WorldWideScience

Sample records for spot disease resistance

  1. Resistance to leaf spot disease in peanut

    International Nuclear Information System (INIS)

    Soriano, J.D.

    1988-01-01

    Full text: Leaf spot disease causes defoliation of peanut plants during pod development thereby reducing yield. To induce mutations for resistance to the disease, dormant seeds of peanut were irradiated with 10-40 kR gamma rays with pre- and post-irradiation treatments to minimize radiation damage. Spores of the causal fungi, Cercospora arachidicola Hori and Cercosporidium personatum (B and C) Deigh., were cultured under asceptic conditions in PDA medium with 2-3 drops of 10% table salt solution to enhance development of spores. The first two leaves of M 2 seedlings were hand-inoculated two or three times in the field at one week intervals. Out of a total of 2,453 M 2 seedlings inoculated thrice, 9 plants showed complete resistance based on degree of infection. However, after recurrent selection, only 3 M 5 lines gave complete resistance, the rest exhibiting only intermediate resistance. The disease resistant lines yielded almost twice as much as several commercial varieties due to extensive leaf defoliation in the latter. One of the mutant lines is being crossed with some popular susceptible varieties. Inheritance studies showed that leaf spot resistance is governed by two recessive mutant genes acting complementary. The F 2 ratio was close to 15:1. The mutant lines are presently evaluated through the Bureau of Plant Industry before seeds are distributed to peanut growers. (author)

  2. Mutant of Japanese pear resistant to Black Spot Disease

    International Nuclear Information System (INIS)

    Sanada, T.; Nishida, T.; Ikeda, F.

    1987-01-01

    Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

  3. Ring spot disease of brassica crops : resistance and epidemiology

    NARCIS (Netherlands)

    Ende, van den J.E.

    1998-01-01

    Ring spot disease of brassica crops is caused by the fungus Mycosphaerella brassicicola . The disease can cause severe qualitative and quantitative losses, depending on the initial inoculum, the environmental conditions during the growing season and the susceptibility

  4. prevalence of angular leaf spot disease and sources of resistance

    African Journals Online (AJOL)

    USER

    la gravité et l'incidence de la maladie et l'effet des pratiques agronomiques et des facteurs environnement aux sur la prévalence de ...... Thika Kenya. Saettler, A.W. 1991. Angular leaf spot. In: Compendium of bean diseases, 15-16. Hall, R. (Ed.). APS Press.St Paul, USA. Sahile, S., Ahmed, S., Fininsa, C., Abang, M. M. and ...

  5. prevalence of angular leaf spot disease and sources of resistance

    African Journals Online (AJOL)

    USER

    2017-02-17

    Feb 17, 2017 ... Some of these varieties possess useful traits, in addition to acceptable seed market class, and are hence recommended as suitable parents for ALS resistant variety development and promotion in ALS prone environments. Key Words: Phaseolus vulgaris, Pseudocercospora griseola, severity. RÉSUMÉ.

  6. Transgenic resistance confers effective field level control of bacterial spot disease in tomato.

    Directory of Open Access Journals (Sweden)

    Diana M Horvath

    Full Text Available We investigated whether lines of transgenic tomato (Solanum lycopersicum expressing the Bs2 resistance gene from pepper, a close relative of tomato, demonstrate improved resistance to bacterial spot disease caused by Xanthomonas species in replicated multi-year field trials under commercial type growing conditions. We report that the presence of the Bs2 gene in the highly susceptible VF 36 background reduced disease to extremely low levels, and VF 36-Bs2 plants displayed the lowest disease severity amongst all tomato varieties tested, including commercial and breeding lines with host resistance. Yields of marketable fruit from transgenic lines were typically 2.5 times that of the non-transformed parent line, but varied between 1.5 and 11.5 fold depending on weather conditions and disease pressure. Trials were conducted without application of any copper-based bactericides, presently in wide use despite negative impacts on the environment. This is the first demonstration of effective field resistance in a transgenic genotype based on a plant R gene and provides an opportunity for control of a devastating pathogen while eliminating ineffective copper pesticides.

  7. Resistant mutant to black spot disease of Japanese pear 'Nijisseiki' induced by gamma rays

    International Nuclear Information System (INIS)

    Sanada, T.; Nishida, T.; Ikeda, F.

    1988-01-01

    A resistant mutant of Japanese pear to black spot disease was induced from the susceptible ‘Nijisseiki’ by chronic irradiation in a gamma-field. The symptoms of black spot disease on the mutant observed under field conditions for a period of 5 years after selection were minimal. Characteristics and degree of resistance of this mutant were examined. 1. The induced mutant obviously differed from ‘Nijisseiki’ in the susceptibility to the disease when spores or the phytotoxin of the pathogen were artificially inoculated on leaves and fruits. Resistance to black spot disease exhibited by this mutant, however, seemed to be rather intermediate when compared to the full resistance exhibited by the resistant ‘Chojuro’. 2. Degree of resistance to alternaria blotch which is one of the apple diseases, was examined in the induced mutant and ‘Nijisseiki’, since it had been reported that ‘Nijisseiki’ was susceptible to this apple disease, too. Both materials were susceptible to alternaria blotch, but the susceptibility of the mutant was very low. These results suggested that there would be no serious problem of infection by black spot or alternaria blotch disease in practical cultivation of this mutant. (author)

  8. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    Science.gov (United States)

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

  9. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot

    OpenAIRE

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-01-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30??C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other impo...

  10. Selection of mutants resistant to black spot disease by chronic irradiation of gamma-rays in Japanese pear 'Osanijisseiki'

    International Nuclear Information System (INIS)

    Masuda, Tetsuo; Yoshioka, Toji; Kotobuki, Kazuo; Sanada, Tetsuro; Inoue, Kosuke; Murata, Kenji; Kitagawa, Kenichi; Tabira, Hiroki; Yoshida, Akira

    1997-01-01

    'Osanijisseiki', a self-compatible, spontaneous bud sport of the Japanese pear 'Nijisseiki' is an excellent cultivar with a smooth skin. However, this cultivar is susceptible to Japanese pear black spot disease caused by Alternaria alternata Japanese pear pathotype. To obtain resistant mutants from 'Osanijisseiki', nursery plants of 'Osanijisseiki' have been irradiated chronically with gamma-rays in the Gamma Field of the Institute of Radiation Breeding, NAR, MAFF, since 1986. Screening tests using AK toxin, a host-specific toxin produced by A. alternata Japanese pear pathotype, were performed form 1988 to 1993. Four branches of young trees planted at a distance of 40 m from the 60 Co source were selected as being resistant mutants in 1991 (IRB 502-13T and IRB 502-14T) and 1993 (IRB 502-17T and IRB 502-18T). Sensitivity of the four resistant mutants to AK-toxin and susceptibility to the pathogen were compared with other of susceptible and resistant cultivars. The results showed that these four mutants possessed intermediate resistance. Furthermore, a mutant, IRB 502-13T, had the same characteristics as the original 'Osanijisseiki', except for the difference in toxin sensitivity. The characteristics of the other mutants, IRB 502 14-T, IRB 502-17T, and IRB 502-18T, care being examined. (author)

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sundeep Kumar

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

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

    Science.gov (United States)

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

    2016-01-01

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

  14. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  15. Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease resistance genes in common bean cultivar Ouro Negro

    Science.gov (United States)

    Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean. Ouro Negro is a highly productive Mesoamerican black-seeded common bean cultivar possessing the dominant Co-10 and Phg-ON genes that confer resistance to ANT and ALS, respectively. In this study we elucidate the ...

  16. Characterizing and identifying black spot resistance genes in polyploid roses

    Science.gov (United States)

    The ornamental quality of outdoor grown roses (Rosa hybrida) is under constant threat from foliar diseases, such as black spot caused by Diplocarpon rosae. Fungicides are primarily used to manage black spot; however, there is a high consumer demand for disease resistant roses which eliminate the nee...

  17. Prevalence of angular leaf spot disease and sources of resistance in ...

    African Journals Online (AJOL)

    Screening of a set of 37 released common bean varieties in DRC using virulent Andean and Mesoamerican isolates identified four resistant bean varieties; ARA 4, COD MLV 059, MLV 224/94B, LSA 144 and Mexico 54. Some of these varieties possess useful traits, in addition to acceptable seed market class, and are hence ...

  18. Inheritance of resistance to angular leaf spot in yellow beans ...

    African Journals Online (AJOL)

    Angular leaf spot (Phaeoisariopsis griseola (Sacc) is an important disease of common bean (Phaseolus vulgaris L.) in most parts of Africa, causing yield losses of 40-80%. This study was carried out to determine the inheritance of resistance to angular leaf spot in yellow beans. Biparental crosses were done between ...

  19. SSR markers associated to early leaf spot disease resistance through selective genotyping and single marker analysis in groundnut (Arachis hypogaea L.

    Directory of Open Access Journals (Sweden)

    Adama Zongo

    2017-09-01

    Full Text Available Groundnut (Arachis hypogaea L. is an important oilseed and food crop of the world. Breeding for disease resistance is one of major objectives in groundnut breeding. Early leaf spot (ELS is one of the major destructive diseases worldwide and in West Africa, particularly in Burkina Faso causing significant yield losses. Conventional breeding approaches have been employed to develop improved varieties resistant to ELS. Molecular dissection of resistance traits using QTL analysis can improve the efficiency of resistance breeding. In the present study, an ELS susceptible genotype QH243C and an ELS resistant genotype NAMA were crossed and the F2 population genotypic and F3 progenies phenotypic data were used for marker-trait association analysis. Parents were surveyed with 179 simple sequence repeat (SSR markers out of which 103 SSR markers were found to be polymorphic between the parents. These polymorphic markers were utilized to genotype the F2 population followed by marker-trait analysis through single marker analysis (SMA and selective genotyping of the population using 23 resistant and 23 susceptible genotypes. The SMA revealed 13 markers while the selective genotyping method identified 8 markers associated with ELS resistance. Four markers (GM1911, GM1883, GM1000 and Seq13E09 were found common between the two trait mapping methods. These four markers could be employed in genomics-assisted breeding for selection of ELS resistant genotypes in groundnut breeding.

  20. Genetic characterization of angular leaf spot resistance in selected ...

    African Journals Online (AJOL)

    Mr Tryphone

    2015-10-28

    Oct 28, 2015 ... Angular leaf spot disease (ALS) caused by Pseudocercospora griseola is one of the most important bean diseases in Tanzania. The bean landraces Beti-10, Nanka, Nanavala and Nkanamna used in this study have been identified as resistant to ALS but the nature of inheritance and mechanisms of.

  1. Resistance in winter barley against Ramularia leaf spot

    DEFF Research Database (Denmark)

    Hjortshøj, Rasmus Lund

    Ramularia leaf spot is an emerging disease in barley caused by R. collo-cygni. At present little is known about the resistance mechanisms carried out by the host plant to avoid disease development. Nor is the lifecycle of the fungus or its populations structure fully understood. To gain insight i...

  2. Combining powers of linkage and association mapping for precise dissection of QTL controlling resistance to gray leaf spot disease in maize (Zea mays L.).

    Science.gov (United States)

    Mammadov, Jafar; Sun, Xiaochun; Gao, Yanxin; Ochsenfeld, Cherie; Bakker, Erica; Ren, Ruihua; Flora, Jonathan; Wang, Xiujuan; Kumpatla, Siva; Meyer, David; Thompson, Steve

    2015-11-10

    Gray Leaf Spot (GLS causal agents Cercospora zeae-maydis and Cercospora zeina) is one of the most important foliar diseases of maize in all areas where the crop is being cultivated. Although in the USA the situation with GLS severity is not as critical as in sub-Saharan Africa or Brazil, the evidence of climate change, increasing corn monoculture as well as the narrow genetic base of North American resistant germplasm can turn the disease into a serious threat to US corn production. The development of GLS resistant cultivars is one way to control the disease. In this study we combined the high QTL detection power of genetic linkage mapping with the high resolution power of genome-wide association study (GWAS) to precisely dissect QTL controlling GLS resistance and identify closely linked molecular markers for robust marker-assisted selection and trait introgression. Using genetic linkage analysis with a small bi-parental mapping population, we identified four GLS resistance QTL on chromosomes 1, 6, 7, and 8, which were validated by GWAS. GWAS enabled us to dramatically increase the resolution within the confidence intervals of the above-mentioned QTL. Particularly, GWAS revealed that QTLGLSchr8, detected by genetic linkage mapping as a locus with major effect, was likely represented by two QTL with smaller effects. Conducted in parallel, GWAS of days-to-silking demonstrated the co-localization of flowering time QTL with GLS resistance QTL on chromosome 7 indicating that either QTLGLSchr7 is a flowering time QTL or it is a GLS resistance QTL that co-segregates with the latter. As a result, this genetic linkage - GWAS hybrid mapping system enabled us to identify one novel GLS resistance QTL (QTLGLSchr8a) and confirm with more refined positions four more previously mapped QTL (QTLGLSchr1, QTLGLSchr6, QTLGLSchr7, and QTLGLSchr8b). Through the novel Single Donor vs. Elite Panel method we were able to identify within QTL confidence intervals SNP markers that would be

  3. High-resolution mapping reveals linkage between genes in common bean cultivar Ouro Negro conferring resistance to the rust, anthracnose, and angular leaf spot diseases.

    Science.gov (United States)

    Valentini, Giseli; Gonçalves-Vidigal, Maria Celeste; Hurtado-Gonzales, Oscar P; de Lima Castro, Sandra Aparecida; Cregan, Perry B; Song, Qijian; Pastor-Corrales, Marcial A

    2017-08-01

    Co-segregation analysis and high-throughput genotyping using SNP, SSR, and KASP markers demonstrated genetic linkage between Ur-14 and Co-3 4 /Phg-3 loci conferring resistance to the rust, anthracnose and angular leaf spot diseases of common bean. Rust, anthracnose, and angular leaf spot are major diseases of common bean in the Americas and Africa. The cultivar Ouro Negro has the Ur-14 gene that confers broad spectrum resistance to rust and the gene cluster Co-3 4 /Phg-3 containing two tightly linked genes conferring resistance to anthracnose and angular leaf spot, respectively. We used co-segregation analysis and high-throughput genotyping of 179 F 2:3 families from the Rudá (susceptible) × Ouro Negro (resistant) cross-phenotyped separately with races of the rust and anthracnose pathogens. The results confirmed that Ur-14 and Co-3 4 /Phg-3 cluster in Ouro Negro conferred resistance to rust and anthracnose, respectively, and that Ur-14 and the Co-3 4 /Phg-3 cluster were closely linked. Genotyping the F 2:3 families, first with 5398 SNPs on the Illumina BeadChip BARCBEAN6K_3 and with 15 SSR, and eight KASP markers, specifically designed for the candidate region containing Ur-14 and Co-3 4 /Phg-3, permitted the creation of a high-resolution genetic linkage map which revealed that Ur-14 was positioned at 2.2 cM from Co-3 4 /Phg-3 on the short arm of chromosome Pv04 of the common bean genome. Five flanking SSR markers were tightly linked at 0.1 and 0.2 cM from Ur-14, and two flanking KASP markers were tightly linked at 0.1 and 0.3 cM from Co-3 4 /Phg-3. Many other SSR, SNP, and KASP markers were also linked to these genes. These markers will be useful for the development of common bean cultivars combining the important Ur-14 and Co-3 4 /Phg-3 genes conferring resistance to three of the most destructive diseases of common bean.

