 ha (11.16%) located in S3 classes, respectively for both. So according to the results the rangelands in this region are most suitable for goat because of terrain and weather but this, in combination with, cow hasbandry will allow diversity of economic production and stability of incomes

  18. RANGELAND DEGRADATION: EXTENT, IMPACTS, AND ALTERNATIVE RESTORATION TECHNIQUES IN THE RANGELANDS OF ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Mohammed Mussa Abdulahi

    2016-12-01

    Full Text Available Rangeland degradation remains a serious impediment to improve pastoral livelihoods in the lowlands of Ethiopia. This review paper presents an overview of the extent of rangeland degradation, explores its drivers, discusses the potential impacts of rangeland degradation and also suggests alternative rangeland restoration techniques. It is intended to serve as an exploratory tool for ensuing more detailed quantitative analyses to support policy and investment programs to address rangeland degradation in Ethiopia. The extent of rangeland degradation increases with time, and the productivity of rangelands are losing if not given due attention. The major drivers leading to rangeland degradation includes climate change, overgrazing, bush encroachment, population pressure, drought, and government policy, encroachment of rain fed agriculture and decline of traditional resource management institution. Degradation of rangeland has resulted in substantial declines in rangeland condition, water potential, soil status, and animal performance, livestock holding at the household level and community become destitute. Another consequence of rangeland degradation is linked to food insecurity, poverty to the extent of food aid, expansion of aridity and the need for alternative livelihood and income diversification. Moreover, it has increasingly become a threat to the pastoral production systems, and has contributed towards increases in poverty and tribal conflicts over grazing land and water resources. In spite of these impacts, the adoption of alternative restoration techniques in the country is highly insufficient. To address rangeland degradation problems, there is a strong need to substantially increase the investments and strengthen the policy support for sustainable land management.

  19. Management of communal rangelands - the dialogue between science and indigenous knowledge: the case of the Eastern Cape

    CSIR Research Space (South Africa)

    Dube, S

    2010-07-01

    Full Text Available Communal area rangeland resource users are an important part of the rangeland ecosystem; rangeland management policies and practice should, therefore, accommodate their socio-cultural practices and knowledge. Indigenous knowledge (IK) is often...

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Science.gov (United States)

    2010-02-23

    ... DEPARTMENT OF AGRICULTURE Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest... Rangeland Project area. The analysis will determine if a change in management direction for livestock grazing is needed to move existing resource conditions within the Monitor-Hot Creek Rangeland Project area...

  2. A Dynamic Model of California's Hardwood Rangelands

    Science.gov (United States)

    Richard B. Standiford; Richard E. Howitt

    1991-01-01

    Low profitability of hardwood rangeland management, and oak tree harvesting for firewood markets and forage enhancement has led to concern about the long-term sustainability of the oak resource on rangelands. New markets for recreational hunting may give value to oaks for the habitat they provide for game species, and broaden the economic base for managers. A ranch...

  3. Remote sensing applications for monitoring rangeland vegetation ...

    African Journals Online (AJOL)

    Remote sensing techniques hold considerable promise for the inventory and monitoring of natural resources on rangelands. A significant lack of information concerning basic spectral characteristics of range vegetation and soils has resulted in a lack of rangeland applications. The parameters of interest for range condition ...

  4. An Application of BLM's Riparian Inventory Procedure to Rangeland Riparian Resources in the Kern and Kaweah River Watersheds

    Science.gov (United States)

    Patricia Gradek; Lawrence Saslaw; Steven Nelson

    1989-01-01

    The Bakersfield District of the Bureau of Land Management conducted an inventory of rangeland riparian systems using a new method developed by a Bureau-wide task force to inventory, monitor and classify riparian areas. Data on vegetation composition were collected for 65 miles of streams and entered into a hierarchical vegetation classification system. Ratings of...

  5. Genomics-based plant germplasm research (GPGR)

    Institute of Scientific and Technical Information of China (English)

    Jizeng Jia; Hongjie Li; Xueyong Zhang; Zichao Li; Lijuan Qiu

    2017-01-01

    Plant germplasm underpins much of crop genetic improvement. Millions of germplasm accessions have been collected and conserved ex situ and/or in situ, and the major challenge is now how to exploit and utilize this abundant resource. Genomics-based plant germplasm research (GPGR) or "Genoplasmics" is a novel cross-disciplinary research field that seeks to apply the principles and techniques of genomics to germplasm research. We describe in this paper the concept, strategy, and approach behind GPGR, and summarize current progress in the areas of the definition and construction of core collections, enhancement of germplasm with core collections, and gene discovery from core collections. GPGR is opening a new era in germplasm research. The contribution, progress and achievements of GPGR in the future are predicted.

  6. (Gossypium barbadense) germplasm resources

    Indian Academy of Sciences (India)

    QI MA

    and JILIAN LI1∗. 1Cotton Research Institute, Xinjiang Academy of Agricultural and Reclamation ... respectively, are the two main methods used for studying ... ized plot design with a single-row plot and 80 individuals .... The mixed linear model.

  7. Management of Collective Rangelands in Rhamna (Morocco ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Management of Collective Rangelands in Rhamna (Morocco) ... reduce the pressure on natural resources and promote sustainable management. ... Project status ... IDRC congratulates first cohort of Women in Climate Change Science Fellows ... and adaptive water management: Innovative solutions from the Global South”.

  8. 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)

  9. Water conservation for semi-arid rangelands

    International Nuclear Information System (INIS)

    Willis, W.O.

    1983-01-01

    Water deficiency is most often the cause for low forage production on rangelands in semi-arid and arid regions. Water conservation methods have been developed but additional research is needed to develop the best management practices for various climatic regions. Poor management is another major cause of low rangeland production. Better management, including the application of research findings, depends on attitudes, policies, adaptability of findings, resources for implementation and a good understanding of the governing biotic and abiotic factors. (author)

  10. Notice of release of Amethyst Germplasm hoaty tansyaster: Selected class of natural germplasm

    Science.gov (United States)

    Derek J. Tilley

    2015-01-01

    The US Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Aberdeen Plant Materials Center, Aberdeen, Idaho, announces the release of Amethyst Germplasm hoary tansyaster (Machaeronthero canescens (Pursh) A. Gray [Asteraceae]}, a selected class natural track germplasm identified by NRCS accession number 9076670 for conservation plantings in...

  11. Pastoral Decision-Making: An Empirical Investigation of Rangeland Use

    International Nuclear Information System (INIS)

    MacPeak, J.

    1999-01-01

    Recent research in range ecology suggests that the process of resource degradation in African arid and semi-arid rangelands may be less reliant on how many animals are kept on the rangeland than on where these animals are kept. Analysis of pastoralist land use decisions indicated that rangeland condition influences livestock keeping. However, it was found that food and income production strategies, herd characteristics play critical roles in livestock keeping decisions

  12. Sustaining working rangelands: Insights from rancher decision making

    Science.gov (United States)

    Grazed rangeland ecosystems encompass diverse global land resources, and are complex social-ecological systems from which society demands both goods (e.g., livestock and forage production) and services (e.g., abundant and high quality water). In the dialogue on rangeland conservation and sustainable...

  13. 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

  14. Core Collection Based Backcrossing: An Efficient Approach for Breeding,Germplasm Enhacement and Gene Discovery

    Institute of Scientific and Technical Information of China (English)

    J.Z. Jia; R.H. Zhou; X.Y. Zhang; L. Zhang; Y.L. Li; J. Wang; X.Z. Liu; L.F. Gao; S.B. Liu

    2007-01-01

    @@ Plant germplasm underpins much of crop development. Millions of germplasm accessions have been collected and conserved ex situ, and the major challenge is now how to exploit and utilize this abundant resource.

  15. Botanical Criteria of Baharkish Rangeland in Quchan, Khorasan ...

    African Journals Online (AJOL)

    ADOWIE PERE

    University of Mashhad International Campus, Mashhad, I.R of IRAN ... ABSTRACT: Rangelands are natural ecosystems containing a range of resources of genetic ..... Ecology of world vegetation. .... Science Journal of Islamic Azad University,.

  16. Forests, rangelands and climate change in Southern Africa

    CSIR Research Space (South Africa)

    Naidoo, Sasha

    2013-09-01

    Full Text Available This paper provides an analysis of the implications of climate change for forests and rangelands in southern Africa. The extent of the resources and their economic and social functions and drivers of change is outlined. The vulnerability...

  17. Valuation of rangeland ecosystem services

    Science.gov (United States)

    Gascoigne, W.R.

    2011-01-01

    Economic valuation lends itself well to the anthropocentric orientation of ecosystem services. An economic perspective on ecosystems portrays them as natural assets providing a flow of goods and services valuable to individuals and society collectively. A few examples include the purification of drinking water, reduced risk from flooding and other extreme events, pollination of agricultural crops, climate regulation, and recreation opportunities from plant and animal habitat maintenance, among many others. Once these goods and services are identified and quantified, they can be monetized to complete the valuation process. The monetization of ecosystem goods and services (in the form of dollars) provides a common metric that allows for cross-comparison of attributes and evaluation of differing ecological scenarios. Complicating the monetization process is the fact that most of these goods and services are public and non-market in nature; meaning they are non-rival and non-exclusive and are typically not sold in a traditional market setting where monetary values are revealed. Instead, one must employ non-market valuation techniques, with primary valuation methods typically being very time and resource consuming, intimidating to non-economists, and often impractical. For these reasons, benefit transfer methods have gained popularity. This methodology harnesses the primary collection results of existing studies to make inferences about the economic values of non-market goods and services at an alternative policy site (in place and/or in time). For instance, if a primary valuation study on oak reestablishment on rangelands in southern California yielded a value of $30 per-acre associated with water regulation, this result can be transferred, with some adjustments, to say something about the value of an acre of oaks on rangelands in northern portions of the state. The economic valuation of rangeland ecosystem services has many roles. Economic values may be used as input

  18. Future scenarios of impacts to ecosystem services on California rangelands

    Science.gov (United States)

    Byrd, Kristin; Alvarez, Pelayo; Flint, Lorraine; Flint, Alan

    2014-01-01

    The 18 million acres of rangelands in the Central Valley of California provide multiple benefits or “ecosystem services” to people—including wildlife habitat, water supply, open space, recreation, and cultural resources. Most of this land is privately owned and managed for livestock production. These rangelands are vulnerable to land-use conversion and climate change. To help resource managers assess the impacts of land-use change and climate change, U.S. Geological Survey scientists and their cooperators developed scenarios to quantify and map changes to three main rangeland ecosystem services—wildlife habitat, water supply, and carbon sequestration. Project results will help prioritize strategies to conserve these rangelands and the ecosystem services that they provide.

  19. Climate change effects on rangelands and rangeland management: Affirming the need for monitoring

    Science.gov (United States)

    Daniel W. Mccollum; John A. Tanaka; Jack A. Morgan; John E. Mitchell; William E. Fox; Kristie A. Maczko; Lori Hidinger; Clifford S. Duke; Urs P. Kreuter

    2017-01-01

    Uncertainty as to the extent and magnitude of changes in conditions that might occur due to climate change poses a problem for land and resource managers as they seek to adapt to changes and mitigate effects of climate variability. We illustrate using scenarios of projected future conditions on rangelands in the Northern Great Plains and Desert Southwest of the United...

  20. Managing the livestock– Wildlife interface on rangelands

    Science.gov (United States)

    du Toit, Johan T.; Cross, Paul C.; Valeix, Marion

    2017-01-01

    On rangelands the livestock–wildlife interface is mostly characterized by management actions aimed at controlling problems associated with competition, disease, and depredation. Wildlife communities (especially the large vertebrate species) are typically incompatible with agricultural development because the opportunity costs of wildlife conservation are unaffordable except in arid and semi-arid regions. Ecological factors including the provision of supplementary food and water for livestock, together with the persecution of large predators, result in livestock replacing wildlife at biomass densities far exceeding those of indigenous ungulates. Diseases are difficult to eradicate from free-ranging wildlife populations and so veterinary controls usually focus on separating commercial livestock herds from wildlife. Persecution of large carnivores due to their depredation of livestock has caused the virtual eradication of apex predators from most rangelands. However, recent research points to a broad range of solutions to reduce conflict at the livestock–wildlife interface. Conserving wildlife bolsters the adaptive capacity of a rangeland by providing stakeholders with options for dealing with environmental change. This is contingent upon local communities being empowered to benefit directly from their wildlife resources within a management framework that integrates land-use sectors at the landscape scale. As rangelands undergo irreversible changes caused by species invasions and climate forcings, the future perspective favors a proactive shift in attitude towards the livestock–wildlife interface, from problem control to asset management.

  1. Earth observation for rangeland monitoring

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available .kashan.co.za] INTRODUCTION Grass nitrogen (N), as an indicator of rangeland quality, plays a crucial role in understanding the distribution, densities and feeding patterns of both wild herbivores and livestock. Zebras and livestock in the grazing and agricultural lands... ? How can grass nitrogen be mapped for assessing and monitoring of rangeland quality at wider or regional scales? ? Conventional point-based techniques for assessing rangeland quality proved to be expensive, laborious and time consuming...

  2. Recovery of rangelands : the functioning of soil seed banks in a semi-arid African savanna

    NARCIS (Netherlands)

    Tessema, Z.K.

    2011-01-01

    Rangelands in Africa provide important forage resources for herbivores; particularly perennial grasses provide grazing for domestic and wild herbivores. However, semi-arid African rangelands experience severe vegetation and soil degradation due to heavy grazing, causing negative impacts

  3. Integrating the Indigenous Knowledge of Borana Pastoralists into Rangeland Management Strategies in Southern Ethiopia

    OpenAIRE

    World Bank

    2005-01-01

    Pastoralists' indigenous knowledge (IK) about ecology and social organization led to rangeland-management strategies appropriate to deal with the erratic rainfall in African drylands. Herd mobility was traditionally practiced as the key strategy to make use of the scattered rangeland resources on a large scale.

  4. A RANGELAND GRASSHOPPER INSURANCE PROGRAM

    OpenAIRE

    Skold, Melvin D.; Davis, Robert M.

    1995-01-01

    The incidence of benefits and costs from controlling rangeland grasshoppers on public grazing lands poses problems of economic efficiency and distributional equity. Public grasshopper control programs operate like public disaster assistance. However, grasshopper infestations are an insurable risk. This article proposes a rangeland grasshopper insurance program which reduces the economic inefficiencies and distributional inequities of the existing program.

  5. A synoptic review of U.S. rangelands: a technical document supporting the Forest Service 2010 RPA Assessment

    Science.gov (United States)

    Matthew Clark Reeves; John E. Mitchell

    2012-01-01

    The Renewable Resources Planning Act of 1974 requires the USDA Forest Service to conduct assessments of resource conditions. This report fulfills that need and focuses on quantifying extent, productivity, and health of U.S. rangelands. Since 1982, the area of U.S. rangelands has decreased at an average rate of 350,000 acres per year owed mostly to conversion to...

  6. 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...

  7. Assessing the impacts of livestock production on biodiversity in rangeland ecosystems

    Science.gov (United States)

    Alkemade, Rob; Reid, Robin S.; van den Berg, Maurits; de Leeuw, Jan; Jeuken, Michel

    2013-01-01

    Biodiversity in rangelands is decreasing, due to intense utilization for livestock production and conversion of rangeland into cropland; yet the outlook of rangeland biodiversity has not been considered in view of future global demand for food. Here we assess the impact of future livestock production on the global rangelands area and their biodiversity. First we formalized existing knowledge about livestock grazing impacts on biodiversity, expressed in mean species abundance (MSA) of the original rangeland native species assemblages, through metaanalysis of peer-reviewed literature. MSA values, ranging from 1 in natural rangelands to 0.3 in man-made grasslands, were entered in the IMAGE-GLOBIO model. This model was used to assess the impact of change in food demand and livestock production on future rangeland biodiversity. The model revealed remarkable regional variation in impact on rangeland area and MSA between two agricultural production scenarios. The area of used rangelands slightly increases globally between 2000 and 2050 in the baseline scenario and reduces under a scenario of enhanced uptake of resource-efficient production technologies increasing production [high levels of agricultural knowledge, science, and technology (high-AKST)], particularly in Africa. Both scenarios suggest a global decrease in MSA for rangelands until 2050. The contribution of livestock grazing to MSA loss is, however, expected to diminish after 2030, in particular in Africa under the high-AKST scenario. Policies fostering agricultural intensification can reduce the overall pressure on rangeland biodiversity, but additional measures, addressing factors such as climate change and infrastructural development, are necessary to totally halt biodiversity loss. PMID:22308313

  8. 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...

  9. Ecology and utilization of desert shrub rangelands in Iraq

    NARCIS (Netherlands)

    Thalen, Derk Catharinus Peter

    1979-01-01

    When grazing is the accepted land use, vegetation is the key resource. The present study deals with the desert shrub rangelands of lraq, which contain the major characteristics of such an area, having been under grazing for many centuries. Emphasis is given to the ecology and utilization of the

  10. EVALUATION AND MAPPING OF RANGELANDS DEGRADATION USING REMOTELY SENSED DATA

    Directory of Open Access Journals (Sweden)

    Majid Ajorlo

    2005-05-01

    Full Text Available The empirical and scientifically documents prove that misuse of natural resource causes degradation in it. So natural resources conservation is important in approaching sustainable development aims. In current study, Landsat Thematic Mapper images and grazing gradient method have been used to map the extent and degree of rangeland degradation. In during ground-based data measuring, factors such as vegetation cover, litter, plant diversity, bare soil, and stone & gravels were estimated as biophysical indicators of degradation. The next stage, after geometric correction and doing some necessary pre-processing practices on the study area’s images; the best and suitable vegetation index has been selected to map rangeland degradation among the Normalized Difference Vegetation Index (NDVI, Soil Adjusted Vegetation Index (SAVI, and Perpendicular Vegetation Index (PVI. Then using suitable vegetation index and distance parameter was produced the rangelands degradation map. The results of ground-based data analysis reveal that there is a significant relation between increasing distance from critical points and plant diversity and also percentage of litter. Also there is significant relation between vegetation cover percent and distance from village, i.e. the vegetation cover percent increases by increasing distance from villages, while it wasn’t the same around the stock watering points. The result of analysis about bare soil and distance from critical point was the same to vegetation cover changes manner. Also there wasn’t significant relation between stones & gravels index and distance from critical points. The results of image processing show that, NDVI appears to be sensitive to vegetation changes along the grazing gradient and it can be suitable vegetation index to map rangeland degradation. The degradation map shows that there is high degradation around the critical points. These areas need urgent attention for soil conservation. Generally, it

  11. In vitro conservation of Dendrobium germplasm.

    Science.gov (United States)

    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.

  12. 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.

  13. The Tropical and Subtropical Germplasm Repositories of The National Germplasm System

    Science.gov (United States)

    Germplasm collections are viewed as a source of genetic diversity to support crop improvement and agricultural research, and germplasm conservation efforts. The United States Department of Agriculture's National Plant Germplasm Repository System (NPGS) is responsible for administering plant genetic ...

  14. Rangeland monitoring and assessment: a review

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2018-04-01

    Full Text Available Rangelands provide vast landscapes for grazing and foraging for livestock and wildlife. Services of rangelands are diverse and generally provide food for millions of the world’s population, especially the rural and sometimes poor communities...

  15. Conserving biodiversity on native rangelands: Symposium proceedings

    Science.gov (United States)

    Daniel W. Uresk; Greg L. Schenbeck; James T. O' Rourke

    1997-01-01

    These proceedings are the result of a symposium, "Conserving biodiversity on native rangelands" held on August 17, 1995 in Fort Robinson State Park, NE. The purpose of this symposium was to provide a forum to discuss how elements of rangeland biodiversity are being conserved today. We asked, "How resilient and sustainable are rangeland systems to the...

  16. Carbon fluxes on North American rangelands

    Science.gov (United States)

    Tony Svejcar; Raymond Angell; James A. Bradford; William Dugas; William Emmerich; Albert B. Frank; Tagir Gilmanov; Marshall Haferkamp; Douglas A. Johnson; Herman Mayeux; Pat Mielnick; Jack Morgan; Nicanor Z. Saliendra; Gerald E. Schuman; Phillip L. Sims; Kereith Snyder

    2008-01-01

    Rangelands account for almost half of the earth's land surface and may play an important role in the global carbon (C) cycle. We studied net ecosystem exchange (NEE) of C on eight North American rangeland sites over a 6-yr period. Management practices and disturbance regimes can influence NEE; for consistency, we compared ungrazed and undisturbed rangelands...

  17. 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...

  18. 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 .

  19. Anthracnose disease evaluation of sorghum germplasm from Honduras

    Science.gov (United States)

    Germplasm collections are important resources for sorghum improvement and 17 accessions from Honduras were inoculated with Colletotrichum sublineolum and evaluated at the Tropical Agriculture Research Station in Isabela, Puerto Rico during the 2005 and 2006 growing seasons to identify sources of ant...

  20. The Role of Rural Communities in Conservation of Rangelands in Mahneshan Township

    Directory of Open Access Journals (Sweden)

    Kobra Karimi

    2016-05-01

    Full Text Available The aim of this study was to investigate the action of rangeland-depended livestock holders regarding rangeland conservation, including protection and rehabilitation activities and to analyse relevant influencing factors, using a mixed method of survey and case study. The data were collected through analysing existing documents, focus groups, semi-structured and structured interviews using questionnaires submitted to 204 rural livestock holders in the Mahneshan Township. The quantitative data were analysed using SPSS and AMOS software. According to the results farmers’ knowledge regarding the role, importance and factors affecting rangeland degradation was relatively high, however they had a low level of knowledge and action about mechanical conservation techniques. The action of livestock holders in terms of biological conservation activities and grazing management showed a positive and signifincat corrletaion with variables such as implementing of rangeland projects, their interaction with external institutions, participating in extension training courses, education level and irrigated and rainfed agricultural land size. Moreover, based on a path analysis, 37% of the variance of the farmers’ actions regarding the rangeland conservation was explained by the variables such as rangeland rehabilitation actions, farmers’ conservation knowledge, farmers’ interaction with natural resources experts, beekeeping, and participating in extension training courses. Promotional and extension activities and farmers’ interaction with experts have a positive effect in enhancing farmers’ knowledge and actions for sustainable rangeland use and conservation.

  1. Criterion III: Maintenance of rangeland productive capacity [Chapter 4

    Science.gov (United States)

    G. R. Evans; R. A. Washmgton-Allen; R. D. Child; J. E. Mitchell; B. R. Bobowskl; R. V. Loper; B. H. Allen-Diaz; D. W. Thompson; G. R. Welling; T. B. Reuwsaat

    2010-01-01

    Maintenance of rangeland productive capacity is one of five criteria established by the Sustainable Rangelands Roundtable (SRR) to monitor and assess rangeland sustainable management. Within this criterion, six indicators were developed through the Delphi Process and the expert opinions of academicians, rangeland scientists, rangeland management agency personnel, non-...

  2. The GEOGLAM Rangelands and Pasture Productivity Activity: Recent Progress and Future Directions

    Science.gov (United States)

    Guerschman, J. P.; Held, A. A.; Donohue, R. J.; Renzullo, L. J.; Sims, N.; Kerblat, F.; Grundy, M.

    2015-12-01

    Rangelands and pastures cover about a third of the world's land area and support livestock production which represents ~40% of global agricultural gross domestic product. The global consumption of animal protein shows a clear increasing trend, driven by both total population and per capita income increases, putting a growing pressure on the sustainability of grazing lands worldwide. Despite their relevance, rangelands have received less attention than croplands regarding global monitoring of the resource productivity and condition. The Rangelands and Pasture Productivity (RaPP) activity is a component within the Global Agricultural Monitoring initiative established under the Group on Earth Observations (GEOGLAM) in 2013. GEOGLAM RaPP is aimed at providing the global community with the means to monitor the world's rangelands and pastures on a routine basis, and the capacity to produce animal protein in real-time, at global, regional and national levels. Since its launch two years ago GEOGLAM RAPP has made progress in the four implementation elements. These include: 1- the establishment of community of practice; 2- the development of a global monitoring system for rangeland condition; 3- the establishment of pilot sites in main rangeland systems for satellite data products validation and model testing; and 4- integration with livestock production models. Three international workshops have been held building the community of practice. A prototype monitoring system that provides global visualisations and querying capability of vegetation cover data and anomalies has been established. Pilot sites, mostly in areas with long records of field measurements of rangeland condition and productivity have been proposed for nine countries. The link to global livestock models, including physical and economic components, have been established. Future challenges for GEOGLAM RaPP have also been identified and include: better representation of the areas occupied by rangelands

  3. Principles of optimizing animal production from rangeland

    International Nuclear Information System (INIS)

    Stubbendieck, J.; Waller, S.S.

    1983-01-01

    Increasing world population is one of the dominant factors escalating demands for the world's natural resources. Range and forage resources, which are used primarily for food and fibre, could be more efficiently used if management techniques were improved. The principles of managing forage resources are directly associated with both the growth and development of plants and the actions and needs of the grazing animal. An understanding of the effects of environmental factors and herbage removal (frequency, intensity and season of defoliation) on growth and regrowth of plants is the first step towards optimizing animal productivity from rangelands. Most potential changes will fit into three categories: (1) increase the quantity of forage, (2) improve the quality of forage, and (3) improve use of forage. The principles of grazing management can be separated into four intricately related categories: (1) proper degree of grazing, (2) proper season of grazing, (3) proper kind of livestock, and (4) proper distribution of grazing. Grazing management is affected by the manner in which both improvements and manipulation of vegetation affect forage yield and quality. The adaptation and application of existing knowledge to individual locations will be one step towards optimizing animal production from rangeland. Some of the problems may be solved through better dissemination of present knowledge through existing educational programmes, while others will require expanded programmes of information dissemination. A third group of problems may also be solved with present technology, but the solutions are not currently economical. Some of the problems will be solved only through expanded research. These research efforts need to be directed towards grazing or browsing animals, plant resources and the interaction between plants and animals. Application of nuclear techniques will be an integral part of this research. (author)

  4. Current situation of rangelands in Mexico

    Science.gov (United States)

    Alicia Melgoza-Castillo

    2006-01-01

    Rangelands are natural areas with certain characteristics that make them unsuitable for agriculture. They include several types of vegetation such as deserts, grasslands, shrubs, forests, and riparian areas. Cattle ranching, along with the products and services it engenders, is a prime activity that rangelands have traditionally supported.

  5. Weather-centric rangeland revegetation planning

    Science.gov (United States)

    Semiarid rangelands in the western United States have been or are being invaded by introduced annual weeds that negatively impact ecosystem services and pose a major conservation threat. Rehabilitation and restoration of these rangelands are challenging due to inter-annual climate and sub-seasonal ...

  6. Meeting wild bees' needs on rangelands

    Science.gov (United States)

    Some arid rangeland regions, notably those with warm dry climates of the temperate zones, host great diversities of native bees, primarily non-social species among which are many floral specialists. Rangeland bee faunas are threatened indirectly by invasive exotic weeds wherever these displace nat...

  7. 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 ...

  8. Measuring ecological function on California's rangelands

    Science.gov (United States)

    Porzig, E.

    2016-12-01

    There is a need for a better understanding of ecosystem processes on rangelands and how management decisions influence these processes on scales that are both ecologically and socially relevant. Point Blue Conservation Science's Rangeland Monitoring Network is a coordinated effort to collect standardized data on birds, vegetation, and soils on rangelands throughout California. We work with partners, including private landowners, land trusts, state and federal agencies, and others, to measure bird and plant abundance and diversity and three soil dynamic properties (water infiltration, bulk density, and organic carbon). Here, we present data from our first two years of monitoring on over 50 ranches in 17 counties. By collecting data on the scope and scale of variation in ecological function across rangelands and the relationship with management practices, we aim to advance rangeland management, restoration, and conservation.

  9. Conflict Management Strategies for Rangeland Resources

    OpenAIRE

    Rasmussen, G.A.

    1995-01-01

    Metadata only record Numerous strategies have been developed to cope with conflicts. Collaborative processes are one group of conflict management strategies used. When successful these processes have several common features: they are voluntary, build trust, develop a shared vision, and use consensus. These techniques have often led to false expectations because the source of the conflict was ignored or adequately trained facilitators were not used. The source of the conflict (lack of infor...

  10. A planning support system for rangeland allocation in Iran : case of Chadegan sub-region

    NARCIS (Netherlands)

    Farahpour, M.

    2002-01-01

    Rangelands, like other natural resources are subject to many changes. In Iran, one of the changes is the land tenure reform, that may have significant effects on both the land and the land user. Land tenure changes not only affect the life of the present, but also that of next generations,

  11. A review of concentrated flow erosion processes on rangelands: fundamental understanding and knowledge gaps

    Science.gov (United States)

    Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil, water and dissolved elements. On rangelands, soil, nutrients and water are scarce and only narrow margins of resource losses are tolera...

  12. Session A5 Rangelands as dynamic systems Role of wildlife in ...

    African Journals Online (AJOL)

    Rangelands in southern Africa are increasingly being used for conservation, ecotourism, game farming and hunting. This impacts people's livelihoods and the state of natural resources. Complimentarity and competition between wildlife and domestic livestock can be explored. Theme: This session focuses on ecosystem ...

  13. Multi-scale wind erosion monitoring and assessment for US rangelands

    Science.gov (United States)

    Wind erosion is a major resource concern for rangeland managers. Although wind erosion is a naturally occurring process in many drylands, land use activities, and land management in particular, can accelerate wind-driven soil loss – impacting ecosystem dynamics and agricultural production, air quali...

  14. Bridging Drought – Resilience in Rangeland Management in Times of Climate Change

    OpenAIRE

    Isele, Judith

    2014-01-01

    Organic livestock farming in semiarid regions greatly depends on the sustainable management of the natural rangeland as the resource for livestock sustenance. High stock density in combination with short grazing and long recovery periods achieve effective rainfall utilisation and considerably higher fodder production resulting in a high degree of resilience in drought situations.

  15. USDA internet tool to estimate runoff and soil loss on rangelands: rangelands hydrology and erosion model

    Science.gov (United States)

    Rangelands are the most dominant land cover type in the United States (770 million acres) with approximately 53% of the nation’s rangelands owned and managed by the private sector, while approximately 43% are managed by the federal government. Information on the type, extent, and spatial location of...

  16. The Rangeland Hydrology and Erosion Model: A dynamic approach for predicting soil loss on rangelands

    Science.gov (United States)

    In this study we present the improved Rangeland Hydrology and Erosion Model (RHEM V2.3), a process-based erosion prediction tool specific for rangeland application. The article provides the mathematical formulation of the model and parameter estimation equations. Model performance is assessed agains...

  17. Rangelands: Where Anthromes Meet Their Limits

    Directory of Open Access Journals (Sweden)

    Nathan F. Sayre

    2017-05-01

    Full Text Available Defining rangelands as anthromes enabled Ellis and Ramankutty (2008 to conclude that more than three-quarters of Earth’s land is anthropogenic; without rangelands, this figure would have been less than half. They classified all lands grazed by domestic livestock as rangelands, provided that human population densities were low; similar areas without livestock were excluded and classified instead as ‘wildlands’. This paper examines the empirical basis and conceptual assumptions of defining and categorizing rangelands in this fashion. Empirically, we conclude that a large proportion of rangelands, although used to varying degrees by domesticated livestock, are not altered significantly by this use, especially in arid, highly variable environments and in settings with long evolutionary histories of herbivory by wild animals. Even where changes have occurred, the dynamics and components of many rangelands remain structurally and functionally equivalent to those that preceded domestic livestock grazing or would be found in its absence. In much of Africa and Asia, grazing is so longstanding as to be inextricable from ‘natural’ or reference conditions for those sites. Thus, the extent of anthropogenic biomes is significantly overstated. Conceptually, rangelands reveal the dependence of the anthromes thesis on outdated assumptions of ecological climax and equilibrium. Coming to terms with rangelands—how they can be classified, understood, and managed sustainably—thus offers important lessons for understanding anthromes and the Anthropocene as a whole. At the root of these lessons, we argue, is not the question of human impacts on ecosystems but property relations among humans.

  18. A systematic review of US rangeland social science

    Science.gov (United States)

    Rangeland science aims to create knowledge to sustain rangeland social-ecological systems over the long term. Range science has made substantial progress on understanding ecological dynamics of rangeland systems and the management practices that sustain them, and these findings have been systematica...

  19. Using remotely sensed imagery to monitor savanna rangeland deterioration through woody plant proliferation: a case study from communal and biodiversity conservation rangeland sites in Mokopane, South Africa

    CSIR Research Space (South Africa)

    Munyati, C

    2011-05-01

    Full Text Available rangeland, whereas the communal rangelands were getting more opened up by livestock trampling. Rangeland management practices of fire utilisation, stocking levels and stock concentration account for the differing trends. Lightly grazed and heavily grazed...

  20. 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.

  1. 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...

  2. PERSPECTIVES ON RANGELAND ECOLOGY AND MANAGEMENT

    OpenAIRE

    Heady, Harold F.

    2011-01-01

    This paper reviews changes in rangeland ecology and management in the U.S.A. over the last 65 years and speculates on future changes. Emphasis has shifted from livestock management to ecological and environmental concerns, hence "rangeland ecology." The term "range management" may have outlived its usefulness and may also be detrimental to our image. The vision that we have of ourselves is not the same as others have of us. Many members of the Society for Range Management (SRM) and most of ou...

  3. Livestock systems and rangeland degradation in the new World Atlas of Desertification

    Science.gov (United States)

    Zucca, Claudio; Reynolds, James F.; Cherlet, Michael

    2015-04-01

    Livestock systems and rangeland degradation in the new World Atlas of Desertification Land degradation and desertification (LDD), which are widespread in global rangelands, are complex processes. They are caused by multiple (but limited) number of biophysical and socioeconomic drivers that lead to an unbalance in the capacity of the land to sustainably produce ecosystem services and economic value. Converging evidence indicates that the key biophysical and socioeconomic drivers include agricultural or pastoral land use and management practices, population growth, societal demands (e.g., urbanization), and climate change (e.g., increasing aridity and drought). The new World Atlas of Desertification (WAD) describes these global issues, documents their spatial change, and highlights the importance of these drivers in relation to land degradation processes. The impacts of LDD on the atmosphere, on water and on biodiversity are also covered. The WAD spatially illustrates relevant types of livestock and rangeland management systems, related (over-under) use of resources, various management activities, and some of the common features and transitions that contribute to LDD. For example, livestock grazing in marginal areas is increasing due to competition with agricultural encroachment and, hence, vulnerable lands are under threat. The integration of stratified global data layers facilitates identifying areas where stress on the land system can be linked to underlying causal issues. One of the objectives of the new WAD is to provide synthesis and tools for scientists and stakeholders to design sustainable solutions for efficient land use in global rangelands.

  4. Weather-centric rangeland revegetation planning

    Science.gov (United States)

    Hardegree, Stuart P.; Abatzoglou, John T.; Brunson, Mark W.; Germino, Matthew; Hegewisch, Katherine C.; Moffet, Corey A.; Pilliod, David S.; Roundy, Bruce A.; Boehm, Alex R.; Meredith, Gwendwr R.

    2018-01-01

    Invasive annual weeds negatively impact ecosystem services and pose a major conservation threat on semiarid rangelands throughout the western United States. Rehabilitation of these rangelands is challenging due to interannual climate and subseasonal weather variability that impacts seed germination, seedling survival and establishment, annual weed dynamics, wildfire frequency, and soil stability. Rehabilitation and restoration outcomes could be improved by adopting a weather-centric approach that uses the full spectrum of available site-specific weather information from historical observations, seasonal climate forecasts, and climate-change projections. Climate data can be used retrospectively to interpret success or failure of past seedings by describing seasonal and longer-term patterns of environmental variability subsequent to planting. A more detailed evaluation of weather impacts on site conditions may yield more flexible adaptive-management strategies for rangeland restoration and rehabilitation, as well as provide estimates of transition probabilities between desirable and undesirable vegetation states. Skillful seasonal climate forecasts could greatly improve the cost efficiency of management treatments by limiting revegetation activities to time periods where forecasts suggest higher probabilities of successful seedling establishment. Climate-change projections are key to the application of current environmental models for development of mitigation and adaptation strategies and for management practices that require a multidecadal planning horizon. Adoption of new weather technology will require collaboration between land managers and revegetation specialists and modifications to the way we currently plan and conduct rangeland rehabilitation and restoration in the Intermountain West.

  5. Invasive Plants on Rangelands: a Global Threat

    Science.gov (United States)

    Invasive plant species are spreading and invading rangelands at an unprecedented rate costing ranchers billions of dollars to control invasive plants each year. In its simplest form, the invasion process has four primary stages, including introduction, establishment, spread and colonization. Th...

  6. Emerging issues and challenges in conservation of biodiversity in the rangelands of Tanzania

    Directory of Open Access Journals (Sweden)

    Jafari Kideghesho

    2013-11-01

    Full Text Available Tanzania rangelands are a stronghold for biodiversity harbouring a variety of animal and plant species of economic, ecological and socio-cultural importance. Efforts to protect these resources against destruction and loss have involved, among other things, setting aside some tracks of land as protected areas in the form of national parks, nature reserves, game reserves, game controlled and wildlife management areas. However, these areas and adjacent lands have long been subjected to a number of emerging issues and challenges, which complicate their management, thus putting the resources at risk of over exploitation and extinction. These issues and challenges include, among other things, government policies, failure of conservation (as a form of land use to compete effectively with alternative land uses, habitat degradation and blockage of wildlife corridors, overexploitation and illegal resource extraction, wildfires, human population growth, poverty, HIV/AIDS pandemic and human-wildlife conflicts. In this paper, we review the emerging issues and challenges in biodiversity conservation by drawing experience from different parts of Tanzania. The paper is based on the premise that, understanding of the issues and challenges underpinning the rangelands is a crucial step towards setting up of plausible objectives, strategies and plans that will improve and lead to effective management of these areas. We conclude by recommending some proactive measures that may enhance the sustainability of the rangeland resources for the benefit of the current and future generations.

  7. 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.

  8. The value of milk in rangelands in Mandera County, Kenya

    Science.gov (United States)

    Ngugi, Keziah; Ertsen, Maurits

    2015-04-01

    Lack of water over expansive regions in Greater Horn of Africa created the rangelands and rangelands created pastoralism. Pastoralism involve keeping of large livestock herds and movement in search of resources, mainly water, pasture, medicine and wild foods. Several studies have been done in the last century and findings pointed at pastoralism being primitive and unsustainable. It has been predicted it would die in the last century but in the rangelands, pastoralism lives on and it is resilient. This study is based in Mandera, a pastoralism county in Kenya that neighbors Ethiopia to the North and Somalia to the East. The study sought to investigate contribution of milk to pastoralism resilience. Interviews were conducted in the field among the pastoralists, women groups, transporters, traders, government officials and consumers of milk. These information was corroborated with actual field investigations in the expansive rangelands of Mandera County. Pastoralists rarely slaughter or sell their livestock even when the animals waste away during droughts. This is because they have been through such cycles before and observed livestock make tremendous recovery when the right conditions were restored. Rangelands lack infrastructure, there are no roads, schools, telephone or hospitals. Pastoralists diet is comprised of rice, wheat and milk. It was established milk was the main source of income among pastoralists in Mandera County. From milk, the pastoralists make income that is used to purchase the other foodstuffs. Milk is available on daily basis in large quantities owing to the large number of livestock. Unfortunately, every pastoralist household produce copious amounts of milk, thus no local demand and transport infrastructure is nonexistent, making sale of milk a near impossible task. The findings showed the pastoralists have established unique routes through which milk reach the markets in urban centers where demand is high. Urbanization sustain pastoralism. These

  9. 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

  10. 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...

  11. 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 ...

  12. Rangeland Brush Estimation Toolbox (RaBET): An Approach for Evaluating Brush Management Conservation Efforts in Western Grazing Lands

    Science.gov (United States)

    Holifield Collins, C.; Kautz, M. A.; Skirvin, S. M.; Metz, L. J.

    2016-12-01

    There are over 180 million hectares of rangelands and grazed forests in the central and western United States. Due to the loss of perennial grasses and subsequent increased runoff and erosion that can degrade the system, woody cover species cannot be allowed to proliferate unchecked. The USDA-Natural Resources Conservation Service (NRCS) has allocated extensive resources to employ brush management (removal) as a conservation practice to control woody species encroachment. The Rangeland-Conservation Effects Assessment Project (CEAP) has been tasked with determining how effective the practice has been, however their land managers lack a cost-effective means to conduct these assessments at the necessary scale. An ArcGIS toolbox for generating large-scale, Landsat-based, spatial maps of woody cover on grazing lands in the western United States was developed through a collaboration with NRCS Rangeland-CEAP. The toolbox contains two main components of operation, image generation and temporal analysis, and utilizes simple interfaces requiring minimum user inputs. The image generation tool utilizes geographically specific algorithms developed from combining moderate-resolution (30-m) Landsat imagery and high-resolution (1-m) National Agricultural Imagery Program (NAIP) aerial photography to produce the woody cover scenes at the Major Land Resource (MLRA) scale. The temporal analysis tool can be used on these scenes to assess treatment effectiveness and monitor woody cover reemergence. RaBET provides rangeland managers an operational, inexpensive decision support tool to aid in the application of brush removal treatments and assessing their effectiveness.

  13. Transcending Landscapes: Working Across Scales and Levels in Pastoralist Rangeland Governance.

    Science.gov (United States)

    Robinson, Lance W; Ontiri, Enoch; Alemu, Tsegaye; Moiko, Stephen S

    2017-08-01

    Landscape approaches can be subjected to mistakenly targeting a single "best" level of governance, and paying too little attention to the role that cross-scale and cross-level interactions play in governance. In rangeland settings, resources, patterns of use of those resources, and the institutions for managing the resources exist at multiple levels and scales. While the scholarship on commons offers some guidance on how to conceptualize governance in rangeland landscapes, some elements of commons scholarship-notably the "design principles" for effective governance of commons-do not seem to apply neatly to governance in pastoralist rangeland settings. This paper examines three cases where attempts have been made to foster effective landscape governance in such settings to consider how the materiality of commons influences the nature of cross-scale and cross-level interactions, and how these interactions affect governance. In all three cases, although external actors seemed to work appropriately and effectively at community and landscape levels, landscape governance mechanisms have been facing great challenges arising from relationships beyond the landscape, both vertically to higher levels of decision-making and horizontally to communities normally residing in other landscapes. The cases demonstrate that fostering effective landscape-level governance cannot be accomplished only through action at the landscape level; it is a task that must be pursued at multiple levels and in relation to the connections across scales and levels. The paper suggests elements of a conceptual framework for understanding cross-level and cross-scale elements of landscape governance, and offers suggestions for governance design in pastoralist rangeland settings.

  14. Soil Moisture Variability and its Effects on Herbage Production in Semi-arid Rangelands of Kenya

    International Nuclear Information System (INIS)

    Too, D.K.; Trlica, M.J.; Swift, D.M.; Musembi, D.K.

    1999-01-01

    Results obtained from recent studies focused on rangelands potential as influenced by human activity and climatic factors in the semi-arid and arid pastoral ecosystems of Northern Kenya indicated great temporal and spatial forage production variability. The objective of the studies was to document primary production in relation to water stress (drought), herbivory and direct human activities. Efforts also focused on finding possibilities of increasing productivity while conserving the finite resources for sustainable use. Laboratory, field and numerical methods were employed over several seasons and years. Forb and grass production was more variable than that of the browse (dwarf shrub) layer. Compared to forbs and dwarf shrubs, the grass layer contributed less to the total production in all seasons, indicating that the region had less potential for grazers compared to browsers. Spatial-temporal variation in rangeland carrying capacity reflected the great spatial heterogeneity in vegetation types and production. Similarly, seasonal differences were very evident, with highest estimates in the long rainy and the lowest during the dry and short rainy seasons, respectively. Factors limiting rangeland production potential were identified to be moisture deficiency, resource-use conflicts, an increasing and partially sedentarised nomadic population, overgrazing, tree felling, and land degradation (desert encroachment). Measures that can improve rangeland production potential and provide a better way of life for the inhabitants of the region include: (a) identification of land degradation (e.g. by means of bio-indicators and Geographical Information Systems, GIS); (b) technical interventions (i.e. soil and water conservation, restoration of degraded areas, fodder production); (c) social-economic interventions (i.e. resolution of resource-use conflicts, alleviation of poverty, infrastructure development improvement of livestock marketing channels etc.) and (d) continued

  15. Transcending Landscapes: Working Across Scales and Levels in Pastoralist Rangeland Governance

    Science.gov (United States)

    Robinson, Lance W.; Ontiri, Enoch; Alemu, Tsegaye; Moiko, Stephen S.

    2017-08-01

    Landscape approaches can be subjected to mistakenly targeting a single "best" level of governance, and paying too little attention to the role that cross-scale and cross-level interactions play in governance. In rangeland settings, resources, patterns of use of those resources, and the institutions for managing the resources exist at multiple levels and scales. While the scholarship on commons offers some guidance on how to conceptualize governance in rangeland landscapes, some elements of commons scholarship—notably the "design principles" for effective governance of commons—do not seem to apply neatly to governance in pastoralist rangeland settings. This paper examines three cases where attempts have been made to foster effective landscape governance in such settings to consider how the materiality of commons influences the nature of cross-scale and cross-level interactions, and how these interactions affect governance. In all three cases, although external actors seemed to work appropriately and effectively at community and landscape levels, landscape governance mechanisms have been facing great challenges arising from relationships beyond the landscape, both vertically to higher levels of decision-making and horizontally to communities normally residing in other landscapes. The cases demonstrate that fostering effective landscape-level governance cannot be accomplished only through action at the landscape level; it is a task that must be pursued at multiple levels and in relation to the connections across scales and levels. The paper suggests elements of a conceptual framework for understanding cross-level and cross-scale elements of landscape governance, and offers suggestions for governance design in pastoralist rangeland settings.

  16. 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.

  17. Multiscale sagebrush rangeland habitat modeling in southwest Wyoming

    Science.gov (United States)

    Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Coan, Michael J.; Bowen, Zachary H.

    2009-01-01

    Sagebrush-steppe ecosystems in North America have experienced dramatic elimination and degradation since European settlement. As a result, sagebrush-steppe dependent species have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, would improve the ability to maintain existing sagebrush habitats. However, current data only identify resource availability locally, with rigorous spatial tools and models that accurately model and map sagebrush habitats over large areas still unavailable. Here we report on an effort to produce a rigorous large-area sagebrush-habitat classification and inventory with statistically validated products and estimates of precision in the State of Wyoming. This research employs a combination of significant new tools, including (1) modeling sagebrush rangeland as a series of independent continuous field components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground-measured plot data on 2.4-meter imagery in the same season the satellite imagery is acquired; (3) effective modeling of ground-measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of an additional two spatial scales of imagery (30 meter and 56 meter) for optimal large-area modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution sensors; and (6) employing rigorous accuracy assessment of model predictions to enable users to understand the inherent uncertainties. First-phase results modeled eight rangeland components (four primary targets and four secondary targets) as continuous field predictions. The primary targets included percent bare ground, percent herbaceousness, percent shrub, and percent litter. The

  18. Fodder Biomass Monitoring in Sahelian Rangelands Using Phenological Metrics from FAPAR Time Series

    Directory of Open Access Journals (Sweden)

    Abdoul Aziz Diouf

    2015-07-01

    Full Text Available Timely monitoring of plant biomass is critical for the management of forage resources in Sahelian rangelands. The estimation of annual biomass production in the Sahel is based on a simple relationship between satellite annual Normalized Difference Vegetation Index (NDVI and in situ biomass data. This study proposes a new methodology using multi-linear models between phenological metrics from the SPOT-VEGETATION time series of Fraction of Absorbed Photosynthetically Active Radiation (FAPAR and in situ biomass. A model with three variables—large seasonal integral (LINTG, length of growing season, and end of season decreasing rate—performed best (MAE = 605 kg·DM/ha; R2 = 0.68 across Sahelian ecosystems in Senegal (data for the period 1999–2013. A model with annual maximum (PEAK and start date of season showed similar performances (MAE = 625 kg·DM/ha; R2 = 0.64, allowing a timely estimation of forage availability. The subdivision of the study area in ecoregions increased overall accuracy (MAE = 489.21 kg·DM/ha; R2 = 0.77, indicating that a relation between metrics and ecosystem properties exists. LINTG was the main explanatory variable for woody rangelands with high leaf biomass, whereas for areas dominated by herbaceous vegetation, it was the PEAK metric. The proposed approach outperformed the established biomass NDVI-based product (MAE = 818 kg·DM/ha and R2 = 0.51 and should improve the operational monitoring of forage resources in Sahelian rangelands.

  19. Robustness and management adaptability in tropical rangelands: a viability-based assessment under the non-equilibrium paradigm.

    Science.gov (United States)

    Accatino, F; Sabatier, R; De Michele, C; Ward, D; Wiegand, K; Meyer, K M

    2014-08-01

    Rangelands provide the main forage resource for livestock in many parts of the world, but maintaining long-term productivity and providing sufficient income for the rancher remains a challenge. One key issue is to maintain the rangeland in conditions where the rancher has the greatest possibility to adapt his/her management choices to a highly fluctuating and uncertain environment. In this study, we address management robustness and adaptability, which increase the resilience of a rangeland. After reviewing how the concept of resilience evolved in parallel to modelling views on rangelands, we present a dynamic model of rangelands to which we applied the mathematical framework of viability theory to quantify the management adaptability of the system in a stochastic environment. This quantification is based on an index that combines the robustness of the system to rainfall variability and the ability of the rancher to adjust his/her management through time. We evaluated the adaptability for four possible scenarios combining two rainfall regimes (high or low) with two herding strategies (grazers only or mixed herd). Results show that pure grazing is viable only for high-rainfall regimes, and that the use of mixed-feeder herds increases the adaptability of the management. The management is the most adaptive with mixed herds and in rangelands composed of an intermediate density of trees and grasses. In such situations, grass provides high quantities of biomass and woody plants ensure robustness to droughts. Beyond the implications for management, our results illustrate the relevance of viability theory for addressing the issue of robustness and adaptability in non-equilibrium environments.

  20. Developing an operational rangeland water requirement satisfaction index

    Science.gov (United States)

    Senay, Gabriel B.; Verdin, James P.; Rowland, James

    2011-01-01

    Developing an operational water requirement satisfaction index (WRSI) for rangeland monitoring is an important goal of the famine early warning systems network. An operational WRSI has been developed for crop monitoring, but until recently a comparable WRSI for rangeland was not successful because of the extremely poor performance of the index when based on published crop coefficients (K c) for rangelands. To improve the rangeland WRSI, we developed a simple calibration technique that adjusts the K c values for rangeland monitoring using long-term rainfall distribution and reference evapotranspiration data. The premise for adjusting the K c values is based on the assumption that a viable rangeland should exhibit above-average WRSI (values >80%) during a normal year. The normal year was represented by a median dekadal rainfall distribution (satellite rainfall estimate from 1996 to 2006). Similarly, a long-term average for potential evapotranspiration was used as input to the famine early warning systems network WRSI model in combination with soil-water-holding capacity data. A dekadal rangeland WRSI has been operational for east and west Africa since 2005. User feedback has been encouraging, especially with regard to the end-of-season WRSI anomaly products that compare the index's performance to ‘normal’ years. Currently, rangeland WRSI products are generated on a dekadal basis and posted for free distribution on the US Geological Survey early warning website at http://earlywarning.usgs.gov/adds/

  1. Managing climate change risks in rangeland systems [Chapter 15

    Science.gov (United States)

    Linda A. Joyce; Nadine A. Marshall

    2017-01-01

    The management of rangelands has long involved adapting to climate variability to ensure that economic enterprises remain viable and ecosystems sustainable; climate change brings the potential for change that surpasses the experience of humans within rangeland systems. Adaptation will require an intentionality to address the effects of climate change. Knowledge of...

  2. Adaptive management for complex communal rangelands in South ...

    African Journals Online (AJOL)

    Many of the intransigent problems facing the world arise in complex systems. In this paper, I propose that communal rangelands in South Africa be recognised as complex social–ecological systems and that one of the reasons that development initiatives have had little impact on improving livelihoods and rangeland ...

  3. A description of rangeland on commercial and communal land ...

    African Journals Online (AJOL)

    Analysis of a Landsat TM image from a rangeland near Peddie, Eastern Cape, revealed differences in two vegetation indices (normalised difference vegetation index, NDVI, and moving standard deviation index, MSDI) between communal and commercial rangeland. It was suggested that the difference in the MSDI reflected ...

  4. Meeting wild bees' needs on Western US rangelands

    Science.gov (United States)

    James H. Cane

    2011-01-01

    Rangelands are areas that are too arid, or with soils too shallow, to support either forests or cultivated agriculture, but that nonetheless produce enough vegetation for livestock grazing. Some arid rangeland regions, notably those with warm, dry climates in temperate zones (e.g., the warm deserts of the United States and adjacent Mexico, parts of Australia, South...

  5. New Tools to Estimate Runoff, Soil Erosion, and Sustainability of Rangeland Plant Communities

    Science.gov (United States)

    Rangelands are the largest land cover type in the world. Degradation from mismanagement, desertification, and drought impact more than 50% of rangelands across the globe. The USDA Agricultural Research Service has been evaluating sustainability of rangeland for over 40-years by conducted rangeland r...

  6. Sustainable rangeland management, economic growth, and a cautious role for the SRM

    Science.gov (United States)

    Interest in the art and science of rangeland management increased dramatically during the 20th century and it was out of this interest that the profession of rangeland management was born. As public interest in rangeland management grew, so did the number, breadth, and depth of rangeland management ...

  7. An Integrated Social, Economic, and Ecologic Conceptual (ISEEC) framework for considering rangeland sustainability

    Science.gov (United States)

    William E. Fox; Daniel W. McCollum; John E. Mitchell; Louis E. Swanson; Urs P. Kreuter; John A. Tanaka; Gary R. Evans; H. Theodore Heintz; Robert P. Breckenridge; Paul H. Geissler

    2009-01-01

    Currently, there is no standard method to assess the complex systems in rangeland ecosystems. Decision makers need baselines to create a common language of current rangeland conditions and standards for continued rangeland assessment. The Sustainable Rangeland Roundtable (SRR), a group of private and public organizations and agencies, has created a forum to discuss...

  8. 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...

  9. 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.

  10. 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.

  11. Rangeland dynamics in South Omo Zone of Southern Ethiopia: Assessment of rangeland condition in relation to altitude and Grazing types

    NARCIS (Netherlands)

    Terefe, A.; Ebro, A.; Tessema, Z.K.

    2010-01-01

    A study was undertaken in Hamer and Benna-Tsemay districts of the Southern Ethiopia with the objective to determine the condition of the rangelands for grazing animals as influenced by altitude and grazing types. The rangelands in each of the study districts were stratified based on altitude and

  12. Maintaining ecosystem services through continued livestock production on California rangelands

    Science.gov (United States)

    Barry, S.; Becchetti, T.

    2015-12-01

    Nearly 40% of California is rangeland comprising the largest land type in California and providing forage for livestock, primarily beef cattle. In addition to forage, rangelands provide a host of ecosystem systems services, including habitat for common and endangered species, fire fuels management, pollination services, clean water, viewsheds, and carbon sequestration. Published research has documented that most of these ecosystem services are positively impacted by managed livestock grazing and rancher stewardship. Ranchers typically do not receive any monetary reimbursement for their stewardship in providing these ecosystem services to the public. Markets have been difficult to establish with limited ability to adequately monitor and measure services provided. At the same time, rangelands have been experiencing rapid conversion to urbanization and more profitable and intensive forms of agriculture such as almond and walnut orchards. To prevent further conversion of rangelands and the loss of the services they provide, there needs to be a mechanism to identify and compensate landowners for the value of all products and services being received from rangelands. This paper considers two methods (opportunity cost and avoided cost) to determine the value of Payment for Ecosystem Services (PES) for rangelands. PES can raise the value of rangelands, making them more competitive financially. Real estate values and University of California Cooperative Extension Cost Studies, were used to demonstrate the difference in value (lost opportunity cost) between the primary products of rangelands (livestock production) and the products of the converted rangelands (almond and walnut orchards). Avoided costs for vegetation management and habitat creation and maintenance were used to establish the value of managed grazing. If conversion is to be slowed or stopped and managed grazing promoted to protect the ecosystem services rangelands provide, this value could be compensated through

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  15. 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

  16. 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...

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

    Science.gov (United States)

    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...

  18. Water resources (Chapter 12)

    Science.gov (United States)

    Thomas C. Brown; Romano Foti; Jorge Ramirez

    2012-01-01

    In this chapter, we focus on the vulnerability of U.S. freshwater supplies considering all lands, not just forest and rangelands. We do not assess the condition of those lands or report on how much of our water supply originates on lands of different land covers or ownerships, because earlier Resources Planning Act (RPA) Assessment work addressed these topics....

  19. Tapping the US sweet sorghum collection to identify biofuel germplasm

    Science.gov (United States)

    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...

  20. Powdery mildew reaction of hop cultivars and USDA germplasm, 2015

    Science.gov (United States)

    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...

  1. The interconnectedness between landowner knowledge, value, belief, attitude, and willingness to act: policy implications for carbon sequestration on private rangelands.

    Science.gov (United States)

    Cook, Seth L; Ma, Zhao

    2014-02-15

    Rangelands can be managed to increase soil carbon and help mitigate emissions of carbon dioxide. This study assessed Utah rangeland owner's environmental values, beliefs about climate change, and awareness of and attitudes towards carbon sequestration, as well as their perceptions of potential policy strategies for promoting carbon sequestration on private rangelands. Data were collected from semi-structured interviews and a statewide survey of Utah rangeland owners, and were analyzed using descriptive and bivariate statistics. Over two-thirds of respondents reported some level of awareness of carbon sequestration and a generally positive attitude towards it, contrasting to their lack of interest in participating in a relevant program in the future. Having a positive attitude was statistically significantly associated with having more "biocentric" environmental values, believing the climate had been changing over the past 30 years, and having a stronger belief of human activities influencing the climate. Respondents valued the potential ecological benefits of carbon sequestration more than the potential financial or climate change benefits. Additionally, respondents indicated a preference for educational approaches over financial incentives. They also preferred to work with a private agricultural entity over a non-profit or government entity on improving land management practices to sequester carbon. These results suggest potential challenges for developing technically sound and socially acceptable policies and programs for promoting carbon sequestration on private rangelands. Potential strategies for overcoming these challenges include emphasizing the ecological benefits associated with sequestering carbon to appeal to landowners with ecologically oriented management objectives, enhancing the cooperation between private agricultural organizations and government agencies, and funneling resources for promoting carbon sequestration into existing land management and

  2. A comparison of the effects of different rangeland management ...

    African Journals Online (AJOL)

    A comparison of the effects of different rangeland management systems on ... Three management systems exploit these areas: commercial livestock ranching, communal livestock ranching and game ranching. ... AJOL African Journals Online.

  3. Ecological evaluation of rangeland quality in dry subtropics of Azerbaijan

    Science.gov (United States)

    Gasanova, A. F.

    2014-12-01

    The results of ecological evaluation of soil-landscape complexes of winter rangelands of Gobustan with the use of energy criteria are discussed. The diagnostic characteristics of soil fertility and correction coefficients for the thickness of texture of soil horizons, soil salinization, soil erosion, and microelemental composition of soils have been used to separate the soils of winter rangelands into several quality groups. A larger part of the soils belongs to the medium quality group with the mean weighted quality factor (bonitet) of 52. Special assessment scales have been suggested for the differential ecological assessment and monitoring of the rangelands. In the past 40 years, the area of steppe landscapes has decreased from 22.7 to 12%, whereas the area of semideserts has increased up to 64%. The area of best-quality soils within the studied rangelands had decreased by three times, and their average quality factor has decreased from 92 to 86.

  4. Effect of management on rangeland phytomass, cover and condition ...

    African Journals Online (AJOL)

    similarity of management effects on rangeland condition and forage provision across major dryland biomes. Taking a macro-ecological perspective, we analysed if management effects differed between South Africa's central grassland and ...

  5. Rangeland degradation in two watersheds of Lebanon

    International Nuclear Information System (INIS)

    Darwish, T; Faour, G.

    2008-01-01

    A complex and rugged nature characterizes the Lebanese mountains.The climatic pattern prevailing in the country, deforestation and man made erosion caused increased rangeland degradation. The purpose of this study was to monitor two contrasting watersheds, representing the Lebanese agro-ecological zones, to analyze the vegetation dynamics and trace the state of rangeland degradation. The Kfarselouane (205 km2) and Aarsal (316.7 km2) watersheds are located in the Lebanon and Anti-Lebanon mountain chain and characterized by sub humid and semi-arid climate respectively.Using multitemporal spot vegetation images between 1999 and 2005 to analyze the normalized differential vegetation index (NDVI) revealed some improvement of the vegetation cover over recent years in Kfaselouane with a steady state in Aarsal. The NDVI trend curve inclines in spring and declines in summer and fall. Judging by the time scale amplitude change and highest magnitude between the peak and lower NDVI level in Aarsal, an increased vulnerability to drought is observed in the dry Lebanese areas. Comparing land cover/use in Aarsal area between 1962 and 2000 using aerial photos and large resolution Indian satellite images (IRS) showed wood fragmentation and slight increase of the degenerated forest cover from 1108 ha to 1168 ha. Landuse change was accompanied by a simultaneous increase of cultivated lands (mostly fruit trees) from 932 ha to 4878 ha with absence of soil conservation and water harvesting practices. On the contrary, grasslands decreased from 29581 ha to 25000 ha. In Kfarselouane, the area of grassland was invaded by forestland where rangeland decreased from 8073 ha to 3568 ha and woodland increased from 5766 ha to 11800 ha. Forest expansion occurred even at the account of unproductive land which decreased from 2668 ha to 248 ha, while cultivated lands did not reveal any substantial change. Based on animals' seasonal feeding pattern, a mismatch between land carrying capacity and grazing

  6. Vegetable Genetic Resources in China

    Directory of Open Access Journals (Sweden)

    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

  7. Restoring Degraded Rangelands in Jordan: Optimizing Mechanized Micro-Water Harvesting Technique Using Rangeland Hydrology and Erosion Model (RHEM)

    Science.gov (United States)

    Continuous population growth, recent refugee movement and migration as well as boundary restrictions and their implications on the nomadic lifestyle are additive pressure on rangelands throughout the Middle East. In particular, overgrazing through increased livestock herds threatens the Jordanian ra...

  8. Study on Rangeland production Potential and its Limitations in the Semi-Arid lands of Northern Kenya

    International Nuclear Information System (INIS)

    Keya, G.A.; Hornetz, B.

    1999-01-01

    Results obtained from recent studies focused on rangeland potential as influenced by human activity and climatic factors in the semi-arid and pastoral ecosystems of Northern Kenya indicated great temporal and spatial forage production variability. The objective of the studies was to document the primary production potential in relation to water stress (drought), herbivory and direct human activities. Efforts also focused on finding possibilities of increasing productivity while conserving the finite resources for sustainable use. Laboratory field and numeric methods were employed over several seasons and years. Forb and grass production was more viable than that of the brows (dwarf shrub) layer. Compared to forbs and dwarf shrubs, The grass layer contributed less to the total of production in all seasons, indicating that the region had less potential for grazers compared to browsers. Spatial-temporal variations in rangeland carrying capacity reflected the great spatial heterogeneity in vegetation types and production. Similarly, seasonal difference were very evident, with highest estimates in the long rainy and lowest during the dry and short rainy seasons, respectively. Factors limiting rangeland production potential and were identified to be moisture deficiency, resource-use conflicts, an increasing and partial sedentarised nomadic population, overgrazing, tree felling, and land degradation (desert encroachment). Measures that can increase rangelands production potential and provide a better way of life for the inhabitants of the region include: (a) identification of land degradation (e.g. by means of bio-indicators and Geographical Information systems, GIS); (b) technical interventions (i.e. soil and water conservation,restoration of degraded ares, fodder production); (c)socio-economic interventions (i.e. resolution of resource-use conflicts, alleviation of poverty, infrastructure development, improvement of livestock marketing channels, etc) and (d) continued

  9. Germplasm enhancement for adaptation to climate changes

    Directory of Open Access Journals (Sweden)

    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.

  10. Very High Resolution Panoramic Photography to Improve Conventional Rangeland Monitoring 1994

    Science.gov (United States)

    Rangeland monitoring often includes repeat photographs as a basis for documentation and although photographic equipment and electronics have been evolving rapidly, basic rangeland photo monitoring methods have changed little over time. Ground based digital photography is underutilized, especially s...

  11. Genetic diversity and germplasm resource research on tung tree ...

    African Journals Online (AJOL)

    SERVER

    2008-04-17

    Apr 17, 2008 ... a 2720 Thermal Cycler under the following cycle profile: 5 min at. 94oC ; followed by 45 cycles of 45 s at 94oC , 1 min at annealing temperature (Ta, depend on primers used, Table 2), .... chrome b5 to Either Endoplasmic Reticulum or Mitochondria. Plant. Cell. 16: 3002-3019. Henderson MP, Hwang YT, ...

  12. 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,.

  13. 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.

  14. 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)

  15. 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.

  16. Regional Standards for Rangeland Health and Guidelines for Livestock Grazing Management ... A Progress Report

    OpenAIRE

    1996-01-01

    In August 1995, new BLM regulations for rangeland administration went into effect. The new regulations require BLM to establish regional standards for rangeland health and guidelines for grazing management. This publication is a report on the alternatives being considered for the Montana/Dakotas Rangeland Health Standards and Guidelines process.

  17. State-and-transition model archetypes: a global taxonomy of rangeland change

    Science.gov (United States)

    State and transition models (STMs) synthesize science-based and local knowledge to formally represent the dynamics of rangeland and other ecosystems. Mental models or concepts of ecosystem dynamics implicitly underlie all management decisions in rangelands and thus how people influence rangeland sus...