  4. Induced resistant mutations in alfalfa and broad bean against rust, leaf spot and wilh diseases by Gamma rays and ethylmethanesulfonate

    International Nuclear Information System (INIS)

    1988-01-01

    In alfalfa after gamma irradiation with 50,100, and 150 krads, 38 rust resistant plants have been selected throughout a screening programme. During four months, cuttings were obtained from these plants individually. Results revealed that 20 plants were remar-kably surpassed the origin in the total fresh weight and in the average weight of each cutting. In broad bean, following gamma irradiation and EMS in two cuitivars for induction of wilt resistance. Seeds of these plants were sown in artificially infested soil . During the growing season, all susceptible plants were removed and at epidemic form of wilt disease

  5. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Angular leaf spot (ALS) caused by the fungus Pseudocercospora griseola and Bean common mosaic and necrosis virus (BCMV/BCMNV) are important diseases of common bean in Tanzania that can cause severe yield reduction when uncontrolled. This study was conducted to incorporate resistant genes for ALS and ...

  6. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Luseko

    2013-07-03

    Jul 3, 2013 ... Angular leaf spot (ALS) caused by the fungus Pseudocercospora griseola and Bean common mosaic and necrosis virus (BCMV/BCMNV) are important diseases of common bean in Tanzania that can cause severe yield reduction when uncontrolled. This study was conducted to incorporate resistant genes ...

  7. Assessing Frogeye Leaf Spot Resistance on Recommended Soybean Cultivars

    Directory of Open Access Journals (Sweden)

    In Jeong Kang

    2015-09-01

    Full Text Available Soybean frogeye leaf spot caused by the fungus Cercospora sojina Hara, has known to lead a severe reduction of crop yield. Since frogeye leaf spot on soybean has recently become a serious problem in Korea, the susceptibility of recent recommended cultivars against C. sojina had been tested. To standardize the disease severity of soybean, the optimum sporulation condition of C. sojina and the disease index were established in this study. Sporulation was maximized on the 10% V8 juice agar with 12 h light and 12 h dark at 25°C. Spore suspension (105 spores/ml was sprayed on the leaves of soybean (V6 stage, and the disease responses to each isolate were evaluated on 28 days after inoculation. As a result, Daepung, Shinpaldal2ho, Yeonpung and Cheonga showed the resistance reaction to 8, 7, 6, 6 isolates of C. sojina, respectively, whereas Cheongja, Hwangkeum, Taekwang, Daewon, Cheonsang and Sinhwa showed the susceptible reaction to 8 isolates of C. sojina. Breeding the resistant soybean cultivars against C. sojina requires a uniform resistance for screening technique. The disease index of frogeye leaf spot on soybean developed in this study can be effectively used for the accurate field assay to select the frogeye leaf spot resistant soybean.

  8. Genetic diversity, QoI fungicide resistance, and mating type distribution of Cercospora sojina-Implications for the disease dynamics of frogeye leaf spot on soybean.

    Science.gov (United States)

    Shrestha, Sandesh Kumar; Cochran, Alicia; Mengistu, Alemu; Lamour, Kurt; Castro-Rocha, Arturo; Young-Kelly, Heather

    2017-01-01

    Frogeye leaf spot (FLS), caused by Cercospora sojina, causes significant damage to soybean in the U.S. One control strategy is the use of quinone outside inhibitor (QoI) fungicides. QoI resistant isolates were first reported in Tennessee (TN) in 2010. To investigate the disease dynamics of C. sojina, we collected 437 C. sojina isolates in 2015 from Jackson and Milan, TN and used 40 historical isolates collected from 2006-2009 from TN and ten additional states for comparison. A subset of 186 isolates, including historical isolates, were genotyped for 49 single nucleotide polymorphism (SNP) markers and the QoI resistance locus, revealing 35 unique genotypes. The genotypes clustered into three groups with two groups containing only sensitive isolates and the remaining group containing all resistant isolates and a dominant clonal lineage of 130 isolates. All 477 C. sojina isolates were genotyped for the QoI locus revealing 344 resistant and 133 sensitive isolates. All isolates collected prior to 2015 were QoI sensitive. Both mating type alleles (MAT1-1-1 and MAT1-2) were found in Jackson and Milan, TN and recovered from single lesions suggesting sexual recombination may play a role in the epidemiology of field populations. Analysis of C. sojina isolates using SNP markers proved useful to investigate population diversity and to elaborate on diversity as it relates to QoI resistance and mating type.

  9. NMR-Based Metabolic Profiling of Field-Grown Leaves from Sugar Beet Plants Harbouring Different Levels of Resistance to Cercospora Leaf Spot Disease

    Science.gov (United States)

    Sekiyama, Yasuyo; Okazaki, Kazuyuki; Kikuchi, Jun; Ikeda, Seishi

    2017-01-01

    Cercospora leaf spot (CLS) is one of the most serious leaf diseases for sugar beet (Beta vulgaris L.) worldwide. The breeding of sugar beet cultivars with both high CLS resistance and high yield is a major challenge for breeders. In this study, we report the nuclear magnetic resonance (NMR)-based metabolic profiling of field-grown leaves for a subset of sugar beet genotypes harbouring different levels of CLS resistance. Leaves were collected from 12 sugar beet genotypes at four time points: seedling, early growth, root enlargement, and disease development stages. 1H-NMR spectra of foliar metabolites soluble in a deuterium-oxide (D2O)-based buffer were acquired and subjected to multivariate analyses. A principal component analysis (PCA) of the NMR data from the sugar beet leaves shows clear differences among the growth stages. At the later time points, the sugar and glycine betaine contents were increased, whereas the choline content was decreased. The relationship between the foliar metabolite profiles and resistance level to CLS was examined by combining partial least squares projection to latent structure (PLS) or orthogonal PLS (OPLS) analysis and univariate analyses. It was difficult to build a robust model for predicting precisely the disease severity indices (DSIs) of each genotype; however, GABA and Gln differentiated susceptible genotypes (genotypes with weak resistance) from resistant genotypes (genotypes with resistance greater than a moderate level) before inoculation tests. The results suggested that breeders might exclude susceptible genotypes from breeding programs based on foliar metabolites profiled without inoculation tests, which require an enormous amount of time and effort. PMID:28134762

  10. NMR-Based Metabolic Profiling of Field-Grown Leaves from Sugar Beet Plants Harbouring Different Levels of Resistance to Cercospora Leaf Spot Disease

    Directory of Open Access Journals (Sweden)

    Yasuyo Sekiyama

    2017-01-01

    Full Text Available Cercospora leaf spot (CLS is one of the most serious leaf diseases for sugar beet (Beta vulgaris L. worldwide. The breeding of sugar beet cultivars with both high CLS resistance and high yield is a major challenge for breeders. In this study, we report the nuclear magnetic resonance (NMR-based metabolic profiling of field-grown leaves for a subset of sugar beet genotypes harbouring different levels of CLS resistance. Leaves were collected from 12 sugar beet genotypes at four time points: seedling, early growth, root enlargement, and disease development stages. 1H-NMR spectra of foliar metabolites soluble in a deuterium-oxide (D2O-based buffer were acquired and subjected to multivariate analyses. A principal component analysis (PCA of the NMR data from the sugar beet leaves shows clear differences among the growth stages. At the later time points, the sugar and glycine betaine contents were increased, whereas the choline content was decreased. The relationship between the foliar metabolite profiles and resistance level to CLS was examined by combining partial least squares projection to latent structure (PLS or orthogonal PLS (OPLS analysis and univariate analyses. It was difficult to build a robust model for predicting precisely the disease severity indices (DSIs of each genotype; however, GABA and Gln differentiated susceptible genotypes (genotypes with weak resistance from resistant genotypes (genotypes with resistance greater than a moderate level before inoculation tests. The results suggested that breeders might exclude susceptible genotypes from breeding programs based on foliar metabolites profiled without inoculation tests, which require an enormous amount of time and effort.

  11. Developing markers for Sigatoka leaf spot disease (Mycosphaerella ...

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... Sigatoka leaf spot (Mycosphaerella musicola Leach) disease is a limiting factor in banana production in. India and other places. Breeding for resistance is the most effective method to control Musa diseases. However, Musa improvement using conventional methods has been hampered due to lack of ...

  12. Nucleus geometry and mechanical properties of resistance spot ...

    Indian Academy of Sciences (India)

    Abstract. In this study, mechanical properties of resistance spot welding of DP450 and DP600, galvanized and ungalvanized automotive sheets have been investigated. The specimens have been joined by resistance spot welding at different weld currents and times. Welded specimens have been examined for their ...

  13. Md-miR156ab and Md-miR395 Target WRKY Transcription Factors to Influence Apple Resistance to Leaf Spot Disease.

    Science.gov (United States)

    Zhang, Qiulei; Li, Yang; Zhang, Yi; Wu, Chuanbao; Wang, Shengnan; Hao, Li; Wang, Shengyuan; Li, Tianzhong

    2017-01-01

    MicroRNAs (miRNAs) are key regulators of gene expression that post-transcriptionally regulate transcription factors involved in plant physiological activities. Little is known about the effects of miRNAs in disease resistance in apple ( Malus × domestica ). We globally profiled miRNAs in the apple cultivar Golden Delicious (GD) infected or not with the apple leaf spot fungus Alternaria alternaria f. sp. mali (ALT1), and identified 58 miRNAs that exhibited more than a 2-fold upregulation upon ALT1 infection. We identified a pair of miRNAs that target protein-coding genes involved in the defense response against fungal pathogens; Md-miR156ab targets a novel WRKY transcription factor, MdWRKYN1, which harbors a TIR and a WRKY domain. Md-miR395 targets another transcription factor, MdWRKY26, which contains two WRKY domains. Real-time PCR analysis showed that Md-miR156ab and Md-miR395 levels increased, while MdWRKYN1 and MdWRKY26 expression decreased in ALT1-inoculated GD leaves; furthermore, the overexpression of Md-miR156ab and Md-miR395 resulted in a significant reduction in MdWRKYN1 and MdWRKY26 expression. To investigate whether these miRNAs and their targets play a crucial role in plant defense, we overexpressed MdWRKYN1 or knocked down Md-miR156ab activity, which in both cases enhanced the disease resistance of the plants by upregulating the expression of the WRKY-regulated pathogenesis-related (PR) protein-encoding genes MdPR3-1, MdPR3-2, MdPR4, MdPR5, MdPR10-1 , and MdPR10-2 . In a similar analysis, we overexpressed MdWRKY26 or suppressed Md-miR395 activity, and found that many PR protein-encoding genes were also regulated by MdWRKY26 . In GD, ALT-induced Md-miR156ab and Md-miR395 suppress MdWRKYN1 and MdWRKY26 expression, thereby decreasing the expression of some PR genes, and resulting in susceptibility to ALT1.

  14. Sugarbeet leaf spot disease (Cercospora beticola Sacc.)dagger.

    Science.gov (United States)

    Weiland, John; Koch, Georg

    2004-05-01

    SUMMARY Leaf spot disease caused by Cercospora beticola Sacc. is the most destructive foliar pathogen of sugarbeet worldwide. In addition to reducing yield and quality of sugarbeet, the control of leaf spot disease by extensive fungicide application incurs added costs to producers and repeatedly has selected for fungicide-tolerant C. beticola strains. The genetics and biochemistry of virulence have been examined less for C. beticola as compared with the related fungi C. nicotianae, C. kikuchii and C. zeae-maydis, fungi to which the physiology of C. beticola is often compared. C. beticola populations generally are not characterized as having race structure, although a case of race-specific resistance in sugarbeet to C. beticola has been reported. Resistance currently implemented in the field is quantitatively inherited and exhibits low to medium heritability. Cercospora beticola Sacc.; Kingdom Fungi, Subdivision Deuteromycetes, Class Hyphomycetes, Order Hyphales, Genus Cercospora. Circular, brown to red delimited spots with ashen-grey centre, 0.5-6 mm diameter; dark brown to black stromata against grey background; pale brown unbranched sparingly septate conidiophores, hyaline acicular conidia, multiseptate, from 2.5 to 4 microm wide and 50-200 microm long. Propagative on Beta vulgaris and most species of Beta. Reported on members of the Chenopodiaceae and on Amaranthus. Disease symptoms: Infected leaves and petioles of B. vulgaris exhibit numerous circular leaf spots that coalesce in severe cases causing complete leaf collapse. Dark specks within a grey spot centre are characteristic for the disease. Older leaves exhibit a greater number of lesions with larger spot diameter. During the latter stage of severe epiphytotics, new leaf growth can be seen emerging from the plant surrounded by prostrate, collapsed leaves. Fungicides in the benzimidazole and triazole class as well as organotin derivatives and strobilurins have successfully been used to control Cercospora

  15. Metallography of Battery Resistance Spot Welds

    Science.gov (United States)

    Martinez, J. E.; Johannes, L. B.; Gonzalez, D.; Yayathi, S.; Figuered, J. M.; Darcy, E. C.; Bilc, Z. M.

    2015-01-01

    Li-ion cells provide an energy dense solution for systems that require rechargeable electrical power. However, these cells can undergo thermal runaway, the point at which the cell becomes thermally unstable and results in hot gas, flame, electrolyte leakage, and in some cases explosion. The heat and fire associated with this type of event is generally violent and can subsequently cause damage to the surrounding system or present a dangerous risk to the personnel nearby. The space flight environment is especially sensitive to risks particularly when it involves potential for fire within the habitable volume of the International Space Station (ISS). In larger battery packs such as Robonaut 2 (R2), numerous Li-ion cells are placed in parallel-series configurations to obtain the required stack voltage and desired run-time or to meet specific power requirements. This raises a second and less obvious concern for batteries that undergo certification for space flight use: the joining quality at the resistance spot weld of battery cells to component wires/leads and battery tabs, bus bars or other electronic components and assemblies. Resistance spot welds undergo materials evaluation, visual inspection, conductivity (resistivity) testing, destructive peel testing, and metallurgical examination in accordance with applicable NASA Process Specifications. Welded components are cross-sectioned to ensure they are free of cracks or voids open to any exterior surface. Pore and voids contained within the weld zone but not open to an exterior surface, and are not determined to have sharp notch like characteristics, shall be acceptable. Depending on requirements, some battery cells are constructed of aluminum canisters while others are constructed of steel. Process specific weld schedules must be developed and certified for each possible joining combination. The aluminum canisters' positive terminals were particularly difficult to weld due to a bi-metal strip that comes ultrasonically

  16. Review: magnetically assisted resistance spot welding

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y. B. [Shanghai Jiao Tong Univ., Shanghai (China); Li, D. L. [Shanghai Jiao Tong Univ., Shanghai (China); Lin, Z. Q. [Shanghai Jiao Tong Univ., Shanghai (China); David, Stan A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-02-25

    Currently, the use of advanced high strength steels (AHSSs) is the most cost effective means of reducing vehicle body weight and maintaining structural integrity at the same time. However, AHSSs present a big challenge to the traditional resistance spot welding (RSW) widely applied in automotive industries because the rapid heating and cooling procedures during RSW produce hardened weld microstructures, which lower the ductility and fatigue properties of welded joints and raise the probability of interfacial failure under external loads. Changing process parameters or post-weld heat treatment may reduce the weld brittleness, but those traditional quality control methods also increase energy consumption and prolong cycle time. In recent years, a magnetically assisted RSW (MA-RSW) method was proposed, in which an externally applied magnetic field would interact with the conduction current to produce a Lorentz force that would affect weld nugget formation. This paper is a review of an experimental MA-RSW platform, the mode of the external magnetic field and the mechanism that controls nugget shape, weld microstructures and joint performance. In conclusion, the advantages of the MA-RSW method in improving the weldability of AHSSs are given, a recent application of the MA-RSW process to light metals is described and the outlook for the MA-RSW process is presented.