  18. Criterion IV: Social and economic indicators of rangeland sustainability (Chapter 5)

    Science.gov (United States)

    Daniel W. McCollum; Louis E. Swanson; John A. Tanaka; Mark W. Brunson; Aaron J. Harp; L. Allen Torell; H. Theodore Heintz

    2010-01-01

    Social and economic systems provide the context and rationale for rangeland management. Sustaining rangeland ecosystems requires attention to the social and economic conditions that accompany the functioning of those systems. We present and discuss economic and social indicators for rangeland sustainability. A brief conceptual basis for each indicator is offered,...

  19. Ecohydrologic impacts of rangeland fire on runoff and erosion: A literature synthesis

    Science.gov (United States)

    Frederick B. Pierson; C. Jason Williams

    2016-01-01

    Fire can dramatically influence rangeland hydrology and erosion by altering ecohydrologic relationships. This synthesis presents an ecohydrologic perspective on the effects of fire on rangeland runoff and erosion through a review of scientific literature spanning many decades. The objectives are: (1) to introduce rangeland hydrology and erosion concepts necessary for...

  20. Ecologic, Economic, and Social Considerations for Rangeland Sustainability: An Integrated Conceptual Framework

    Science.gov (United States)

    Daniel W. McCollum; H. Theodore Jr. Heintz; Aaron J. Harp; John A. Tanaka; Gary R. Evans; David Radloff; Louis E. Swanson; William E. III Fox; Michael G. Sherm Karl; John E. Mitchell

    2006-01-01

    Use and sustainability of rangelands are inherently linked to the health and sustainability of the land. They are also inherently linked to the social and economic infrastructures that complement and support those rangelands and rangeland uses. Ecological systems and processes provide the biological interactions underlying ecosystem health and viability. Social and...

  1. Stakeholder Theory and Rangeland Management: The Importance of Ranch Income Dependence

    Science.gov (United States)

    Elias, S.; Roche, L. M.; Elias, E.

    2016-12-01

    The California drought beginning in 2012 has been driven by reduced precipitation and record high temperatures. Hydrologic drought in the Southwest United States is projected to become the new climatology of the region. While ranchers are considered naturally adaptive, often adeptly altering management based upon conditions, the projected increased aridity may challenge rangeland management. Certain rancher characteristics are likely to impact how well ranchers adapt. Based on Stakeholder Theory (ST), we hypothesize that the extent to which ranchers are dependent on their ranches as a source of income would serve as a predictor of several key variables related to ranching adaptation and success. Data were obtained from 507 ranchers throughout the State of California via the Rangeland Decision-Making Survey implemented by University of California, Davis in 2010, just prior to the unprecedented California drought. Consistent with the ST urgency facet, results of linear regression analyses indicate the more dependent ranchers are on their ranches for their income, the more aware they are of USDA ranching initiatives (β = 0.19, p < .001) and state ranching initiatives (β = 0.10, p < .05). In addition, more dependent ranchers are more likely to use multiple and diverse sources of information about ranching (β = 0.18, p < .001), are more likely to realize the severity and extent of the most recent drought's impacts (β = 0.18, p < .001), and were more likely to have a drought management plan in place during the most recent drought (β = 0.18, p < .001). These findings are important in relation to both outreach/extension efforts and rangeland research. Outreach/extension efforts should take into account that people less dependent on their ranches are less aware of resources, as well as, less prepared to adapt to drought. Researchers should control for the extent to which ranchers are dependent on their ranches for income in order to ensure more accurate findings.

  2. Rangeland monitoring using remote sensing: comparison of cover estimates from field measurements and image analysis

    Directory of Open Access Journals (Sweden)

    Ammon Boswell

    2017-01-01

    Full Text Available Rangeland monitoring is important for evaluating and assessing semi-arid plant communities. Remote sensing provides an effective tool for rapidly and accurately assessing rangeland vegetation and other surface attributes such as bare soil and rock. The purpose of this study was to evaluate the efficacy of remote sensing as a surrogate for field-based sampling techniques in detecting ground cover features (i.e., trees, shrubs, herbaceous cover, litter, surface, and comparing results with field-based measurements collected by the Utah Division of Wildlife Resources Range Trent Program. In the field, five 152 m long transects were used to sample plant, litter, rock, and bare-ground cover using the Daubenmire ocular estimate method. At the same location of each field plot, a 4-band (R,G,B,NIR, 25 cm pixel resolution, remotely sensed image was taken from a fixed-wing aircraft. Each image was spectrally classified producing 4 cover classes (tree, shrub, herbaceous, surface. No significant differences were detected between canopy cover collected remotely and in the field for tree (P = 0.652, shrub (P = 0.800, and herbaceous vegetation (P = 0.258. Surface cover was higher in field plots (P < 0.001, likely in response to the methods used to sample surface features by field crews. Accurately classifying vegetation and other features from remote sensed information can improve the efficiency of collecting vegetation and surface data. This information can also be used to improve data collection frequency for rangeland monitoring and to efficiently quantify ecological succession patterns.

  3. 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

  4. 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 ...

  5. 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...

  6. Climate impacts on agriculture: Implications for forage and rangeland production

    Energy Technology Data Exchange (ETDEWEB)

    Izaurralde, Roberto C.; Thomson, Allison M.; Morgan, Jack; Fay, Philip; Polley, Wayne; Hatfield, Jerry L.

    2011-04-19

    Projections of temperature and precipitation patterns across the United States during the next 50 years anticipate a 1.5 to 2°C warming and a slight increase in precipitation as a result of global climate change. There have been relatively few studies of climate change impacts on pasture and rangeland (grazingland) species compared to those on crop species, despite the economic and ecological importance of the former. Here we review the literature on pastureland and rangeland species to rising CO2 and climate change (temperature, and precipitation) and discuss plant and management factors likely to influence pastureland and rangeland responses to change (e.g., community composition, plant competition, perennial growth habit, seasonal productivity, and management methods). Overall, the response of pasture species to increased [CO2] is consistent with the general response of C3 and C4 type vegetation, although significant exceptions exist. Both pastureland and rangeland species should exhibit an acceleration of metabolism and development due to earlier onset of spring green-up and longer growing seasons. However, in the studies reviewed here, C3 pasture species increased their photosynthetic rates by up to 40% while C4 species exhibited no increase in photosynthesis. In general, it is expected that increases in [CO2] and precipitation would enhance rangeland net primary production (NPP) while increased air temperatures would either increase or decrease NPP. Much of this uncertainty in response is due to uncertain future projections of precipitation, both globally and regionally. For example, if annual precipitation changes little or declines, rangeland plant response to warming temperatures and rising [CO2] may be neutral or may decline due to increased water stress. This review reveals the need for comprehensive studies of climate change impacts on the pasture ecosystem including grazing regimes, mutualistic relationships (e.g., plant roots-nematodes; N

  7. Phytosanitary evaluation of olive germplasm in Albania

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    K. V. Derkach

    2017-08-01

    group within the general set of analyzed inbred lines. Two-dimensional component analysis showed that the first principal component (PCA1 accounted for 36.0% of total variation and divided the investigated set of 91 inbred lines into two fractions, while all the inbred lines which are considered Lancaster based on pedigree information were included in one of the fractions. The second principal component (PCA2, which accounted for 12.1% of total variation, separated most of the Lancaster germplasm inbred lines from the others in this fraction, although the overlapping of the locations of Lancaster and non-Lancaster inbred lines was observed. Qualitative cluster analysis of 31 Lancaster germplasm inbred lines allowed to identify two clusters: the first one includes 23 inbred lines of Ukrainian selection and the well known Mo17 inbred line (77.4% of total number of analysed lines inbred line, and the second cluster included 6 inbred lines of Ukrainian selection and the well known Oh43 inbred line (22.6% of total number of analysed lines inbred line. The isolation of two clusters within Lancaster germplasm indicates the genetic diversity in this plasm. The evaluation of genome similarities through allelic states of SNP-markers can successfully be used for classification and systematization of the gene pool of maize genetic resources.

  9. Soil Properties and Plant Biomass Production in Natural Rangeland Management Systems

    Directory of Open Access Journals (Sweden)

    Romeu de Souza Werner

    Full Text Available ABSTRACT Improper management of rangelands can cause land degradation and reduce the economic efficiency of livestock activity. The aim of this study was to evaluate soil properties and quantify plant biomass production in four natural rangeland management systems in the Santa Catarina Plateau (Planalto Catarinense of Brazil. The treatments, which included mowed natural rangeland (NR, burned natural rangeland (BR, natural rangeland improved through the introduction of plant species after harrowing (IH, and natural rangeland improved through the introduction of plant species after chisel plowing (IC, were evaluated in a Nitossolo Bruno (Nitisol. In the improved treatments, soil acidity was corrected, phosphate fertilizer was applied, and intercropped annual ryegrass (Lolium multiflorum, velvet grass (Holcus lanatus, and white clover (Trifolium repens were sown. Management systems with harrowed or chisel plowed soil showed improved soil physical properties; however, the effect decreased over time and values approached those of burned and mowed natural rangelands. Natural rangeland systems in the establishment phase had little influence on soil organic C. The mowed natural rangeland and improved natural rangeland exhibited greater production of grazing material, while burning the field decreased production and increased the proportion of weeds. Improvement of the natural rangelands increased leguminous biomass for pasture.

  10. Threats to Mediterranean rangelands: a case study based on the views of citizens in the Viotia prefecture, Greece.

    Science.gov (United States)

    Kyriazopoulos, Apostolos P; Arabatzis, Garyfallos; Abraham, Eleni M; Parissi, Zoi M

    2013-11-15

    Rangelands in Greece constitute a very important natural resource as they occupy 40% of the total surface. Not only is their forage production essential for the development of extensive livestock farming, but also they play a key role in outdoor recreational activities, protection from erosion, provision of water supplies and biodiversity conservation. However, land use changes, inappropriate management and wildfires threaten their existence. The research was conducted among the citizens of Viotia prefecture, an area close to Athens, Greece, using personal interviews with a structured questionnaire in 2008. The aim was to record citizens' opinions regarding the threats to rangelands. The results suggest that the main threats as perceived by the respondents, are land use changes especially for urban development, and wildfires. The application of cluster analysis highlighted the differentiation among the respondents in ranking these threats. The more ecologically aware citizens recognised that mismanagement, abandonment and agriculture also threaten rangelands. These threats can have a considerable impact on the lives of the local people. Policy makers and managers should take the opinions of local citizens into consideration, and engage them in decision making so that sustainable management policies could be applied. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Advances in modeling soil erosion after disturbance on rangelands

    Science.gov (United States)

    Research has been undertaken to develop process based models that predict soil erosion rate after disturbance on rangelands. In these models soil detachment is predicted as a combination of multiple erosion processes, rain splash and thin sheet flow (splash and sheet) detachment and concentrated flo...

  12. Session B1 Management for sustainable use — Rangeland auditing ...

    African Journals Online (AJOL)

    We need to monitor the capacity of healthy rangeland to support a broad suite of ecosystem services for a wide range of stakeholders — in a fair, objective and representative way. ... A hybrid session structure will be utilised: distilling wisdom from relevant posters; formal presentations; and stimulating structured debate.

  13. Rangeland restoration for Hirola, the world's most endangered antelope

    Science.gov (United States)

    Rangeland restoration can improve habitat for threatened species such as the hirola antelope (Beatragus hunteri) that inhabit savannas of eastern Kenya. However, restoration success likely varies across soil types and target restoration species, as well as according to restoration approach. We teste...

  14. A conceptual tool for improving rangeland management decision ...

    African Journals Online (AJOL)

    ... the LLM concept should be seen as a continuous and evolving learning process that will be updated over the long term through decision support to include several other components essential to implement effective and sustainable rangeland management practices by local land users. Keywords: desertification; indicators ...

  15. Yield Response of Mediterranean Rangelands under a Changing Climate

    NARCIS (Netherlands)

    Daliakopoulos, Ioannis N.; Panagea, Ioanna S.; Tsanis, Ioannis K.; Grillakis, Manolis G.; Koutroulis, Aristeidis G.; Hessel, Rudi; Mayor, Angeles G.; Ritsema, Coen J.

    2017-01-01

    Understanding the Mediterranean rangelands degradation trends is a key element of mitigating their vulnerability and enhancing their resilience. Climate change and its inherent effects on mean temperature and the precipitation variability can regulate the magnitude, frequency and duration of

  16. Runoff and soil erosion from two rangeland sites

    Science.gov (United States)

    Historically over 50 years of rainfall/runoff research using rainfall simulators has been conducted at various rangeland sites in the West, however these sites rarely have consecutive yearly measurements. This limits the understanding of dynamic annual conditions and the interactions of grazing, pla...

  17. Session B1 Management for sustainable use — Rangeland auditing ...

    African Journals Online (AJOL)

    Social, economic and cultural needs, values and expectations will be examined together with the biophysical technologies and approaches which underlie auditing in rangeland science. Adaptive frameworks which enhance sustainable strategic responses, and the state of art in scale dilemmas will be addressed. A hybrid ...

  18. Presidential address - 1999 Towards a national rangeland policy ...

    African Journals Online (AJOL)

    There are some problems with the publication of the journal, but Council hopes to have our ... The first is that all agencies funded through DACST will be reviewed ... to improve our understanding of management issues in communal rangeland. ... All current programmes to rehabilitate degraded land contain budgets for the ...

  19. Ecology and Conservation of Acacia senegal in the Rangelands ...

    African Journals Online (AJOL)

    Ecology and Conservation of Acacia senegal in the Rangelands ofLuwero and Nakasongola Districts. Jacob Godfrey Agea, Joseph Obua, Sara Namirembe, Mukadasi Buyinza, Daniel Waiswa. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  20. Agroforestry potential of Acacia senegal in the rangelands of luwero ...

    African Journals Online (AJOL)

    Agroforestry potential of Acacia senegal in the rangelands of luwero and Nakasongola districts. Jacob Godfrey Agea, Joseph Obua, Sara Namirembe, Mukadasi Buyinza, Daniel Waiswa. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  1. Impact of Rangeland Degradation on Soil Physical, Chemical

    African Journals Online (AJOL)

    major threats to enhance a sustainable pastoral-livestock production in Ethiopia. ... overall negative impact on the soil physical and chemical characteristics, demanding ... chemical properties (Gemedo et al., 2006) as well as the rangeland .... parameters such as life forms (annuals and perennials), plant forms (woody plant,.

  2. A review of climate change effects on terrestrial rangeland birds

    Science.gov (United States)

    D. M. Finch; K. E. Bagne; M. M. Friggens; D. M. Smith; K. M. Brodhead

    2011-01-01

    We evaluated existing literature on predicted and known climate change effects on terrestrial rangeland birds. We asked the following questions: 1) How does climate change affect birds? 2) How will birds respond to climate change? 3) Are species already responding? 4) How will habitats be impacted?

  3. The challenge of integrated rangeland monitoring: synthesis address

    African Journals Online (AJOL)

    The utility of monitoring and its guiding principles will only work effectively where good environmental governance is practiced by users and producers affecting rangeland ecosystems. Keywords: adaptive management, complex, environmental governance, human impacts, multi-scale, socio-ecological. African Journal of ...

  4. Determining termite diversity in arid Namibian rangelands – a ...

    African Journals Online (AJOL)

    Three methods of sampling termite diversity in arid rangelands were tested in Namibia during the wet (March) and dry (October) seasons of 1998. Six sites were chosen: one pair on each of three farms representing a gradient of land use intensity. At each site, two adjacent plots of 1 ha each were sampled: one plot by a ...

  5. Session A6 Rangelands as dynamic systems — Fragmentation of ...

    African Journals Online (AJOL)

    Biological complexity in rangelands arises from spatially-linked ecological states and processes. Herbivores, humans and other agents integrate distinct spatial units into complex systems by moving among and exploiting these units. Spatial heterogeneity plays a central role in the structure and function of grazed ...

  6. Parameterization of erodibility in the Rangeland Hydrology and Erosion Model

    Science.gov (United States)

    The magnitude of erosion from a hillslope is governed by the availability of sediment and connectivity of runoff and erosion processes. For undisturbed rangelands, sediment is primarily detached and transported by rainsplash and sheetflow (splash-sheet) processes in isolated bare batches, but sedime...

  7. Vulnerability of amphibians to climate change: implications for rangeland management

    Science.gov (United States)

    Karen E. Bagne; Deborah M. Finch; Megan M. Friggens

    2011-01-01

    Many amphibian populations have declined drastically in recent years due to a large number of factors including the emerging threat of climate change (Wake 2007). Rangelands provide important habitat for amphibians. In addition to natural wetlands, stock tanks and other artificial water catchments provide habitat for many amphibian species (Euliss et al. 2004).

  8. Exploring the invasion of rangelands by Acacia mearnsii (black ...

    African Journals Online (AJOL)

    Reducing A. mearnsii canopy could promote grass production while encouraging carbon sequestration. Given the high AGB and clearing costs, it may be prudent to adopt the 'novel ecosystems' approach in managing infested landscapes. Keywords: grassland, invasive plants, landscape ecology, rangeland condition ...

  9. Rangeland Ecosystem Services: Nature's Supply and Humans' Demand

    Science.gov (United States)

    Ecosystem services are the benefits that society receives from nature and they include the regulation of climate, the pollination of crops, the provisioning of intellectual inspiration and recreational environment, as well as many essential goods such as food, fiber, and wood. Rangeland ecosystem se...

  10. 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

  11. 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.

  12. Vegetation restoration on degraded rangelands through the use of microcatchment and brush packs in the communal areas of the Eastern Cape

    CSIR Research Space (South Africa)

    Lesoli, MS

    2010-07-01

    Full Text Available Rangeland degradation results in declining functional capacity, increased poverty, and food insecurity. Major changes in rangeland surface morphology and soil characteristics have a drastic effect on the primary productivity of the rangeland...

  13. Livestock-rangeland management practices and community perceptions towards rangeland degradation in South Omo zone of Southern Ethiopia

    NARCIS (Netherlands)

    Admasu, T.; Abule, E.; Tessema, Z.K.

    2010-01-01

    A survey was conducted in Hamer and Benna-Tsemay districts of the South Omo zone of Ethiopia, with the objectives of assessing the range-livestock management practices and perceptions of the different pastoral groups (Hamer, Benna, and Tsemay) towards rangeland degradation. This information is

  14. 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

  15. Fodder Biomass Monitoring in Sahelian Rangelands Using Phenological Metrics from FAPAR Time Series

    DEFF Research Database (Denmark)

    Diouf, Abdoul Aziz; Brandt, Martin Stefan; Verger, Aleixandre

    2015-01-01

    Timely monitoring of plant biomass is critical for the management of forage resources in Sahelian rangelands. The estimation of annual biomass production in the Sahel is based on a simple relationship between satellite annual Normalized Difference Vegetation Index (NDVI) and in situ biomass data....... This study proposes a new methodology using multi-linear models between phenological metrics from the SPOT-VEGETATION time series of Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) and in situ biomass. A model with three variables—large seasonal integral (LINTG), length of growing season......, and end of season decreasing rate—performed best (MAE = 605 kg·DM/ha; R2 = 0.68) across Sahelian ecosystems in Senegal (data for the period 1999–2013). A model with annual maximum (PEAK) and start date of season showed similar performances (MAE = 625 kg·DM/ha; R2 = 0.64), allowing a timely estimation...

  16. Spatial distribution of overland flow and sediment yield in semi-arid rangelands

    International Nuclear Information System (INIS)

    Sarah, P.; Lavee, H.

    2009-01-01

    Feedbacks and mutual links exist among soil, vegetation and water; they enable co-evolution of these features within eco-geomorphic systems, These relations are fragile, especially in semi-arid areas where grazing is the main land use. The simples subdivision of the surface of many semi-arid rangelands is into a two-component mosaic pattern comprising shrub patches interspersed with open spaces, with the former acting s skinks for water and other resources, and the latter as sources. However close observations in areas under grazing in the northern Negev region of Israel suggested that the spatial patterns of surface components is more complicated, and that the open space between shrubs consists of two components: herbaceous areas, separated by trampling routes that support no vegetation. (Author)

  17. 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)

  18. 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.

  19. 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 ...

  20. 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.

  1. 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 ...

  2. 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.

  3. 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 ...

  4. 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.

  5. 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 ...

  6. 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 (...

  7. Cryopreservation of eucalyptus genetic resources

    Science.gov (United States)

    The long-term preservation of forest genetic resources is a vital part of preserving our forest crops for future generations. Unfortunately there are few genebanks dedicated to forest trees and very few methods aside from field plantings of germplasm collections of elite clonal individuals. The use ...

  8. Vegetation - Herbivory Dynamics in Rangeland Ecosystems: Geospatial Modeling for Savanna and Wildlife Conservation in California and Namibia

    OpenAIRE

    Tsalyuk, Miriam

    2014-01-01

    Rangelands cover about half of Earth's land surface, encompass considerable biodiversity, and provide pivotal ecosystem services. However, rangelands across the globe face degradation due to changes in climate, land use, and management. Moreover, since herbivory is fundamental to rangeland ecosystem dynamics, shifts in the distribution of herbivores lead to overgrazing and desertification. To better understand, predict, and prevent changes on rangelands it is important to monitor these landsc...

  9. Meat fatty acid and cholesterol level of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau.

    Science.gov (United States)

    Sun, Tao; Liu, Zhiyun; Qin, Liping; Long, Ruijun

    2012-08-30

    Meat safety and nutrition are major concerns of consumers. The development of distinctive poultry production methods based on locally available natural resources is important. Grasshoppers are rich in important nutrients and occur in dense concentrations in most rangelands of northern China. Foraging chickens could be used to suppress grasshopper infestations. However, knowledge of the fatty acid content of meat from free-range broilers reared on alpine rangeland is required. Rearing conditions and diet did not significantly (P > 0.05) affect concentrations of saturated fatty acid (SFA), arachidonic acid, docosahexaenoic acid or the ratio of total n-6 to total n-3 fatty acids. Breast muscle of chickens that had consumed grasshoppers contained significantly (P 0.05) higher than intensively reared birds. Compared with meat from intensively reared birds, meat from free-range broilers had less cholesterol and higher concentrations of total lipid and phospholipids. Chickens eating grasshoppers in rangeland produce superior quality meat and reduce the grasshopper populations that damage the pastures. This provides an economic system of enhanced poultry-meat production, which derives benefits from natural resources rather than artificial additives. Copyright © 2012 Society of Chemical Industry.

  10. Bush encroachment dynamics and rangeland management implications in the Horn of Africa

    Science.gov (United States)

    Rangelands in the Horn of Africa have been undergoing a rapid shift from herbaceous to woody plant dominance in the past decades, threatening subsistence livestock herding and pastoral food security. Despite of significant rangeland management implications, quantification of the spatial extent of en...

  11. Rehabilitation of community-owned, mixed-use rangelands: Lessons from the Ewaso ecosystem in Kenya

    Science.gov (United States)

    Globally, 10-20% of arid and semi-arid rangelands have been classified as severely degraded (UNCCD 1994; MEA 2005), and in sub-Saharan Africa specifically, 70% of rangelands are considered moderately to severely degraded (Dregne 1992; UNCCD 1994). Given that these drylands make up 43% of Africa’s la...

  12. Bayesian estimation of shrubs diversity in rangelands under two management systems in northern Syria

    NARCIS (Netherlands)

    Niane, A.A.; Singh, M.; Struik, P.C.

    2014-01-01

    The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the

  13. Heat dosage and oviposition depth influence egg mortality of two common rangeland grasshopper species

    Science.gov (United States)

    Rangeland fire is a common naturally occurring event and management tool, with the amount and structure of biomass controlling transfer of heat belowground. Temperatures grasshopper eggs are exposed to during rangeland fires are mediated by species specific oviposition traits. This experiment examin...

  14. Effects of climate change on rangeland vegetation in the Northern Rockies Region [Chapter 7

    Science.gov (United States)

    Matt C. Reeves; Mary E. Manning; Jeff P. DiBenedetto; Kyle A. Palmquist; William K. Lauenroth; John B. Bradford; Daniel R. Schlaepfer

    2018-01-01

    Rangelands are dominated by grass, forb, or shrub species, but are usually not modified by using agronomic improvements such as fertilization or irrigation (Lund 2007; Reeves and Mitchell 2011) as these lands would normally be considered pastures. Rangeland includes grassland, shrubland, and desert ecosystems, alpine areas, and some woodlands (box 7.1). This chapter...

  15. Earth stewardship on rangelands: Coping with ecological, economic, and political marginality

    Science.gov (United States)

    Rangelands encompass 30-40 percent of Earth's land surface and support 1-2 billion people. Their predominant use is extensive livestock production by pastoralists and ranchers. But rangelands are characterized by ecological, economic, and political marginality, and higher-value, more intensive land ...

  16. Global view of remote sensing of rangelands: Evolution, applications, future pathways [Chapter 10

    Science.gov (United States)

    Matt Reeves; Robert A. Washington-Allen; Jay Angerer; E. Raymond Hunt; Ranjani Wasantha Kulawardhana; Lalit Kumar; Tatiana Loboda; Thomas Loveland; Graciela Metternicht; R. Douglas. Ramsey

    2015-01-01

    The term "rangeland" is rather nebulous, and there is no single definition of rangeland that is universally accepted by land managers, scientists, or international bodies (Lund, 2007; Reeves and Mitchell, 2011). Dozens and possibly hundreds (Lund, 2007) of definitions and ideologies exist because various stakeholders often have unique objectives...

  17. China's Rangelands under Stress : A comparative study of pasture commons in the Ningxia Hui Autonomous Region

    NARCIS (Netherlands)

    Ho, P.P.S.

    2000-01-01

    China's economic reforms have exacerbated the problems of over-grazing and desertification in the country's pastoral areas. In order to deal with rangeland degradation, the Chinese government has resorted to nationalization, or semi-privatization. Since the implementation of rangeland policy has

  18. Hydrologic ramifications of an increased role of wildland fire across the rangeland-dry forest continuum

    Science.gov (United States)

    The increased role of wildland fire across the rangeland-dry forest continuum in the western United States (US) presents landscape-scale consequences relative runoff and erosion. Much of the Intermountain West now exists in a state in which rangeland and woodland wildfires stimulated by invasive che...

  19. Climate change and North American rangelands: Assessment of mitigation and adaptation strategies

    Science.gov (United States)

    Linda A. Joyce; David D. Briske; Joel R. Brown; H. Wayne Polley; Bruce A. McCarl; Derek W. Bailey

    2013-01-01

    Recent climatic trends and climate model projections indicate that climate change will modify rangeland ecosystem functions and the services and livelihoods that they provision. Recent history has demonstrated that climatic variability has a strong influence on both ecological and social components of rangeland systems and that these systems possess substantial...

  20. Book title: Rangelands systems: Processes, management and challenges - Chapter title: Invasive plant species and novel ecosystems

    Science.gov (United States)

    Rangelands represent the dominant land use systems in many countries of the world and provide sociological and cultural benefits to millions of people in both rural and urban areas. The undesirable impacts of rangeland weeds have been recognized for well over 100 years and infest between 41 and 51 ...

  1. Agricultural, Runoff, Erosion and Salinity (ARES) Database to Better Evaluate Rangeland State and Sustainability

    Science.gov (United States)

    Rangelands comprise approximately 40% of the earth’s surface and are the largest land cover type in the world. Degradation from mismanagement, desertification, and drought impact more than 50% of rangelands across the globe. The USDA Agricultural Research Service (ARS) has been evaluating means of r...

  2. Plant/life form considerations in the rangeland hydrology and erosion model (RHEM)

    Science.gov (United States)

    Resilience of rangeland to erosion has largely been attributed to adequate plant cover; however, plant life/growth form, and individual species presence can have a dramatic effect on hydrologic and erosion dynamics on rangelands. Plant life/growth form refers to genetic tendency of a plant to grow i...

  3. Application of the Rangeland Hydrology and Erosion Model to Ecological Site Descriptions and Management

    Science.gov (United States)

    The utility of Ecological Site Descriptions (ESDs) and State-and-Transition Models (STMs) concepts in guiding rangeland management hinges on their ability to accurately describe and predict community dynamics and the associated consequences. For many rangeland ecosystems, plant community dynamics ar...

  4. IMPACT OF WOODY PLANTS SPECIES ON SOIL PHYSIO-CHEMICAL PROPERTIES ALONG GRAZING GRADIENTS IN RANGELANDS OF EASTERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Mohammed Mussa Abdulahi

    2016-12-01

    Full Text Available In the lowlands of arid and semiarid rangelands woody plants plays an important role in soil fertility maintenance, providing food, medicine, cosmetics, fodder, fuel wood and pesticides. A better understanding of the interaction of woody plants on their immediate environment is needed to guide optimum management of native vegetation in the production landscapes. However, the impact of woody plant species on soil properties remains poorly understood. This study evaluates the impact of two dominant woody plant species (A. senegal and B. aegyptica on soil physico-chemical properties along grazing gradients in rangelands of eastern Ethiopia. Six trees of each species were selected from light, moderate and heavy grazing sites.  Soil sample data at two depths (0-15 and 16-30 cm were collected from under and open areas of A. senegal and B. aegyptica from each grazing sites, and analysed for nutrient contents. The nutrient status of soil under both woody species was significantly higher especially with regard to soil organic matter (4.37%, total nitrogen (0.313%, and available phosphorus (11.62 than the open grassland with soil organic matter (3.82%, total nitrogen (0.246%, and available phosphorus (10.94 mg/Kg soil for A. Senegal. The soil organic matter (3.93%, total nitrogen (0.285%, available phosphorus (11.66 mg/Kg soil were significantly higher than open grassland with soil organic matter (3.52%, total nitrogen (0.218%, available phosphorus (10.73 mg/Kg soil for B. aegyptica. This was more pronounced in the top 15 cm of soil under A. senegal woody plant species and on the light and moderate grazing site. Therefore, this tree has a significant effect on soil fertility improvement in resource poor rangelands and as a result, it is important to retain scattered A. senegal and B. aegyptica plants in the lowlands of eastern Ethiopia.

  5. 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...

  6. Buffel grass morphoagronomic characterization from cenchrus germplasm active bank.

    OpenAIRE

    BRUNO, L. R. G. P.; ANTONIO, R. P.; ASSIS, J. G. de A.; MOREIRA, J. N.; LIRA, I. C. de S. A.

    2017-01-01

    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 ...

  7. 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...

  8. 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...

  9. Hydrologic Impacts Associated with the Increased Role of Wildland Fire Across the Rangeland-Xeric Forest Continuum of the Great Basin and Intermountain West, USA

    Science.gov (United States)

    Williams, C. J.; Pierson, F. B.; Robichaud, P. R.; Boll, J.; Al-Hamdan, O. Z.

    2011-12-01

    The increased role of wildland fire across the rangeland-xeric forest continuum in the western United States (US) presents landscape-scale consequences relative runoff and erosion. Concomitant climate conditions and altered plant community transitions in recent decades along grassland-shrubland-woodland-xeric forest transitions have promoted frequent and large wildland fires, and the continuance of the trend appears likely if current or warming climate conditions prevail. Much of the Great Basin and Intermountain West in the US now exists in a state in which rangeland and woodland wildfires stimulated by invasive cheatgrass and dense, horizontal and vertical fuel layers have a greater likelihood of progressing upslope into xeric forests. Drier moisture conditions and warmer seasonal air temperatures, along with dense fuel loads, have lengthened fire seasons and facilitated an increase in the frequency, severity and area burned in mid-elevation western US forests. These changes potentially increase the overall hydrologic vulnerability across the rangeland-xeric forest continuum by spatially and temporally increasing soil surface exposure to runoff and erosion processes. Plot-to-hillslope scale studies demonstrate burning may increase event runoff and/or erosion by factors of 2-40 over small-plots scales and more than 100-fold over large-plot to hillslope scales. Anecdotal reports of large-scale flooding and debris-flow events from rangelands and xeric forests following burning document the potential risk to resources (soil loss, water quality, degraded aquatic habitat, etc.), property and infrastructure, and human life. Such risks are particularly concerning for urban centers near the urban-wildland interface. We do not yet know the long-term ramifications of frequent soil loss associated with commonly occurring runoff events on repeatedly burned sites. However, plot to landscape-scale post-fire erosion rate estimates suggest potential losses of biologically

  10. Evaluation of Maize Germplasm for Resistance to Aflatoxin Accumulation

    Directory of Open Access Journals (Sweden)

    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.

  11. 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 ...

  12. Influencing adaptation processes on the Australian rangelands for social and ecological resilience

    Directory of Open Access Journals (Sweden)

    Nadine A. Marshall

    2014-06-01

    Full Text Available Resource users require the capacity to cope and adapt to climate changes affecting resource condition if they, and their industries, are to remain viable. Understanding individual-scale responses to a changing climate will be an important component of designing well-targeted, broad-scale strategies and policies. Because of the interdependencies between people and ecosystems, understanding and supporting resilience of resource-dependent people may be as important an aspect of effective resource management as managing the resilience of ecological components. We refer to the northern Australian rangelands as an example of a system that is particularly vulnerable to the impacts of climate change and look for ways to enhance the resilience of the system. Vulnerability of the social system comprises elements of adaptive capacity and sensitivity to change (resource dependency as well as exposure, which is not examined here. We assessed the adaptive capacity of 240 cattle producers, using four established dimensions, and investigated the association between adaptive capacity and climate sensitivity (or resource dependency as measured through 14 established dimensions. We found that occupational identity, employability, networks, strategic approach, environmental awareness, dynamic resource use, and use of technology were all positively correlated with at least one dimension of adaptive capacity and that place attachment was negatively correlated with adaptive capacity. These results suggest that adaptation processes could be influenced by focusing on adaptive capacity and these aspects of climate sensitivity. Managing the resilience of individuals is critical to processes of adaptation at higher levels and needs greater attention if adaptation processes are to be shaped and influenced.

  13. 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...

  14. 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

    1) The success in crop improvement programs depends largely on the extent of genetic variability available. Germplasm collections assembles all the available genetic resources and are critical for long-term crop improvement. This world sugarcane germplasm collection contains enormous genetic variability for various morphological traits, biomass yield components, adaptation and many quality traits, prospectively imbeds a large number of valuable alleles for biofuel traits such as high biomass yield, quantity and quality of lignocelluloses, stress tolerance, and nutrient use efficiency. The germplasm collection is of little value unless it is characterized and utilized for crop improvement. In this project, we phenotypically and genotypically characterized the sugarcane world germplasm collection (The results were published in two papers already and another two papers are to be published). This data will be made available for public to refer to for germplasm unitization specifically in the sugarcane and energy cane breeding programs. In addition, we are identifying the alleles contributing to the biomass traits in sugarcane germplasm. This part of project is very challenging due to the large genome and highly polyploid level of this crop. We firstly established a high throughput sugarcane genotyping pipeline in the genome and bioinformatics era (a paper is published in 2016). We identified and modified a software for genome-wide association analysis of polyploid species. The results of the alleles associated to the biomass traits will be published soon, which will help the scientific community understand the genetic makeup of the biomass components of sugarcane. Molecular breeders can develop markers for marker assisted selection of biomass traits improvement. Further, the development and release of new energy cane cultivars through this project not only improved genetic diversity but also improved dry biomass yields and resistance to diseases. These new cultivars

  15. Re-creating the commons and re-configuring Maasai women’s roles on the rangelands in the face of fragmentation

    Directory of Open Access Journals (Sweden)

    Caroline S Archambault

    2016-09-01

    Full Text Available Throughout the world pastoralists today face a particularly daunting challenge of intensified rangeland fragmentation combined with human population growth and climate change. In many pastoral settings, rangelands are undergoing processes of fragmentation due to tenure transformations, as previously communal lands are privatized into individual holdings. Such processes of enclosure have raised concerns over the long-term costs on pastoral communities and on rangeland eco-systems. This paper explores pastoral responses and adaptations to enclosure based on long-term ethnographic engagement in a Maasai community in Southern Kenya that has recently privatized. Detailed family case studies and herd tracking illuminate the ways in which families try to re-create the commons by relying on social networks for free access to resources. In particular, women’s social networks (for example, their kin, affines, friends, or religious associates seem to play an important role. This paper calls attention to the need to better understand women’s changing roles in pastoral governance and production and the implications these new roles have for women’s well-being and for pastoralism in the face of fragmentation.

  16. 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.

  17. 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

  18. 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

  19. 1976 Inter-university symposium on renewable resource assessment and programming: executive summary

    Science.gov (United States)

    Billy G. Pemberton

    1977-01-01

    The Forest and Rangeland Renewable Resources Planning Act of 1974 directs the Secretary of Agriculture to prepare an assessment of the nation's renewable resources and a program that will assure an adequate future supply of these resources. Responsibility for this work is assigned to the Forest Service. An inter-university symposium was held in 1976 to evaluate...

  20. Forage seeding in rangelands increases production and prevents weed invasion

    Directory of Open Access Journals (Sweden)

    Josh Davy

    2017-07-01

    Full Text Available Increasing forage productivity in the Sierra foothill rangelands would help sustain the livestock industry as land availability shrinks and lease rates rise, but hardly any studies have been done on forage selections. From 2009 to 2014, in one of the first long-term and replicated studies of seeding Northern California's Mediterranean annual rangeland, we compared the cover of 22 diverse forages to determine their establishment and survivability over time. Among the annual herbs, forage brassica (Brassica napus L. and chicory (Cichorium intybus L. proved viable options. Among the annual grasses, soft brome (Bromus hordeaceus and annual ryegrass (Lolium multiflorum performed well. However, these species will likely require frequent reseeding to maintain dominance. Long-term goals of sustained dominant cover (> 3 years are best achieved with perennial grasses. Perennial grasses that persisted with greater than 50% cover were Berber orchardgrass (Dactylis glomerata, Flecha tall fescue (Lolium arundinaceum and several varieties of hardinggrass (Phalaris aquatica L., Perla koleagrass, Holdfast, Advanced AT. In 2014, these successful perennials produced over three times more dry matter (pounds per acre than the unseeded control and also suppressed annual grasses and yellow starthistle (Centaurea solstitialis L. cover.

  1. Analysis reveals potential rangeland impacts if Williamson Act eliminated

    Directory of Open Access Journals (Sweden)

    William C. Wetzel

    2012-10-01

    Full Text Available California budget cuts have resulted in dramatic reductions in state funding for the Williamson Act, a land protection program that reduces property taxes for the owners of 15 million acres of California farms and rangeland. With state reimbursements to counties eliminated, the decision to continue Williamson Act contracts lies with individual counties. We investigated the consequences of eliminating the Williamson Act, using a geospatial analysis and a mail questionnaire asking ranchers for plans under a hypothetical elimination scenario. The geospatial analysis revealed that 72% of rangeland parcels enrolled in Williamson Act contracts contained habitat important for statewide conservation goals. Presented with the elimination scenario, survey respondents reported an intention to sell 20% of their total 496,889 acres. The tendency of survey participants to respond that they would sell land was highest among full-time ranchers with low household incomes and without off-ranch employment. A majority (76% of the ranchers who reported that they would sell land predicted that the buyers would develop it for nonagricultural uses, suggesting substantial changes to California's landscape in a future without the Williamson Act.

  2. Use of biosolids to enhance rangeland forage quality.

    Science.gov (United States)

    McFarland, Michael J; Vasquez, Issaak Romero; Vutran, MaiAnh; Schmitz, Mark; Brobst, Robert B

    2010-05-01

    Biosolids land application was demonstrated to be a potentially cost-effective means for restoring forage productivity and enhancing soil-moisture-holding capacity on disturbed rangelands. By land-applying aerobically digested, anaerobically digested, composted, and lime-stabilized biosolids on rangeland test plots at rates of up to 20 times (20X) the estimated nitrogen-based agronomic rate, forage yields were found to increase from 132.8 kg/ha (118.2 lb/ac) (control plots) to 1182.3 kg/ha (1052.8 lb/ac). Despite the environmental benefits associated with increased forage yield (e.g., reduced soil erosion, improved drainage, and enhanced terrestrial carbon sequestration), the type of forage generated both before and after biosolids land application was found to be dominated by invasive weeds, all of which were characterized as having fair to poor nutritional value. Opportunistic and shallow rooting invasive weeds not only have marginal nutritional value, they also limit the establishment of native perennial grasses and thus biodiversity. Many of the identified invasive species (e.g., Cheatgrass) mature early, a characteristic that significantly increases the fuel loads that support the increased frequency and extent of western wildfires.

  3. Scales of snow depth variability in high elevation rangeland sagebrush

    Science.gov (United States)

    Tedesche, Molly E.; Fassnacht, Steven R.; Meiman, Paul J.

    2017-09-01

    In high elevation semi-arid rangelands, sagebrush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush ( Artemisia tridentata Nutt.) at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions (0.05 to 25 m) and extents (2 to 1000 m). Finer scale data were collected specifically for this study to examine the correlation between snow depth, sagebrush microtopography, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Variograms were used to identify the spatial structure and the Moran's I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

  4. Assessments of genetic diversity and anthracnose disease response among Zimbabwe sorghum germplasm.

    Science.gov (United States)

    The USDA-ARS National Plant Germplasm System maintains a Zimbabwe sorghum collection of 1,235 accessions from different provinces. This germplasm has not been extensively employed in U.S. breeding programs due to the lack of phenotypic and genetic characterization. Therefore, 68 accessions from th...

  5. Comparison of LANDSAT-2 and field spectrometer reflectance signatures of south Texas rangeland plant communities

    Science.gov (United States)

    Richardson, A. J.; Escobar, D. E.; Gausman, H. W.; Everitt, J. H. (Principal Investigator)

    1982-01-01

    The accuracy was assessed for an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the LANDSAT satellite multispectral scanner (MSS) and a ground based spectroradiometer. The rangeland plant reflectances produced by the two sensors were correlated with no significant deviation of the slope from unity or of the intercept from zero. These results indicated that the atmospheric correction produced LANDSAT MSS estimates of rangeland plant reflectances that are as accurate as the ground based spectroradiometer.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. Reality of rangeland degradation mapping with remote sensing: the South African experience

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2008-09-01

    Full Text Available Globally there is an urgent need for standardized, quantitative measures rangeland degradation. Over the past 10 years in South Africa (SA), significant research efforts have been directed at this challenge, using diverse methods and data...

  9. Human-modified landscapes: patterns of fine-scale woody vegetation structure in communal savannah rangelands

    CSIR Research Space (South Africa)

    Fisher, T

    2011-11-01

    Full Text Available structure in five communal rangelands around 12 settlements in Bushbuckridge, a municipality in the Kruger to Canyons Biosphere Reserve (South Africa). The importance of underlying abiotic factors was evaluated by measuring size class distributions across...

  10. Success of seeding native compared with introduced perennial vegetation for revegetating medusahead-invaded sagebrush rangeland

    Science.gov (United States)

    Millions of hectares of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) rangeland have been invaded by medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass that degrades wildlife habitat, reduces forage production, and decreases biodiversity....

  11. Separating the cows from the trees: toward development of national definitions of forest and rangeland

    Science.gov (United States)

    H. Gyde Lund

    2007-01-01

    This paper introduces issues surrounding the need for national definitions of forest and rangeland, and it review types of definitions in use, reviews past agreements and their status, and finally gives recommendations as to what should be done next.

  12. 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.

  13. Rangeland Use Rights Privatisation Based on the Tragedy of the Commons: A Case Study from Tibet

    Directory of Open Access Journals (Sweden)

    Yonten Nyima Yundannima

    2017-01-01

    Full Text Available Rangeland use rights privatisation based on a tragedy of the commons assumption has been the backbone of state policy on rangeland management and pastoralism in China. Through an empirical case study from Pelgon county, Tibet Autonomous Region in China, this paper provides an empirical analysis of rangeland use rights privatisation. It shows that the tragedy of the commons is not the correct model to apply to Tibetan pastoralism because pasture use in Tibet has never been an open-access institution. Thus, when the tragedy of the commons model is applied as a rationale for rangeland use rights privatisation, the result is not what is intended by the policy, but rather a misfit to features of pastoralism and thus disruption of the essence of pastoralism, i.e. mobility and flexibility. The paper further shows that a hybrid institution combining household rangeland tenure with community-based use with user fees is a restoration of the pastoralist institution. This demonstrates the capacity of pastoralists to create adaptive new institutions congruent with the interdependent and integrated nature of pastoralism consisting of three components: pastoralists, livestock, and rangeland.

  14. Evaluating soil moisture and hydraulic conductivity in semi-arid rangeland soils

    International Nuclear Information System (INIS)

    Whitaker, M.P.L.

    1993-01-01

    The US DOE's Office of Civilian Radioactive Waste Management (DOE-OCRWM) Fellowship Program supports various disciplines of academic research related to the isolation of radionuclides from the biosphere. The purpose of this paper is to provide an example of a university research application in the specific discipline of hydrology and water resources (a multi-disciplinary field encompassing engineering and the earth sciences), and to discuss how this research pertains to the objectives of the DOE-OCRWM Fellowship Program. The university research application is twofold: One portion focuses on the spatial variability of soil moisture (θ) and the other section compares point measurements with small watershed estimates of hydraulic conductivity (K) in a semi-arid rangeland soil in Arizona. For soil moisture measurements collected over a range of horizontal sampling intervals, no spatial correlation was evident. This outcome is reassuring to computer modelers who have assumed no spatial correlation for soil moisture over smaller scales. In regard to hydraulic conductivity, point measurements differed significantly from small watershed estimates of hydraulic conductivity which were derived from a calibrated and verified rainfall-runoff computer model. The estimates of saturated hydraulic conductivity (Ks) were obtained from previous computer simulations in which measured data was collected in the same research location as the present study

  15. AERO: A Decision Support Tool for Wind Erosion Assessment in Rangelands and Croplands

    Science.gov (United States)

    Galloza, M.; Webb, N.; Herrick, J.

    2015-12-01

    Wind erosion is a key driver of global land degradation, with on- and off-site impacts on agricultural production, air quality, ecosystem services and climate. Measuring rates of wind erosion and dust emission across land use and land cover types is important for quantifying the impacts and identifying and testing practical management options. This process can be assisted by the application of predictive models, which can be a powerful tool for land management agencies. The Aeolian EROsion (AERO) model, a wind erosion and dust emission model interface provides access by non-expert land managers to a sophisticated wind erosion decision-support tool. AERO incorporates land surface processes and sediment transport equations from existing wind erosion models and was designed for application with available national long-term monitoring datasets (e.g. USDI BLM Assessment, Inventory and Monitoring, USDA NRCS Natural Resources Inventory) and monitoring protocols. Ongoing AERO model calibration and validation are supported by geographically diverse data on wind erosion rates and land surface conditions collected by the new National Wind Erosion Research Network. Here we present the new AERO interface, describe parameterization of the underpinning wind erosion model, and provide a summary of the model applications across agricultural lands and rangelands in the United States.

  16. IDESSA: An Integrative Decision Support System for Sustainable Rangeland Management in Southern African Savannas

    Science.gov (United States)

    Meyer, Hanna; Authmann, Christian; Dreber, Niels; Hess, Bastian; Kellner, Klaus; Morgenthal, Theunis; Nauss, Thomas; Seeger, Bernhard; Tsvuura, Zivanai; Wiegand, Kerstin

    2017-04-01

    Bush encroachment is a syndrome of land degradation that occurs in many savannas including those of southern Africa. The increase in density, cover or biomass of woody vegetation often has negative effects on a range of ecosystem functions and services, which are hardly reversible. However, despite its importance, neither the causes of bush encroachment, nor the consequences of different resource management strategies to combat or mitigate related shifts in savanna states are fully understood. The project "IDESSA" (An Integrative Decision Support System for Sustainable Rangeland Management in Southern African Savannas) aims to improve the understanding of the complex interplays between land use, climate patterns and vegetation dynamics and to implement an integrative monitoring and decision-support system for the sustainable management of different savanna types. For this purpose, IDESSA follows an innovative approach that integrates local knowledge, botanical surveys, remote-sensing and machine-learning based time-series of atmospheric and land-cover dynamics, spatially explicit simulation modeling and analytical database management. The integration of the heterogeneous data will be implemented in a user oriented database infrastructure and scientific workflow system. Accessible via web-based interfaces, this database and analysis system will allow scientists to manage and analyze monitoring data and scenario computations, as well as allow stakeholders (e. g. land users, policy makers) to retrieve current ecosystem information and seasonal outlooks. We present the concept of the project and show preliminary results of the realization steps towards the integrative savanna management and decision-support system.

  17. Remote sensing data in Rangeland assessment and monitoring

    International Nuclear Information System (INIS)

    Hamid, Amna Ahmed; Ali, Mohamed M.

    1999-01-01

    The main objective of the paper is to illustrate the potential of remote sensing data in the study and monitoring of environmental changes in western Sudan where considerable part of the area is under rangeland use. Data from NOAA satellite AVHRR sensor as well as thematic mapper Tm was used to assess the environment of the area during 1982-1997. The AVHRR data was processed into vegetation index (NDVI) images. Image analysis and classification was done using image display and analysis (IDA) GIS method to study vegetation condition in time series. The obtained information from field observations. The result showed high correlation between the information the work concluded the followings: NDVI images and thematic mapper data proved to be efficient in environment change analysis. NOAA AVHRR satellite data can provide an early-warning indicator of an approaching disaster. Remote sensing integrated into a GIS can contribute effectively to improve land management through better understanding of environment variability.(Author)

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

    Science.gov (United States)

    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.

  19. 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.

  20. Monitoring Forage Production of California Rangeland Using Remote Sensing Observations

    Science.gov (United States)

    Liu, H.; Jin, Y.; Dahlgren, R. A.; O'Geen, A. T.; Roche, L. M.; Smith, A. M.; Flavell, D.

    2016-12-01

    Pastures and rangeland cover more than 10 million hectares in California's coastal and inland foothill regions, providing feeds to livestock and important ecosystem services. Forage production in California has a large year-to-year variation due to large inter-annual and seasonal variabilities in precipitation and temperature. It also varies spatially due to the variability in climate and soils. Our goal is to develop a robust and cost-effective tool to map the near-real-time and historical forage productivity in California using remote sensing observations from Landsat and MODIS satellites. We used a Monteith's eco-physiological plant growth theory: the aboveground net primary production (ANPP) is determined by (i) the absorbed photosynthetically active radiation (APAR) and the (ii) light use efficiency (LUE): ANPP = APAR * LUEmax * f(T) * f(SM), where LUEmax is the maximum LUE, and f(T) and f(SM) are the temperature and soil moisture constrains on LUE. APAR was estimated with Landsat and MODIS vegetation index (VI), and LUE was calibrated with a statewide point dataset of peak forage production measurements at 75 annual rangeland sites. A non-linear optimization was performed to derive maximum LUE and the parameters for temperature and soil moisture regulation on LUE by minimizing the differences between the estimated and measured ANPP. Our results showed the satellite-derived annual forage production estimates correlated well withcontemporaneous in-situ forage measurements and captured both the spatial and temporal productivity patterns of forage productivity well. This remote sensing algorithm can be further improved as new field measurements become available. This tool will have a great importance in maintaining a sustainable range industry by providing key knowledge for ranchers and the stakeholders to make managerial decisions.

  1. Fire impact on soil-water repellency and functioning of semi-arid croplands and rangelands: Implications for prescribed burnings and wildfires

    Science.gov (United States)

    Stavi, Ilan; Barkai, Daniel; Knoll, Yaakov M.; Glion, Hiam Abu; Katra, Itzhak; Brook, Anna; Zaady, Eli

    2017-03-01

    An unintended fire outbreak during summer 2015 in the semi-arid Israeli Negev resulted in the burning of extensive croplands and rangelands. The rangelands have been managed over the long term for occasional grazing, while the croplands have been utilized for rainfed wheat cropping. Yet, during the studied year, the croplands were left fallow, allowing the growth of herbaceous vegetation, which was harvested and baled for hay before the fire outbreak. The study objectives were to investigate the impacts of fire, land-use, and soil depth on water-repellency and on the status and dynamics of some of the most important organic and mineral soil resources. Additionally, we aimed to assess the severity of this fire outbreak. The soil-water repellency was studied by measuring the soil's water drop penetration time (WDPT) and critical surface tension (CST). A significant effect of fire on soil hydrophobicity was recorded, with a slight increase in mean WDPT and a slight decrease in mean CST in the burnt sites than in the non-burnt sites. Yet, soil hydrophobicity in the burnt lands was rather moderate and remained within the water repellency's lowest class. A significant effect of land-use on the means of WDPT and CST was also recorded, being eleven-fold greater and 7% smaller, respectively, in the rangelands than in the croplands. This is consistent with the almost eightfold greater mean above-ground biomass recorded in the non-burnt rangelands than in the non-burnt post-harvest croplands, revealing the positive relations between available fuel load and soil-water repellency. The effect of soil depth was significant for CST but not for WDPT. Overall, the gathered data suggest that fire severity was low to moderate. Fire was also found to significantly affect the fire severity only slightly increased the soil water repellency, and at the same time, increased on-site availability of some important soil resources. Nevertheless, it is acknowledged that such fires could impose

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

    Directory of Open Access Journals (Sweden)

    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.

  4. Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers.

    Science.gov (United States)

    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.

  5. 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

  6. Introduced and invasive species in novel rangeland ecosystems: friends or foes?

    Science.gov (United States)

    Belnap, Jayne; Ludwig, John A.; Wilcox, Bradford P.; Betancourt, Julio L.; Dean, W. Richard J.; Hoffmann, Benjamin D.; Milton, Sue J.

    2012-01-01

    Globally, new combinations of introduced and native plant and animal species have changed rangelands into novel ecosystems. Whereas many rangeland stakeholders (people who use or have an interest in rangelands) view intentional species introductions to improve forage and control erosion as beneficial, others focus on unintended costs, such as increased fire risk, loss of rangeland biodiversity, and threats to conservation efforts, specifically in nature reserves and parks. These conflicting views challenge all rangeland stakeholders, especially those making decisions on how best to manage novel ecosystems. To formulate a conceptual framework for decision making, we examined a wide range of novel ecosystems, created by intentional and unintentional introductions of nonnative species and land-use–facilitated spread of native ones. This framework simply divides decision making into two types: 1) straightforward–certain, and 2) complex–uncertain. We argue that management decisions to retain novel ecosystems are certain when goods and services provided by the system far outweigh the costs of restoration, for example in the case of intensively managed Cenchrus pastures. Decisions to return novel ecosystems to natural systems are also certain when the value of the system is low and restoration is easy and inexpensive as in the case of biocontrol of Opuntia infestations. In contrast, decisions whether to retain or restore novel ecosystems become complex and uncertain in cases where benefits are low and costs of control are high as, for example, in the case of stopping the expansion of Prosopis and Juniperus into semiarid rangelands. Decisions to retain or restore novel ecosystems are also complex and uncertain when, for example, nonnative Eucalyptus trees expand along natural streams, negatively affecting biodiversity, but also providing timber and honey. When decision making is complex and uncertain, we suggest that rangeland managers utilize cost–benefit analyses

  7. Genetic diversity of worldwide Jerusalem artichoke (Helianthus tuberosus) germplasm as revealed by RAPD markers.

    Science.gov (United States)

    Wangsomnuk, P P; Khampa, S; Wangsomnuk, P; Jogloy, S; Mornkham, T; Ruttawat, B; Patanothai, A; Fu, Y B

    2011-12-12

    Jerusalem artichoke (Helianthus tuberosus) is a wild relative of the cultivated sunflower (H. annuus); it is an old tuber crop that has recently received renewed interest. We used RAPD markers to characterize 147 Jerusalem artichoke accessions from nine countries. Thirty RAPD primers were screened; 13 of them detected 357 reproducible RAPD bands, of which 337 were polymorphic. Various diversity analyses revealed several different patterns of RAPD variation. More than 93% of the RAPD variation was found within accessions of a country. Weak genetic differentiation was observed between wild and cultivated accessions. Six groups were detected in this germplasm set. Four ancestral groups were found for the Canadian germplasm. The most genetically distinct accessions were identified. These findings provide useful diversity information for understanding the Jerusalem artichoke gene pool, for conserving Jerusalem artichoke germplasm, and for choosing germplasm for genetic improvement.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  10. 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.

  11. Seasonal food habits of swift fox (Vulpes velox) in cropland and rangeland landscapes in western Kansas

    Science.gov (United States)

    Sovada, M.A.; Roy, C.C.; Telesco, D.J.

    2001-01-01

    Food habits of swift foxes (Vulpes velox) occupying two distinct landscapes (dominated by cropland versus rangeland) in western Kansas were determined by analysis of scats collected in 1993 and 1996. Frequencies of occurrence of prey items in scats were compared between cropland and rangeland areas by season. Overall, the most frequently occurring foods of swift foxes were mammals (92% of all scats) and arthropods (87%), followed by birds (24%), carrion (23%), plants (15%) and reptiles (4%). No differences were detected between landscapes for occurrence of mammals, arthropods or carrion in any season (P ≥ 0.100). Plants, specifically commercial sunflower seeds, were consumed more frequently in cropland than in rangeland in spring (P = 0.004) and fall (P = 0.001). Birds were more common in the swift fox diet in cropland than in rangeland during the fall (P = 0.008), whereas reptiles occurred more frequently in the diet in rangeland than in cropland during spring (P = 0.042). Variation in the diet of the swift fox between areas was most likely due to its opportunistic foraging behavior, resulting in a diet that closely links prey use with availability.

  12. Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems.

    Science.gov (United States)

    Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

    2015-03-15

    This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Scale effects on runoff and soil erosion in rangelands: observations and estimations with predictors of different availability

    Science.gov (United States)

    Runoff and erosion estimates are needed for rangeland management decisions and evaluation of ecosystem services derived from rangeland conservation practices. The information on the effect of scale on the runoff and erosion, and on the choice of runoff and erosion predictors, remains scarce. The obj...

  14. Multi-agency Oregon Pilot: Working towards a national inventory and assessment of rangelands using onsite data

    Science.gov (United States)

    Paul L. Patterson; James Alegria; Leonard Jolley; Doug Powell; J. Jeffery Goebel; Gregg M. Riegel; Kurt H. Riitters; Craig. Ducey

    2014-01-01

    Rangelands are lands dominated by grasses, forbs, and shrubs and are managed as a natural ecosystem. Although these lands comprise approximately 40 percent of the landmass of the continental United States, there is no coordinated effort designed to inventory, monitor, or assess rangeland conditions at the national scale. A pilot project in central Oregon with the U.S....

  15. State and transition models: Theory, applications, and challenges. In: Briske, D.D. Rangeland Systems: Processes, Management and Challenges

    Science.gov (United States)

    State and transition models (STMs) are used for communicating about ecosystem change in rangelands and other ecosystems, especially the implications for management. The fundamental premise that rangelands can exhibit multiple states is now widely accepted. The current application of STMs for managem...

  16. Fish and other aquatic resource trends in the United States: a technical document supporting the Forest Service 2010 RPA Assessment

    Science.gov (United States)

    Andrew J. Loftus; Curtis H. Flather

    2012-01-01

    The Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974 requires periodic assessments of the status and trends in the Nation's renewable natural resources including fish and other aquatic species and their habitats. Data from a number of sources are used to document trends in habitat quality, populations, resource use, and patterns of imperilment...

  17. Prescribed Fire Effects on Runoff, Erosion, and Soil Water Repellency on Steeply-Sloped Sagebrush Rangeland over a Five Year Period

    Science.gov (United States)

    Williams, C. J.; Pierson, F. B.; Al-Hamdan, O. Z.

    2014-12-01

    Fire is an inherent component of sagebrush steppe rangelands in western North America and can dramatically affect runoff and erosion processes. Post-fire flooding and erosion events pose substantial threats to proximal resources, property, and human life. Yet, prescribed fire can serve as a tool to manage vegetation and fuels on sagebrush rangelands and to reduce the potential for large catastrophic fires and mass erosion events. The impact of burning on event hydrologic and erosion responses is strongly related to the degree to which burning alters vegetation, ground cover, and surface soils and the intensity and duration of precipitation. Fire impacts on hydrologic and erosion response may be intensified or reduced by inherent site characteristics such as topography and soil properties. Parameterization of these diverse conditions in predictive tools is often limited by a lack of data and/or understanding for the domain of interest. Furthermore, hydrologic and erosion functioning change as vegetation and ground cover recover in the years following burning and few studies track these changes over time. In this study, we evaluated the impacts of prescribed fire on vegetation, ground cover, soil water repellency, and hydrologic and erosion responses 1, 2, and 5 yr following burning of a mountain big sagebrush community on steep hillslopes with fine-textured soils. The study site is within the Reynolds Creek Experimental Watershed, southwestern Idaho, USA. Vegetation, ground cover, and soil properties were measured over plot scales of 0.5 m2 to 9 m2. Rainfall simulations (0.5 m2) were used to assess the impacts of fire on soil water repellency, infiltration, runoff generation, and splash-sheet erosion. Overland flow experiments (9 m2) were used to assess the effects of fire-reduced ground cover on concentrated-flow runoff and erosion processes. The study results provide insight regarding fire impacts on runoff, erosion, and soil water repellency in the immediate and

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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...

  20. Survey of Beaver-related Restoration Practices in Rangeland Streams of the Western USA

    Science.gov (United States)

    Pilliod, David S.; Rohde, Ashley T.; Charnley, Susan; Davee, Rachael R.; Dunham, Jason B.; Gosnell, Hannah; Grant, Gordon E.; Hausner, Mark B.; Huntington, Justin L.; Nash, Caroline

    2018-01-01

    Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the effects of beaver dams are restoration alternatives that have recently gained popularity because of their potential socioeconomic and ecological benefits. However, beaver dams and dam-like structures also harbor a history of social conflict. Hence, we identified a need to assess the use of beaver-related restoration projects in western rangelands to increase awareness and accountability, and identify gaps in scientific knowledge. We inventoried 97 projects implemented by 32 organizations, most in the last 10 years. We found that beaver-related stream restoration projects undertaken mostly involved the relocation of nuisance beavers. The most common goal was to store water, either with beaver dams or artificial structures. Beavers were often moved without regard to genetics, disease, or potential conflicts with nearby landowners. Few projects included post-implementation monitoring or planned for longer term issues, such as what happens when beavers abandon a site or when beaver dams or structures breach. Human dimensions were rarely considered and water rights and other issues were mostly unresolved or addressed through ad-hoc agreements. We conclude that the practice and implementation of beaver-related restoration has outpaced research on its efficacy and best practices. Further scientific research is necessary, especially research that informs the establishment of clear guidelines for best practices.

  1. Survey of beaver-related restoration practices in rangeland streams of the western USA

    Science.gov (United States)

    Pilliod, David S.; Rohde, Ashley T.; Charnley, Susan; Davee, Rachael R; Dunham, Jason B.; Gosnell, Hannah; Grant, Gordon E.; Hausner, Mark B.; Huntington, Justin L.; Nash, Caroline

    2018-01-01

    Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the effects of beaver dams are restoration alternatives that have recently gained popularity because of their potential socioeconomic and ecological benefits. However, beaver dams and dam-like structures also harbor a history of social conflict. Hence, we identified a need to assess the use of beaver-related restoration projects in western rangelands to increase awareness and accountability, and identify gaps in scientific knowledge. We inventoried 97 projects implemented by 32 organizations, most in the last 10 years. We found that beaver-related stream restoration projects undertaken mostly involved the relocation of nuisance beavers. The most common goal was to store water, either with beaver dams or artificial structures. Beavers were often moved without regard to genetics, disease, or potential conflicts with nearby landowners. Few projects included post-implementation monitoring or planned for longer term issues, such as what happens when beavers abandon a site or when beaver dams or structures breach. Human dimensions were rarely considered and water rights and other issues were mostly unresolved or addressed through ad-hoc agreements. We conclude that the practice and implementation of beaver-related restoration has outpaced research on its efficacy and best practices. Further scientific research is necessary, especially research that informs the establishment of clear guidelines for best practices.

  2. Decision Making in Rangelands: An Integrated Modeling Approach to Resilience and Change

    Science.gov (United States)

    Galvin, K. A.; Ojima, D. S.; Boone, R. B.

    2007-12-01

    Rangelands comprise approximately 25% of the earth's surface and these landscapes support more than 20 million people and most of the world's charismatic megafauna. Most of the people who live in these regions of the world herd domestic livestock and some do limited cultivation so they are dependent directly on the environment for their livelihoods. But change is rapidly changing the environments upon which these people depend through such factors as population pressures, land use and land tenure changes, climate variability, and policy changes which fragment their resources and thus their ability to earn a living. How can we understand change in this linked human-environment system? The study of complex biophysical and human systems can be greatly assisted by appropriate simulation models that integrate what is known about ecological and human decision-making processes. We have developed an integrated modeling system for Kajiado, Kenya where land use management decisions have implications for economics and the ecosystem. In this paper we look at how land use decisions, that is, livestock movement patterns have implications for societal economics and ecosystem services. Research that focuses on local behavior is important because it is at that level where fundamental decisions are made regarding events like extreme climate and changes such as land tenure policy and it is here where resilience is manifested. The notion that broad recommendation domains can be identified for a broad set of people and large regions coping with change is becoming increasingly hard to trust given the spatial and temporal heterogeneity of the systems we are looking at, and the complexity of the world we now live in. Why is this important? The only way the research community is going to make great progress in attaining objectives that do confer resilience (on social and ecological systems) is through much better targeting ability, a large part of which seem to be intimately entwined with

  3. Spatially explicit rangeland erosion monitoring using high-resolution digital aerial imagery

    Science.gov (United States)

    Gillan, Jeffrey K.; Karl, Jason W.; Barger, Nichole N.; Elaksher, Ahmed; Duniway, Michael C.