  17. QTL mapping of resistance to gray leaf spot in maize.

    Science.gov (United States)

    Zhang, Yan; Xu, Ling; Fan, Xingming; Tan, Jing; Chen, Wei; Xu, Mingliang

    2012-12-01

    Gray leaf spot (GLS), caused by the causal fungal pathogen Cercospora zeae-maydis, is one of the most serious foliar diseases of maize worldwide. In the current study, a highly resistant inbred line Y32 and a susceptible line Q11 were used to produce segregating populations for both genetic analysis and QTL mapping. The broad-sense heritability (H (2)) for GLS resistance was estimated to be as high as 0.85, indicating that genetic factors played key roles in phenotypic variation. In initial QTL analysis, four QTL, located on chromosomes 1, 2, 5, and 8, were detected to confer GLS resistance. Each QTL could explain 2.53-23.90 % of the total phenotypic variation, predominantly due to additive genetic effects. Two major QTL, qRgls1 and qRgls2 on chromosomes 8 and 5, were consistently detected across different locations and replicates. Compared to the previous results, qRgls2 is located in a 'hotspot' for GLS resistance; while, qRgls1 does not overlap with any other known resistance QTL. Furthermore, the major QTL-qRgls1 was fine-mapped into an interval of 1.4 Mb, flanked by the markers GZ204 and IDP5. The QTL-qRgls1 could enhance the resistance percentages by 19.70-61.28 %, suggesting its usefulness to improve maize resistance to GLS.

  18. Ultrasonic assessment of tension shear strength in resistance spot welding

    Science.gov (United States)

    Moghanizadeh, Abbas

    2015-05-01

    Resistance spot welding is extensively used to join sheet steel in the automotive industry. Ultrasonic non-destructive techniques for evaluation of the mechanical properties of resistance spot welding are presented. The aim of this study is to develop the capability of the ultrasonic techniques as an efficient tool in the assessment of the welding characterization. Previous researches have indicated that the measurements of ultrasonic attenuation are sensitive to grain- size variations in an extensive range of metallic alloys. Other researchers have frequently described grain sizes which are able to have significant effects on the physical characteristics of the material. This research provides a novel method to estimate the tension-shear strengths of the resistance spot welding directly from the ultrasonic attenuation measurements. The effects of spot welding parameters on the ultrasonic waves are further investigated. The results confirm that it is possible to determine the spot welding parameters for individual quality by using ultrasonic test.

  19. Resistance Spot Welding with Middelfrequency-Inverter Weling Gun

    DEFF Research Database (Denmark)

    Rasmussen, Mogens H.

    The paper presents the results of investigations concerning the process stability and weldability lobes for uncoated sheets of 1.0 mm thickness when performing resistance spot welding with a middlefrequency-inverter welding gun......The paper presents the results of investigations concerning the process stability and weldability lobes for uncoated sheets of 1.0 mm thickness when performing resistance spot welding with a middlefrequency-inverter welding gun...

  20. Sustainable control of white spot disease

    DEFF Research Database (Denmark)

    Heinecke, Rasmus Demuth; Buchmann, Kurt

    White spot disease caused by the ciliate Ichthyophthirius multifiliis Fouquet, 1876 is a serious problem in freshwater aquaculture worldwide. This parasitosis is of frequent occurrence in both conventional earth pond fish farms and in fish farms using new high technology re-circulation systems...... all had significant influences on parasite survival. Strategic treatment using the environmentally friendly chemical sodium percarbonate in combination with continuous micro-filtering of the pond water is suggested for control and management of this parasitosis....

  1. Optimization of resistance spot welding parameters for microalloyed steel sheets

    Science.gov (United States)

    Viňáš, Ján; Kaščák, Ľuboš; Greš, Miroslav

    2016-11-01

    The paper presents the results of resistance spot welding of hot-dip galvanized microalloyed steel sheets used in car body production. The spot welds were made with various welding currents and welding time values, but with a constant pressing force of welding electrodes. The welding current and welding time are the dominant characteristics in spot welding that affect the quality of spot welds, as well as their dimensions and load-bearing capacity. The load-bearing capacity of welded joints was evaluated by tensile test according to STN 05 1122 standard and dimensions and inner defects were evaluated by metallographic analysis by light optical microscope. Thewelding parameters of investigated microalloyed steel sheets were optimized for resistance spot welding on the pneumatic welding machine BPK 20.

  2. Diallel analysis for frogeye leaf spot resistance in soybean

    Directory of Open Access Journals (Sweden)

    Gravina Geraldo de Amaral

    2003-01-01

    Full Text Available Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná and Uberaba, with different levels of resistance to Cercospora sojina, were crossed in a diallel design to determine the general (GCA and specific (SCA combining abilities relative to the inheritance of the resistance. Race 04 of the fungus was inoculated in the parents and in the 21 F1 hybrids in a greenhouse in a completely randomized design, with 12 replications. The reactions to the disease were evaluated 20 days after the inoculation, always on the most infected leaflet. Both GCA and SCA were significant for all the evaluated characters, being inferred that, for the expression of the characters, the additive, dominant and, possibly, epistatic genic actions were important. The largest values of estimated SCA effect (ij were observed in the hybrid combinations where at least one parent presented high GCA. Cristalina, Davis and Uberaba cultivars showed the largest estimates for GCA effect (i, and from the analysis of ii, the contribution of these parents to heterosis of their hybrids will be towards the reduction of the disease symptoms. Therefore, these cultivars are indicated as parents in breeding programs that seek the development of soybean cultivars with resistance to frogeye leaf spot.

  3. Reliability of copper based alloys for electric resistance spot welding

    International Nuclear Information System (INIS)

    Jovanovicj, M.; Mihajlovicj, A.; Sherbedzhija, B.

    1977-01-01

    Durability of copper based alloys (B-5 and B-6) for electric resistance spot-welding was examined. The total amount of Be, Ni and Zr was up to 2 and 1 wt.% respectively. Good durability and satisfactory quality of welded spots were obtained in previous laboratory experiments carried out on the fixed spot-welding machine of an industrial type (only B-5 alloy was examined). Electrodes made of both B-5 and B-6 alloy were tested on spot-welding grips and fixed spot-welding machines in Tvornica automobila Sarajevo (TAS). The obtained results suggest that the durability of electrodes made of B-5 and B-6 alloys is more than twice better than of that used in TAS

  4. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    NARCIS (Netherlands)

    Haan, de P.; Ultzen, T.; Prins, M.; Gielen, J.; Goldbach, R.; Grinsven, van M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can

  5. NOTE - Genetic control of resistance to gray leaf spot of maize in tropical germplasm

    Directory of Open Access Journals (Sweden)

    André Humberto de Brito

    2012-01-01

    Full Text Available The main goal of this study was to assess the nature and magnitude of gene effects for resistance to Cercospora leaf spot. A randomized block design with three replications was used. The data were obtained at the plant level by assessing the disease severity. The data were analyzed per experiment, using the average data per plot. A dominant-additive genetic model without epistasis was considered, with estimation of the components of means and variance. The genetic control of resistance to gray leaf spot is polygenic with predominance of the additive effects. Dominance was observed in a few small-effect loci and high heritability values.

  6. Field evaluations of leaf spot resistance and yield in peanut genotypes in the United States and Bolivia

    Science.gov (United States)

    Field experiments were conducted in 2002-2006 to characterize yield potential and disease resistance to Cercospora arachidicola (early leaf spot) and Cercosporidium personatum (late leaf spot) in the Bolivian peanut (Arachis hypogaea) cultivar, Bayo Grande, and breeding lines developed from crosses ...

  7. RESISTANCE TO ALTERNARIA BROWN SPOT OF NEW CITRUS HYBRIDS

    Directory of Open Access Journals (Sweden)

    KELLY APARECIDA FERNANDES DE CAMPOS

    2017-12-01

    Full Text Available ABSTRACT Alternaria brown spot (ABS disease is caused by the fungus of Alternaria alternata f. sp. citri, which causes injury in leaves, branches and fruits of citrus. The action of the pathogen is directly related to the presence of toxin receptors in susceptible genotypes. The objective of this study was to characterize a population of citrus hybrids obtained from controlled crosses between Pêra de Abril sweet orange and the hybrid of Murcott tangor x Pêra sweet orange (TM x LP 163 for response to ABS through the in vitro inoculation of fungal spores in young detached leaves. The fungus was isolated from the lesions of Murcott tangor fruits that exhibited ABS symptoms. Two hundred thirty-five hybrids were evaluated, and 70 (30% showed different levels of disease symptoms on detached leaves after 72 hours of inoculation with the fungus, and 165 (70% were asymptomatic. The frequency of segregation observed (165R:70S and high level of heritability (h2g = 0.91 suggest that few genes may be involved in controlling the inheritance of ABS resistance in citrus.

  8. Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease-resistance genes in the common bean cultivar Ouro Negro.

    Science.gov (United States)

    Gonçalves-Vidigal, M C; Cruz, A S; Lacanallo, G F; Vidigal Filho, P S; Sousa, L L; Pacheco, C M N A; McClean, P; Gepts, P; Pastor-Corrales, M A

    2013-09-01

    Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean (Phaseolus vulgaris L.). Ouro Negro is a highly productive common bean cultivar, which contains the Co-10 and Phg-ON genes for resistance to ANT and ALS, respectively. In this study, we performed a genetic co-segregation analysis of resistance to ANT and ALS using an F2 population from the Rudá × Ouro Negro cross and the F2:3 families from the AND 277 × Ouro Negro cross. Ouro Negro is resistant to races 7 and 73 of the ANT and race 63-39 of the ALS pathogens. Conversely, cultivars AND 277 and Rudá are susceptible to races 7 and 73 of ANT, respectively. Both cultivars are susceptible to race 63-39 of ALS. Co-segregation analysis revealed that Co-10 and Phg-ON were inherited together, conferring resistance to races 7 and 73 of ANT and race 63-39 of ALS. The Co-10 and Phg-ON genes were co-segregated and were tightly linked at a distance of 0.0 cM on chromosome Pv04. The molecular marker g2303 was linked to Co-10 and Phg-ON at a distance of 0.0 cM. Because of their physical linkage in a cis configuration, the Co-10 and Phg-ON resistance alleles are inherited together and can be monitored with great efficiency using g2303. The close linkage between the Co-10 and Phg-ON genes and prior evidence are consistent with the existence of a resistance gene cluster at one end of chromosome Pv04, which also contains the Co-3 locus and ANT resistance quantitative trait loci. These results will be very useful for breeding programs aimed at developing bean cultivars with ANT and ALS resistance using marker-assisted selection.

  9. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Zhang, Wenqi; Bay, Niels

    Through years, the dynamic resistance across the electrodes has been used for weld quality estimation and contact resistance measurement. However, the previous methods of determining the dynamic resistance were mostly based on measuring the voltage and current on the secondary side...... of the transformer in resistance welding machines, implying defects from induction noise and interference with the leads connected to the electrodes for measuring the voltage. In this study, the dynamic resistance is determined by measuring the voltage on the primary side and the current on the secondary side......, as another application, the proposed method is used to measure the faying surface contact resistance....

  10. Working Towards Disease Resistance in Peanuts Through Biotechnology

    Science.gov (United States)

    Resistant cultivars are the most desirable approach to disease control in agriculture. Early and late leaf spot are the most important foliar diseases of peanut worldwide. Significant progress for leaf spot resistance in peanut can be achieved through biotechnology. The National Peanut Research ...

  11. Angular leaf spot disease status and characterization of the causative pathgen (P. Griseola) in Tanzania

    Science.gov (United States)

    Angular leaf spot caused by the fungus Pseudocercospora griseola is one of the most important disease of common bean in Tanzania. Breeding for resistance to this disease is complicated by the variable nature of the pathogen. In Tanzania no thorough attempt has been completed to evaluate the variabil...

  12. Foliar Application of the Fungicide Pyraclostrobin Reduced Bacterial Spot Disease of Pepper

    Directory of Open Access Journals (Sweden)

    Beom Ryong Kang

    2018-03-01

    Full Text Available Pyraclostrobin is a broad-spectrum fungicide that inhibits mitochondrial respiration. However, it may also induce systemic resistance effective against bacterial and viral diseases. In this study, we evaluated whether pyraclostrobin enhanced resistance against the bacterial spot pathogen, Xanthomonas euvesicatora on pepper (Capsicum annuum. Although pyraclostrobin alone did not suppressed the in vitro growth of X. euvesicatoria, disease severity in pepper was significantly lower by 69% after treatments with pyraclostrobin alone. A combination of pyraclostrobin with streptomycin reduced disease by over 90% that of the control plants. The preventive control of the pyraclostrobin against bacterial spot was required application 1-3 days before pathogen inoculation. Our findings suggest that the fungicide pyraclostrobin can be used with a chemical pesticide to control bacterial leaf spot diseases in pepper.

  13. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Lu, J.; Zhang, Wenqi

    2007-01-01

    The conventional methods of determining the dynamic resistance were mostly done by measuring the voltage and current at secondary side of transformer in resistance welding machines, in which the measuring set-up normally interferes with the movement of electrode, and the measuring precision is in...

  14. Foliar Application of the Fungicide Pyraclostrobin Reduced Bacterial Spot Disease of Pepper

    OpenAIRE

    Beom Ryong Kang; Jang Hoon Lee; Young Cheol Kim

    2018-01-01

    Pyraclostrobin is a broad-spectrum fungicide that inhibits mitochondrial respiration. However, it may also induce systemic resistance effective against bacterial and viral diseases. In this study, we evaluated whether pyraclostrobin enhanced resistance against the bacterial spot pathogen, Xanthomonas euvesicatora on pepper (Capsicum annuum). Although pyraclostrobin alone did not suppressed the in vitro growth of X. euvesicatoria, disease severity in pepper was significantly lower by 69% after...