    2016-01-01

    Nearly all of the ecosystem services supported by rangelands, including production of livestock forage, carbon sequestration, and provisioning of clean water, are negatively impacted by soil erosion. Accordingly, monitoring the severity, spatial extent, and rate of soil erosion is essential for long-term sustainable management. Traditional field-based methods of monitoring erosion (sediment traps, erosion pins, and bridges) can be labor intensive and therefore are generally limited in spatial intensity and/or extent. There is a growing effort to monitor natural resources at broad scales, which is driving the need for new soil erosion monitoring tools. One remote-sensing technique that can be used to monitor soil movement is a time series of digital elevation models (DEMs) created using aerial photogrammetry methods. By geographically coregistering the DEMs and subtracting one surface from the other, an estimate of soil elevation change can be created. Such analysis enables spatially explicit quantification and visualization of net soil movement including erosion, deposition, and redistribution. We constructed DEMs (12-cm ground sampling distance) on the basis of aerial photography immediately before and 1 year after a vegetation removal treatment on a 31-ha Piñon-Juniper woodland in southeastern Utah to evaluate the use of aerial photography in detecting soil surface change. On average, we were able to detect surface elevation change of ± 8−9cm and greater, which was sufficient for the large amount of soil movement exhibited on the study area. Detecting more subtle soil erosion could be achieved using the same technique with higher-resolution imagery from lower-flying aircraft such as unmanned aerial vehicles. DEM differencing and process-focused field methods provided complementary information and a more complete assessment of soil loss and movement than any single technique alone. Photogrammetric DEM differencing could be used as a technique to

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Drought Stress Responses of Sunflower Germplasm Developed after Wide Hybridization

    Directory of Open Access Journals (Sweden)

    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.

  10. 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

  11. Evaluating new SMAP soil moisture for drought monitoring in the rangelands of the US High Plains

    Science.gov (United States)

    Velpuri, Naga Manohar; Senay, Gabriel B.; Morisette, Jeffrey T.

    2016-01-01

    Level 3 soil moisture datasets from the recently launched Soil Moisture Active Passive (SMAP) satellite are evaluated for drought monitoring in rangelands.Validation of SMAP soil moisture (SSM) with in situ and modeled estimates showed high level of agreement.SSM showed the highest correlation with surface soil moisture (0-5 cm) and a strong correlation to depths up to 20 cm.SSM showed a reliable and expected response of capturing seasonal dynamics in relation to precipitation, land surface temperature, and evapotranspiration.Further evaluation using multi-year SMAP datasets is necessary to quantify the full benefits and limitations for drought monitoring in rangelands.

  12. DEVELOPMENTS IN MONITORING RANGELANDS USING REMOTELY-SENSED CROSS-FENCE COMPARISONS

    Directory of Open Access Journals (Sweden)

    A. D. Kilpatrick

    2012-07-01

    Full Text Available This paper presents a new method for the use of earth-observation images to assess relative land condition over broad regions, using a cross-fence comparison methodology. It controls for natural spatial and temporal variables (e.g. rainfall, temperature soils, ecosystem so that we can objectively monitor rangelands and other areas for the effects of management. The method has been tested with small and large scale theoretical models, as well as a case study in South Australian rangelands. This method can also be applied in other systems and experiments such as field trials of crop varieties as a robust spatial statistic.

  13. Maize Genetic Resources Collections – Utilizing a Treasure Trove

    Science.gov (United States)

    The maize genetic resource collection managed by the USDA-ARS's National Plant Germplasm System is heavily utilized by researchers and educators. A collection of landraces, inbred lines from public and private sector sources, synthetics and key populations, it serves both as a living snapshot of th...

  14. Genetic diversity and a population structure analysis of accessions in the Chinese cowpea [Vigna unguiculata (L. Walp.] germplasm collection

    Directory of Open Access Journals (Sweden)

    Honglin Chen

    2017-10-01

    Full Text Available Cowpea (Vigna unguiculata is an important legume crop with diverse uses. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, a total of 200 genic and 100 genomic simple sequence repeat (SSR markers were developed from cowpea unigene and genome sequences, respectively. Among them, 27 genic and 27 genomic SSR markers were polymorphic and were used for assessment of genetic diversity and population structure in 105 selected cowpea accessions. A total of 155 alleles and 2.9 alleles per marker were identified, and the average polymorphic information content (PIC value was 0.3615. The average PIC of genomic SSRs (0.3996 was higher than that of genic SSRs (0.3235, and most of the polymorphic genomic SSRs were composed of di- and trinucleotide repeats (51.9% and 37.0% of all loci, respectively. The low level of detected genetic diversity may be attributed to a severe genetic bottleneck that occurred during the cowpea domestication process. The accessions were classified by structure and cluster analysis into four subgroups that correlated well with their geographic origins or collection sites. The classification results were also consistent with the results from principal coordinate analysis and can be used as a guide during future germplasm collection and selection of accessions as breeding materials for cultivar improvement. The newly developed genic and genomic SSR markers described in this study will be valuable genomic resources for the assessment of genetic diversity, population structure, evaluation of germplasm accessions, construction of genetic maps, identification of genes of interest, and application of marker-assisted selection in cowpea breeding programs.

  15. Evaluation of Watermelon Germplasm for Resistance to Phytophthora Blight Caused by Phytophthora capsici

    Directory of Open Access Journals (Sweden)

    Min-Jeong Kim

    2013-03-01

    Full Text Available This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension (10⁶ sporangia/ml. At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840 showed moderate resistance and two accessions (IT185446 and IT187904 were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

  16. Genetic resources of vegetable crops: a survey in the Brazilian germplasm collections pictured through papers published in the journals of the Brazilian Society for Horticultural Science Recursos genéticos de hortaliças: as atividades nas coleções brasileiras de germoplasma retratadas nas publicações da Associação Brasileira de Horticultura

    Directory of Open Access Journals (Sweden)

    Cláudia P Sudré

    2007-12-01

    Full Text Available The research on plant genetic resources is essential for the conservation of genetic diversity and accessions' divergence studies, as a basis for plant breeding. Aiming to know the state of art in this subject, a historical survey was carried out in Revista de Olericultura and in Horticultura Brasileira, from 1961 to 2006, searching for papers dealing with vegetable crops genetic resources. In each of the papers, the species studied, first author institution, publication year, applied software, number of accessions and descriptors, and the multivariate techniques used were registered. Based on these characteristics, papers were grouped using multivariate analysis. Sixty-one papers dealt somehow with genetic resources in the time covered by the survey, from which 91.8% were published after 1990 (60.7% from 2001 to 2005. The use of multivariate analysis was reported in 57.3% of the papers, with an average of 2.3 and maximum of 6 multivariate procedures per paper. The Tocher Method, reported in 34% of the papers, was the most frequently used multivariate analysis. Twenty-five species were studied. Capsicum was the most frequently studied genus, either considering number of papers (seven or accessions (664. Research institutions located in the Southeast region concentrated the highest number of papers. UFV (Federal University of Viçosa, UENF (North Fluminense State University Darcy Ribeiro, Embrapa Vegetables, and UNESP (São Paulo State University Campus of Jaboticabal responded for 45% of the papers. There was an improvement in the adequacy of the statistical techniques used along time, due mainly to the development of free-access software. The software Genes was the most frequently reported in the papers surveyed. Nevertheless, almost 50% of the authors did not mention the software used for data analysis. Quantitative morphoagronomic and evaluation descriptors were the most often used. The multivariate analysis allowed grouping the papers in

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 75 FR 33239 - Rangeland Allotment Management Planning on the Fall River West and Oglala Geographic Areas, Fall...

    Science.gov (United States)

    2010-06-11

    ...The USDA, Forest Service, will prepare an environmental impact statement (EIS) analyzing the management of rangeland vegetation resources, which includes livestock grazing, on the National Forest System (NFS) lands within the Oglala Geographic Area (OGA) of the Oglala National Grassland on the Pine Ridge Ranger District and the West Geographic Area (WGA) of the Buffalo Gap National Grassland on the Fall River Ranger District of the Nebraska National Forest (Analysis Area) areas as mapped by the 2001 Nebraska National Forest Revised Land and Resource Management Plan (Forest Plan). A Notice of Intent (NOI) for this project was published February 22, 2008 (73 No. 36 FR 9760- 9762). More than six months have elapsed since the projected draft environmental impact statement (DEIS) date in that original NOI. This revised NOI is being issued to update the project schedule. There will be a record of decision (ROD) for each geographic area. Proposed management actions would be implemented beginning in the year 2012. The agency gives notice of the full environmental analysis and decision-making process that will occur on the proposal so interested and affected people may become aware of how they may participate in the process and contribute to the final decision.

  19. Multivariate analysis of quantitative traits can effectively classify rapeseed germplasm

    Directory of Open Access Journals (Sweden)

    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

  20. 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)

  1. 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

  2. Development of Pineapple Microsatellite Markers and Germplasm Genetic Diversity Analysis

    Directory of Open Access Journals (Sweden)

    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.

  3. 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

  4. Association Mapping for Fusarium Wilt Resistance in Chinese Asparagus Bean Germplasm

    Directory of Open Access Journals (Sweden)

    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.

  5. Basin wildrye (Leymus cinereus) pooled tetraploid accessions for U.S. Intermountain rangeland reclamation

    Science.gov (United States)

    Stanford A. Young; Jason Vernon; Nancy Shaw

    2013-01-01

    Basin wildrye (Leymus cinereus [Scribn. & Merr.] A. Love) is an important perennial, hardy, long-lived, cool season C3 native grass of rangeland plant communities throughout much of western United States and Canada. All classes of livestock and wildlife, including large and small birds and mammals, utilise the grass year round for food and protection due to its 2-3...

  6. Analytical approaches to quality assurance and quality control in rangeland monitoring data

    Science.gov (United States)

    Producing quality data to support land management decisions is the goal of every rangeland monitoring program. However, the results of quality assurance (QA) and quality control (QC) efforts to improve data quality are rarely reported. The purpose of QA and QC is to prevent and describe non-sampling...

  7. Dairy cattle on Norwegian alpine rangelands – grazing preferences and milk quality

    NARCIS (Netherlands)

    Sickel, H; Abrahamsen, R K; Eldegard, K; Lunnan, T; Norderhaug, A; Petersen, M.A.; Sickel, M.; Steenhuisen, F.; Ohlson, M.

    2014-01-01

    The results from the study ‘Effects of vegetation and grazing preferences on the quality of alpine dairy products’ will be presented. The main objective of the project was to investigate the connections bet - ween alpine rangeland vegetation, landscape use and grazing preferences of free ranging

  8. Vulnerability of cattle production to climate change on U.S. rangelands

    Science.gov (United States)

    Matt C. Reeves; Karen E. Bagne

    2016-01-01

    We examined multiple climate change effects on cattle production for U.S. rangelands to estimate relative change and identify sources of vulnerability among seven regions. Climate change effects to 2100 were projected from published models for four elements: forage quantity, vegetation type trajectory, heat stress, and forage variability. Departure of projections from...

  9. Assessing Rangeland Attributes On Semi-Arid Zone Of North Darfur State Sudan

    Directory of Open Access Journals (Sweden)

    Mohamed Almontasir A. M. Mohamed

    2015-08-01

    Full Text Available Abstract The study was conducted over a two years period of 2012 and 2013 at three sites of Alfashir locality Ummarahik 25km north of Alfashir Fashar in eastern part of Alfashir about 5km and Berka 30km west of Alfashir Western Sudan in semi-arid zone. The aim of this study was to assess rangeland attributes. Measurements of plant density vegetation cover range production and carrying capacity were assessed. Results showed that total forage production was low and inadequate to satisfy requirements of livestock for inhabiting the area average range production all over the area was found to be 50.68 kgha and 59.21 kgha for the seasons 2012 and 2013 respectively. The average ground cover was about 34.71 and 42.41 for two seasons. The average plant density for the first season was 27.1 plantm2 while the average plant density for the second season was 29.4 plantm2. The study concluded that unwise utilization and exploitation of the rangelands particularly by man causes range deterioration and serious reduction in range production in both quantity and quality so the study suggested that improvement and rehabilitation such lands rangelands should be done. Further research work is needed to assess rangeland attributes across different ecological zones in North Darfur State.

  10. Rangelands Vegetation under Different Management Systems and Growth Stages in North Darfur State, Sudan (Range Attributes

    Directory of Open Access Journals (Sweden)

    Mohamed AAMA Mohamed

    2014-09-01

    Full Text Available This study was conducted at Um Kaddada, North Darfur State, Sudan, at two sites (closed and open for two consecutive seasons 2008 and 2009 during flowering and seed setting stages to evaluate range attributes at the locality. A split plot design was used to study vegetation attributes. Factors studied were management systems (closed and open and growth stages (flowering and seed setting. Vegetation cover, plant density, carrying capacity, and biomass production were assessed. Chemical analyses were done for selected plants to determine their nutritive values. The results showed high significant differences in vegetation attributes (density, cover and biomass production between closed and open areas. Closed areas had higher carrying capacity compared to open rangelands. Crude protein (CP and ash contents of range vegetation were found to decrease while Crude fiber (CF and Dry matter yield (DM had increased with growth. The study concluded that closed rangelands are better than open rangelands because it fenced and protected. Erosion index and vegetation degradation rate were very high. Future research work is needed to assess rangelands characteristics and habitat condition across different ecological zones in North Darfur State, Sudan.DOI: http://dx.doi.org/10.3126/ije.v3i3.11093 International Journal of Environment Vol.3(3 2014: 332-343

  11. Rangeland livestock production: Developing the concept of sustainability on the Santa Rita Experimental Range

    Science.gov (United States)

    George B. Ruyle

    2003-01-01

    The Santa Rita Experimental Range (SRER) was established in 1903 at the behest of concerned stockmen and researchers as the first facility in the United States set aside to study range livestock production. At the time, severe overgrazing of the public domain had seriously reduced carrying capacities of Southwestern rangelands. Researchers on the SRER developed and...

  12. Estimating climate change effects on net primary production of rangelands in the United States

    Science.gov (United States)

    Matthew C. Reeves; Adam L. Moreno; Karen E. Bagne; Steven W. Running

    2014-01-01

    The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen...

  13. Composted manure application promotes long-term invasion of semi-arid rangeland by Bromus tectorum

    Science.gov (United States)

    Composted organic matter derived from sewage treatment facilities or livestock manure from feedlots is often applied to rangelands of western North America to increase soil fertility, forage production, forage quality, and soil carbon (C) storage. This practice can have a number of undesirable side ...

  14. Weight gain and behavior of Raramuri Criollo versus Corriente steers developed on Chihuahuan Desert rangeland

    Science.gov (United States)

    Ranchers that raise Criollo cattle must overcome the challenge of lack of markets for weaned calves. Raramuri Criollo (RC) steers are commonly raised for beef and finished on rangelands, while Corriente (CR) are often raised for rodeo sports. No data exist on weight gains and grazing behavior of ran...

  15. Movement and spatial proximity patterns of rangeland-raised Raramuri Criollo cow-calf pairs

    Science.gov (United States)

    The objective of this study was to compare movement patterns of nursing vs. nonnursing mature cows and to characterize cow-calf proximity patterns in two herds of Raramuri Criollo cattle. Herds grazed rangeland pastures in southern New Mexico (4355 ha) and west-central Chihuahua, Mexico (633 ha)'' A...

  16. Mother-Offspring Interactions in Raramuri Criollo Cattle on New Mexico and Chihuahua (Mexico) Rangelands

    Science.gov (United States)

    Rangeland beef cows spend approximately six months of a typical year raising their calf. This endeavor is known to significantly alter a dam’s grazing behavior and spatial distribution patterns. The objective of this study was to characterize cow-calf contact events in two herds of Raramuri Criollo ...

  17. Weight gain and behavior of Raramuri Criollo versus crossbred steers developed on Chihuahuan Desert rangeland

    Science.gov (United States)

    Ranchers that raise Raramuri Criollo (RC) cattle must overcome the challenge of lack of markets for weaned calves. Growing and finishing RC or RC-crossbred steers on rangeland pastures is increasingly common; however, no data exist on their weight gains or grazing behavior. We tracked the weight a...

  18. Influence of forest and rangeland management on anadromous fish habitat in Western North America: economic considerations.

    Science.gov (United States)

    William R. tech. ed. Meehan

    1985-01-01

    Although many effects of forest and rangeland management on anadromous fisheries are difficult to measure, economic methods for the evaluation of costs and benefits can be helpful. Such methods can be used to address questions of equity as well as efficiency. Evaluations of equity can show who bears the costs and who captures the benefits of management actions, but...

  19. Salinity mobilization and transport from rangelands: assessment, recommendations, and knowledge gaps

    Science.gov (United States)

    The purpose of the salinity project is to improve the understanding of sources and transport mechanisms in rangeland catchments that deliver dissolved solids (salts) to streams within the Upper Colorado River Basin (UCRB) through a review of relevant literature on what is known about the impact of r...

  20. The Role of Rangelands in Diversified Farming Systems: Innovations, Obstacles, and Opportunities in the USA

    Directory of Open Access Journals (Sweden)

    Nathan F. Sayre

    2012-12-01

    Full Text Available Discussions of diversified farming systems (DFS rarely mention rangelands: the grasslands, shrublands, and savannas that make up roughly one-third of Earth's ice-free terrestrial area, including some 312 million ha of the United States. Although ranching has been criticized by environmentalists for decades, it is probably the most ecologically sustainable segment of the U.S. meat industry, and it exemplifies many of the defining characteristics of DFS: it relies on the functional diversity of natural ecological processes of plant and animal (reproduction at multiple scales, based on ecosystem services generated and regenerated on site rather than imported, often nonrenewable, inputs. Rangelands also provide other ecosystem services, including watershed, wildlife habitat, recreation, and tourism. Even where non-native or invasive plants have encroached on or replaced native species, rangelands retain unusually high levels of plant diversity compared with croplands or plantation forests. Innovations in management, marketing, incentives, and easement programs that augment ranch income, creative land tenure arrangements, and collaborations among ranchers all support diversification. Some obstacles include rapid landownership turnover, lack of accessible U.S. Department of Agriculture certified processing facilities, tenure uncertainty, fragmentation of rangelands, and low and variable income, especially relative to land costs. Taking advantage of rancher knowledge and stewardship, and aligning incentives with production of diverse goods and services, will support the sustainability of ranching and its associated public benefits. The creation of positive feedbacks between economic and ecological diversity should be the ultimate goal.

  1. Grazing management, resilience and the dynamics of a fire driven rangeland system

    NARCIS (Netherlands)

    Anderies, J.M.; Janssen, M.A.; Walker, B.H.

    2002-01-01

    We developed a stylized mathematical model to explore the effects of physical, ecological, and economic factors on the resilience of a managed fire-driven rangeland system. Depending on grazing pressure, the model exhibits one of three distinct configurations: a fire-dominated, grazing-dominated, or

  2. Towards a remote sensing based indicator of rangeland ecosystem resistance and resilience

    Science.gov (United States)

    Understanding ecosystem resistance and resilience to disturbance and invasive species is critical to the sustainable management of rangeland systems. In this context, resistance refers to the inherent ability of an ecosystem to resist disturbance, while resilience refers to the capacity of an ecosys...

  3. Comparative Assessment of Goods and Services Provided by Grazing Regulation and Reforestation in Degraded Mediterranean Rangelands

    NARCIS (Netherlands)

    Papanastasis, Vasilios P.; Bautista, Susana; Chouvardas, Dimitrios; Mantzanas, Konstantinos; Papadimitriou, Maria; Garcia Mayor, Angeles; Koukioumi, Polina; Papaioannou, Athanasios; Vallejo, Ramon V.

    2017-01-01

    Several management actions are applied to restore ecosystem services in degraded Mediterranean rangelands, which range from adjusting the grazing pressure to the removal of grazers and pine plantations. Four such actions were assessed in Quercus coccifera L. shrublands in northern Greece: (i)

  4. Revolutionary land use change in the 21st century: Is (rangeland) science relevant?

    Science.gov (United States)

    Rapidly increasing demand for food, fiber and fuel together with new technologies and the mobility of global capital are driving revolutionary changes in land use throughout the world. Efforts to increase land productivity include conversion of millions of hectares of rangelands to crop production, ...

  5. Searls prairie clover (Dalea searlsiae) for rangeland revegetation: Phenotypic and genetic evaluations

    Science.gov (United States)

    Kishor Bhattarai; Shaun Bushman; Douglas A. Johnson; John G. Carman

    2011-01-01

    Few North American legumes are available for use in rangeland revegetation in the western USA, but Searls prairie clover [Dalea searlsiae (A. Gray) Barneby] is one that holds promise. Commercial-scale seed production of this species could address the issues of unreliable seed availability and high seed costs associated with its wildland seed collection. To evaluate its...

  6. Ecosystem water availability in juniper versus sagebrush snow-dominated rangelands

    Science.gov (United States)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  7. Climate-change adaptation on rangelands: Linking regional exposure with diverse adaptive capacity

    Science.gov (United States)

    David D. Briske; Linda A. Joyce; H. Wayne Polley; Joel R. Brown; Klaus Wolter; Jack A. Morgan; Bruce A. McCarl; Derek W. Bailey

    2015-01-01

    The ecological consequences of climate change are predicted to vary greatly throughout US rangelands. Projections show warming and drying in the southern Great Plains and the Southwest, warmer and drier summers with reduced winter snowpack in the Northwest, and warmer and wetter conditions in the northern Great Plains. Primarily through their combined effects on soil...

  8. Deforestation of "degraded" rangelands: The Argentine Chaco enters the next stage of the Anthropocene

    Science.gov (United States)

    Twenty years ago I completed my Master’s work in the Chaco forests of northern Argentina. The native forests are, in fact, rangelands. In addition to livestock grazing, there is timber extraction, wildlife harvest (think tegu lizard cowboy boots), and charcoal production. I took part in a project co...

  9. Mapping Erosion and Salinity Risk Categories Using GIS and the Rangeland Hydrology Erosion Model

    Science.gov (United States)

    Up to fifteen percent of rangelands in the state of Utah in the United States are classified as being in severely eroding condition. Some of these degraded lands are located on saline, erodible soils of the Mancos Shale formation. This results in a disproportionate contribution of sediment, salinity...

  10. Temperament affects rangeland use patterns and reproductive performance of beef cows

    Science.gov (United States)

    • The American beef industry is paying more attention to cattle temperament, but studies examining relationships between temperaments and grazing behavior or animal performance on rangelands are limited. • We studied range beef cow temperaments using the behavioral syndromes framework. Cows classifi...

  11. Applying a dryland degradation framework for rangelands: the case of Mongolia.

    Science.gov (United States)

    Jamsranjav, C; Reid, R S; Fernández-Giménez, M E; Tsevlee, A; Yadamsuren, B; Heiner, M

    2018-04-01

    Livestock-caused rangeland degradation remains a major policy concern globally and the subject of widespread scientific study. This concern persists in part because it is difficult to isolate the effects of livestock from climate and other factors that influence ecosystem conditions. Further, degradation studies seldom use multiple plant and soil indicators linked to a clear definition of and ecologically grounded framework for degradation assessment that distinguishes different levels of degradation. Here, we integrate two globally applicable rangeland degradation frameworks and apply them to a broad-scale empirical data set for the country of Mongolia. We compare our assessment results with two other recent national rangeland degradation assessments in Mongolia to gauge consistency of findings across assessments and evaluate the utility of our framework. We measured livestock-use impacts across Mongolia's major ecological zones: mountain and forest steppe, eastern steppe, steppe, and desert steppe. At 143 sites in 36 counties, we measured livestock-use and degradation indicators at increasing distances from livestock corrals in winter-grazed pastures. At each site, we measured multiple indicators linked to our degradation framework, including plant cover, standing biomass, palatability, species richness, forage quality, vegetation gaps, and soil surface characteristics. Livestock use had no effect on soils, plant species richness, or standing crop biomass in any ecological zone, but subtly affected plant cover and palatable plant abundance. Livestock effects were strongest in the steppe zone, moderate in the desert steppe, and limited in the mountain/forest and eastern steppes. Our results aligned closely with those of two other recent country-wide assessments, suggesting that our framework may have widespread application. All three assessments found that very severe and irreversible degradation is rare in Mongolia (1-18% of land area), with most rangelands

  12. Opportunities and obstacles for rangeland conservation in San Diego County, California, USA

    Directory of Open Access Journals (Sweden)

    Kathleen A. Farley

    2017-03-01

    Full Text Available Working landscapes such as rangelands are increasingly recognized as having high conservation value, providing a variety of ecosystem services, including food, fiber, habitat, recreation, open space, carbon storage, and water, in addition to a broad range of social benefits. However, conversion of rangelands to other land uses has been prevalent throughout the western United States, leading to greater attention in the conservation community to the importance of collaborating with private landowners. The level of interest in collaborative conservation among private landowners and the types of conservation programs they choose to participate in depend on the social, economic, and environmental context. We used GIS analysis and interviews with ranchers to evaluate rangeland conversion and participation in conservation programs among ranchers in San Diego County, California, USA, which is part of a biodiversity hotspot with high plant species richness and a large number of endemic and rare species. We found that > 25% of rangelands were converted to other uses, primarily urbanization, over the past 25 years while the area of public rangeland increased by 9%. Interviews revealed that ranchers in San Diego County have had limited involvement with most conservation programs, and a critical factor for nonparticipation was providing programs access to private land, along with other issues related to trust and social values. Among ranchers who had participated in conservation programs, the payment level and the agency or organization administering the program were key factors. Our results provide insight into factors influencing whether and when ranchers are likely to participate in conservation initiatives and illustrate that private and public land conservation are strongly linked and would be more effective if the two strategies were better integrated.

  13. Use of local pastoral species to increase fodder production of the saline rangelands in southern Tunisia

    Science.gov (United States)

    Tlili, Abderrazak; Tarhouni, Mohamed; Cardà, Artemi; Neffati, Mohamed

    2017-04-01

    Climate changes associated with multiple destructive human activities accelerate the degradation process of the natural rangelands around the world and especially the vulnerable areas such as the dryland ecosystems (Anaya-Romero et al., 2015; Eskandari et al., 2016; Muños Rojas et al., 2016; Vicente-Serrano et al., 2016). The vegetation cover and the biomass production of these ecosystems are decreasing and this is resulting in land degradation due to the soil erosion and changes in soil quality due to the abuse and misuse of the soil resources (Cerdà et al., 2016; Prosdocimi et al., 2016; Keesstra et al., 2016). To cope with such threats, it is necessary to develop some management techniques (restoration, plantation…) to enhance the biomass production and the carbon sequestration of the degraded rangelands (Muñoz-Rojas et al., 2016; Tarhouni et al., 2016). The valorization of saline water by planting pastoral halophyte species in salt-affected soils as well as the marginal areas are considered among the valuable tools to increase the rangeland production in dry areas. In this work, the ability of four plants (Atriplex halimus L. (Amaranthaceae), Atriplex mollis Desf. (Amaranthaceae), Lotus creticus L. (Fabaceae) and Cenchrus ciliaris L. (Poaceae)) to grow and to produce are tested under a field saline conditions (water and soil). Non-destructive method (Vegmeasure) is used to estimate the biomass production of these species. Chemical (crude protein, moisture and ash contents) and biochemical analyses (sugars, tannins and polyphenols contents) are also undertaken. Two years after plantation, the obtained results showed the ability of the four species to survive and to grow under high salinity degree. A strong positive correlation was obtained between the canopy cover and the dry biomass of the four studied species. Hence, the restoration of saline soils can be ensured by planting local halophytes. Acknowledgements. The research leading to these results has

  14. Development of the crop residue and rangeland burning in the 2014 National Emissions Inventory using information from multiple sources

    Data.gov (United States)

    U.S. Environmental Protection Agency — This workbook contains all the activity data, emission factor data, and ancillary data used to compute crop residue burning and rangeland emissions for the 2014 NEI...

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

    Directory of Open Access Journals (Sweden)

    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

  16. Grasshopper (Orthoptera: Acrididae) community composition in the rangeland of the northern slopes of The Qilian Mountains in northwestern China.

    Science.gov (United States)

    Sun, T; Liu, Z Y; Qin, L P; Long, R J

    2015-01-01

    In order to describe grasshopper (Orthoptera: Acrididae) species composition, diversity, abundance, and density of four rangelands types, we compared the grasshopper community composition and dynamics in the rangeland of the northern slopes of the Qilian Mountains. In total, 55 grasshopper species were collected from 2007 to 2009, representing three families and six subfamilies. The subfamily Oedipodinae was dominant, followed by Gomphocerinae and Catantopinae. Species abundance varied among rangeland types (RTs). The greatest abundance of grasshoppers was found in mountain rangeland, while the lowest abundance of grasshoppers was caught in alpine shrublands. Three species (Chorthippus cf. brunneus (Thunberg) (Acrididae), Chorthippus Dubius (Zubovski), and Gomphocerus licenti (Chang) were broadly distributed in the four RTs and constituted 7.5% of all grasshoppers collected. Ch. dubius was very abundant in desert rangeland and alpine shrubland. Bryodema dolichoptera Yin et Feng Eremippus qilianshanensis Lian and Zheng, and Filchnerella qilianshanensis Xi and Zheng (Pamphagidae) were endemic to the region of the Qilian Mountains. Species similarity between RTs ranged from 17.8 to 51.6 based on the Renkonen index. Similarly, the Sörensen index indicated a wide separation in species composition among RTs. The abundance of the eight most common species showed obvious differences among RTs and years. On average, mountain rangeland had the highest density values in 2007 and 2008, and alpine shrubland supported the smallest density. The densities in desert and mountain rangeland in 2007 were significantly higher than in 2008, while alpine rangeland and shrublands did not present obvious differences among years. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  17. Resources and testing of endophyte-infected germplasm in national grass repository collections

    Science.gov (United States)

    A. D. Wilson

    1996-01-01

    Clavicipitaceous endophytes have been known to exist in grasses since the discovery of an endophyte in seeds of damel (Lolium temulentum L.) by Vogl in 1898 (26). The oldest known specimens of damel with endophytic mycelium were seeds retrieved from a pharoah's tomb in an Egyptian pyramid dating back to 3400 B.C. (16). Subsequent work by...

  18. 'HoneySweet' plum - a valuable genetically engineered fruit-tree cultivar and germplasm resource

    Science.gov (United States)

    ‘HoneySweet’ is a plum variety developed through genetic engineering to be highly resistant to plum pox potyvirus (PPV), the causal agent of sharka disease, that threatens stone-fruit industries world-wide and most specifically, in Europe. Field testing for over 15 years in Europe has demonstrated ...

  19. Genetic resources in the USDA, ARS, PGRCU legume crop germplasm collections with phyto-pharmaceutical uses

    Science.gov (United States)

    Seventeen health functional legumes including butterfly pea (Clitoria ternatea L.), Indigofera cassioides Rottler ex DC., I. linnaei Ali, I. suffruticosa Mill., hyacinth bean [Lablab purpureus (L.) Sweet], velvetbean [Mucuna pruriens (L.) DC], jicama [Pachyrhizus erosus (L.) Urb.], winged bean [Psop...

  20. Cornelian Cherry Germplasm Resource and Physicochemical Characterization of Its Fruit in Iran

    Directory of Open Access Journals (Sweden)

    Hamid Hassanpour

    2017-08-01

    Full Text Available Introduction: Cornus is a very large genus which comprises 40 species of shrubs and trees native to Central and Southern Europe and parts of Western Asia. Many species are grown as ornamentals. Only a few species are grown for their fruits, chief among which is the cornelian cherry (Cornus mas L.. Study on the nutritional value of the cornelian cherry has focused on nutrients which play a role in preventing diseases such as scurvy. Fresh cornelian cherry fruits contain twice as much vitamin C as oranges. The aim of this study was to investigate the distribution and physicochemical properties of cornelian cherry (Cornus mas L. fruits in Iran. Materials and Methods: Distribution of cornelian cherry was traced on the map according to the visitation of the different provinces. In order to study the characteristics of the fruit, samples were taken from five different areas and various parameters were evaluated. Fruit and seed weight (g were measured by a digital balance with a sensitivity of 0.001 g (Scaltec Company, Gottingen, Germany; model SPB31. Fruit length (mm, fruit diameter (mm, seed diameter (mm and seed length (mm were measured using a digital vernier caliper with a sensitivity of 0.01 mm. TSS was determined by refrectometry of one drop extracted juice of each fruit at 25°C (Kyoto Electronics Manufacturing Co. Ltd., Japan, and Model RA-250HE. TA was determined by titration and the pH value was indicated by pH meter (HBJ-260. In addition, total ascorbic acid content was determined by the dinitrophenylhydrazine (DNPH method. Data were subjected to calculate of descriptive statistics by SPPSS and means were separated by Duncan’s multiple range test at p

  1. 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...

  2. 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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  7. 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

  8. Characterization of Sugar Concentration Among Edible Podded Accessions in the USDA Phaseolus vulgaris Germplasm Collection

    Science.gov (United States)

    The objective is to gain knowledge regarding variation in sugar and flavor content among a sample of dry bean and green pod-type accessions from the USDA Phaseolus Germplasm Core Collection, Pullman, WA. The results could be used to market product quality and offer unique opportunities to expand ma...

  9. 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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  14. Bird-resistant pollination bags for sorghum breeding and germplasm maintenance

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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 ...

  16. Evaluation of Lettuce Germplasm Resistance to Gray Mold Disease for Organic Cultivations

    Directory of Open Access Journals (Sweden)

    Chang Ki Shim

    2014-03-01

    Full Text Available This study was conducted to evaluate the resistance of 212 accessions of lettuce germplasm to gray mold disease caused by Botrytis cinerea. The lettuce germplasm were composed of five species: Lactuca sativa (193 accessions, L. sativa var. longifolia (2 accessions, L. sativa var. crispa (2 accessions, L. saligna (2 accessions, and L. serriola (1 accession; majority of these originated from Korea, Netherlands, USA, Russia, and Bulgaria. After 35 days of spray inoculation with conidial suspension (3×10⁷ conidia/ml of B. cinerea on the surface of lettuce leaves, tested lettuce germplasm showed severe symptoms of gray mold disease. There were 208 susceptible accessions to B. cinerea counted with 100% of disease incidence and four resistant accessions, IT908801, K000598, K000599, and K021055. Two moderately resistant accessions of L. sativa, K021055 and IT908801, showed 20% of disease incidence of gray mold disease at 45 days after inoculation; and two accessions of L. saligna, K000598 and K000599, which are wild relatives of lettuce germplasm with loose-leaf type, showed complete resistance to B. cinerea. These four accessions are candidates for breeding lettuce cultivars resistant to gray mold disease.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  19. Minimum number and best combinations of harvests to evaluate accessions of tomato plants from germplasm banks

    Directory of Open Access Journals (Sweden)

    Flávia Barbosa Abreu

    2006-01-01

    Full Text Available This study presents the minimum number and the best combination of tomato harvests needed to compare tomato accessions from germplasm banks. Number and weight of fruit in tomato plants are important as auxiliary traits in the evaluation of germplasm banks and should be studied simultaneously with other desirable characteristics such as pest and disease resistance, improved flavor and early production. Brazilian tomato breeding programs should consider not only the number of fruit but also fruit size because Brazilian consumers value fruit that are homogeneous, large and heavy. Our experiment was a randomized block design with three replicates of 32 tomato accessions from the Vegetable Germplasm Bank (Banco de Germoplasma de Hortaliças at the Federal University of Viçosa, Minas Gerais, Brazil plus two control cultivars (Debora Plus and Santa Clara. Nine harvests were evaluated for four production-related traits. The results indicate that six successive harvests are sufficient to compare tomato genotypes and germplasm bank accessions. Evaluation of genotypes according to the number of fruit requires analysis from the second to the seventh harvest. Evaluation of fruit weight by genotype requires analysis from the fourth to the ninth harvest. Evaluation of both number and weight of fruit require analysis from the second to the ninth harvest.

  20. 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...

  1. 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 ...

  2. 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...

  3. 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...

  4. 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 ...

  5. Resource analysis of the Chinese society 1980-2002 based on energy-Part 5: Resource structure and intensity

    International Nuclear Information System (INIS)

    Chen, G.Q.; Chen, B.

    2007-01-01

    This paper is the continuation of the fourth part on fishery and rangeland. The total resource inflow to the Chinese society from 1980 to 2002 is investigated in four parts published afore. The total resource energy input corresponds to GDP is presented in comparison with the purchasing power parity in this paper. The structure of the resource energy inflow is also outlined. Finally, a novel concept referred to as resource intensity is suggested to serve as a basic indicator to illustrate the real status of the economic development in China

  6. Fusing MODIS with Landsat 8 data to downscale weekly normalized difference vegetation index estimates for central Great Basin rangelands, USA

    Science.gov (United States)

    Boyte, Stephen; Wylie, Bruce K.; Rigge, Matthew B.; Dahal, Devendra

    2018-01-01

    Data fused from distinct but complementary satellite sensors mitigate tradeoffs that researchers make when selecting between spatial and temporal resolutions of remotely sensed data. We integrated data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra satellite and the Operational Land Imager sensor aboard the Landsat 8 satellite into four regression-tree models and applied those data to a mapping application. This application produced downscaled maps that utilize the 30-m spatial resolution of Landsat in conjunction with daily acquisitions of MODIS normalized difference vegetation index (NDVI) that are composited and temporally smoothed. We produced four weekly, atmospherically corrected, and nearly cloud-free, downscaled 30-m synthetic MODIS NDVI predictions (maps) built from these models. Model results were strong with R2 values ranging from 0.74 to 0.85. The correlation coefficients (r ≥ 0.89) were strong for all predictions when compared to corresponding original MODIS NDVI data. Downscaled products incorporated into independently developed sagebrush ecosystem models yielded mixed results. The visual quality of the downscaled 30-m synthetic MODIS NDVI predictions were remarkable when compared to the original 250-m MODIS NDVI. These 30-m maps improve knowledge of dynamic rangeland seasonal processes in the central Great Basin, United States, and provide land managers improved resource maps.

  7. Inventory of forest and rangeland resources, including forest stress. [Black Hills, Manitou, Colorado, and Atlanta, Georgia

    Science.gov (United States)

    Aldrich, R. C.; Weber, F. P.; Driscoll, R. S. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Road systems being developed within the Manitou, Colorado area for human habitation are readily discernible on the S192 normal-color photographs. These are dirt roads, some of which are about 20 feet wide. These data should provide the District Ranger of the Pike National Forest required information on the size and extent of these developing areas, information which he does not now have but is required for total management of the District.

  8. 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

  9. Phenomapping of rangelands in South Africa using time series of RapidEye data

    Science.gov (United States)

    Parplies, André; Dubovyk, Olena; Tewes, Andreas; Mund, Jan-Peter; Schellberg, Jürgen

    2016-12-01

    Phenomapping is an approach which allows the derivation of spatial patterns of vegetation phenology and rangeland productivity based on time series of vegetation indices. In our study, we propose a new spatial mapping approach which combines phenometrics derived from high resolution (HR) satellite time series with spatial logistic regression modeling to discriminate land management systems in rangelands. From the RapidEye time series for selected rangelands in South Africa, we calculated bi-weekly noise reduced Normalized Difference Vegetation Index (NDVI) images. For the growing season of 2011⿿2012, we further derived principal phenology metrics such as start, end and length of growing season and related phenological variables such as amplitude, left derivative and small integral of the NDVI curve. We then mapped these phenometrics across two different tenure systems, communal and commercial, at the very detailed spatial resolution of 5 m. The result of a binary logistic regression (BLR) has shown that the amplitude and the left derivative of the NDVI curve were statistically significant. These indicators are useful to discriminate commercial from communal rangeland systems. We conclude that phenomapping combined with spatial modeling is a powerful tool that allows efficient aggregation of phenology and productivity metrics for spatially explicit analysis of the relationships of crop phenology with site conditions and management. This approach has particular potential for disaggregated and patchy environments such as in farming systems in semi-arid South Africa, where phenology varies considerably among and within years. Further, we see a strong perspective for phenomapping to support spatially explicit modelling of vegetation.

  10. Management applicability of the intermediate disturbance hypothesis across Mongolian rangeland ecosystems.

    Science.gov (United States)

    Sasaki, Takehiro; Okubo, Satoru; Okayasu, Tomoo; Jamsran, Undarmaa; Ohkuro, Toshiya; Takeuchi, Kazuhiko

    2009-03-01

    The current growing body of evidence for diversity-disturbance relationships suggests that the peaked pattern predicted by the intermediate disturbance hypothesis (IDH) may not be the rule. Even if ecologists could quantify the diversity-disturbance relationship consistent with the IDH, the applicability of the IDH to land management has rarely been addressed. We examined two hypotheses related to the generality and management applicability of the IDH to Mongolian rangeland ecosystems: that the diversity-disturbance relationship varies as a function of landscape condition and that some intermediate scales of grazing can play an important role in terms of sustainable rangeland management through a grazing gradient approach. We quantified the landscape condition of each ecological site using an ordination technique and determined two types of landscape conditions: relatively benign and harsh environmental conditions. At the ecological sites characterized by relatively benign environmental conditions, diversity-disturbance relationships were generally consistent with the IDH, and maximum diversity was observed at some intermediate distance from the source of the grazing gradient. In contrast, the IDH was not supported at most (but not all) sites characterized by relatively harsh environmental conditions. The intermediate levels of grazing were generally located below the ecological threshold representing the points or zones at which disturbance should be limited to prevent drastic changes in ecological conditions, suggesting that there is little "conundrum" with regard to intermediate disturbance in the studied systems in terms of land management. We suggest that the landscape condition is one of the primary factors that cause inconsistencies in diversity-disturbance relationships. The ecological threshold can extend its utility in rangeland management because it also has the compatibility with the maintenance of species diversity. This study thus suggests that some

  11. Linking ecosystem services with state-and-transition models to evaluate rangeland management decisions

    Science.gov (United States)

    Lohani, S.; Heilman, P.; deSteiguer, J. E.; Guertin, D. P.; Wissler, C.; McClaran, M. P.

    2014-12-01

    Quantifying ecosystem services is a crucial topic for land management decision making. However, market prices are usually not able to capture all the ecosystem services and disservices. Ecosystem services from rangelands, that cover 70% of the world's land area, are even less well-understood since knowledge of rangelands is limited. This study generated a management framework for rangelands that uses remote sensing to generate state and transition models (STMs) for a large area and a linear programming (LP) model that uses ecosystem services to evaluate natural and/or management induced transitions as described in the STM. The LP optimization model determines the best management plan for a plot of semi-arid land in the Empire Ranch in southeastern Arizona. The model allocated land among management activities (do nothing, grazing, fire, and brush removal) to optimize net benefits and determined the impact of monetizing environmental services and disservices on net benefits, acreage allocation and production output. The ecosystem services under study were forage production (AUM/ac/yr), sediment (lbs/ac/yr), water runoff (inches/yr), soil loss (lbs/ac/yr) and recreation (thousands of number of visitors/ac/yr). The optimization model was run for three different scenarios - private rancher, public rancher including environmental services and excluding disservices, and public rancher including both services and disservices. The net benefit was the highest for the public rancher excluding the disservices. A result from the study is a constrained optimization model that incorporates ecosystem services to analyze investments on conservation and management activities. Rangeland managers can use this model to understand and explain, not prescribe, the tradeoffs of management investments.

  12. Effect of canopy cover and canopy background variables on spectral profiles of savanna rangeland bush encroachment species based on selected Acacia species (mellifera, tortilis, karroo) and Dichrostachys cinerea at Mokopane, South Africa

    CSIR Research Space (South Africa)

    Munyati, C

    2013-07-01

    Full Text Available The proliferation of woody plant species on savanna rangelands (i.e. bush encroachment) degrades rangeland quality, thereby threatening the biodiversity conservation effort as well as pastoral farming. Hyperspectral remote sensing offers...

  13. 75 FR 55345 - Notice of Availability of Record of Decision for the Socorro Field Office Resource Management...

    Science.gov (United States)

    2010-09-10

    ... where public and private lands abut one another); and (6) Regional heritage/tourism opportunities on the... rangeland resources, lands with wilderness characteristics, and the Continental Divide National Scenic Trail (Trail). As a result of the protests, minor editorial modifications and technical clarifications were...

  14. Introducing cattle grazing to a noxious weed-dominated rangeland shifts plant communities

    Directory of Open Access Journals (Sweden)

    Josh S. Davy

    2015-10-01

    Full Text Available Invasive weed species in California's rangelands can reduce herbaceous diversity, forage quality and wildlife habitat. Small-scale studies (5 acres or fewer have shown reductions of medusahead and yellow starthistle using prescribed grazing on rangelands, but little is published on the effects of pasture-scale (greater than 80 acres prescribed grazing on weed control and plant community responses. We report the results of a 6-year collaborative study of manager-applied prescribed grazing implemented on rangeland that had not been grazed for 4 years. Grazing reduced medusahead but did not alter yellow starthistle cover. Medusahead reductions were only seen in years that did not have significant late spring rainfall, suggesting that it is able to recover from heavy grazing if soil moisture is present. Later season grazing appears to have the potential to suppress medusahead in all years. In practice, however, such grazing is constrained by livestock drinking water availability and forage quality, which were limited even in years with late spring rainfall. Thus, we expect that grazing treatments under real-world constraints would reduce medusahead only in years with little late spring rainfall. After 10 years of grazing exclusion, the ungrazed plant communities began to shift, replacing medusahead with species that have little value, such as ripgut and red brome.

  15. Current stage of the restoration of Chernozems in rangeland ecosystems of the steppe zone

    Science.gov (United States)

    Rusanov, A. M.

    2015-06-01

    The results of two rounds of soil and geobotanic surveys of rangeland ecosystems in the steppe zone are presented. The same sites with southern chernozems (Calcic Chernozems) under steppe plant communities at different stages of pasture degradation were investigated at the end of the 1980s, when they suffered maximum anthropogenic loads, and in 2011-2013, after a long period of relative rest. In the 1980s, degradation of soil physical properties in rangeland ecosystems under the impact of long-term unsustainable management was noted. At the same time, it was found that the major qualitative and quantitative properties of humus in the chernozems were preserved independently from the level of pasture degradation. The following period of moderate grazing pressure had a favorable effect on the soil properties. Owing to the good characteristics of the soil humus, the restoration of the physical properties of chernozems-including their structural state, water permeability, and bulk density-took place in a relatively short period. It is argued that the soil bulk density is a natural regulator of the species composition of steppe vegetation, because true grasses (Poaceae)-typical representatives of the steppe flora-have a fibrous root system requiring the soils with low density values. The improvement of the properties of chernozems is related to the development of secondary ecosystems with a higher portion of grasses in place of damaged rangelands and to the increase in the area of nominal virgin phytocenoses.

  16. The importance and implication of genetic resources in agriculture

    Directory of Open Access Journals (Sweden)

    Milošević Mirjana

    2010-01-01

    Full Text Available The maintenance and preservation of biodiversity is going through the processes of conservation and restoration of disturbed ecosystems and habitats, as well as the preservation and recovery of species. Genetic diversity means the variety and total number of genes contained in plant and animal species and microorganisms. Genetic diversity is the basic unit of diversity, which is responsible for differences between individuals, populations and species. Genetic diversity is very important for the preservation of biodiversity and can be saved in several ways. Part of the germplasm is maintained through breeding programs as they evaluate germplasm stored and used as a source of needed diversity. The Convention on Biological Diversity is one of the most important international agreements to protect nature and conserve genetic resources. International treaties governing the use of genetic resources for food and agriculture are a way to ensure the conservation and sustainable use of plant resources for food and agriculture, and to regulate the rights of farmers.

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

    Science.gov (United States)

    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

  18. California's forest resources. Preliminary assessment

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    This Preliminary Assessment was prepared in response to the California Forest Resources Assessment and Policy Act of 1977 (FRAPA). This Act was passed to improve the information base upon which State resource administrators formulate forest policy. The Act provides for this report and a full assessment by 1987 and at five year intervals thereafter. Information is presented under the following chapter titles: introduction to the forest resources assessment program; the forest area: a general description; classifications of the forest lands; the watersheds; forest lands and the air resource; fish and wildlife resources; the forested rangelands; the wilderness; forest lands as a recreation resource; the timber resource; wood energy; forest lands and the mineral, fossil fuels, and geothermal energy resources; mathematically modeling California's forest lands; vegetation mapping using remote sensing technology; important forest resources legislation; and, State and cooperative State/Federal forestry programs. Twelve indexes, a bibliography, and glossary are included. (JGB)

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Assessing and Exploiting Functional Diversity in Germplasm Pools to Enhance Abiotic Stress Adaptation and Yield in Cereals and Food Legumes

    Science.gov (United States)

    Dwivedi, Sangam L.; Scheben, Armin; Edwards, David; Spillane, Charles; Ortiz, Rodomiro

    2017-01-01

    There is a need to accelerate crop improvement by introducing alleles conferring host plant resistance, abiotic stress adaptation, and high yield potential. Elite cultivars, landraces and wild relatives harbor useful genetic variation that needs to be more easily utilized in plant breeding. We review genome-wide approaches for assessing and identifying alleles associated with desirable agronomic traits in diverse germplasm pools of cereals and legumes. Major quantitative trait loci and single nucleotide polymorphisms (SNPs) associated with desirable agronomic traits have been deployed to enhance crop productivity and resilience. These include alleles associated with variation conferring enhanced photoperiod and flowering traits. Genetic variants in the florigen pathway can provide both environmental flexibility and improved yields. SNPs associated with length of growing season and tolerance to abiotic stresses (precipitation, high temperature) are valuable resources for accelerating breeding for drought-prone environments. Both genomic selection and genome editing can also harness allelic diversity and increase productivity by improving multiple traits, including phenology, plant architecture, yield potential and adaptation to abiotic stresses. Discovering rare alleles and useful haplotypes also provides opportunities to enhance abiotic stress adaptation, while epigenetic variation has potential to enhance abiotic stress adaptation and productivity in crops. By reviewing current knowledge on specific traits and their genetic basis, we highlight recent developments in the understanding of crop functional diversity and identify potential candidate genes for future use. The storage and integration of genetic, genomic and phenotypic information will play an important role in ensuring broad and rapid application of novel genetic discoveries by the plant breeding community. Exploiting alleles for yield-related traits would allow improvement of selection efficiency and

  1. Assessing and Exploiting Functional Diversity in Germplasm Pools to Enhance Abiotic Stress Adaptation and Yield in Cereals and Food Legumes

    Directory of Open Access Journals (Sweden)

    Sangam L. Dwivedi

    2017-08-01

    Full Text Available There is a need to accelerate crop improvement by introducing alleles conferring host plant resistance, abiotic stress adaptation, and high yield potential. Elite cultivars, landraces and wild relatives harbor useful genetic variation that needs to be more easily utilized in plant breeding. We review genome-wide approaches for assessing and identifying alleles associated with desirable agronomic traits in diverse germplasm pools of cereals and legumes. Major quantitative trait loci and single nucleotide polymorphisms (SNPs associated with desirable agronomic traits have been deployed to enhance crop productivity and resilience. These include alleles associated with variation conferring enhanced photoperiod and flowering traits. Genetic variants in the florigen pathway can provide both environmental flexibility and improved yields. SNPs associated with length of growing season and tolerance to abiotic stresses (precipitation, high temperature are valuable resources for accelerating breeding for drought-prone environments. Both genomic selection and genome editing can also harness allelic diversity and increase productivity by improving multiple traits, including phenology, plant architecture, yield potential and adaptation to abiotic stresses. Discovering rare alleles and useful haplotypes also provides opportunities to enhance abiotic stress adaptation, while epigenetic variation has potential to enhance abiotic stress adaptation and productivity in crops. By reviewing current knowledge on specific traits and their genetic basis, we highlight recent developments in the understanding of crop functional diversity and identify potential candidate genes for future use. The storage and integration of genetic, genomic and phenotypic information will play an important role in ensuring broad and rapid application of novel genetic discoveries by the plant breeding community. Exploiting alleles for yield-related traits would allow improvement of selection

  2. Determining RUSLE P-factors for stonebunds and trenches in rangeland and cropland, Northern Ethiopia

    Science.gov (United States)

    Taye, Gebeyehu; Poesen, Jean; Vanmaercke, Matthias; Van Wesemael, Bas; Tesfay, Samuel; Teka, Daniel; Nyssen, Jan; Deckers, Jozef; Haregeweyn, Nigussie

    2017-04-01

    The implementation of soil and water conservation (SWC) measures in the Ethiopian highlands is a top priority to reduce soil erosion rates and to enhance the sustainability of agroecosystem. Nonetheless, the effectiveness of many of these measures for different hillslope and land use conditions remains currently poorly understood. As a result, the overall effects of these measures at regional or catchment scale remain hard to quantify. This study addresses this knowledge gap by determining the cover-management (C) and support practice (P) factors of the Revised Universal Soil Loss Equation (RUSLE), for commonly used SWC measures in semi-arid environments (i.e. stone bunds, trenches and a combination of both). Calculations were based on soil loss data collected with runoff plots in Tigray, northern Ethiopia (i.e. 21 runoff plots of 600 to 1000 m2, monitored during 2010, 2011 and 2012). The runoff plots were installed in rangeland and cropland sites corresponding to a gentle (5%), medium (12%) and steep (16%) slope gradients. The C and P factors of the RUSLE were calculated following the recommended standard procedures. Results show that the C-factor for rangeland ranges from 0.31 to 0.98 and from 0.06 to 0.39 for cropland. For rangeland, this large variability is due to variations in vegetation cover caused by grazing. In cropland, C-factors vary with tillage practices and crop types. The calculated P-factors ranged from 0.32 to 0.74 for stone bunds, from 0.07 to 0.65 for trenches and from 0.03 to 0.22 for a combination of both stone bunds and trenches. This variability is partly due to variations in the density of the implemented measures in relation to land use (cropland vs rangeland) and slope angles. However, also annual variations in P factor values are highly significant. Especially trenches showed a very significant decline of effectiveness over time, which is attributable to their reduced static storage capacity as a result of sediment deposition (e.g. for

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  5. The genetic makeup of a global barnyard millet germplasm collection

    Science.gov (United States)

    Barnyard millet (Echinochloa spp.) is an important crop for many smallholder farmers in southern and eastern Asia. It is valued for its drought tolerance, rapid maturation, and superior nutritional qualities. Despite these characteristics there are almost no genetic or genomic resources for this cro...

  6. 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...

  7. Interpreting and Correcting Cross-scale Mismatches in Resilience Analysis: a Procedure and Examples from Australia's Rangelands

    Directory of Open Access Journals (Sweden)

    John A. Ludwig

    2005-12-01

    Full Text Available Many rangelands around the globe are degraded because of mismatches between the goals and actions of managers operating at different spatial scales. In this paper, we focus on identifying, interpreting, and correcting cross-scale mismatches in rangeland management by building on an existing four-step resilience analysis procedure. Resilience analysis is an evaluation of the capacity of a system to persist in the face of disturbances. We provide three examples of cross-scale resilience analysis using a rangeland system located in northern Australia. The system was summarized in a diagram showing key interactions between three attributes (water quality, regional biodiversity, and beef quality, which can be used to indicate the degree of resilience of the system, and other components that affect these attributes at different scales. The strengths of cross-scale interactions were rated as strong or weak, and the likely causes of mismatches in strength were interpreted. Possible actions to correct cross-scale mismatches were suggested and evaluated. We found this four-step, cross-scale resilience analysis procedure very helpful because it reduced a complex problem down to manageable parts without losing sight of the larger-scale whole. To build rangeland resilience, many such cross-scale mismatches in management will need to be corrected, especially as the global use of rangelands increases over the coming decades.

  8. 25 CFR 166.307 - Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not...

    Science.gov (United States)

    2010-04-01

    ... § 166.307 Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not... trust or non-trust rangeland in common with the permitted land. Grazing capacity will be established... 25 Indians 1 2010-04-01 2010-04-01 false Will the grazing capacity be increased if I graze...

  9. Power and limitation of soil properties as predictors of rangeland health and ecosystem functioning in a Northern mixed-grass prairie[Abstract

    Science.gov (United States)

    Soil properties are thought to affect rangeland ecosystem functioning (e.g. primary productivity, hydrology), and thus soil variables that are consistently correlated with key ecosystem functions may be general indicators of rangeland health. We summarize results from several studies in mixed-grass...

  10. The Ellis paradigm — humans, herbivores and rangeland systems ...

    African Journals Online (AJOL)

    A leader of the South Turkana Ecosystem Project (STEP), he showed the adaptive basis for opportunistic and spatially extensive resource use in temporally and spatially variable environments. After the STEP, he examined pastoral ecosystems in northern and central Asia and elsewhere in Africa. Spatial extensivity, or scale ...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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)

  13. 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)

  14. 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)

  15. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Rangeland management and fluvial geomorphology in northern Tanzania

    Science.gov (United States)

    Miller, Brian W.; Doyle, Martin W.

    2014-01-01

    Researchers have independently documented the effects of land use on rivers and threats to river management institutions, but the relationship between changes in institutional context and river condition is not well described. This study assesses the connections between resource management institutions, land use, and rivers by integrating social science, geospatial analysis, and geomorphology. In particular, we measured hydraulic geometry, sediment size distributions, and estimated sediment yield for four rivers in northern Tanzania and conducted semistructured interviews that assessed corresponding resource management institutions. Communities managed rivers through both customary (traditional, nonstate) and government institutions, but the differences in the resource management policies and practices of the study rivers themselves were fairly subtle. Clearer differences were found at broader scales; the four watersheds exhibited substantial differences in land cover change and sediment yield associated with the location of settlements, roadways, and cultivation. Unexpectedly, these recent land use changes did not initiate a geomorphic response in rivers. The long history of grazing by domestic and wild ungulates may have influenced water and sediment supplies such that river channel dimensions are more resistant to changes in land use than other systems or have already adjusted to predominant changes in boundary conditions. This would suggest that not all rivers will have the anticipated responses to contemporary land use changes because of antecedent land use patterns; over long time scales (centuries to millennia), the presence of grazers may actually increase the ability of rivers to withstand changes in land use. Our findings point to a need for further interdisciplinary study of dryland rivers and their shifts between system states, especially in areas with a long history of grazing, relatively recent changes in land use, and a dynamic social and

  18. Rangeland management and fluvial geomorphology in northern Tanzania.

    Science.gov (United States)

    Miller, Brian W; Doyle, Martin W

    2014-06-01

    Researchers have independently documented the effects of land use on rivers and threats to river management institutions, but the relationship between changes in institutional context and river condition is not well described. This study assesses the connections between resource management institutions, land use, and rivers by integrating social science, geospatial analysis, and geomorphology. In particular, we measured hydraulic geometry, sediment size distributions, and estimated sediment yield for four rivers in northern Tanzania and conducted semistructured interviews that assessed corresponding resource management institutions. Communities managed rivers through both customary (traditional, nonstate) and government institutions, but the differences in the resource management policies and practices of the study rivers themselves were fairly subtle. Clearer differences were found at broader scales; the four watersheds exhibited substantial differences in land cover change and sediment yield associated with the location of settlements, roadways, and cultivation. Unexpectedly, these recent land use changes did not initiate a geomorphic response in rivers. The long history of grazing by domestic and wild ungulates may have influenced water and sediment supplies such that river channel dimensions are more resistant to changes in land use than other systems or have already adjusted to predominant changes in boundary conditions. This would suggest that not all rivers will have the anticipated responses to contemporary land use changes because of antecedent land use patterns; over long time scales (centuries to millennia), the presence of grazers may actually increase the ability of rivers to withstand changes in land use. Our findings point to a need for further interdisciplinary study of dryland rivers and their shifts between system states, especially in areas with a long history of grazing, relatively recent changes in land use, and a dynamic social and

  19. The economic impact of global climate change on Mediterranean rangeland ecosystems. A Space-for-Time approach

    International Nuclear Information System (INIS)

    Fleischer, Aliza; Sternberg, Marcelo

    2006-01-01

    Global Climate Change (GCC) can bring about changes in ecosystems and consequently in their services value. Here we show that the urban population in Israel values the green landscape of rangelands in the mesic Mediterranean climate region and is willing to pay for preserving it in light of the expected increasing aridity conditions in this region. Their valuation of the landscape is higher than that of the grazing services these rangelands provide for livestock growers. These results stem from a Time-for-Space approach with which we were able to measure changes in biomass production and rainfall at four experimental sites along an aridity gradient. (author)

  20. A potential to monitor nutrients as an indicator of rangeland quality using space borne remote sensing

    International Nuclear Information System (INIS)

    Ramoelo, A; Madonsela, S; Mathieu, R; Van der Korchove, R; Kaszta, Z; Wolf, E; Cho, M A

    2014-01-01

    Global change consisting of land use and climate change could have huge impacts on food security and the health of various ecosystems. Leaf nitrogen (N) is one of the key factors limiting agricultural production and ecosystem functioning. Leaf N can be used as an indicator of rangeland quality which could provide information for the farmers, decision makers, land planners and managers. Leaf N plays a crucial role in understanding the feeding patterns and distribution of wildlife and livestock. Assessment of this vegetation parameter using conventional methods at landscape scale level is time consuming and tedious. Remote sensing provides a synoptic view of the landscape, which engenders an opportunity to assess leaf N over wider rangeland areas from protected to communal areas. Estimation of leaf N has been successful during peak productivity or high biomass and limited studies estimated leaf N in dry season. The objective of this study is to monitor leaf N as an indicator of rangeland quality using WorldView 2 satellite images in the north-eastern part of South Africa. Series of field work to collect samples for leaf N were undertaken in the beginning of May (end of wet season) and July (dry season). Several conventional and red edge based vegetation indices were computed. Simple regression was used to develop prediction model for leaf N. Using bootstrapping, indicator of precision and accuracy were analyzed to select a best model for the combined data sets (May and July). The may model for red edge based simple ratio explained over 90% of leaf N variations. The model developed from the combined data sets with normalized difference vegetation index explained 62% of leaf N variation, and this is a model used to estimate and map leaf N for two seasons. The study demonstrated that leaf N could be monitored using high spatial resolution with the red edge band capability

  1. Infection of Melanoplus sanguinipes Grasshoppers following Ingestion of Rangeland Plant Species Harboring Vesicular Stomatitis Virus▿

    Science.gov (United States)

    Drolet, Barbara S.; Stuart, Melissa A.; Derner, Justin D.

    2009-01-01

    Knowledge of the many mechanisms of vesicular stomatitis virus (VSV) transmission is critical for understanding of the epidemiology of sporadic disease outbreaks in the western United States. Migratory grasshoppers [Melanoplus sanguinipes (Fabricius)] have been implicated as reservoirs and mechanical vectors of VSV. The grasshopper-cattle-grasshopper transmission cycle is based on the assumptions that (i) virus shed from clinically infected animals would contaminate pasture plants and remain infectious on plant surfaces and (ii) grasshoppers would become infected by eating the virus-contaminated plants. Our objectives were to determine the stability of VSV on common plant species of U.S. Northern Plains rangelands and to assess the potential of these plant species as a source of virus for grasshoppers. Fourteen plant species were exposed to VSV and assayed for infectious virus over time (0 to 24 h). The frequency of viable virus recovery at 24 h postexposure was as high as 73%. The two most common plant species in Northern Plains rangelands (western wheatgrass [Pascopyrum smithii] and needle and thread [Hesperostipa comata]) were fed to groups of grasshoppers. At 3 weeks postfeeding, the grasshopper infection rate was 44 to 50%. Exposure of VSV to a commonly used grasshopper pesticide resulted in complete viral inactivation. This is the first report demonstrating the stability of VSV on rangeland plant surfaces, and it suggests that a significant window of opportunity exists for grasshoppers to ingest VSV from contaminated plants. The use of grasshopper pesticides on pastures would decrease the incidence of a virus-amplifying mechanical vector and might also decontaminate pastures, thereby decreasing the inter- and intraherd spread of VSV. PMID:19286779

  2. Infection of Melanoplus sanguinipes grasshoppers following ingestion of rangeland plant species harboring vesicular stomatitis virus.

    Science.gov (United States)

    Drolet, Barbara S; Stuart, Melissa A; Derner, Justin D

    2009-05-01

    Knowledge of the many mechanisms of vesicular stomatitis virus (VSV) transmission is critical for understanding of the epidemiology of sporadic disease outbreaks in the western United States. Migratory grasshoppers [Melanoplus sanguinipes (Fabricius)] have been implicated as reservoirs and mechanical vectors of VSV. The grasshopper-cattle-grasshopper transmission cycle is based on the assumptions that (i) virus shed from clinically infected animals would contaminate pasture plants and remain infectious on plant surfaces and (ii) grasshoppers would become infected by eating the virus-contaminated plants. Our objectives were to determine the stability of VSV on common plant species of U.S. Northern Plains rangelands and to assess the potential of these plant species as a source of virus for grasshoppers. Fourteen plant species were exposed to VSV and assayed for infectious virus over time (0 to 24 h). The frequency of viable virus recovery at 24 h postexposure was as high as 73%. The two most common plant species in Northern Plains rangelands (western wheatgrass [Pascopyrum smithii] and needle and thread [Hesperostipa comata]) were fed to groups of grasshoppers. At 3 weeks postfeeding, the grasshopper infection rate was 44 to 50%. Exposure of VSV to a commonly used grasshopper pesticide resulted in complete viral inactivation. This is the first report demonstrating the stability of VSV on rangeland plant surfaces, and it suggests that a significant window of opportunity exists for grasshoppers to ingest VSV from contaminated plants. The use of grasshopper pesticides on pastures would decrease the incidence of a virus-amplifying mechanical vector and might also decontaminate pastures, thereby decreasing the inter- and intraherd spread of VSV.

  3. Revolutionary land use change in the 21st century: Is (rangeland) science relevant?

    Science.gov (United States)

    Herrick, J.E.; Brown, J.R.; Bestelmeyer, B.T.; Andrews, S.S.; Baldi, G.; Davies, J.; Duniway, M.; Havstad, K.M.; Karl, J.W.; Karlen, D.L.; Peters, Debra P.C.; Quinton, J.N.; Riginos, C.; Shaver, P.L.; Steinaker, D.; Twomlow, S.