  15. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Lu, J.; Zhang, Wenqi

    2007-01-01

    The conventional methods of determining the dynamic resistance were mostly done by measuring the voltage and current at secondary side of transformer in resistance welding machines, in which the measuring set-up normally interferes with the movement of electrode, and the measuring precision...... is influenced by inductive noise caused by the high welding current. In this study, the dynamic resistance is determined by measuring the voltage at primary side and current at secondary side. This increases the accuracy of measurement because of higher signal-noise ratio, and allows to apply to in...

  16. A study of dynamic resistance during small scale resistance spot welding of thin Ni sheets

    International Nuclear Information System (INIS)

    Tan, W; Zhou, Y; Kerr, H W; Lawson, S

    2004-01-01

    The dynamic resistance has been investigated during small scale resistance spot welding (SSRSW) of Ni sheets. Electrical measurements have been correlated with scanning electron microscope images of joint development. The results show that the dynamic resistance curve can be divided into the following stages based on physical change in the workpieces: asperity heating, surface breakdown, asperity softening, partial surface melting, nugget growth and expulsion. These results are also compared and contrasted with dynamic resistance behaviour in large scale RSW

  17. Three-dimensional simulations of resistance spot welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Zhang, Wenqi; Perret, William

    2014-01-01

    This paper draws from the fundamentals of electro-thermo-mechanical coupling to the main aspects of finite element implementation and three-dimensional modelling of resistance welding. A new simulation environment is proposed in order to perform three-dimensional simulations and optimization of r....... The overall presentation is supported by numerical simulations of electrode misalignment caused by the flexibility of the welding machine arms and electrical shunting due to consecutive welds in the resistance spot welding of two sheets.......This paper draws from the fundamentals of electro-thermo-mechanical coupling to the main aspects of finite element implementation and three-dimensional modelling of resistance welding. A new simulation environment is proposed in order to perform three-dimensional simulations and optimization...... of resistance welding together with the simulations of conventional and special-purpose quasi-static mechanical tests. Three-dimensional simulations of resistance welding consider the electrical, thermal, mechanical and metallurgical characteristics of the material as well as the operating conditions...

  18. Status of grey leaf spot disease in Kenyan maize production ...

    African Journals Online (AJOL)

    Grey leaf spot disease (GLS), Cercospora zeae-maydis, which has previously been attributed to diverse pathogen species in other countries, has become a serious biotic constraint to production of maize (Zea mays L.) in Kenya. It is necessary to determine the distribution and aetiology of the disease across all the maize ...

  19. Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.

    Science.gov (United States)

    Ning, Dongfeng; Song, Alin; Fan, Fenliang; Li, Zhaojun; Liang, Yongchao

    2014-01-01

    It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si) in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae), including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.

  20. A review on threat of gray leaf spot disease of maize in Asia

    Directory of Open Access Journals (Sweden)

    Narayan Bahadur Dhami

    2015-12-01

    Full Text Available Biotic and biotic constraints are yield limiting factors in maize producing regions. Among these gray leaf spot is a yield limiting foliar disease of maize in high land regions of Asia. This review is done from related different national and international journals, thesis, books, research papers etc. The objectives of this review are to become familiar with genetics and inheritance, epidemiology, symptoms and disease management strategies etc. High relative humidity, temperature, minimum tillage and maize monoculture are important factors responsible for disease development. The sibling species of Cercospora zeae-maydis (Tehon and Daniels, 1925 Group I and Group II and Cercospora sorghai var. maydis (Chupp, 1954 are associated with this disease. Pathogens colonize in maize debris. Conidia are the source of inoculums for disease spread. Severe blighting of leaves reduces sugars, stalk lodging and causes premature death of plants resulting in yield losses of up to 100%. Disease management through cultural practices is provisional. The use of fungicides for emergencies is effective however; their prohibitive cost and detrimental effects on the environment are negative consequences. The inheritance of tolerance is quantitative with small additive effects. The introgression of resistant genes among the crosses of resistant germplasm enhances the resistance. The crosses of resistant and susceptible germplasm possess greater stability than the crosses of susceptible and resistant germplasm. The development of gray leaf spot tolerant populations through tolerance breeding principle is an economical and sustainable approach to manage the disease.

  1. The disease prevalence and severity of Cercospora leaf spot in sugar beet cultivations in Kayseri

    Directory of Open Access Journals (Sweden)

    Hacer Handan ALTINOK

    2012-12-01

    Full Text Available Cercospora leaf spot disease (Cercospora beticola Sacc., is one of the most economically important fungal diseases in sugar beet growing. Under appropriate climatic conditions, the disease can reach epidemic levels. Although some fungicides exist for disease control, resistance development by pathogen against fungicides is creating difficulties. Besides, use of resistant varieties which is considered as the most efficient and environment-friendly method is adversely affected by pathogen’s ability to exhibit high genetic variations and varying resistance levels against different races of pathogen restricts the success of resistance breeding studies. In order to reveal status of this disease in Kayseri province, surveys were conducted in 2010 and 2011 in sugar beet growing areas and disease prevalence and severity were determined. Approximately, 1500 da area in 90 fields were examined and about 700 da of this area found as infected with Cercospora leaf spot disease in both years of the survey. Highest disease prevalence and severity were found as 80 % and 45 %, respectively, in Sarıoğlan district, which is followed by central district, Develi and Bünyan. Among surveyed districts, lowest prevalence and severity were detected as approx. 65 % and 35 %, respectively, in Yeşilhisar.

  2. Biocontrol of bacterial spot diseases of muskmelon using ...

    African Journals Online (AJOL)

    The biocontrol activity of PpG14 was examined by pot and field tests. Results show that the strain significantly reduced the development and suppressed the incidence of bacterial spot diseases. Moreover, the prevention treatment was better than the therapy treatment when using this strain. Based on its main bacteriological ...

  3. Competition studies of QoI resistant and sensitive Cercospora sojina isolates the causal agent of frogeye leaf spot

    Science.gov (United States)

    Frogeye leaf spot (FLS), caused by Cercospora sojina, is a yearly foliar disease in Tennessee and causes substantial economic losses if not properly managed. Quinone outside inhibitor (QoI) fungicides are often used to manage FLS, but C. sojina isolates have developed resistance to this class of fun...

  4. Salicylic acid confers enhanced resistance to Glomerella leaf spot in apple.

    Science.gov (United States)

    Zhang, Ying; Shi, Xiangpeng; Li, Baohua; Zhang, Qingming; Liang, Wenxing; Wang, Caixia

    2016-09-01

    Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots in apple. Currently, there are no effective means to control this disease except for the traditional fungicide sprays. Induced resistance by elicitors against pathogens infection is a widely accepted eco-friendly strategy. In the present study, we investigated whether exogenous application of salicylic acid (SA) could improve resistance to GLS in a highly susceptible apple cultivar (Malus domestica Borkh. cv. 'Gala') and the underlying mechanisms. The results showed that pretreatment with SA, at 0.1-1.0 mM, induced strong resistance against GLS in 'Gala' apple leaves, with SA treated leaves showing significant reduction in lesion numbers and disease index. Concurrent with the enhanced disease resistance, SA treatment markedly increased the total antioxidant capacity (T-AOC) and defence-related enzyme activities, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). As expected, SA treatment also induced the expression levels of five pathogenesis-related (PR) genes including PR1, PR5, PR8, Chitinase and β-1,3-glucanase. Furthermore, the most pronounced and/or rapid increase was observed in leaves treated with SA and subsequently inoculated with G. cingulata compared to the treatment with SA or inoculation with the pathogen. Together, these results suggest that exogenous SA triggered increase in reactive oxygen species levels and the antioxidant system might be responsible for enhanced resistance against G. cingulata in 'Gala' apple leaves. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. RNA-Seq analysis of resistant and susceptible sub-tropical maize lines reveals a role for kauralexins in resistance to grey leaf spot disease, caused by Cercospora zeina

    Science.gov (United States)

    Cercospora zeina is a foliar pathogen responsible for maize grey leaf spot in southern Africa that negatively impacts maize production. Plants use a variety of chemical and structural mechanisms to defend themselves against invading pathogens such as C. zeina, including the production of secondary m...

  6. Online resistance spot weld NDE using infrared thermography

    Science.gov (United States)

    Chen, Jian; Feng, Zhili

    2017-04-01

    A new online resistance spot weld non-destructive evaluation (NDE) technique based on infrared (IR) thermography has been developed. It is capable of both real-time online (during welding) and post-weld online/offline (after welding) inspections. The system mainly consists of an IR camera and a computer program with proprietary thermal imaging analysis algorithms integrated into existing production lines. For real-time inspection, the heat flow generated from the welding process (with temperature exceeding 1000°C) is monitored by the IR camera. For post-weld inspection, a novel auxiliary heating device is applied to locally heat the weld region, resulting in temperature changes on the order of 10°C, and the transmitted heat flow is monitored. Unlike the conventional IR NDE method that requires surface coating to reduce the influence of unknown emissivity, the new method can be applied on as-is bare metal surface thanks to the unique "thermal signatures" extracted from infrared thermal images, which positively correlates to weld quality with a high degree of confidence. The new method can be used to reliably detect weld size, surface indents and defects such as cold weld with sufficient accuracy for welds made from various combinations of materials, thickness, stack-up configuration, surface coating conditions and welding conditions.

  7. Identification and Precise Mapping of Resistant QTLs of Cercospora Leaf Spot Resistance in Sugar Beet (Beta vulgaris L.).

    Science.gov (United States)

    Taguchi, Kazunori; Kubo, Tomohiko; Takahashi, Hiroyuki; Abe, Hideyuki

    2011-09-01

    The complex inheritance of resistance to Cercospora leaf spot (CLS), the most severe fungal foliar disease in sugar beet, was investigated by means of quantitative trait loci (QTL) analysis. Over a three year period, recombinant inbred lines (RILs) of sugar beet (Beta vulgaris L.), generated through a cross between lines resistant ('NK-310mm-O') and susceptible ('NK-184mm-O') to CLS, were field-tested for their resistance to the pathogen. Composite interval mapping (CIM) showed four QTL involved in CLS resistance to be consistently detected. Two resistant QTL (qcr1 on chromosome III, qcr4 on chromosome IX) bearing 'NK-310mm-O' derived alleles promoted resistance. Across 11 investigations, the qcr1 and qcr4 QTL explained approximately 10% and over 20%, respectively, of the variance in the resistance index. Two further QTL (qcr2 on chromosome IV, qcr3 on chromosome VI) bearing 'NK-184mm-O' derived alleles each explained about 10% of the variance. To identify the monogenic effect of the resistance, two QTL derived from 'NK-310mm-O' against the genetic background of 'NK-184mm-O', using molecular markers. The qcr1 and qcr4 were precisely mapped as single QTL, using progenies BC(5)F(1) and BC(2)F(1), respectively. The qcr1 that was located near e11m36-8 had CLS disease severity indices (DSI) about 15% lower than plants homozygous for the 'NK-184mm-O' genotype. As with qcr1, heterozygosis of the qcr4 that was located near e17m47-81 reduced DSI by about 45% compared to homozygosis. These two resistant QTL might be of particular value in marker-assisted selection (MAS) programs in CLS resistance progression.

  8. inheritance of resistance to angular leaf spot in yellow beans ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Susceptible. II -indeterminate erect; III -indeterminate semi-prostate; ALS = Angular leaf spot. Isolation of Phaeoisariopsis griseola and plant inoculation. Isolation of angular leaf spot was made from lesions of naturally infected bean leaves showing fungal sporulation. In the case of non-sporulating lesions, the fungus was.

  9. Evolutionary analysis of tomato Sw-5 resistance-breaking isolates of Tomato spotted wilt virus.

    Science.gov (United States)

    López, Carmelo; Aramburu, José; Galipienso, Luis; Soler, Salvador; Nuez, Fernando; Rubio, Luis

    2011-01-01

    Tomato spotted wilt virus (TSWV) causes severe economic losses in many crops worldwide and often overcomes resistant cultivars used for disease control. Comparison of nucleotide and amino acid sequences suggested that tomato resistance conferred by the gene Sw-5 can be overcome by the amino acid substitution C to Y at position 118 (C118Y) or T120N in the TSWV movement protein, NSm. Phylogenetic analysis revealed that substitution C118Y has occurred independently three times in the studied isolates by convergent evolution, whereas the substitution T120N was a unique event. Analysis of rates of non-synonymous and synonymous changes at individual codons showed that substitution C118Y was positively selected.

  10. Chromosomal location and molecular mapping of tan spot resistance genes in common wheat (T. aestivum L.)

    OpenAIRE

    Tadesse, Wuletaw

    2008-01-01

    In this study, 75 cultivars highly resistant to tan spot were identified. A positive correlation (r = 0.864; P = 0.001) was found between seedling resistance and adult plant resistance. Inheritance of tan spot resistance was found to be qualitative goverened by single major genes. Three novel resistance genes: tsn3, tsn4 and tsn5 were identified and located on chromosomes 3D, 3A and 3B, respectively. Linkage analysis using SSR markers showed that both the tsn3 (tsn3a, Tsn3b and tsn3c) and ts...

  11. Seed treatment for control leaf spot diseases of spring wheat

    Directory of Open Access Journals (Sweden)

    Barbara Krzyzińska

    2012-12-01

    Full Text Available In the years 2001 and 2002 at the Institute of Plant Protection Branch in Sooenicowice research work was performed on seed treatment with fungicides against leaf diseases of spring wheat cv. Ismena caused by pathogenic fungi: Blumeria graminis, Phaeasphaeria nodorum, Puccinia recondita i Pyrenophora tritici-repentis. Two variants of protection were included in the experiment: seed dressing with fungicides or seed dressing and single application of foliar spray at GS 49. At early growth stages of spring wheat a very high biological activity against powdery mildew, septoria leaf spot, brown rust and tan spot was recorded for seed dressing containing triticonazole+prochloraz. In the case of triadimenol+imazalil+fuberidazole only a weak, but long-lasting effect against brown rust and septoria leaf spot was observed. Leaf infection as well as 1000 grain mass and yield, in the experimental combination with using triticonazole+prochloraz were on the same level as in the experimental variant where after seed dressing with triadimenol+imazalil+fuberidazole plots were sprayed with tridemorf+epoxykonazole at GS 49. It was concluded that seed dressing preparation containing triticonazole+prochloraz constituted a good base for protection of spring wheat against foliar diseases.

  12. BREEDING OF TOMATO (LYCOPERSICON ESCULENTUM RESISTANT TO TOMATO SPOTTED WILT VIRUS

    Directory of Open Access Journals (Sweden)

    G. F. Monakhos

    2014-01-01

    Full Text Available The results of tomato lines resistance test to tomato spotted wilt virus and its comparison to molecular marker SCAR Sw421 genotyping data is shown. A molecular marker SCAR Sw421 analysis allowed identifying homozygous and heterozygous tomato genotypes possessing Sw5 alleles in segregating populations. Selected tomato lines possessing dominant homozygous alleles of Sw5 gene represent a tomato germplasm resistant to tomato spotted wilt virus and would be useful for following crop improvement.