    2012-01-01

    Rapidly increasing demand for food, fiber, and fuel together with new technologies and the mobility of global capital are driving revolutionary changes in land use throughout the world. Efforts to increase land productivity include conversion of millions of hectares of rangelands to crop production, including many marginal lands with low resistance and resilience to degradation. Sustaining the productivity of these lands requires careful land use planning and innovative management systems. Historically, this responsibility has been left to agronomists and others with expertise in crop production. In this article, we argue that the revolutionary land use changes necessary to support national and global food security potentially make rangeland science more relevant now than ever. Maintaining and increasing relevance will require a revolutionary change in range science from a discipline that focuses on a particular land use or land cover to one that addresses the challenge of managing all lands that, at one time, were considered to be marginal for crop production. We propose four strategies to increase the relevance of rangeland science to global land management: 1) expand our awareness and understanding of local to global economic, social, and technological trends in order to anticipate and identify drivers and patterns of conversion; 2) emphasize empirical studies and modeling that anticipate the biophysical (ecosystem services) and societal consequences of large-scale changes in land cover and use; 3) significantly increase communication and collaboration with the disciplines and sectors of society currently responsible for managing the new land uses; and 4) develop and adopt a dynamic and flexible resilience-based land classification system and data-supported conceptual models (e.g., state-and-transition models) that represent all lands, regardless of use and the consequences of land conversion to various uses instead of changes in state or condition that are

  4. Incorporating biodiversity into rangeland health: Plant species richness and diversity in great plains grasslands

    Science.gov (United States)

    Symstad, Amy J.; Jonas, Jayne L.

    2011-01-01

    Indicators of rangeland health generally do not include a measure of biodiversity. Increasing attention to maintaining biodiversity in rangelands suggests that this omission should be reconsidered, and plant species richness and diversity are two metrics that may be useful and appropriate. Ideally, their response to a variety of anthropogenic and natural drivers in the ecosystem of interest would be clearly understood, thereby providing a means to diagnose the cause of decline in an ecosystem. Conceptual ecological models based on ecological principles and hypotheses provide a framework for this understanding, but these models must be supported by empirical evidence if they are to be used for decision making. To that end, we synthesize results from published studies regarding the responses of plant species richness and diversity to drivers that are of management concern in Great Plains grasslands, one of North America's most imperiled ecosystems. In the published literature, moderate grazing generally has a positive effect on these metrics in tallgrass prairie and a neutral to negative effect in shortgrass prairie. The largest published effects on richness and diversity were caused by moderate grazing in tallgrass prairies and nitrogen fertilization in shortgrass prairies. Although weather is often cited as the reason for considerable annual fluctuations in richness and diversity, little information about the responses of these metrics to weather is available. Responses of the two metrics often diverged, reflecting differences in their sensitivity to different types of changes in the plant community. Although sufficient information has not yet been published for these metrics to meet all the criteria of a good indicator in Great Plains Grasslands, augmenting current methods of evaluating rangeland health with a measure of plant species richness would reduce these shortcomings and provide information critical to managing for biodiversity.

  5. Alternate data sources for soil surveys on rangeland

    Science.gov (United States)

    Horvath, Emil H.; Klingebiel, A.A.; Moore, D.G.; Fosnight, E.A.

    1983-01-01

    Soil information is an essential theme in a digital information base for land management and resource monitoring, but public land management agencies seldom have detailed soil maps available for all of the area under their administration. Most of these agencies conduct soil surveys on a scheduled basis, but escalating costs and declining budgets are reducing the number of surveys that can be scheduled. Digital elevation and satellite spectral data are available or are obtainable for all areas in the continental United States and may be used as an aid to produce soils data. A study was conducted in the Grass Creek Resource Area in north-central Wyoming to assess the utility of incorporating digital elevation and Landsat data into an information base for soil survey and to evaluate the usefulness of these data as an input to an order-three soil survey. Slope-interval maps were produced from digital elevation data and topographic maps of three 7.5-minute quadrangle areas. These slope-interval maps were then overlaid on orthophotoquadrangles and used to produce photo-interpreted physiographic maps. These physiographic maps were digitized into a data base and used with Landsat multispectral scanner data to produce tabular summaries that describe each map polygon in terms of physiographic unit, slope, aspect, elevation, area, and spectral values. A good

  6. Biomass increases go under cover: woody vegetation dynamics in South African rangelands

    CSIR Research Space (South Africa)

    Mograbi, PJ

    2015-05-01

    Full Text Available and ranging (LiDAR) data The communal rangelands were surveyed with airborne laser mapping as part of a Carnegie Airborne Observatory (http://cao.ciw.edu/) campaign in April 2008 and April 2012, concur- rently with the collected fieldwork data in 2012. Small... permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All data necessary to replicate the results of this study are contained within the paper and its...

  7. 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.

  8. 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.

    Science.gov (United States)

    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.

  9. Abandoned seasonal livestock migration reflected by plant functional traits: A case study in Kyrgyz rangelands

    Science.gov (United States)

    Hoppe, Franziska; Zhusui Kyzy, Taalaigul; Usupbaev, Adilet; Schickoff, Udo

    2017-04-01

    At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people's livelihoods, rangeland degradation presents a threat for the majority of the population. Recently, the usage of plant functional traits as a powerful tool for the characterization of vegetation dynamics in response to anthropogenic and natural disturbances has been put forward. Grazing is one of the most severe disturbances on vegetation, which concerns equally the loss of area and biomass. Because grazing is both depending on and affecting plant functional traits, important insights can be generated, based on this codependency. We hypothesized that the contrasting grazing intensity of summer and winter pastures is reflected by the chosen traits. We used traits such as plant height, flowering start, growth form as well as SLA (Specific Leaf Area) and LMA (Leaf Mass per Area). Based on former phytosociological classification of the main pasture types (summer and winter pastures), community structure and the traits of dominant plant species were analyzed. Our results showed that on winter pastures grazing decreased plant height and SLA and favored plants with an earlier flowering start as well as rosette plants and ascending plants. We conclude that the study of trait composition in relation to anthropogenic disturbances can provide important insights into the mechanism of plant response to grazing in high-altitude rangelands.

  10. Energy budgets and resistances to energy transport in sparsely vegetated rangeland

    Science.gov (United States)

    Nichols, W.D.

    1992-01-01

    Partitioning available energy between plants and bare soil in sparsely vegetated rangelands will allow hydrologists and others to gain a greater understanding of water use by native vegetation, especially phreatophytes. Standard methods of conducting energy budget studies result in measurements of latent and sensible heat fluxes above the plant canopy which therefore include the energy fluxes from both the canopy and the soil. One-dimensional theoretical numerical models have been proposed recently for the partitioning of energy in sparse crops. Bowen ratio and other micrometeorological data collected over phreatophytes growing in areas of shallow ground water in central Nevada were used to evaluate the feasibility of using these models, which are based on surface and within-canopy aerodynamic resistances, to determine heat and water vapor transport in sparsely vegetated rangelands. The models appear to provide reasonably good estimates of sensible heat flux from the soil and latent heat flux from the canopy. Estimates of latent heat flux from the soil were less satisfactory. Sensible heat flux from the canopy was not well predicted by the present resistance formulations. Also, estimates of total above-canopy fluxes were not satisfactory when using a single value for above-canopy bulk aerodynamic resistance. ?? 1992.

  11. The usefullness of ERTS-1 and supporting aircraft data for monitoring plant development in rangeland environments

    Science.gov (United States)

    Carneggie, D. M.; Degloria, S. D.

    1972-01-01

    The author has identified the following significant results. Preliminary analysis of ERTS-1 MSS imagery of annual and perennial rangeland in California yields the following observations: (1) Sufficient geomorphological detail can be resolved to differentiate upland and bottomland range sites in the foothill range areas. (2) Dry and green meadowland can be differentiated on MSS band 5. (3) Color composites prepared by NASA-Goddard were useful for locating perennial rangeland with varying amounts of herbaceous ground cover. (4) The ERTS-1 images received and interpreted cover nearly 50% of the state of California and show nearly two-thirds of the annual grassland type. (5) Satellite imagery obtained during the late summer season should be optimum for differentiating grassland from brushland and forested land. (6) The ERTS-1 imagery clearly shows areas which at one time were part of the annual grassland but which are now used for dry land farming (cropping of cereal grains). Similarly, the imagery show areas which have been converted from brushland to grassland.

  12. An overview of the rangelands atmosphere hydrosphere biosphere interaction study experiment in northeastern Asia (RAISE)

    Science.gov (United States)

    Sugita, Michiaki; Asanuma, Jun; Tsujimura, Maki; Mariko, Shigeru; Lu, Minjiao; Kimura, Fujio; Azzaya, Dolgorsuren; Adyasuren, Tsokhio

    2007-01-01

    SummaryIntensive observations, analysis and modeling within the framework of the rangelands atmosphere-hydrosphere-biosphere interaction study experiment in northeastern Asia (RAISE) project, have allowed investigations into the hydrologic cycle in the ecotone of forest-steppe, and its relation to atmosphere and ecosystem in the eastern part of Mongolia. In this region, changes in the climate have been reported and a market oriented economy was introduced recently, but their impact on the natural environment is still not well understood. In this RAISE special issue, the outcome is presented of the studies carried out by six groups within RAISE, namely: (1) Land-atmosphere interaction analysis, (2) ecosystem analysis and modeling, (3) hydrologic cycle analysis, (4) climatic modeling, (5) hydrologic modeling, and (6) integration. The results are organized in five relevant categories comprising (i) hydrologic cycle including precipitation, groundwater, and surface water, (ii) hydrologic cycle and ecosystem, (iii) surface-atmosphere interaction, (iv) effect of grazing activities on soils, plant ecosystem and surface fluxes, and (v) future prediction. Comparison with studies on rangelands in other parts of the world, and some future directions of studies still needed in this region are also summarized.

  13. Bio solids Effects in Chihuahuan Desert Rangelands: A Ten-Year Study

    International Nuclear Information System (INIS)

    Wester, D.B; Sosebee, R.E; Fish, E.B; Villalobos, J.C; Zartman, R.E; Gonzalez, R.M; Jurado, P.; Moffet, C.A

    2011-01-01

    Arid and semiarid rangelands are suitable for responsible bio solids application. Topical application is critical to avoid soil and vegetation disturbance. Surface-applied bio solids have long-lasting effects in these ecosystems. We conducted a 10-year research program investigating effects of bio solids applied at rates from 0 to 90 dry Mg ha -1 on soil water infiltration; runoff and leachate water quality; soil erosion; forage production and quality; seedling establishment; plant physiological responses; nitrogen dynamics; bio solids decomposition; and grazing animal behavior and management. Bio solids increased soil water infiltration and reduced erosion. Effects on soil water quality were observed only at the highest application rates. Bio solids increased soil nitrate-nitrogen. Bio solids increased forage production and improved forage quality. Bio solids increased leaf area of grasses; photosynthetic rates were not necessarily increased by bio solids. Bio solids effects on plant establishment are expected only under moderately favorable conditions. Over an 82-mo exposure period, total organic carbon, nitrogen, and total and available phosphorus decreased and inorganic matter increased. Grazing animals spent more time grazing, ruminating, and resting in bio solids-treated areas; positive effects on average daily gain were observed during periods of higher rainfall. Our results suggest that annual bio solids application rates of up to 18 Mg ha -1 are appropriate for desert rangelands.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. An informational view of accession rarity and allele specificity in germplasm banks for management and conservation.

    Science.gov (United States)

    Reyes-Valdés, M Humberto; Burgueño, Juan; Singh, Sukhwinder; Martínez, Octavio; Sansaloni, Carolina Paola

    2018-01-01

    Germplasm banks are growing in their importance, number of accessions and amount of characterization data, with a large emphasis on molecular genetic markers. In this work, we offer an integrated view of accessions and marker data in an information theory framework. The basis of this development is the mutual information between accessions and allele frequencies for molecular marker loci, which can be decomposed in allele specificities, as well as in rarity and divergence of accessions. In this way, formulas are provided to calculate the specificity of the different marker alleles with reference to their distribution across accessions, accession rarity, defined as the weighted average of the specificity of its alleles, and divergence, defined by the Kullback-Leibler formula. Albeit being different measures, it is demonstrated that average rarity and divergence are equal for any collection. These parameters can contribute to the knowledge of the structure of a germplasm collection and to make decisions about the preservation of rare variants. The concepts herein developed served as the basis for a strategy for core subset selection called HCore, implemented in a publicly available R script. As a proof of concept, the mathematical view and tools developed in this research were applied to a large collection of Mexican wheat accessions, widely characterized by SNP markers. The most specific alleles were found to be private of a single accession, and the distribution of this parameter had its highest frequencies at low levels of specificity. Accession rarity and divergence had largely symmetrical distributions, and had a positive, albeit non-strictly linear relationship. Comparison of the HCore approach for core subset selection, with three state-of-the-art methods, showed it to be superior for average divergence and rarity, mean genetic distance and diversity. The proposed approach can be used for knowledge extraction and decision making in germplasm collections of

  16. The role of fire in managing for biological diversity on native rangelands of the Northern Great Plains

    Science.gov (United States)

    Carolyn Hull Sieg

    1997-01-01

    A strategy for using fire to manage for biological diversity on native rangelands in the Northern Great Plains incorporates an understanding of its past frequency, timing and intensity. Historically, lightning and humans were the major fire setters, and the role of fire varied both in space and time. A burning regime that includes fires at various intervals, seasons...

  17. National projections of forest and rangeland condition indicators: a supporting technical document for the 1999 RPA assessment.

    Science.gov (United States)

    John Hof; Curtis Flather; Tony Baltic; Stephen. Davies

    1999-01-01

    The 1999 forest and rangeland condition indicator model is a set of independent econometric production functions for environmental outputs (measured with condition indicators) at the national scale. This report documents the development of the database and the statistical estimation required by this particular production structure with emphasis on two special...

  18. Moisture, plant-plant interactions and herbivory as drivers of rangeland restoration success in the western US

    Science.gov (United States)

    Restoration efforts in the western US occur across a diverse array of plant communities and climatic conditions. Restoration is likely constrained by different factors in different locations, but few efforts have compared the outcomes of rangeland restoration experiments across broad spatial scales....

  19. Effects of feral free-roaming horses on semi-arid rangeland ecosystems: an example from the sagebrush steppe

    Science.gov (United States)

    Feral horses (Equus caballus) are viewed as a symbol of freedom and power; however, they are also a largely unmanaged, non-native grazer in North America, South America, and Australia. Information on their influence on vegetation and soil characteristics in semi-arid rangelands has been limited by ...

  20. Effects of different management regimes on soil erosion and surface runoff in semi-arid to sub-humid rangelands

    NARCIS (Netherlands)

    Oudenhoven, van A.P.E.; Veerkamp, C.J.; Alkemade, Rob; Leemans, Rik

    2015-01-01

    Over one billion people's livelihoods depend on dry rangelands through livestock grazing and agriculture. Livestock grazing and other management activities can cause soil erosion, increase surface runoff and reduce water availability. We studied the effects of different management regimes on soil

  1. Estimating grass nutrients and biomass as an indicator of rangeland (forage) quality and quantity using remote sensing in Savanna ecosystems

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available and grass quantity, respectively. The objective of the study is to estimate and map leaf N and biomass as an indicator of rangeland quality and quantity using vegetation indices derived from one RapidEye image taken at peak productivity. The study...

  2. The changing role of shrubs in rangeland-based livestock production systems: Can shrubs increase our forage supply?

    Science.gov (United States)

    Projected global increases in ruminant numbers and loss of native grasslands will present a number of challenges for livestock agriculture. Escalated demand for livestock products may stimulate interest in using shrubs on western rangelands. A paradigm shift is needed to change the role of shrubs in...

  3. Common garden comparisons of reproductive, forage and weed suppression potential of rangeland rehabilitation grasses of the Great Basin

    Science.gov (United States)

    Common garden experiments are a means to remove environmental effects. Using 8 species of perennial rangeland grasses, we established a common garden (3 reps x28 plants = 84 plants/species). We found that ‘Hycrest’ crested wheatgrass (Agropyron cristatum) and bluebunch wheatgrass (Pseudoroegneria sp...

  4. Asymmetric ecological and economic responses for rangeland restoration: A case study of tree thickening in Queensland, Australia

    Science.gov (United States)

    Ecological and economic thresholds are important considerations when making decisions about safeguarding or restoring degraded rangelands. When degradation levels have passed a threshold, most managers figure it is either time to take action or too late to take action depending on the particular c...

  5. The Integrated Rangeland Fire Management Strategy Actionable Science Plan: U.S. Department of the Interior, Washington D.C.

    Science.gov (United States)

    Integrated Rangeland Fire Management Strategy Actionable Science Plan Team

    2016-01-01

    The Integrated Rangeland Fire Management Strategy (hereafter Strategy, DOI 2015) outlined the need for coordinated, science-based adaptive management to achieve long-term protection, conservation, and restoration of the sagebrush (Artemisia spp.) ecosystem. A key component of this management approach is the identification of knowledge gaps that limit...

  6. 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。

  7. Mutant germplasm characterization using molecular markers. A manual

    International Nuclear Information System (INIS)

    2002-01-01

    Plant biotechnology applications must not only respond to the challenge of improving food security and fostering socio-economic development, but in doing so, promote the conservation, diversification and sustainable use of plant genetic resources for food and agriculture. Nowadays the biotechnology toolbox available to plant breeders offers several new possibilities for increasing productivity, crop diversification and production, while developing a more sustainable agriculture. This training course focuses on one of the most promising set of techniques used in modern crop improvement programmes, i.e. on molecular markers. These are rapidly being adopted by plant breeders and molecular biologists as effective and appropriate tools for basic and applied studies addressing biological components in agricultural production systems. Their use in applied breeding programmes can range from facilitating the appropriate choice of parents for crosses, to mapping/tagging of gene blocks associated with economically important traits (often termed 'quantitative trait loci' (QTLs)). Gene tagging and QTL mapping in turn permit marker-assisted selection (MAS) in backcross, pedigree, and population improvement programmes, thereby facilitating more efficient incremental improvement of specific individual target traits. And through comparative genomics, molecular markers can be used in ways that allow us to more effectively discover and efficiently exploit biodiversity and the evolutionary relationships between organisms. Substantial progress has been made in recent years in mapping, tagging and isolating many agriculturally important genes using molecular markers due in large part to improvements in the techniques that have been developed to help find markers of interest. Among the techniques that are particularly promising are Restriction Fragment Length Polymorphism (RFLPs), Amplified Fragment Length Polymorphism (AFLPs), Random Amplified Polymorphic DNA (RAPDs), Microsatellites

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

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

    Science.gov (United States)

    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.

  11. 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.

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

    Science.gov (United States)

    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.

  13. Genetic variability in common wheat germplasm based on coefficients of parentage

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Variation in cooking and eating quality traits in Japanese rice germplasm accessions.

    Science.gov (United States)

    Hori, Kiyosumi; Suzuki, Keitaro; Iijima, Ken; Ebana, Kaworu

    2016-03-01

    The eating quality of cooked rice is important and determines its market price and consumer acceptance. To comprehensively describe the variation of eating quality in 183 rice germplasm accessions, we evaluated 33 eating-quality traits including amylose and protein contents, pasting properties of rice flour, and texture of cooked rice grains. All eating-quality traits varied widely in the germplasm accessions. Principal-components analysis (PCA) revealed that allelic differences in the Wx gene explained the largest proportion of phenotypic variation of the eating-quality traits. In 146 accessions of non-glutinous temperate japonica rice, PCA revealed that protein content and surface texture of the cooked rice grains significantly explained phenotypic variations of the eating-quality traits. An allelic difference based on simple sequence repeats, which was located near a quantitative trait locus (QTL) on the short arm of chromosome 3, was associated with differences in the eating quality of non-glutinous temperate japonica rice. These results suggest that eating quality is controlled by genetic factors, including the Wx gene and the QTL on chromosome 3, in Japanese rice accessions. These genetic factors have been consciously selected for eating quality during rice breeding programs in Japan.

  20. Geospatial Data as a Service: The GEOGLAM Rangelands and Pasture Productivity Map Experience

    Science.gov (United States)

    Evans, B. J. K.; Antony, J.; Guerschman, J. P.; Larraondo, P. R.; Richards, C. J.

    2017-12-01

    Empowering end-users like pastoralists, land management specialists and land policy makers in the use of earth observation data for both day-to-day and seasonal planning needs both interactive delivery of multiple geospatial datasets and the capability of supporting on-the-fly dynamic queries while simultaneously fostering a community around the effort. The use of and wide adoption of large data archives, like those produced by earth observation missions, are often limited by compute and storage capabilities of the remote user. We demonstrate that wide-scale use of large data archives can be facilitated by end-users dynamically requesting value-added products using open standards (WCS, WMS, WPS), with compute running in the cloud or dedicated data-centres and visualizing outputs on web-front ends. As an example, we will demonstrate how a tool called GSKY can empower a remote end-user by providing the data delivery and analytics capabilities for the GEOGLAM Rangelands and Pasture Productivity (RAPP) Map tool. The GEOGLAM RAPP initiative from the Group on Earth Observations (GEO) and its Agricultural Monitoring subgroup aims at providing practical tools to end-users focusing on the important role of rangelands and pasture systems in providing food production security from both agricultural crops and animal protein. Figure 1, is a screen capture from the RAPP Map interface for an important pasture area in the Namibian rangelands. The RAPP Map has been in production for six months and has garnered significant interest from groups and users all over the world. GSKY, being formulated around the theme of Open Geospatial Data-as-a-Service capabilities uses distributed computing and storage to facilitate this. It works behind the scenes, accepting OGC standard requests in WCS, WMS and WPS. Results from these requests are rendered on a web-front end. In this way, the complexities of data locality and compute execution are masked from an end user. On-the-fly computation of

  1. Sediment budgets and source determinations using fallout Cesium-137 in a semiarid rangeland watershed, Arizona, USA

    International Nuclear Information System (INIS)

    Ritchie, Jerry C.; Nearing, Mark A.; Rhoton, Fred E.

    2009-01-01

    Analysis of soil redistribution and sediment sources in semiarid and arid watersheds provides information for implementing management practices to improve rangeland conditions and reduce sediment loads to streams. The purpose of this research was to develop sediment budgets and identify potential sediment sources using 137 Cs and other soil properties in a series of small semiarid subwatersheds on the USDA ARS Walnut Gulch Experimental Watershed near Tombstone, Arizona, USA. Soils were sampled in a grid pattern on two small subwatersheds and along transects associated with soils and geomorphology on six larger subwatersheds. Soil samples were analyzed for 137 Cs and selected physical and chemical properties (i.e., bulk density, rocks, particle size, soil organic carbon). Suspended sediment samples collected at measuring flume sites on the Walnut Gulch Experimental Watershed were also analyzed for these properties. Soil redistribution measured using 137 Cs inventories for a small shrub-dominated subwatershed and a small grass-dominated subwatershed found eroding areas in these subwatersheds were losing -5.6 and -3.2 t ha -1 yr -1 , respectively; however, a sediment budget for each of these subwatersheds, including depositional areas, found net soil loss to be -4.3 t ha -1 yr -1 from the shrub-dominated subwatershed and -0.1 t ha -1 yr -1 from the grass-dominated subwatershed. Generally, the suspended sediment collected at the flumes of the six other subwatersheds was enriched in silt and clay. Using a mixing model to determine sediment source indicated that shrub-dominated subwatersheds were contributing most of the suspended sediment that was measured at the outlet flume of the Walnut Gulch Experimental Watershed. The two methodologies (sediment budgets and sediment source analyses) indicate that shrub-dominated systems provide more suspended sediment to the stream systems. The sediment budget studies also suggest that sediment yields measured at the outlet of a

  2. IMPACT OF Acacia drepanolobium (AN INVASIVE WOODY SPECIES ON GUM-RESIN RESOURCES AND LOCAL LIVELIHOOD IN BORANA, SOUTHERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Ayana Abdeta

    2011-10-01

    Full Text Available We investigated the impact of Acacia drepanolobium, a species threatening rangeland resources including Gum-resin production and pastoralists’ livelihoods in Borana. Data were collected through vegetation surveys, key informant interviews, use of formal questionnaires and focus group discussions. We found a total of 22 woody species in the study area. A. drepanolobium was found to be the most dominant (22% and abundant (65% invasive woody species with an importance value index (IVI of 103. According to our respondents, A. drepanolobium was the first widely expanded woody species followed by Dichrostachys cinerea and A. mellifera. Eighty seven percent of our respondents ranked A. drepanolobium as the most invading woody species during their life time. Overall, our results demonstrated that the impact of A. drepanolobium had greatly affected the condition of rangeland vegetation. The implication is that the reduction in the capacity of rangelands for livestock grazing could reduce the resilience of local livelihood under changing environmental conditions. Furthermore, pastoralists’ perception indicated that the expansion of A. drepanolobium had reduced the survival of Gum-resin producing species. Generally, the shift from cattle based pastoral economy to mixed livestock types could be attributed to the expansion of A. drepanolobium that forced the community to shift their mode of production. We confirmed that A. drepanolobium is an invasive indigenous woody species with multiple effects on the ecology of rangelands and on the livelihood security of pastoral communities.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Rangeland -- Plant response to elevated CO{sub 2}. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    An experiment is being designed to examine the influence of elevating CO2 levels on tallgrass prairie rangeland. Changes in biomass production, photosynthesis rates, and species composition (C3 versus C4) over time are to be examined. This report covers the period from August 15, 1988 to January 1, 1989. During this period the authors have had planning meetings in Manhattan, KS, and Washington, DC, with various investigators of the measurement and modeling groups within the elevated CO{sub 2} program. During this period detailed discussions with regard to the methodology were carried out. In addition, short-term experiments and prototype constructions were completed to assess design and materials. Because of changes in the methodology and, to a certain degree, the scope, they are requesting changes in the funding cycle to implement the project at the beginning of the growing cycle of the tallgrass prairie.

  5. Assessment of Landsat multispectral scanner spectral indexes for monitoring arid rangeland

    Science.gov (United States)

    Musick, H. B.

    1984-01-01

    Correlations between spectral indices and vegetation parameters in south-central New Mexico were used to determine the utility of Landsat Multispectral Scanner (MSS) spectral indices in arid rangeland monitoring. In addition, spectral index change for 1976-1980 was calculated from retrospective MSS data and compared with qualitative ground truth in order to evaluate vegetation change detection by means of spectral indices. Brightness index change consistently differentiated between cover increase and decrease, but index change appears to have been offset from true cover change; this may at least partly be attributed to the failure of the methods used to standardize MSS scenes for differences in sensor response. Green vegetation indices, by contrast to brightness indices, failed to consistently differentiate between cover increase and decrease.

  6. Evaluation of environmental change in rangelands of Uzbekistan with application of nuclear techniques approach

    International Nuclear Information System (INIS)

    Nasyrov, M.G.; Safarov, A.N.; Osmanov, B.S.

    2004-01-01

    Full text: Desertification and land degradation are a problem of major importance in the arid and semi-arid regions of the world. Deterioration of soil and plant cover has adversely affected nearly 50% of land areas as a result of extended droughts and human mismanagement of cultivated and rangelands. Due to several factors such as soil erosion, overgrazing, collection of plants and other anthropogenic activities the most part of these biomes are under degradation. The problem of assessments of current status of rangelands becomes very important days after days. Therefore, it needs to work out and implement new time and labor saving methods of assessment of current status of natural biomes. Soil erosion is a natural process caused by water, wind, and ice that have affected the earth's surface since the beginning if time. Man's activities often accelerate soil erosion. Soil erosion and its off-site, downstream damages are major concerns around the world causing losses in soil productivity, degradation of landscape, degradation of water quality, and loss of soil organic carbon. Current techniques for assessing soil erosion are (1) long-term soil erosion plot monitoring, (2) field surveys, and (3) soil erosion models (Evans, 1995). Each of this techniques has strengths and weaknesses. Over the last 30 years, research has shown the potential of using radioactive fallout 137 Cs to provide timely and quantitative estimates of soil erosion and redeposition at point, field, and reconnaissance scales. Applications of 137 Cs o provide an independent measurement of soil erosion rates, patterns, and redepositions are well-documented (Ritchie and McHenry, 1990). The unique advantages of the 137 Cs technique to study soil erosion rates and patterns are that it (a) requires only one trip to the field; (b) provides results quickly; (c) allows retrospective assessment of soil erosion rates; (d) provides average losses for 35 to 40 year period thus is less influenced by extreme

  7. Multifrequency passive microwave observations of soil moisture in an arid rangeland environment

    Science.gov (United States)

    Jackson, T. J.; Schmugge, T. J.; Parry, R.; Kustas, W. P.; Ritchie, J. C.; Shutko, A. M.; Khaldin, A.; Reutov, E.; Novichikhin, E.; Liberman, B.

    1992-01-01

    A cooperative experiment was conducted by teams from the U.S. and U.S.S.R. to evaluate passive microwave instruments and algorithms used to estimate surface soil moisture. Experiments were conducted as part of an interdisciplinary experiment in an arid rangeland watershed located in the southwest United States. Soviet microwave radiometers operating at wavelengths of 2.25, 21 and 27 cm were flown on a U.S. aircraft. Radio frequency interference limited usable data to the 2.25 and 21 cm systems. Data have been calibrated and compared to ground observations of soil moisture. These analyses showed that the 21 cm system could produce reliable and useful soil moisture information and that the 2.25 cm system was of no value for soil moisture estimation in this experiment.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Directory of Open Access Journals (Sweden)

    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. 

  11. Integrating Science and Land Management for the Conservation Effects Assessment Project (CEAP) in Southwestern Rangelands

    Science.gov (United States)

    Goodrich, D. C.; Heilman, P.; Nearing, M.; Speath, K.; Hernandez, M.; Wei, H.; Holifield-Collins, C.; Kautz, M.; Nichols, M.; Barlow, J.; Guertin, P.; Burns, S.; Stone, J. J.; Weltz, M.; Metz, L.; Norfleet, L.; Duriancik, L.; Johnson, M.

    2013-12-01

    Farm Bill legislation enacted by Congress in 2002 directed the U.S. Department of Agriculture to assess of the benefits and efficacy of conservation practices provided by a variety of USDA programs. Benefits include improved agricultural production, reduction of erosion and associated nutrient losses, improved water quality, improved soil resilience, and improved habitat among others. To conduct the assessment, the USDA initiated CEAP or the Conservation Effects Assessment Project in 2003, which included a national assessment complemented by small watershed studies. The national assessment started in eastern and midwestern cultivated croplands and has now progressed to western rangelands. This presentation will discuss the challenges of assessing the effects of rangeland conservation practices in a period of unusually hot and dry climatic conditions in the Cienega Creek Watershed (CCW) located southeast of Tucson, Arizona. As is common in the western U.S., the CCW consists of a patchwork of private and public lands in the west with much of the public lands leased for grazing cattle. The watershed also has high recreational value and provides many ecosystem services, including wildlife habitat qualities and flood protection to Tucson. A combination of monitoring, modeling, and remote sensing was utilized in the assessment. Conservation spending in the watershed ramped up in 1997. However, the 16-year period from 1997-2012 contains almost half of the 23 driest seasons (lowest 20 percentile) from the 117-year observed precipitation record. Initial results indicate that Landsat remotely sensed images can be effectively used to estimate both green and senescent canopy cover. This enabled detection of the impacts of drought and changes in canopy cover from practices such as prescribed fire and mechanical brush removal. Cienega Creek Watershed - Land Ownership

  12. The geomorphic legacy of water and erosion control structures in a semiarid rangeland watershed

    Science.gov (United States)

    Nichols, Mary H.; Magirl, Christopher S.; Sayre, N.F.; Shaw, Jeremy R.

    2018-01-01

    Control over water supply and distribution is critical for agriculture in drylands where manipulating surface runoff often serves the dual purpose of erosion control. However, little is known of the geomorphic impacts and legacy effects of rangeland water manipulation infrastructure, especially if not maintained. This study investigated the geomorphic impacts of structures such as earthen berms, water control gates, and stock tanks, in a semiarid rangeland in the southwestern USA that is responding to both regional channel incision that was initiated over a century ago, and a more recent land use change that involved cattle removal and abandonment of structures. The functional condition of remnant structures was inventoried, mapped, and assessed using aerial imagery and lidar data. Headcut initiation, scour, and channel incision associated with compromised lateral channel berms, concrete water control structures, floodplain water spreader berms, and stock tanks were identified as threats to floodplains and associated habitat. Almost half of 27 identified lateral channel berms (48%) have been breached and 15% have experienced lateral scour; 18% of 218 shorter water spreader berms have been breached and 17% have experienced lateral scour. A relatively small number of 117 stock tanks (6%) are identified as structurally compromised based on analysis of aerial imagery, although many currently do not provide consistent water supplies. In some cases, the onset of localized disturbance is recent enough that opportunities for mitigation can be identified to alter the potentially damaging erosion trajectories that are ultimately driven by regional geomorphic instability. Understanding the effects of prior land use and remnant structures on channel and floodplain morphologic condition is critical because both current land management and future land use options are constrained by inherited land use legacy effects.

  13. Mapping Erosion Risk in California's Rangelands Using the Universal Soil Loss Equation (USLE)

    Science.gov (United States)

    Salls, W. B.; O'Geen, T. T.