  13. Adult Onset Still's Disease and Rocky Mountain Spotted Fever

    Directory of Open Access Journals (Sweden)

    Paul Persad

    2010-01-01

    Full Text Available Adult Still's Disease was first described in 1971 by Bywaters in fourteen adult female patients who presented with symptoms indistinguishable from that of classic childhood Still's Disease (Bywaters, 1971. George Still in 1896 first recognized this triad of quotidian (daily fevers, evanescent rash, and arthritis in children with what later became known as juvenile inflammatory arthritis (Still, 1990. Adult Onset Still's Disease (AOSD is an inflammatory condition of unknown etiology characterized by an evanescent rash, quotidian fevers, and arthralgias. Numerous infectious agents have been associated with its presentation. This case is to our knowledge the first presentation of AOSD in the setting of Rocky Mountain Spotted Fever. Although numerous infectious agents have been suggested, the etiology of this disorder remains elusive. Nevertheless, infection may in fact play a role in triggering the onset of symptoms in those with this disorder. Our case presentation is, to our knowledge, the first case of Adult Onset Still's Disease associated with Rocky Mountain spotted fever (RMSF.

  14. Adult Onset Still's Disease and Rocky Mountain Spotted Fever

    Science.gov (United States)

    Persad, Paul; Patel, Rajendrakumar; Patel, Niki

    2010-01-01

    Adult Still's Disease was first described in 1971 by Bywaters in fourteen adult female patients who presented with symptoms indistinguishable from that of classic childhood Still's Disease (Bywaters, 1971). George Still in 1896 first recognized this triad of quotidian (daily) fevers, evanescent rash, and arthritis in children with what later became known as juvenile inflammatory arthritis (Still, 1990). Adult Onset Still's Disease (AOSD) is an inflammatory condition of unknown etiology characterized by an evanescent rash, quotidian fevers, and arthralgias. Numerous infectious agents have been associated with its presentation. This case is to our knowledge the first presentation of AOSD in the setting of Rocky Mountain Spotted Fever. Although numerous infectious agents have been suggested, the etiology of this disorder remains elusive. Nevertheless, infection may in fact play a role in triggering the onset of symptoms in those with this disorder. Our case presentation is, to our knowledge, the first case of Adult Onset Still's Disease associated with Rocky Mountain spotted fever (RMSF). PMID:20811570

  15. A new measurement method for the dynamic resistance signal during the resistance spot welding process

    International Nuclear Information System (INIS)

    Wang, Lijing; Hou, Yanyan; Zhao, Jian; Zhang, Hongjie; Xi, Tao; Qi, Xiangyang; Li, Yafeng

    2016-01-01

    To measure the dynamic resistance signal during the resistance spot welding process, some original work was carried out and a new measurement method was developed. Compared with the traditional method, using the instantaneous electrode voltage and welding current at peak current point in each half cycle, the resistance curve from the newly proposed method can provide more details of the dynamic resistance changes over time. To test the specific performance of the proposed method, a series of welding experiments were carried out and the tensile shear strengths of the weld samples were measured. Then, the measurement error of the proposed method was evaluated. Several features were extracted from the dynamic resistance curves. The correlations between the extracted features and weld strength were analyzed and the results show that these features are closely related to the weld strength and they can be used for welding quality monitoring. Moreover, the dynamic resistance curve from the newly proposed method can also be used to monitor some abnormal welding conditions. (paper)

  16. Molecular markers linked to papaya ring spot virus resistance and Fusarium race 2 resistance in melon.

    Science.gov (United States)

    Brotman, Yariv; Kovalski, Irina; Dogimont, Catherine; Pitrat, Michel; Portnoy, Vitaly; Katzir, Nurit; Perl-Treves, Rafael

    2005-01-01

    In melon, the Fom-1 gene confers monogenic resistance against the soil-borne fungus Fusarium oxysporum f. sp. melonis, races 0 and 2, while the closely linked Prv gene specifies resistance against the papaya ring spot virus. Markers linked to these resistance (R) genes were identified using two recombinant inbred line populations, derived from crosses between Cucumis melo Vedrantais and C. melo PI 161375, and between C. melo Vedrantais and C. melo PI 414723, respectively. Using bulked segregant analysis, as well as systematic scoring of the mapping populations, we developed two amplified fragment length polymorphism markers, two random amplified polymorphic DNA markers and five restriction fragment length polymorphism (RFLP) markers linked to this locus. Four of the RFLP sequences bear homology to nucleotide-binding site-leucine-rich repeat R genes, indicating the presence of a significant R-gene cluster in this locus. Our study provides the most closely linked markers published so far for these important traits. It also improves the resolution of the whole linkage group IX, which was difficult to order in our previous studies. Two of the markers were converted to cleaved amplified polymorphic sequence markers to facilitate their application in marker-assisted selection. Testing these two markers in several melon lines revealed different marker haplotypes in the melon germplasm and supported multiple, independent origin of the Fusarium races 0 and 2 resistance trait.

  17. Association analysis of bacterial leaf spot resistance and SNP markers derived from expressed sequence tags (ESTs) in lettuce (Lactuca sativa L.)

    Science.gov (United States)

    Bacterial leaf spot of lettuce, caused by Xanthomonas campestris pv. vitians, is a devastating disease of lettuce worldwide. Since there are no chemicals available for effective control of the disease, host-plant resistance is highly desirable to protect lettuce production. A total of 179 lettuce ge...

  18. Identifying Future Disease Hot Spots: Infectious Disease Vulnerability Index.

    Science.gov (United States)

    Moore, Melinda; Gelfeld, Bill; Okunogbe, Adeyemi; Paul, Christopher

    2017-06-01

    Recent high-profile outbreaks, such as Ebola and Zika, have illustrated the transnational nature of infectious diseases. Countries that are most vulnerable to such outbreaks might be higher priorities for technical support. RAND created the Infectious Disease Vulnerability Index to help U.S. government and international agencies identify these countries and thereby inform programming to preemptively help mitigate the spread and effects of potential transnational outbreaks. The authors employed a rigorous methodology to identify the countries most vulnerable to disease outbreaks. They conducted a comprehensive review of relevant literature to identify factors influencing infectious disease vulnerability. Using widely available data, the authors created an index for identifying potentially vulnerable countries and then ranked countries by overall vulnerability score. Policymakers should focus on the 25 most-vulnerable countries with an eye toward a potential "disease belt" in the Sahel region of Africa. The infectious disease vulnerability scores for several countries were better than what would have been predicted on the basis of economic status alone. This suggests that low-income countries can overcome economic challenges and become more resilient to public health challenges, such as infectious disease outbreaks.

  19. The Research of Disease Spots Extraction Based on Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    Kangshun Li

    2017-01-01

    Full Text Available According to the characteristics of maize disease spot performance in the image, this paper designs two-histogram segmentation method based on evolutionary algorithm, which combined with the analysis of image of maize diseases and insect pests, with full consideration of color and texture characteristic of the lesion of pests and diseases, the chroma and gray image, composed of two tuples to build a two-dimensional histogram, solves the problem of one-dimensional histograms that cannot be clearly divided into target and background bimodal distribution and improved the traditional two-dimensional histogram application in pest damage lesion extraction. The chromosome coding suitable for the characteristics of lesion image is designed based on second segmentation of the genetic algorithm Otsu. Determining initial population with analysis results of lesion image, parallel selection, optimal preservation strategy, and adaptive mutation operator are used to improve the search efficiency. Finally, by setting the fluctuation threshold, we continue to search for the best threshold in the range of fluctuations for implementation of global search and local search.

  20. RAPD and SCAR markers linked to resistance to frogeye leaf spot in soybean

    Directory of Open Access Journals (Sweden)

    Sebastião Martins Filho

    2002-01-01

    Full Text Available The soybean (Glycine max (L. Merrill frogeye leaf spot is caused by the fungus Cercospora sojina Hara and is a widespread disease in Brazil and other countries, causing severe losses in grain yield and also affecting seed quality. The availability of DNA markers linked to genes for resistance to this disease would accelerate breeding programs, particularly when other traits are also being evaluated. Bulked segregant analysis was applied to 3 F2 populations derived from crosses between the resistant cultivars Parana, Cristalina and Uberaba, and the susceptible cultivar Bossier. In the cross 'Parana' x 'Bossier', 2 RAPD markers were identified, CSOPA1(800C and CSOPA2(1,250C, located at 4.4 ± 1.8 centiMorgans (cM and 3.4 ± 1.7 cM respectively from the resistance locus. DNA fragments of similar molecular weight were observed in the population derived from the cross 'Cristalina' x 'Bossier' at 2.3 ± 1.2 and 4.7 ± 1.5 cM from the resistance locus, respectively. In the offspring of the cross 'Uberaba' x 'Bossier', a DNA fragment corresponding to marker CSOPA1(800C was detected at 5.6 ± 2.1 cM from the resistance locus. Although marker CSOPA2(1,250C was not observed in this population, an additional marker was detected (CSOUB1(1,100C at 6.7 ± 2.2 cM from the resistance locus. The 1,250 bp fragment of CSOPA2(1,250C was cloned and converted into a SCAR marker, which amplified a single fragment whose size corresponded to the cloned segment of the crosses involving cultivars Cristalina and Parana. Markers CSOPA1(800C, CSOPA2(1,250C and CSOUB1(1,100C were mapped to soybean linkage group J with the aid of known SSRs linked to the Rcs3 locus, indicating that the RAPD and SCAR markers identified in our research also tag this resistance gene.

  1. Insulin Resistance in Liver Diseases

    OpenAIRE

    Irshad, M

    2011-01-01

    Present report gives a brief and consolidated review of insulin resistance developed in chronic liver diseases. Insulin resistance remains an important feature of chronic liver diseases and progresses disease towards fibrogenesis. Of hepatitis viral infections, hepatitis C virus (HCV) was reported to have a significant role in inducing insulin resistance. Both viral particles as such, as well its structural components induce insulin resistance. Hepatitis C virus core protein, specially, cause...

  2. Mapping of angular leaf spot resistance QTL in common bean (Phaseolus vulgaris L.) under different environments

    Science.gov (United States)

    2012-01-01

    Background Common bean (Phaseolus vulgaris L.) is the most important grain legume for human diet worldwide and the angular leaf spot (ALS) is one of the most devastating diseases of this crop, leading to yield losses as high as 80%. In an attempt to breed resistant cultivars, it is important to first understand the inheritance mode of resistance and to develop tools that could be used in assisted breeding. Therefore, the aim of this study was to identify quantitative trait loci (QTL) controlling resistance to ALS under natural infection conditions in the field and under inoculated conditions in the greenhouse. Results QTL analyses were made using phenotypic data from 346 recombinant inbreed lines from the IAC-UNA x CAL 143 cross, gathered in three experiments, two of which were conducted in the field in different seasons and one in the greenhouse. Joint composite interval mapping analysis of QTL x environment interaction was performed. In all, seven QTLs were mapped on five linkage groups. Most of them, with the exception of two, were significant in all experiments. Among these, ALS10.1DG,UC presented major effects (R2 between 16% - 22%). This QTL was found linked to the GATS11b marker of linkage group B10, which was consistently amplified across a set of common bean lines and was associated with the resistance. Four new QTLs were identified. Between them the ALS5.2 showed an important effect (9.4%) under inoculated conditions in the greenhouse. ALS4.2 was another major QTL, under natural infection in the field, explaining 10.8% of the variability for resistance reaction. The other QTLs showed minor effects on resistance. Conclusions The results indicated a quantitative inheritance pattern of ALS resistance in the common bean line CAL 143. QTL x environment interactions were observed. Moreover, the major QTL identified on linkage group B10 could be important for bean breeding, as it was stable in all the environments. Thereby, the GATS11b marker is a potential tool

  3. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Perseguini, Juliana Morini Küpper Cardoso; Oblessuc, Paula Rodrigues; Rosa, João Ricardo Bachega Feijó; Gomes, Kleber Alves; Chiorato, Alisson Fernando; Carbonell, Sérgio Augusto Morais; Garcia, Antonio Augusto Franco; Vianello, Rosana Pereira; Benchimol-Reis, Luciana Lasry

    2016-01-01

    The common bean (Phaseolus vulgaris L.) is the world’s most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum) and angular leaf spot (ALS; Pseudocercospora griseola) are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL) controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will contribute to more

  4. Characterization of Microstructure and Mechanical Properties of Resistance Spot Welded DP600 Steel

    Directory of Open Access Journals (Sweden)

    Ali Ramazani

    2015-09-01

    Full Text Available Resistance spot welding (RSW as a predominant welding technique used for joining steels in automotive applications needs to be studied carefully in order to improve the mechanical properties of the spot welds. The objectives of the present work are to characterize the resistance spot weldment of DP600 sheet steels. The mechanical properties of the welded joints were evaluated using tensile-shear and cross-tensile tests. The time-temperature evolution during the welding cycle was measured. The microstructures observed in different sites of the welds were correlated to thermal history recorded by thermocouples in the corresponding areas. It was found that cracks initiated in the periphery region of weld nuggets with a martensitic microstructure and a pull-out failure mode was observed. It was also concluded that tempering during RSW was the main reason for hardness decrease in HAZ.

  5. Screening lowland rice varieties for resistance to brown spot ...

    African Journals Online (AJOL)

    PAT

    Twelve lowland rice varieties (BG 90-2, Cisadane, FARO 12, FARO 15 (early maturing), FARO 15 (late maturing), IR 5, ITA 123, ITA 306, MAS 2401, Suakoko 8 and TOS 2578) were planted in 2008 and 2009 growing seasons in Enyong creek rice field in Akwa Ibom State. The varieties were screened for resistance to brown ...

  6. Genetic characterization of angular leaf spot resistance in selected ...

    African Journals Online (AJOL)

    The parents, F1, F2 and backcrosses derived plants were used for inheritance studies and for molecular marker screening using 30 SSR markers. Results indicate that, a single dominant gene control resistance against ALS in each of the four landraces; also the SSR marker Pv-ag004 was found to be polymorphic between ...

  7. First report of dollar spot disease, caused by Sclerotinia homoeocarpa, of Agrostis stolonifera in Sweden

    Science.gov (United States)

    Dollar spot is a destructive and widespread disease affecting most grass species grown as turf, but until recently it has been absent from the Scandinavian countries of northern Europe. In the fall of 2014, disease symptoms consistent with dollar spot were observed on a golf course fairway in Sweden...

  8. Resistance spot welding of a complicated joint in new advanced high strength steel

    NARCIS (Netherlands)

    Joop Pauwelussen; Nick den Uijl

    2015-01-01

    The goal of this article is to investigate resistance spot welding of a complicated welding configuration of three sheets of dissimilar steel sheet materials with shunt welds, using simulations. The configuration used resembles a case study of actual welds in automotive applications. One of the

  9. Influence of surface pretreatment in resistance spot welding of aluminum AA1050

    DEFF Research Database (Denmark)

    Al Naimi, Ihsan K.; Al Saadi, Moneer H.; Daws, Kasim M.