    2015-12-01

    Soil loss constitutes a multi-faceted problem for agriculture: in addition to reducing soil fertility and crop yield, it compromises downstream water quality. Sediment itself is a major issue for aquatic ecosystems, but also serves as a vector for transporting nutrients, pesticides, and pathogens. Rangelands are thought to be a contributor to water quality degradation in California, particularly in the northern Coast Range. Though total maximum daily loads (TMDLs) have been imposed in some watersheds, and countless rangeland water quality outreach activities have been conducted, the connection between grazing intensity recommendations and changes in water quality is poorly understood at the state level. This disconnect gives rise to poorly informed regulations and discourages adoption of best management practices by ranchers. By applying the Universal Soil Loss Equation (USLE) at a statewide scale, we highlighted areas most prone to erosion. We also investigated how two different grazing intensity scenarios affect modeled soil loss. Geospatial data layers representing the USLE parameters—rainfall erosivity, soil erodibility, slope length and steepness, and cover—were overlaid to model annual soil loss. Monitored suspended sediment data from a small North Coast watershed with grazing as the predominant land use was used to validate the model. Modeled soil loss values were nearly one order of magnitude higher than monitored values; average soil loss feeding the downstream-most site was modeled at 0.329 t ha-1 yr-1, whereas storm-derived sediment passing the site over two years was calculated to be 0.037 t ha-1 yr-1. This discrepancy may stem from the fact that the USLE models detached sediment, whereas stream monitoring reflects sediment detached and subsequently transported to the waterway. Preliminary findings from the statewide map support the concern that the North Coast is particularly at risk given its combination of intense rain, erodible soils, and

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. 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

  17. 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.

  18. Genetic divergence among Brazilian turmeric germplasm using morpho-agronomical descriptors

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya

    OpenAIRE

    Opiyo, Francis EO; Ekaya, Wellington N; Nyariki, Dickson M; Mureithi, Stephen Mwangi

    2011-01-01

    Semi-arid rangelands in Kenya are an important source of forage for both domestic and wild animals. However, indigenous perennial grasses notably Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye grass) are disappearing at an alarming rate. Efforts to re-introduce them through restoration programs have often yielded little success. This can partly be attributed to failure of topsoil to capture and store scarce water to me...

  6. Grazing exclusion, substrate type, and drought frequency affect plant community structure in rangelands of the arid unpredictable Arabian Deserts

    Science.gov (United States)

    El-Keblawy, Ali; El-Sheikh, Mohamed

    2017-04-01

    Grazing and drought can adversely affect the ecology and management of rangeland ecosystems. Several management actions have been applied to restore species diversity and community structure in degraded rangelands of the unpredictable arid environment. Protection from grazing is considered as a proper approach for restoration of degraded rangelands, but this depends on substrate type and sometime is hindered with water deficiency (drought). In this study, the effect of protection from grazing animals on species diversity and plant community structure was assessed after a dry and wet periods in both sandy and gravelly substrates in the Dubai Desert Conservation reserve (DDCR), United Arab Emirates. Two sites were selected during November 2012 on the two substrate types (fixed sandy flat and gravel plain) in the arid DDCR. An enclosure was established in each site. Plant community attributes (plant cover, density, frequency, species composition, and diversity indices) were assessed in a number of permanent plots laid inside and outside each enclosure during November 2012, April 2014 and April 2016. The results showed that protection improved clay content, but decreased the organic matters. Interestingly, the protection reduced the concentrations of most estimated nutrients, which could be attributed to the high turnover rate of nutrients associated grazing and low decomposition of accumulated dry plants of non-protected sites. Protection significantly increased all plant community attributes, but the only significant effect was for plant density. Plant density was almost twice greater inside than outside the enclosures. During the dry period, protection resulted in significantly greater deterioration in cover, density and all diversity indices in gravel, compared to sandy sites. Most of the grasses and shrubby plants had died in the gravel plains. However, plant community of the gravel plains was significantly restored after receiving considerable rainfalls. The

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  10. Effects of land use change and management on SOC and soil quality in Mediterranean rangelands areas

    Science.gov (United States)

    Parras-Alcántara, Luis; Lozano-García, Beatriz; Requejo, Ana; Zornoza, Raúl

    2017-04-01

    INTRODUCTION Rangelands in the Iberian Peninsula occupy more than 90,000 km2. These rangelands were created from the former Mediterranean oak forests, mainly composed of holm oak and cork oak (Quercus ilex rotundifolia and Quercus suber), by clear-cutting shrubs, removing selected trees and cultivating. These man-made landscapes are called 'dehesas' in Spain and 'montados' in Portugal. Between 1955 and 1981, more than 5,000 km2 of dehesas was converted from pastureland to cultivated land. This process has been accelerated since 1986 owing to subsidies from the European Common Agricultural Policy (Parras-Alcántara et al., 2015a). The role that natural rangelands play in the global carbon cycle is extremely important, accounting for 10-30% of the world's total soil organic carbon (SOC), in addition, SOC concentration is closely related to soil quality and vegetation productivity (Brevik, 2012). Therefore, to study the land use and management changes is important, particularly in Mediterranean soils, as they are characterized by low organic carbon content, furthermore, the continuous use of ploughing for grain production is the principal cause of soil degradation. Therefore, land use decisions and management systems can increase or decrease SOC content and stock (Corral-Fernández et al., 2013; Parras-Alcántara et al., 2014, 2015a and 2015b; Parras-Alcántara and Lozano-García, 2014) MATERIAL AND METHODS A field study was conducted to determine the land use change (Mediterranean evergreen oak woodland to olive grove and cereal, all of them managed under conventional tillage and under conservationist practices) effects on SOC stocks and the soil quality (Stratification Ratio) in Los Pedroches valley, southern Spain. RESULTS Results for the present study indicate that management practices had little effect on SOC storage in dehesas. The stratification ratio was >2 both under conventional tillage and under organic farming, so, soils under dehesa had high quality

  11. Genome resource banking of biomedically important laboratory animals.

    Science.gov (United States)

    Agca, Yuksel

    2012-11-01

    Genome resource banking is the systematic collection, storage, and redistribution of biomaterials in an organized, logistical, and secure manner. Genome cryobanks usually contain biomaterials and associated genomic information essential for progression of biomedicine, human health, and research. In that regard, appropriate genome cryobanks could provide essential biomaterials for both current and future research projects in the form of various cell types and tissues, including sperm, oocytes, embryos, embryonic or adult stem cells, induced pluripotent stem cells, and gonadal tissues. In addition to cryobanked germplasm, cryobanking of DNA, serum, blood products, and tissues from scientifically, economically, and ecologically important species has become a common practice. For revitalization of the whole organism, cryopreserved germplasm in conjunction with assisted reproductive technologies, offer a powerful approach for research model management, as well as assisting in animal production for agriculture, conservation, and human reproductive medicine. Recently, many developed and developing countries have allocated substantial resources to establish genome resources banks which are responsible for safeguarding scientifically, economically, and ecologically important wild type, mutant, and transgenic plants, fish, and local livestock breeds, as well as wildlife species. This review is dedicated to the memory of Dr. John K. Critser, who has made profound contributions to the science of cryobiology and establishment of genome research and resources centers for mice, rats, and swine. Emphasis will be given to application of genome resource banks to species with substantial contributions to the advancement of biomedicine and human health. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Online Resources

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Online Resources. Journal of Genetics. Online Resources. Volume 97. 2018 | Online resources. Volume 96. 2017 | Online resources. Volume 95. 2016 | Online resources. Volume 94. 2015 | Online resources. Volume 93. 2014 | Online resources. Volume 92. 2013 | Online resources ...

  13. Estimating Rangeland Forage Production Using Remote Sensing Data from a Small Unmanned Aerial System (sUAS)

    Science.gov (United States)

    Liu, H.; Jin, Y.; Devine, S.; Dahlgren, R. A.; Covello, S.; Larsen, R.; O'Geen, A. T.

    2017-12-01

    California rangelands cover 23 million hectares and support a $3.4 billion annual cattle industry. Rangeland forage production varies appreciably from year-to-year and across short distances on the landscape. Spatially explicit and near real-time information on forage production at a high resolution is critical for effective rangeland management, especially during an era of climatic extremes. We here integrated a multispectral MicaSense RedEdge camera with a 3DR solo quad-copter and acquired time-series images during the 2017 growing season over a topographically complex 10-hectare rangeland in San Luis Obispo County, CA. Soil moisture and temperature sensors were installed at 16 landscape positions, and vegetation clippings were collected at 36 plots to quantify forage dry biomass. We built four centimeter-level models for forage production mapping using time series of sUAS images and ground measurements of forage biomass and soil temperature and moisture. The biophysical model based on Monteith's eco-physiological plant growth theory estimated forage production reasonably well with a coefficient of determination (R2) of 0.86 and a root-mean-square error (RMSE) of 424 kg/ha when the soil parameters were included, and a R2 of 0.79 and a RMSE of 510 kg/ha when only remote sensing and topographical variables were included. We built two empirical models of forage production using a stepwise variable selection technique, one with soil variables. Results showed that cumulative absorbed photosynthetically active radiation (APAR) and elevation were the most important variables in both models, explaining more than 40% of the spatio-temporal variance in forage production. Soil moisture accounted for an additional 29% of the variance. Illumination condition was selected as a proxy for soil moisture in the model without soil variables, and accounted for 18% of the variance. We applied the remote sensing-based models to map daily forage production at 30-cm resolution for the

  14. Improving dynamic global vegetation model (DGVM) simulation of western U.S. rangelands vegetation seasonal phenology and productivity

    Science.gov (United States)

    Kerns, B. K.; Kim, J. B.; Day, M. A.; Pitts, B.; Drapek, R. J.

    2017-12-01

    Ecosystem process models are increasingly being used in regional assessments to explore potential changes in future vegetation and NPP due to climate change. We use the dynamic global vegetation model MAPSS-Century 2 (MC2) as one line of evidence for regional climate change vulnerability assessments for the US Forest Service, focusing our fine tuning model calibration from observational sources related to forest vegetation. However, there is much interest in understanding projected changes for arid rangelands in the western US such as grasslands, shrublands, and woodlands. Rangelands provide many ecosystem service benefits and local rural human community sustainability, habitat for threatened and endangered species, and are threatened by annual grass invasion. Past work suggested MC2 performance related to arid rangeland plant functional types (PFT's) was poor, and the model has difficulty distinguishing annual versus perennial grasslands. Our objectives are to increase the model performance for rangeland simulations and explore the potential for splitting the grass plant functional type into annual and perennial. We used the tri-state Blue Mountain Ecoregion as our study area and maps of potential vegetation from interpolated ground data, the National Land Cover Data Database, and ancillary NPP data derived from the MODIS satellite. MC2 historical simulations for the area overestimated woodland occurrence and underestimated shrubland and grassland PFT's. The spatial location of the rangeland PFT's also often did not align well with observational data. While some disagreement may be due to differences in the respective classification rules, the errors are largely linked to MC2's tree and grass biogeography and physiology algorithms. Presently, only grass and forest productivity measures and carbon stocks are used to distinguish PFT's. MC2 grass and tree productivity simulation is problematic, in particular grass seasonal phenology in relation to seasonal patterns

  15. Modeling vegetation heights from high resolution stereo aerial photography: an application for broad-scale rangeland monitoring.

    Science.gov (United States)

    Gillan, Jeffrey K; Karl, Jason W; Duniway, Michael; Elaksher, Ahmed

    2014-11-01

    Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights are often too costly and time consuming to apply at these broad scales. Most emerging remote sensing techniques capable of measuring surface and vegetation height (e.g., LiDAR or synthetic aperture radar) are often too expensive, and require specialized sensors. An alternative remote sensing approach that is potentially more practical for managers is to measure vegetation heights from digital stereo aerial photographs. As aerial photography is already commonly used for rangeland monitoring, acquiring it in stereo enables three-dimensional modeling and estimation of vegetation height. The purpose of this study was to test the feasibility and accuracy of estimating shrub heights from high-resolution (HR, 3-cm ground sampling distance) digital stereo-pair aerial images. Overlapping HR imagery was taken in March 2009 near Lake Mead, Nevada and 5-cm resolution digital surface models (DSMs) were created by photogrammetric methods (aerial triangulation, digital image matching) for twenty-six test plots. We compared the heights of individual shrubs and plot averages derived from the DSMs to field measurements. We found strong positive correlations between field and image measurements for several metrics. Individual shrub heights tended to be underestimated in the imagery, however, accuracy was higher for dense, compact shrubs compared with shrubs with thin branches. Plot averages of shrub height from DSMs were also strongly correlated to field measurements but consistently underestimated. Grasses and forbs were generally too small to be detected with the resolution of the DSMs. Estimates of

  16. Soils as a Solution: The Potential of Rangelands to Contribute to Climate Change Mitigation

    Science.gov (United States)

    Silver, W. L.; Ryals, R.; DeLonge, M. S.; Owen, J. J.

    2015-12-01

    The majority of soil-related climate change research has focused on describing the problem - estimating rates of carbon (C) losses and greenhouse gas (GHG) emissions from natural and managed ecosystems. More research is needed to explore potential solutions to climate change through mitigation and adaptation. Here we report on an integrated set of studies aimed at critically evaluating the biogeochemical potential of rangeland soils to help mitigate climate change, while improving the sustainability and productivity of food production systems. We explored direct effects through enhanced net primary production (NPP) and soil C sequestration, and indirect effects through diversion of high emitting sources to lower emitting organic matter dynamics. We used a combination of long- and short-term field experiments, modeling, laboratory assays, life cycle assessment (LCA), and meta-analyses in consultation with a diverse group of stakeholders from both the private and public sectors. We found that organic matter amendments held particularly strong potential. Compost amendments increased soil C storage by 0.5-1.0 Mg C ha-1 y-1 in surface soils over 5 y, and increased NPP and water holding capacity. We measured 1.0 Mg of new C ha-1 y-1 over 3 y. Long-term amendment of cattle manure increased surface soil C by 19.0±7.3 Mg C ha-1 relative to unmanured fields. However, field and modeling experiments suggested that manure amendments lead to large nitrous oxide emissions that eventually eliminated CO2e benefits, whereas compost amendments continued to benefit climate for decades longer. An LCA identified a broader range of climate impacts. When scaled to an area of 25% of California's rangelands, new C sequestered following compost amendments (21 million Mg CO2e) exceeded emissions from cattle (15 million Mg CO2e); diverting organics from waste streams to amendments led to additional GHG savings. In collaboration with our partners, our research contributed to the development of

  17. Combined effects of leaf litter and soil microsite on decomposition process in arid rangelands.

    Science.gov (United States)

    Carrera, Analía Lorena; Bertiller, Mónica Beatriz

    2013-01-15

    The objective of this study was to analyze the combined effects of leaf litter quality and soil properties on litter decomposition and soil nitrogen (N) mineralization at conserved (C) and disturbed by sheep grazing (D) vegetation states in arid rangelands of the Patagonian Monte. It was hypothesized that spatial differences in soil inorganic-N levels have larger impact on decomposition processes of non-recalcitrant than recalcitrant leaf litter (low and high concentration of secondary compounds, respectively). Leaf litter and upper soil were extracted from modal size plant patches (patch microsite) and the associated inter-patch area (inter-patch microsite) in C and D. Leaf litter was pooled per vegetation state and soil was pooled combining vegetation state and microsite. Concentrations of N and secondary compounds in leaf litter and total and inorganic-N in soil were assessed at each pooled sample. Leaf litter decay and soil N mineralization at microsites of C and D were estimated in 160 microcosms incubated at field capacity (16 month). C soils had higher total N than D soils (0.58 and 0.41 mg/g, respectively). Patch soil of C and inter-patch soil of D exhibited the highest values of inorganic-N (8.8 and 8.4 μg/g, respectively). Leaf litter of C was less recalcitrant and decomposed faster than that of D. Non-recalcitrant leaf litter decay and induced soil N mineralization had larger variation among microsites (coefficients of variation = 25 and 41%, respectively) than recalcitrant leaf litter (coefficients of variation = 12 and 32%, respectively). Changes in the canopy structure induced by grazing disturbance increased leaf litter recalcitrance, and reduced litter decay and soil N mineralization, independently of soil N levels. This highlights the importance of the combined effects of soil and leaf litter properties on N cycling probably with consequences for vegetation reestablishment and dynamics, rangeland resistance and resilience with implications

  18. Using a dynamic model to assess trends in land degradation by water erosion in Spanish Rangelands

    Science.gov (United States)

    Ibáñez, Javier; Francisco Lavado-Contador, Joaquín; Schnabel, Susanne; Pulido-Fernández, Manuel; Martínez Valderrama, Jaime

    2014-05-01

    This work presents a model aimed at evaluating land degradation by water erosion in dehesas and montados of the Iberian Peninsula, that constitute valuable rangelands in the area. A multidisciplinary dynamic model was built including weather, biophysical and economic variables that reflect the main causes and processes affecting sheet erosion on hillsides of the study areas. The model has two main and two derived purposes: Purpose 1: Assessing the risk of degradation that a land-use system is running. Derived purpose 1: Early warning about land-use systems that are particularly threatened by degradation. Purpose 2: Assessing the degree to which different factors would hasten degradation if they changed from the typical values they show at present. Derived purpose 2: Evaluating the role of human activities on degradation. Model variables and parameters have been calibrated for a typical open woodland rangeland (dehesa or montado) defined along 22 working units selected from 10 representative farms and distributed throughout the Spanish region of Extremadura. The model is the basis for a straightforward assessment methodology which is summarized by the three following points: i) The risk of losing a given amount of soil before a given number of years was specifically estimated as the percentage of 1000 simulations where such a loss occurs, being the simulations run under randomly-generated scenarios of rainfall amount and intensity and meat and supplemental feed market prices; ii) Statistics about the length of time that a given amount of soil takes to be lost were calculated over 1000 stochastic simulations run until year 1000, thereby ensuring that such amount of soil has been lost in all of the simulations, i.e. the total risk is 100%; iii) Exogenous factors potentially affecting degradation, mainly climatic and economic, were ranked in order of importance by means of a sensitivity analysis. Particularly remarkable in terms of model performance is the major role

  19. Application of MODIS Land Products to Assessment of Land Degradation of Alpine Rangeland in Northern India with Limited Ground-Based Information

    Directory of Open Access Journals (Sweden)

    Masahiro Tasumi

    2014-09-01

    Full Text Available Land degradation of alpine rangeland in Dachigam National Park, Northern India, was evaluated in this study using MODerate resolution Imaging Spectroradiometer (MODIS land products. The park has been used by a variety of livestock holders. With increasing numbers of livestock, the managers and users of the park are apprehensive about degradation of the grazing land. However, owing to weak infrastructure for scientific and statistical data collection and sociopolitical restrictions in the region, a lack of quality ground-based weather, vegetation, and livestock statistical data had prevented scientific assessment. Under these circumstances, the present study aimed to assess the rangeland environment and its degradation using MODIS vegetation, snow, and evapotranspiration products as primary input data for assessment. The result of the analysis indicated that soil water content and the timing of snowmelt play an important role in grass production in the area. Additionally, the possibility of land degradation in heavily-grazed rangeland was indicated via a multiple regression analysis at a decadal timescale, whereas weather conditions, such as rainfall and snow cover, primarily explained year-by-year differences in grass production. Although statistical uncertainties remain in the results derived in this study, the satellite-based data and the analyses will promote understanding of the rangeland environment and suggest the potential for unsustainable land management based on statistical probability. This study provides an important initial evaluation of alpine rangeland, for which ground-based information is limited.

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

    Directory of Open Access Journals (Sweden)

    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

  1. 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

  2. Inventory of forest and rangeland resources, including forest stress. [Atlanta, Georgia, Black Hills, and Manitou, Colorado test sites

    Science.gov (United States)

    Heller, R. C.; Aldrich, R. C.; Weber, F. P.; Driscoll, R. S. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Some current beetle-killed ponderosa pine can be detected on S190-B photography imaged over the Bear Lodge mountains in the Black Hills National Forest. Detections were made on SL-3 imagery (September 13, 1973) using a zoom lens microscope to view the photography. At this time correlations have not been made to all of the known infestation spots in the Bear Lodge mountains; rather, known infestations have been located on the SL-3 imagery. It was determined that the beetle-killed trees were current kills by stereo viewing of SL-3 imagery on one side and SL-2 on the other. A successful technique was developed for mapping current beetle-killed pine using MSS imagery from mission 247 flown by the C-130 over the Black Hills test site in September 1973. Color enhancement processing on the NASA/JSC, DAS system using three MSS channels produced an excellent quality detection map for current kill pine. More importantly it provides a way to inventory the dead trees by relating PCM counts to actual numbers of dead trees.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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)

  9. Herpes - resources

    Science.gov (United States)

    Genital herpes - resources; Resources - genital herpes ... following organizations are good resources for information on genital herpes : March of Dimes -- www.marchofdimes.org/complications/sexually- ...

  10. Effects of livestock grazing on grasshopper abundance on a native rangeland in Montana.

    Science.gov (United States)

    O'Neill, Kevin M; Olson, Bret E; Wallander, Roseann; Rolston, Marni G; Seibert, Catherine E

    2010-06-01

    Livestock grazing can affect habitat quality for grasshoppers through effects on food and oviposition site availability, microclimate, and other factors. Because of this, some authors have suggested that grazing programs can be used to help manage pest grasshopper populations. In a 6-yr study, we controlled access of cattle to replicated experimental plots on an Agropyron spicatum/Poa sandbergii pasture to create consistent year-to-year differences in postgrazing plant cover, with resultant affects on microclimate. After sampling grasshoppers multiple times after grazing treatments each summer, we found evidence of between-treatment differences in grasshopper abundance for the entire assemblage during 4 of the 6 yr. Some species, including Melanoplus sanguinipes (perhaps the worse rangeland grasshopper pest in the western United States), tended to be more abundant on ungrazed plots, whereas Melanoplus gladstoni often had greater densities on heavily-grazed plots. The effect of grazing on grasshopper densities in this study was lower in magnitude and less consistent among years than in a study we conducted simultaneously at a nearby site where the vegetation was dominated by the exotic species crested wheatgrass (Agropyron cristatum). Our results generally support proposals that grazing could be used to reduce pest grasshopper densities, although the effectiveness of a particular grazing scheme may vary among sites, years, and grasshopper and vegetation assemblages.

  11. Prevalence of gastrointestinal nematode infections in goat flocks on semi-arid rangelands of northeastern Mexico.

    Science.gov (United States)

    Olivas-Salazar, Raquel; Estrada-Angulo, Alfredo; Mellado, Miguel; Aguilar-Caballero, Armando Jacinto; Castro-Pérez, Beatriz Isabel; Gutiérrez-Blanco, Eduardo; Ruiz-Zárate, Fernando

    2018-04-01

    The objective of this study was to determine the prevalence of gastrointestinal nematode (GIN) infection in goat flocks on semi-arid rangelands of northeastern Mexico (25° N, 350-400 mm annual precipitation). The study included 668 pluriparous goats from 18 herds in five municipalities of Coahuila and Nuevo Leon, Mexico. Five genetic groups were considered (predominance of Boer, Nubian, Alpine, Saanen, and Toggenburg). Fecal samples were taken from the rectum of each animal to determine the number of eggs per gram (EPG) of GIN. The prevalence of flocks with GIN infections was 88.9%. Similar results were observed for the number of goats infected in the flocks. The Alpine breed presented the highest prevalence and highest EPG loads of GIN, whereas Boer and Nubian were the genetic groups with the lowest (P arid zones of Mexico was found a high prevalence of infections with gastrointestinal nematodes. The municipality and the breed of the animals were factors that showed influence on this prevalence and the level of infection of the goats.

  12. BITES RATE ON NATIVE VEGETATION BY TRASHUMANCE GOATS GRAZING IN MOUNTAIN RANGELAND IN NUDO MIXTECO, MEXICO

    Directory of Open Access Journals (Sweden)

    F.J. Franco-Guerra

    2014-08-01

    Full Text Available The objective of the present study was to determine the habits of grazing-browsing by the rate of bites and rate of consumption in the dry matter (MS of the diet of goats under transhumance grazing in mountain rangelands of Nudo Mixteco, being the natural vegetation in the different strata. Six animals of different age and sex were randomly chosen. Direct observation of grazing method was used to determine the rate of bites/min and the rate of consumption by layers. Analyzes of variance was performed and the Tukey test was used for mean comparison test was used (HSD Tukey (α, 0.05. The values of both variables were small, which may be due to the great diversity of plants and their varied morphology which induces the goat won on the one hand to spend more time in the choice of food becoming more selective and on the other, to carry out bites smaller in those plants whose leaf surface is of the type megafilia or in those woody whose leaves are very small (microphilia 2.25 cm2 to 20.25 cm2.

  13. Pastoralism and wildlife: historical and current perspectives in the East African rangelands of Kenya and Tanzania.

    Science.gov (United States)

    Lankester, F; Davis, A

    2016-11-01

    The relationship between pastoralists, their livestock, wildlife and the rangelands of East Africa is multi-directional, complex and long-standing. The tumultuous events of the past century, however, have rewritten the nature of this relationship, reshaping the landscapes that were created, and relied upon, by both pastoralists and wildlife. Presently, much of the interaction between wildlife and pastoralists takes place in and around protected areas, the most contentious occurring in pastoral lands surrounding national parks. In conservation terminology these areas are called buffer zones. In the past century buffer zones have been shaped by, and contributed to, restrictive conservation policies, expropriation of land, efforts to include communities in conservation, both positive and negative wildlife/livestock interactions, and political tensions. In this review paper, the authors outline the history that shaped the current relationship between pastoralists, livestock and wildlife in buffer zones in East Africa and highlight some of the broader issues that pastoralists (and pastoralism as an effective livelihood strategy) now face. Finally, they consider some of the sustainable and equitable practices that could be implemented to improve livelihoods and benefit wildlife and pastoralism alike.

  14. 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

  15. The Current Status of Germplum Database: a Tool for Characterization of Plum Genetic Resources in Romania

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    Monica Harta

    2016-11-01

    Full Text Available In Romania, Prunus genetic resources are kept in collections of varieties, populations and biotypes, mainly located in research and development institutes or fruit growing stations and, in the last years, by some private enterprises. Creating the experimental model for the Germplum database based on phenotypic descriptors and SSR molecular markers analysis is an important and topical objective for the efficient characterization of genetic resources and also for establishing a public-private partnership for the effective management of plum germplasm resources in Romania. The technical development of the Germplum database was completed and data will be added continuously after characterizing each new accession.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Seed biometric parameters in oil palm accessions from a Brazilian germplasm bank

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    Julcéia Camillo

    2014-08-01

    Full Text Available The objective of this work was to evaluate the morphological diversity of oil palm seeds and to cluster the accessions according to their morphological characteristics. Forty-one accessions from the oil palm germplasm bank of Embrapa Amazônia Ocidental were evaluated - 18 of Elaeis oleifera and 23 of E. guineensis. The groups were formed based on morphological characteristics, by principal component analysis. In E. oleifera, four groups were formed, tied to their region of origin, but with significant morphological differences between accessions from the same population. For tenera-type E. guineensis seeds, three widely divergent groups were formed, especially as to external parameters, which differentiated them from the other ones. The parameter endocarp thickness stood out in intra- and inter-population differentiation. For dura-type E. guineensis, three groups were formed, with larger seeds and thicker endocarps, which differed from all the other ones. The variability observed for seed characteristics in the analyzed accessions allows the establishment of different groups, to define strategies for genetic improvement.

  2. 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)

  3. 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)

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

    Science.gov (United States)

    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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Endemic shrubs in temperate arid and semiarid regions of northern China and their potentials for rangeland restoration.

    Science.gov (United States)

    Chu, Jianmin; Yang, Hongxiao; Lu, Qi; Zhang, Xiaoyan

    2015-06-03

    Some endemic shrubs in arid and semiarid ecosystems are in danger of extinction, and yet they can play useful roles in maintaining or restoring these ecosystems, thus practical efforts are needed to conserve them. The shrubs Amygdalus pedunculata Pall., Amygdalus mongolica (Maxim.) Ricker and Ammopiptanthus mongolicus (Maxim. ex Kom.) Cheng f. are endemic species in arid and semiarid regions of northern China, where rangeland desertification is pronounced due to chronic overgrazing. In this study, we tested the hypothesis that these endemic shrubs have developed adaptations to arid and semiarid environments and could play critical roles as nurse species to initiate the process of rangeland recovery. Based on careful vegetation surveys, we analysed the niches of these species in relation to precipitation, temperature and habitats. All sampling plots were categorized by these endemics and sorted by the non-metric multidimensional scaling method. Species ratios of each life form and species co-occurrence rates with the endemics were also evaluated. Annual average temperature and annual precipitation were found to be the key factors determining vegetation diversity and distributions. Amygdalus pedunculata prefers low hills and sandy land in temperate semiarid regions. Amygdalus mongolica prefers gravel deserts of temperate semiarid regions. Ammopiptanthus mongolicus prefers sandy land of temperate arid regions. Communities of A. pedunculata have the highest diversity and the largest ratios of long-lived grass species, whereas those of A. mongolicus have the lowest diversity but the largest ratios of shrub species. Communities of A. mongolica are a transition between the first two community types. These findings demonstrate that our focal endemic shrubs have evolved adaptations to arid and semiarid conditions, thus they can be nurse plants to stabilize sand ground for vegetation restoration. We suggest that land managers begin using these shrub species to restore

  17. Herbaceous Legume Encroachment Reduces Grass Productivity and Density in Arid Rangelands.

    Directory of Open Access Journals (Sweden)

    Thomas C Wagner

    Full Text Available Worldwide savannas and arid grasslands are mainly used for livestock grazing, providing livelihood to over a billion people. While normally dominated by perennial C4 grasses, these rangelands are increasingly affected by the massive spread of native, mainly woody legumes. The consequences are often a repression of grass cover and productivity, leading to a reduced carrying capacity. While such encroachment by woody plants has been extensively researched, studies on similar processes involving herbaceous species are rare. We studied the impact of a sustained and massive spread of the native herbaceous legume Crotalaria podocarpa in Namibia's escarpment region on the locally dominant fodder grasses Stipagrostis ciliata and Stipagrostis uniplumis. We measured tussock densities, biomass production of individual tussocks and tussock dormancy state of Stipagrostis on ten 10 m x 10 m plots affected and ten similarly-sized plots unaffected by C. podocarpa over eight consecutive years and under different seasonal rainfalls and estimated the potential relative productivity of the land. We found the percentage of active Stipagrostis tussocks and the biomass production of individual tussocks to increase asymptotically with higher seasonal rainfall reaching a maximum around 300 mm while the land's relative productivity under average local rainfall conditions reached only 40% of its potential. Crotalaria podocarpa encroachment had no effect on the proportion of productive grass tussocks, but reduced he productivity of individual Stipagrostis tussocks by a third. This effect of C. podocarpa on grass productivity was immediate and direct and was not compensated for by above-average rainfall. Besides this immediate effect, over time, the density of grass tussocks declined by more than 50% in areas encroached by C. podocarpa further and lastingly reducing the lands carrying capacity. The effects of C. podocarpa on grass productivity hereby resemble those of woody

  18. How best to quantify soil seed banks in arid rangelands of the Nama Karoo?

    Science.gov (United States)

    Dreber, Niels

    2011-02-01

    Sampling design and three sample treatments prior the application of the seedling emergence method were tested in order to find the best method for seed bank quantification in arid Nama Karoo rangelands. I analyzed species composition and seed densities by contrasting undercanopy and open-matrix samples from two soil depths and by comparing the effects of cold-, heat-, and no stratification on germination rates of species in a greenhouse setting. The soil seed bank showed minimal similarity to the standing vegetation, with only 20 plant species germinated. Spatial distribution of seeds was highly heterogeneous. Nearly 90% of germinated seeds were located in 0- to 4-cm compared to >4- to 8-cm soil depth. Undercanopy seed banks contained significantly more species and seeds than open-matrix seed banks. Neither the number nor the diversity of seeds germinated differed significantly among the three treatments. Cold stratification tended to detect more species and seeds only at >4- to 8-cm soil depth. The results highlight the importance of spatial heterogeneity in the accurate evaluation of soil seed banks in the arid Nama Karoo and the importance of considering seasonal variability in the availability of readily germinable seeds. Data also suggest that sample pretreatment in germination trials may give little return for cost and effort, which emphasizes that it is more important to choose the sampling design most likely to give a representative number of seed bank species. Further studies are needed to analyze seed bank dynamics and species-specific germination requirements to promote recruitment of plant taxa underrepresented in the seed bank.

  19. Mountain home known geothermal resource area: an environmental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, S.G.; Russell, B.F. (eds.)

    1979-09-01

    The Mountain Home KGRA encompasses an area of 3853 hectares (ha) at the foot of the Mount Bennett Hills in Elmore County, Idaho. The site is associated with an arid climate and high winds that generate an acute dust problem. The KGRA lies adjacent to the northwest-southeast trending fault zone that reflects the northern boundary of the western Snake River Plain graben. Data indicate that a careful analysis of the subsidence potential is needed prior to extensive geothermal development. Surface water resources are confined to several small creeks. Lands are utilized for irrigated farmlands and rangeland for livestock. There are no apparent soil limitations to geothermal development. Sage grouse and mule deer are the major species of concern. The potential of locating significant heritage resources other than the Oregon Trail or the bathhouse debris appears to be relatively slight.

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

    Directory of Open Access Journals (Sweden)

    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.