    2015-01-01

    -, medium-, and high-energy inputs. The as-received sheet showed higher electrical contact resistance because of thicker oxide layer. Lower values were noticed with pickled surfaces, whereas the lowest electrical contact resistance was obtained when glass blasting, resulting in the roughest surface......Resistance spot welding (RSW) of aluminum alloys implies a major problem of inconsistent quality from weld to weld due to problems of varying thickness of the oxide layer. The high resistivity of oxide layer causes strong heat development, which has significant influence on electrode life and weld...

  10. Fitness and competition studies of QoI resistant and sensitive Cercospora sojina isolates, the causal agent of frogeye leaf spot

    Science.gov (United States)

    Frogeye leaf spot (FLS), caused by Cercospora sojina, is a yearly foliar disease of soybean in Tennessee and causes substantial economic losses if not properly managed. Quinone outside inhibitor (QoI) fungicides are often used to manage FLS, but C. sojina isolates have developed resistance to this c...

  11. Quantitative trait loci (QTLs) for resistance to gray leaf spot and ...

    African Journals Online (AJOL)

    Gray leaf spot and common rust diseases can greatly reduce grain yield of maize in susceptible genotypes by between 10 and 70% on average. Control of these diseases through conventional measures has been quite ineffective and difficult to sustain. The most feasible way to control them is by breeding and deploying ...

  12. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Luseko

    2013-07-03

    Jul 3, 2013 ... Key words: Common bean, Pseudocercospora griseola, marker assisted selection, genotype, inheritance. INTRODUCTION. Common beans (Phaseolus ... and to determine the inheritance pattern of the diseases. MATERIALS AND METHODS ..... environmental effects. These results agree with what is.

  13. Mapping Late Leaf Spot Resistance in Peanut (Arachis hypogaea Using QTL-seq Reveals Markers for Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Josh Clevenger

    2018-02-01

    Full Text Available Late leaf spot (LLS; Cercosporidium personatum is a major fungal disease of cultivated peanut (Arachis hypogaea. A recombinant inbred line population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTLs. To resolve this problem, robust parental SNPs were first identified using polyploid-specific SNP identification pipelines, leading to discovery of significant QTLs for LLS resistance. These QTLs were confirmed over 4 years of field data. Selection with markers linked to these QTLs resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs. This study demonstrates that QTL-seq can be used to rapidly identify QTLs controlling highly quantitative traits in polyploid crops with complex genomes. Markers identified can then be deployed in breeding programs, increasing the efficiency of selection using molecular tools.Key Message: Field resistance to late leaf spot is a quantitative trait controlled by many QTLs. Using polyploid-specific methods, QTL-seq is faster and more cost effective than QTL mapping.

  14. Induced resistance to rust disease in lentil

    International Nuclear Information System (INIS)

    Paul, Amitava; Singh, D.P.

    2006-01-01

    Considerable yield reduction in lentil is due to rust caused by Uromyces fabae. So far the sources of resistance to rust are available in the small seeded background. There is a need to develop rust resistant/tolerant bold seeded cultivars. Mutations were induced by gamma rays (10 and 15 kR) for incorporating resistance to rust in K-75(Mallika), a high yielding bold seeded, but rust susceptible cultivar at Pantnagar which is the hot spot for this disease. Dry seeds (300) were irradiated for each treatment. In M 1 generation, individual plants from each treatment were selfed and harvested separately which constituted the M 2 generation. In M 2 individual plant progenies were scored following a rating scale of 1 (Free) to 9(highly susceptible). At 15 kR dose, 8 plants were resistant (score 3.0) and 14 plants were tolerant (score 5.0) to rust, while in control and 10 kR populations, all plants were susceptible or highly susceptible having score of 7 or 9, respectively. The M 2 plants segregated in ratio of 1 resistant: 3 susceptible. The progenies of resistant/tolerant M 2 plants were bred true in the M 3 generation suggesting that the resistance to rust is controlled by one recessive gene. (author)

  15. Powdery Mildew Disease Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, Shauna C.

    2010-08-31

    The overall goal of this project was to characterize the PMR5 protein, a member of the DUF231/TBR family, and to determine its role in plant cell wall biogenesis. Since the pmr5 mutants are also resistant to the fungal powdery mildew pathogen, we wished to determine what specific cell wall changes are associated with disease resistance and why. The graduate student working on this project made mutations in the putative active site of PMR5, assuming it is a member of the SGNH/GDSL esterase superfamily (Anantharaman and Aravind, 2010, Biology Direct 5, 1). These mutants were inactive in planta suggesting that PMR5 is a functional enzyme and not a binding protein or chaperone. In addition, she determined that cell wall preparations from the pmr5 mutant exhibited a modest reduction (13%) in total acetyl groups. To pursue characterization further, the graduate student expressed the PMR5 protein in a heterologous E. coli system. She could purify PMR5 using a two step protocol based on tags added to the N and C terminus of the protein. She was able to show the PMR5 protein bound to pectins, including homogalacturonan, but not to other cell wall components (e.g., xyloglucans, arabinans). Based on these observations, a postdoctoral fellow is currently developing an enzyme assay for PMR5 based on the idea that it may be acetylating the homogalacturonic acid pectin fraction. Our initial experiments to localize PMR5 subcellularly suggested that it occurred in the endoplasmic reticulum. However, since the various pectins are believed to be synthesized in the Golgi apparatus, we felt it necessary to repeat our results using a native promoter expression system. Within the past year, we have demonstrated conclusively that PMR5 is localized to the endoplasmic reticulum, a location that sets it apart from most cell wall biogenesis and modification enzymes. The graduate student contributed to the characterization of two suppressor mutants, which were selected as restoring powdery

  16. Solid-state and fusion resistance spot welding of TD-NiCr sheet

    Science.gov (United States)

    Moore, T. J.

    1973-01-01

    By using specially processed TD-NiCr sheet in both 0.4-mm (0.015-in.) and 1.6-mm (0.062-in.) thicknesses and carefully selected welding procedures, solid state resistance spot welds were produced which, after postheating at 1200 C, were indistinguishable from the parent material. Stress-rupture shear tests of single-spot lap joints in 0.4-mm (0.015-in.) thick sheet showed that these welds were as strong as the parent material. Similar results were obtained in tensile-shear tests at room temperature and 1100 C and in fatigue tests. Conventional fusion spot welds in commercial sheet were unsatisfactory because of poor stress-rupture shear properties resulting from metallurgical damage to the parent material.

  17. Genetic characterization and linkage disequilibrium mapping of resistance to gray leaf spot in maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Liyu Shi

    2014-04-01

    Full Text Available Gray leaf spot (GLS, caused by Cercospora zeae-maydis, is an important foliar disease of maize (Zea mays L. worldwide, resistance to which is controlled by multiple quantitative trait loci (QTL. To gain insights into the genetic architecture underlying the resistance to this disease, an association mapping population consisting of 161 inbred lines was evaluated for resistance to GLS in a plant pathology nursery at Shenyang in 2010 and 2011. Subsequently, a genome-wide association study, using 41,101 single-nucleotide polymorphisms (SNPs, identified 51 SNPs significantly (P < 0.001 associated with GLS resistance, which could be converted into 31 QTL. In addition, three candidate genes related to plant defense were identified, including nucleotide-binding-site/leucine-rich repeat, receptor-like kinase genes similar to those involved in basal defense. Two genic SNPs, PZE-103142893 and PZE-109119001, associated with GLS resistance in chromosome bins 3.07 and 9.07, can be used for marker-assisted selection (MAS of GLS resistance. These results provide an important resource for developing molecular markers closely linked with the target trait, enhancing breeding efficiency.

  18. Global Diffusion Pattern and Hot SPOT Analysis of Vaccine-Preventable Diseases

    Science.gov (United States)

    Jiang, Y.; Fan, F.; Zanoni, I. Holly; Li, Y.

    2017-10-01

    Spatial characteristics reveal the concentration of vaccine-preventable disease in Africa and the Near East and that disease dispersion is variable depending on disease. The exception is whooping cough, which has a highly variable center of concentration from year to year. Measles exhibited the only statistically significant spatial autocorrelation among all the diseases under investigation. Hottest spots of measles are in Africa and coldest spots are in United States, warm spots are in Near East and cool spots are in Western Europe. Finally, cases of measles could not be explained by the independent variables, including Gini index, health expenditure, or rate of immunization. Since the literature confirms that each of the selected variables is considered determinants of disease dissemination, it is anticipated that the global dataset of disease cases was influenced by reporting bias.

  19. Intermetallic Cu3Sn Phase Layer on Electrode’s Tip of Galvanized Resistance Spot Welding

    Directory of Open Access Journals (Sweden)

    Muhammad Anis

    2010-10-01

    Full Text Available A resistance spot welding method is commonly used in automotive industries application. In a resistance spot welding method, the copper electrode has a significant role as an electric current carrier for joining thin metal sheet. This research was focused on studying the effect of tin layer at the electrode tip for joining galvanized steel sheet. The main variable of this research is in the thickness of the intermetallic Cu3Sn layer. The result showed that the introduction of tin layer less than 1 μm in thickness on the electrode tip gives a comparable shear strength and nugget diameter distribution with the unplated electrode tip.

  20. Weld-brazing - a new joining process. [combination resistance spot welding and brazing of titanium alloys

    Science.gov (United States)

    Bales, T. T.; Royster, D. M.; Arnold, W. E., Jr.

    1972-01-01

    A joining process designated weld brazing which combines resistance spot welding and brazing has been developed. Resistance spot welding is used to position and align the parts as well as to establish a suitable faying surface gap for brazing. Fabrication is then completed by capillary flow of the braze alloy into the joint. The process has been used successfully to fabricate Ti-6Al-4V titanium alloy joints using 3003 aluminum braze alloy. Test results obtained on single overlap and hat-stiffened structural specimens show that weld brazed joints are superior in tensile shear, stress rupture, fatigue, and buckling than joint fabricated by spotwelding or brazing. Another attractive feature of the process is that the brazed joints is hermetically sealed by the braze material.

  1. Two alternative recessive quantitative trait loci influence resistance to spring black stem and leaf spot in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Oliver Richard P

    2008-03-01

    Full Text Available Abstract Background Knowledge of the genetic basis of plant resistance to necrotrophic pathogens is incomplete and has been characterised in relatively few pathosystems. In this study, the cytology and genetics of resistance to spring black stem and leaf spot caused by Phoma medicaginis, an economically important necrotrophic pathogen of Medicago spp., was examined in the model legume M. truncatula. Results Macroscopically, the resistant response of accession SA27063 was characterised by small, hypersensitive-like spots following inoculation while the susceptible interaction with accessions A17 and SA3054 showed necrotic lesions and spreading chlorosis. No unique cytological differences were observed during early infection (2 populations segregating for resistance to spring black stem and leaf spot were established between SA27063 and the two susceptible accessions, A17 and SA3054. The cross between SA27063 and A17 represented a wider cross than between SA27063 and SA3054, as evidenced by higher genetic polymorphism, reduced fertility and aberrant phenotypes of F2 progeny. In the SA27063 × A17 F2 population a highly significant quantitative trait locus (QTL, LOD = 7.37; P Phoma medicaginis one (rnpm1 genetically mapped to the top arm of linkage group 4 (LG4. rnpm1 explained 33.6% of the phenotypic variance in the population's response to infection depicted on a 1–5 scale and was tightly linked to marker AW256637. A second highly significant QTL (LOD = 6.77; P rnpm2, was located on the lower arm of LG8 in the SA27063 × SA3054 map. rnpm2 explained 29.6% of the phenotypic variance and was fine mapped to a 0.8 cM interval between markers h2_16a6a and h2_21h11d. rnpm1 is tightly linked to a cluster of Toll/Interleukin1 receptor-nucleotide binding site-leucine-rich repeat (TIR-NBS-LRR genes and disease resistance protein-like genes, while no resistance gene analogues (RGAs are apparent in the genomic sequence of the reference accession A17 at the

  2. Metallurgical Effects of Shunting Current on Resistance Spot-Welded Joints of AA2219 Sheets

    Science.gov (United States)

    Jafari Vardanjani, M.; Araee, A.; Senkara, J.; Jakubowski, J.; Godek, J.

    2016-08-01

    Shunting effect is the loss of electrical current via the secondary circuit provided due to the existence of previous nugget in a series of welding spots. This phenomenon influences on metallurgical aspects of resistance spot-welded (RSW) joints in terms of quality and performance. In this paper RSW joints of AA2219 sheets with 1 mm thickness are investigated metallurgically for shunted and single spots. An electro-thermal finite element analysis is performed on the RSW process of shunted spot and temperature distribution and variation are obtained. These predictions are then compared with experimental micrographs. Three values of 5 mm, 20 mm, and infinite (i.e., single spot) are assumed for welding distance. Numerical and experimental results are matching each other in terms of nugget and HAZ geometry as increasing distance raised nugget size and symmetry of HAZ. In addition, important effect of shunting current on nugget thickness, microstructure, and Copper segregation on HAZ grain boundaries were discovered. A quantitative analysis is also performed about the influence of welding distance on important properties including ratio of nugget thickness and diameter ( r t), ratio of HAZ area on shunted and free side of nugget ( r HA), and ratio of equivalent segregated and total amount of Copper, measured in sample ( r Cu) on HAZ. Increasing distance from 5 mm to infinite, indicated a gain of 111.04, -45.55, and -75.15% in r t, r HA, and r Cu, respectively, while obtained ratios for 20 mm welding distance was suitable compared to single spot.

  3. Chemical control of Cercospora leaf spot disease of cowpea ( Vigna ...

    African Journals Online (AJOL)

    Abstract. Three fungicides, benlate (methy'I -1- (butylcarbamoyl) - 2 - benzimidazole carbamate), dithane M -45 (zinc and magnesium ethylene bisdithiocarbamate) and difolatan (5 Cis - N - 1, l ,2,2 - tetrachloroethy 1) thio - .4 - cyclohexane - 1, 2 – di-carboximide) were tested in the field for Cercospora leaf spot control.

  4. Resistance Spot Welding of Aluminum Alloy to Steel with Transition Material - From Process to Performance

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.; Shao, H; Kimchi, Menachem; Menachem Kimchi and Wanda Newman

    2004-05-11

    This paper summarizes work to date on resistance spot welding (RSW) of aluminum alloy to mild steel from process development to performance evaluation. A cold-rolled strip material is introduced as a transition material to aid the resistance welding process. The optimal welding parameters and electrode selections were established using a combination of experimental and analytical approaches. The mechanical behaviors of welded samples was evaluated using static and dynamic strength tests and cyclic fatigue tests. A statistical analysis was also performed to analyze the effect of different failure modes on the sample's peak load and energy absorption.

  5. Genetic diversity within and among two-spotted spider mite resistant and susceptible common bean genotypes

    Directory of Open Access Journals (Sweden)

    Zeinab YOUSEFI

    2017-12-01

    Full Text Available Two-spotted spider mite (Tetranychus urticae C. L. Koch, 1836, is one of the most destructive herbivores of common bean. Very little is known about the diversity among resistant sources in this crop. The present study was conducted to characterize 22 resistant and susceptible common bean genotypes by 8 Simple Sequence Repeats (SSRs and 8 Random Amplified Polymorphic DNA (RAPD markers. These SSR and RAPD primers produced 100 % and 81.8 % polymorphic bands. Based on RAPD fingerprints and SSR profiles, pairwise genetic similarity ranged from 0.0 to 0.857 and from 0.125 to 1, respectively. The resistant and susceptible common bean accessions were grouped together in the dendrograms generated from RAPD and SSR clustering analyses. The results indicate that RAPD and SSR analysis could be successfully used for the estimation of genetic diversity among genotypes. SSR markers could group genotypes according to their resistibility and susceptibility to the spotted spider mite but RAPD could not. Therefore, the SSR markers can facilitate the development of resistant common bean cultivars through breeding programs against T. urticae.

  6. Spotted-Leaf Mutants of Rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    Qi-na HUANG

    2010-12-01

    Full Text Available Many rice spotted-leaf (spl mutants are ideal sources for understanding the mechanisms involved in blast resistance, bacterial blight resistance and programmed cell death in plants. The genetic controls of 50 spotted-leaf mutants in rice have been characterized and a few spotted-leaf genes have been isolated as well. This article reviews the origin, genetic modes, isolation and characterization of spotted-leaf genes responsible for their phenotypes, and their resistance responses to main rice diseases.

  7. Microstructure and fatigue properties of Mg-to-steel dissimilar resistance spot welds

    International Nuclear Information System (INIS)

    Liu, L.; Xiao, L.; Chen, D.L.; Feng, J.C.; Kim, S.; Zhou, Y.

    2013-01-01

    Highlights: ► Mg/steel dissimilar spot weld had the same fatigue strength as Mg/Mg similar weld. ► Crack propagation path of Mg/Mg and Mg/steel welds was the same. ► Penetration of Zn into the Mg base metal led to crack initiation of Mg/steel weld. ► HAZ weakening and stress concentration led to crack initiation of Mg/Mg weld. -- Abstract: The structural application of lightweight magnesium alloys in the automotive industry inevitably involves dissimilar welding with steels and the related durability issues. This study was aimed at evaluating the microstructural change and fatigue resistance of Mg/steel resistance spot welds, in comparison with Mg/Mg welds. The microstructure of Mg/Mg spot welds can be divided into: base metal, heat affected zone and fusion zone (nugget). However, the microstructure of Mg/steel dissimilar spot welds had three different regions along the joined interface: weld brazing, solid-state joining and soldering. The horizontal and vertical Mg hardness profiles of Mg/steel and Mg/Mg welds were similar. Both Mg/steel and Mg/Mg welds were observed to have an equivalent fatigue resistance due to similar crack propagation characteristics and failure mode. Both Mg/steel and Mg/Mg welds failed through thickness in the magnesium sheet under stress-controlled cyclic loading, but fatigue crack initiation of the two types of welds was different. The crack initiation of Mg/Mg welds was occurred due to a combined effect of stress concentration, grain growth in the heat affected zone (HAZ), and the presence of Al-rich phases at HAZ grain boundaries, while the penetration of small amounts of Zn coating into the Mg base metal stemming from the liquid metal induced embrittlement led to crack initiation in the Mg/steel welds.

  8. Rapid Molecular detection of citrus brown spot disease using ACT gene in Alternaria alternata

    Directory of Open Access Journals (Sweden)

    Hamid Moghimi

    2017-06-01

    Full Text Available Introduction:Using rapid detection methods is important for detection of plant pathogens and also prevention through spreading pests in agriculture. Citrus brown spot disease caused by pathogenic isolates of Alternaria alternata is a common disease in Iran. Materials and methods: In this study, for the first time a PCR based molecular method was used for rapid diagnosis of brown spot disease. Nine isolates of A. Alternata were isolated in PDA medium from different citrus gardens. The plant pathogenic activity was examined in tangerine leaves for isolates. Results showed that these isolates are the agents of brown spot disease. PCR amplification of specific ACT-toxin gene was performed for DNA extracted from A. alternata isolates, with 11 different fungal isolates as negative controls and 5 DNA samples extracted from soil. Results: Results showed that A. alternata, the causal agent of brown spot disease, can be carefully distinguished from other pathogenic agents by performing PCR amplification with specific primers for ACT toxin gene. Also, the results from Nested-PCR method confirmed the primary reaction and the specificity of A. alternata for brown spot disease. PCR results to control samples of the other standard fungal isolates, showed no amplification band. In addition, PCR with the DNA extracted from contaminated soils confirmed the presence of ACT toxin gene. Discussion and conclusion: Molecular procedure presented here can be used in rapid identification and prevention of brown spot infection in citrus gardens all over the country.

  9. Effectiveness of combining resistance to Thielaviopsis basicola and Tomato spotted wilt virus in haploid tobacco genotypes.

    Science.gov (United States)

    Trojak-Goluch, Anna; Laskowska, Dorota; Agacka, Monika; Czarnecka, Diana; Kawka, Magdalena; Czubacka, Anna

    2011-12-01

    Black root rot (BRR) caused by Thielaviopsis basicola as well as Tomato spotted wilt virus (TSWV) are the most serious problems in tobacco growing regions. We crossed the breeding line WGL 3 carrying BRR resistance derived from N.glauca with the line PW-834 the resistance of which to TSWV was transferred from cultivar Polalta. Anthers obtained from F(1) hybrid plants were cultured to induce haploids combining resistance to Th. basicola and TSWV. Flow cytometry analysis revealed 242 haploids and 2 spontaneous doubled haploids among regenerants. All haploids were cloned and then evaluated for BRR as well as TSWV resistance. The presence of pathogens was detected by microscopic evaluation of roots or using DAS-ELISA test. Microscopic assessment showed that, 132 haploids had no symptoms of Th. basicola which, together with the absence of symptoms in the F(1) hybrids, indicated a dominant monogenic mode of inheritance. At the same time only 30 haploids demonstrated resistance to TSWV. SCAR markers associated with TSWV resistance gene detection was applied. The results indicate that small proportion of TSWV-resistant haploids is probably due to the influence of deleterious genes flanking the resistance factor that reduced vitality of gametophytes. Altogether, 24 haploids showed multiple resistance to Th. basicola and TSWV.

  10. Tsw gene-based resistance is triggered by a functional RNA silencing suppressor protein of the Tomato spotted wilt virus

    NARCIS (Netherlands)

    Ronde, de D.; Butterbach, P.B.E.; Lohuis, H.; Hedil, M.; Lent, van J.W.M.; Kormelink, R.J.M.

    2013-01-01

    As a result of contradictory reports, the avirulence (Avr) determinant that triggers Tsw gene-based resistance in Capsicum annuum against the Tomato spotted wilt virus (TSWV) is still unresolved. Here, the N and NSs genes of resistance-inducing (RI) and resistance-breaking (RB) isolates were cloned

  11. Development of a test method for determining the cracking susceptibility of resistance spot welded high strength steel sheets

    OpenAIRE

    Rethmeier, Michael; Suwala, Hubert

    2014-01-01

    In this study a test method for determining the cracking susceptibility of resistance spot welded high strength steel sheets was investigated. The development of a suitable test procedure is based on the External-Loaded Hot Crack Test (PVC-Test). The test modification for resistance spot welding contains a constant tensile force load. The test method for determining the cracking susceptibility was experimentally verified for a high strength steel, a transformation induced plasticity steel (TR...

  12. Resistance Spot Welding of AA5052 Sheet Metal of Dissimilar Thickness

    Science.gov (United States)

    Mat Din, N. A.; Zuhailawati, H.; Anasyida, A. S.

    2016-02-01

    Resistance spot welding of dissimilar thickness of AA5052 aluminum alloy was performed in order to investigate the effect of metal thickness on the weldment strength. Resistance spot welding was done using a spot welder machine available in Coraza Systems Sdn Bhd using a hemispherical of chromium copper electrode tip with radius of 6.00 mm under 14 kA of current and 0.02 bar of pressure for all thickness combinations. Lap joint configuration was produced between 2.0 mm thick sheet and 1.2 - 3.2 mm thick sheet, respectively. Microstructure of joint showed asymmetrical nugget shape that was larger on the thicker side indicating larger molten metal volume. Joint 2.0 mm x 3.2 mm sheets has the lowest hardness in both transverse direction and through thickness direction because less heat left in the weld nugget. The microstructure shows that this joint has coarse grains of HAZ. As thickness of sheet metal increased, the failure load of the joints increased. However, there was no linear correlation established between joint strength and metal thickness due to different shape of fusion zone in dissimilar thickness sheet metal.

  13. Engineering disease resistance in plants

    NARCIS (Netherlands)

    Custers, J.H.H.V.

    2007-01-01

    The genetic engineering of plants for increased pathogen resistance has engaged researchers and companies for decades. Until now, thenumberof crops with genetically engineered disease resistance traits which have entered the market are limited to products displaying virus

  14. Studies on the Etiology of a Leaf Spot Disease of Rough Lemon ...

    African Journals Online (AJOL)

    ... similar foliar lesions when artificially inoculated on healthy citrus leaves. The fungus was also re-isolated. A. niger did not elicite any disease under the conditions of this study. Rhizoctonia sp. is therefore, the causal organism of the disease under study. Keywords: Etiology, Leaf spot disease, Rough lemon, Citrus jambhiri, ...

  15. Host resistance to Botrytis bunch rot in Vitis spp. and its correlation with Botrytis leaf spot

    Science.gov (United States)

    Botrytis cinerea, the causal agent of Botrytis bunch rot, is the number one postharvest disease of fresh grapes in the U.S. Fungicide applications are used to manage the disease, but resistant isolates are common and postharvest losses occur annually. Host resistance is needed for long-term manageme...

  16. Characteristics of Resistance Spot Welded Ti6Al4V Titanium Alloy Sheets

    Directory of Open Access Journals (Sweden)

    Xinge Zhang

    2017-10-01

    Full Text Available Ti6Al4V titanium alloy is applied extensively in the aviation, aerospace, jet engine, and marine industries owing to its strength-to-weight ratio, excellent high-temperature properties and corrosion resistance. In order to extend the application range, investigations on welding characteristics of Ti6Al4V alloy using more welding methods are required. In the present study, Ti6Al4V alloy sheets were joined using resistance spot welding, and the weld nugget formation, mechanical properties (including tensile strength and hardness, and microstructure features of the resistance spot-welded joints were analyzed and evaluated. The visible indentations on the weld nugget surfaces caused by the electrode force and the surface expulsion were severe due to the high welding current. The weld nugget width at the sheets’ faying surface was mainly affected by the welding current and welding time, and the welded joint height at weld nugget center was chiefly associated with electrode force. The maximum tensile load of welded joint was up to 14.3 kN in the pullout failure mode. The hardness of the weld nugget was the highest because of the coarse acicular α′ structure, and the hardness of the heat-affected zone increased in comparison to the base metal due to the transformation of the β phase to some fine acicular α′ phase.

  17. Symptom and Resistance of Cultivated and Wild Capsicum Accessions to Tomato Spotted Wilt Virus

    Directory of Open Access Journals (Sweden)

    Jung-Heon Han

    2011-04-01

    Full Text Available One hundred Capsicum accessions were screened for symptomatic response and resistance to Tomato spotted wilt virus-pb1 (TSWV-pb1. Symptom and its severity rating were checked by visual observation at 9, 12, 14, and 45 days after inoculation, respectively. Enzyme-linked immune-sorbent assay was performed all tested individuals on non-inoculated upper leaves after the third rating to indentify viral infection. Leaf curling was predominant in almost susceptible individuals of each accession. Stem necrosis was most frequent in wild species while yellowing in commercial hybrids and Korean land race cultivars. Ring spot, a typical symptom of TSWV, was rarely detected in some of a few accessions. Different levels of resistance to TSWV-pb1 were observed among the tested accessions. High level of resistance was detected in 4 commercial cultivars of Kpc- 35, -36, -57, and -62, and 8 wild species of PBI-11, C00105, PBC076, PBC280, PBC426, PBC495, PBC537, and PI201238 through seedling test by mechanical inoculation.

  18. Structure of Ti-6Al-4V nanostructured titanium alloy joint obtained by resistance spot welding

    Science.gov (United States)

    Klimenov, V. A.; Kurgan, K. A.; Chumaevskii, A. V.; Klopotov, A. A.; Gnyusov, S. F.

    2016-01-01

    The structure of weld joints of the titanium alloy Ti-6Al-4V in the initial ultrafine-grained state, obtained by resistance spot welding, is studied using the optical and scanning electron microscopy method and the X-ray structure analysis. The carried out studies show the relationship of the metal structure in the weld zone with main joint zones. The structure in the core zone and the heat affected zone is represented by finely dispersed grains of needle-shaped martensite, differently oriented in these zones. The change in the microhardness in the longitudinal section of the weld joint clearly correlates with structural changes during welding.

  19. Structure of Ti-6Al-4V nanostructured titanium alloy joint obtained by resistance spot welding

    Energy Technology Data Exchange (ETDEWEB)

    Klimenov, V. A., E-mail: klimenov@tpu.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Kurgan, K. A., E-mail: kirill-k2.777@mail.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); Chumaevskii, A. V., E-mail: tch7av@gmail.com [Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, 2/4 Akademicheskii pr., Tomsk, 634021 (Russian Federation); Klopotov, A. A., E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36 Lenin Ave., Tomsk, 634050 (Russian Federation); Gnyusov, S. F., E-mail: gnusov@rambler.ru [National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation)

    2016-01-15

    The structure of weld joints of the titanium alloy Ti-6Al-4V in the initial ultrafine-grained state, obtained by resistance spot welding, is studied using the optical and scanning electron microscopy method and the X-ray structure analysis. The carried out studies show the relationship of the metal structure in the weld zone with main joint zones. The structure in the core zone and the heat affected zone is represented by finely dispersed grains of needle-shaped martensite, differently oriented in these zones. The change in the microhardness in the longitudinal section of the weld joint clearly correlates with structural changes during welding.

  20. Comparison of Metallurgical and Ultrasonic Inspections of Galvanized Steel Resistance Spot Welds

    International Nuclear Information System (INIS)

    Potter, Timothy J.; Ghaffari, Bita; Mozurkewich, George; Reverdy, Frederic; Hopkins, Deborah

    2006-01-01

    Metallurgical examination of galvanized steel resistance spot welds was used to gauge the capabilities of two ultrasonic, non-destructive, scanning techniques. One method utilized the amplitude of the echo from the weld faying surface, while the other used the spectral content of the echo train to map the fused area. The specimens were subsequently sectioned and etched, to distinguish the fused, zinc-brazed, and non-fused areas. The spectral maps better matched the metallurgical maps, while the interface-amplitude method consistently overestimated the weld size

  1. Evaluation of High Temperature Properties and Microstructural Characterization of Resistance Spot Welded Steel Lap Shear Joints

    Science.gov (United States)

    Gupta, R. K.; Anil Kumar, V.; Panicker, Paul G.

    2016-02-01

    Joining of thin sheets (0.5 mm) of stainless steel 304 and 17-4PH through resistance spot welding is highly challenging especially when joint is used for high temperature applications. Various combinations of stainless steel sheets of thickness 0.5 mm are spot welded and tested at room temperature as well as at high temperatures (800 K, 1,000 K, 1,200 K). Parent metal as well as spot welded joints are tested and characterized. It is observed that joint strength of 17-4PH steel is highest and then dissimilar steel joint of 17-4PH with SS-304 is moderate and of SS-304 is lowest at all the temperatures. Joint strength of 17-4PH steel is found to be >80% of parent metal properties up to 1,000 K then drastic reduction in strength is noted at 1,200 K. Gradual reduction in strength of SS-304 joint with increase in temperature from 800 to 1,200 K is noted. At 1,200 K, joint strength of all combinations of joints is found to be nearly same. Microstructural evaluation of weld nugget after testing at different temperatures shows presence of tempered martensite in 17-4PH containing welds and homogenized structure in stainless steel 304 weld.

  2. Mud crab susceptibility to disease from white spot syndrome virus is species-dependent

    Directory of Open Access Journals (Sweden)

    Sritunyalucksana Kallaya

    2010-11-01

    Full Text Available Abstract Background Based on a report for one species (Scylla serrata, it is widely believed that mud crabs are relatively resistant to disease caused by white spot syndrome virus (WSSV. We tested this hypothesis by determining the degree of susceptibility in two species of mud crabs, Scylla olivacea and Scylla paramamosain, both of which were identified by mitochondrial 16 S ribosomal gene analysis. We compared single-dose and serial-dose WSSV challenges on S. olivacea and S. paramamosain. Findings In a preliminary test using S. olivacea alone, a dose of 1 × 106 WSSV copies/g gave 100% mortality within 7 days. In a subsequent test, 17 S. olivacea and 13 S. paramamosain were divided into test and control groups for challenge with WSSV at 5 incremental, biweekly doses starting from 1 × 104 and ending at 5 × 106 copies/g. For 11 S. olivacea challenged, 3 specimens died at doses between 1 × 105 and 5 × 105 copies/g and none died for 2 weeks after the subsequent dose (1 × 106 copies/g that was lethal within 7 days in the preliminary test. However, after the final challenge on day 56 (5 × 106 copies/g, the remaining 7 of 11 S. olivacea (63.64% died within 2 weeks. There was no mortality in the buffer-injected control crabs. For 9 S. paramamosain challenged in the same way, 5 (55.56% died after challenge doses between 1 × 104 and 5 × 105 copies/g, and none died for 2 weeks after the challenge dose of 1 × 106 copies/g. After the final challenge (5 × 106 copies/g on day 56, no S. paramamosain died during 2 weeks after the challenge, and 2 of 9 WSSV-infected S. paramamosain (22.22% remained alive together with the control crabs until the end of the test on day 106. Viral loads in these survivors were low when compared to those in the moribund crabs. Conclusions S. olivacea and S. paramamosain show wide variation in response to challenge with WSSV. S. olivacea and S. paramamosain are susceptible to white spot disease, and S. olivacea is more

  3. Mud crab susceptibility to disease from white spot syndrome virus is species-dependent.

    Science.gov (United States)

    Somboonna, Naraporn; Mangkalanan, Seksan; Udompetcharaporn, Attasit; Krittanai, Chartchai; Sritunyalucksana, Kallaya; Flegel, Tw

    2010-11-20

    Based on a report for one species (Scylla serrata), it is widely believed that mud crabs are relatively resistant to disease caused by white spot syndrome virus (WSSV). We tested this hypothesis by determining the degree of susceptibility in two species of mud crabs, Scylla olivacea and Scylla paramamosain, both of which were identified by mitochondrial 16 S ribosomal gene analysis. We compared single-dose and serial-dose WSSV challenges on S. olivacea and S. paramamosain. In a preliminary test using S. olivacea alone, a dose of 1 × 106 WSSV copies/g gave 100% mortality within 7 days. In a subsequent test, 17 S. olivacea and 13 S. paramamosain were divided into test and control groups for challenge with WSSV at 5 incremental, biweekly doses starting from 1 × 104 and ending at 5 × 106 copies/g. For 11 S. olivacea challenged, 3 specimens died at doses between 1 × 105 and 5 × 105 copies/g and none died for 2 weeks after the subsequent dose (1 × 106 copies/g) that was lethal within 7 days in the preliminary test. However, after the final challenge on day 56 (5 × 106 copies/g), the remaining 7 of 11 S. olivacea (63.64%) died within 2 weeks. There was no mortality in the buffer-injected control crabs. For 9 S. paramamosain challenged in the same way, 5 (55.56%) died after challenge doses between 1 × 104 and 5 × 105 copies/g, and none died for 2 weeks after the challenge dose of 1 × 106 copies/g. After the final challenge (5 × 106 copies/g) on day 56, no S. paramamosain died during 2 weeks after the challenge, and 2 of 9 WSSV-infected S. paramamosain (22.22%) remained alive together with the control crabs until the end of the test on day 106. Viral loads in these survivors were low when compared to those in the moribund crabs. S. olivacea and S. paramamosain show wide variation in response to challenge with WSSV. S. olivacea and S. paramamosain are susceptible to white spot disease, and S. olivacea is more susceptible than S. paramamosain. Based on our single

  4. Induced disease resistance

    NARCIS (Netherlands)

    Pieterse, Corné; van Wees, Saskia

    2015-01-01

    During the co-evolutionary arms race between plants and pathogens, plants evolved a sophisticated defense system to ward off their enemies. In this plant immune system, plant receptor proteins recognize non-self molecules of microbial origin, which leads to the activation of a basal level of disease

  5. ASPIRIN RESISTANCE IN NEUROVASCULAR DISEASES

    OpenAIRE

    Martin Vališ; Dagmar Krajíčková; Jaroslav Malý; Radovan Malý; Ilona Fátorová; Oldřich Vyšata; Roman Herzig

    2014-01-01

    Introduction: The issue of resistance to antiplatelet therapy has raised many questions in the area of neurovascular diseases. The first objective of this work was to determine the prevalence of aspirin resistance in neurovascular patients with clinical non-responsiveness to aspirin treatment and a high-risk of atherothrombotic complications using two interpretable and independent methods (aggregation and PFA 100). The second objective was to find the correlation between both assays and to ev...

  6. Isolation and identification of fungi responsible for leaf spots disease ...

    African Journals Online (AJOL)

    The diseased plant leaves were taken to the laboratory for culture, isolation, and identification of pathogens. Plant disease incidence was determined using disease index and severity scale of 0-4 rating. Eleven fungal pathogens were isolated and identified. These included; Alternaria longipes, Aspergillus fumigatus, ...

  7. Comparison of white spot syndrome virus infection resistance between Exopalaemon carinicauda and Litopenaeus vannamei under different salinity stresses

    Science.gov (United States)

    Ge, Qianqian; Yu, Ge; Sun, Ming; Li, Jitao; Li, Jian

    2017-12-01

    Exopalaemon carinicauda is one of the important economic shrimp species in China, and can tolerate a wide range of salinities. However, its disease resistance remains to be unclear in comparison with other shrimp species under salinity stress. In this study, the resistance to white spot syndrome virus (WSSV) of E. carinicauda and Litopenaeus vannamei was determined by comparing their hemocyanin (Hc) and phenoloxidase (PO) activities under different salinity stresses. In E. carinicauda, the PO activity and Hc gene transcript abundance showed a coherent pattern of increase and decrease while Hc content showed a slightly decrease with Vibrio anguillarum and WSSV infections. For both E. carinicauda and L. vannamei under salinity stress, the PO activity showed a positive correlation with the salinity while the Hc content and expression level of its gene increased significantly in salinities of 5, 15 and 25 g L-1. The survival rate of E. carinicauda with WSSV infection was higher than that of L. vannamei in the first 24 h under different salinity stresses. Drastic mortality of E.carinicauda and L. vannamei appeared at 48 h and 3 h post-injection, respectively. Furthermore, compared with L. vannamei, E. carinicauda displayed higher PO activity, Hc content and abundance of Hc gene mRNA. The results collectively indicated that Hc and PO have obviously functional connection in resisting pathogens and tolerating salinity stress, and PO activity and Hc gene mRNA abundance may reflect the resistance of shrimp to disease. E. carinicauda has higher level of immune potential than L. vannamei, suggesting its greater capacity in resisting pathogens under salinity stresses.

  8. Application of infrared imaging for quality inspection in resistance spot welds

    Science.gov (United States)

    Woo, Wanchuck; Chin, Charles W.; Feng, Zhili; Wang, Hsin; Zhang, Wei; Xu, Hanbing; Sklad, Philip S.

    2009-05-01

    Infrared thermal imaging method was applied for the development of a non-destructive inspection technique to determine the quality of resistance spot welds. The current work is an initial feasibility study based on post-mortem inspection. First, resistance spot welds were fabricated on dual phase steel sheets (DP 590 steel) with carefullycontrolled welding parameters. It created welds with desirable and undesirable qualities in terms of nugget size, indentation depth, and voids and cracks. Second, five different heating and cooling methods were evaluated. The heating or cooling source was applied on one side of the weld stack while the surface temperature change on the other side of the weld was recorded using an infrared camera. Correlation between the weld quality and the "thermal signature" of each weld was established. Finally, a simplified thermal finite element analysis was developed to simulate the heat flow during inspection. The thermal model provided insight into the effect of the nugget size and indentation depth on the peak temperature and heating rate. The results reported in this work indicate that the IR thermography technique is feasible for weld quality inspection due to the distinguish temperature profiles for different welds and the repeatability and consistency in measurement.

  9. Characterization and genetic dissection of resistance to spotted alfalfa aphid (Therioaphis trifolii) in Medicago truncatula

    Science.gov (United States)

    Kamphuis, Lars G.; Lichtenzveig, Judith; Peng, Kefan; Guo, Su-Min; Klingler, John P.

    2013-01-01

    Aphids cause significant yield losses in agricultural crops worldwide. Medicago truncatula, a model legume, cultivated pasture species in Australia and close relative of alfalfa (Medicago sativa), was used to study the defence response against Therioaphis trifolii f. maculate [spotted alfalfa aphid (SAA)]. Aphid performance and plant damage were compared among three accessions. A20 is highly susceptible, A17 has moderate resistance, and Jester is strongly resistant. Subsequent analyses using A17 and A20, reciprocal F1s and an A17×A20 recombinant inbred line (RIL) population revealed that this moderate resistance is phloem mediated and involves antibiosis and tolerance but not antixenosis. Electrical penetration graph analysis also identified a novel waveform termed extended potential drop, which occurred following SAA infestation of M. truncatula. Genetic dissection using the RIL population revealed three quantitative trait loci on chromosomes 3, 6, and 7 involved in distinct modes of aphid defence including antibiosis and tolerance. An antibiosis locus resides on linkage group 3 (LG3) and is derived from A17, whereas a plant tolerance and antibiosis locus resides on LG6 and is derived from A20, which exhibits strong temporary tolerance. The loci identified reside in regions harbouring classical resistance genes, and introgression of these loci in current medic cultivars may help provide durable resistance to SAA, while elucidation of their molecular mechanisms may provide valuable insight into other aphid–plant interactions. PMID:24058162

  10. Characterization and genetic dissection of resistance to spotted alfalfa aphid (Therioaphis trifolii) in Medicago truncatula

    KAUST Repository

    Kamphuis, L. G.

    2013-09-21

    Aphids cause significant yield losses in agricultural crops worldwide. Medicago truncatula, a model legume, cultivated pasture species in Australia and close relative of alfalfa (Medicago sativa), was used to study the defence response against Therioaphis trifolii f. maculate [spotted alfalfa aphid (SAA)]. Aphid performance and plant damage were compared among three accessions. A20 is highly susceptible, A17 has moderate resistance, and Jester is strongly resistant. Subsequent analyses using A17 and A20, reciprocal F1s and an A17×A20 recombinant inbred line (RIL) population revealed that this moderate resistance is phloem mediated and involves antibiosis and tolerance but not antixenosis. Electrical penetration graph analysis also identified a novel waveform termed extended potential drop, which occurred following SAA infestation of M. truncatula. Genetic dissection using the RIL population revealed three quantitative trait loci on chromosomes 3, 6, and 7 involved in distinct modes of aphid defence including antibiosis and tolerance. An antibiosis locus resides on linkage group 3 (LG3) and is derived from A17, whereas a plant tolerance and antibiosis locus resides on LG6 and is derived from A20, which exhibits strong temporary tolerance. The loci identified reside in regions harbouring classical resistance genes, and introgression of these loci in current medic cultivars may help provide durable resistance to SAA, while elucidation of their molecular mechanisms may provide valuable insight into other aphid–plant interactions.

  11. Evaluation of onion cultivars for resistance to onion thrips (Thysanoptera: Thripidae) and Iris yellow spot virus.

    Science.gov (United States)

    Diaz-Montano, John; Fuchs, Marc; Nault, Brian A; Shelton, Anthony M

    2010-06-01

    Onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), a worldwide pest of onion, Allium cepa L., can reduce onion yield by > 50% and be even more problematic when it transmits Iris yellow spot virus (family Bunyaviridae, genus Tospovirus, IYSV). Because T. tabaci is difficult to control with insecticides and other strategies, field studies on onion, Allium cepa L., resistance to T. tabaci and IYSV were conducted in 2007 and 2008 in two locations in New York state. Forty-nine cultivars were evaluated for resistance by counting the number of larvae weekly and recording leaf damage. In another experiment, the impact of T. tabaci and IYSV on plant growth and yield was examined by spraying half of the plants with an insecticide. Eleven of the 49 cultivars had very little leaf damage and were considered resistant to T. tabaci. Visual assessment indicated that all resistant cultivars had yellow-green- colored foliage, whereas the other 38 had blue-green- colored foliage. The visual assessment of color agreed with data on color taken with a HunterLab Ultra Scan XE colorimeter. The onions 'Colorado 6' and 'NMSU 03-52-1' had the lowest numbers of T. tabaci, suggesting strong antibiosis and/or antixenosis. The other nine cultivars had variable numbers of T. tabaci, indicating a possible combination of categories of resistance. In the nonprotected treatments there were significant reductions in plant height and plant weight in most of the resistant cultivars, but there were reductions in bulb weight only in a few of them. The average of plants infected with IYSV was 10% in 2007 and 60% in 2008. Our findings indicate potential for developing onion resistance to T. tabaci as part of an overall integrated pest management strategy but suggest difficulties in identifying resistance to IYSV.

  12. Application of Pre-heating to Improve the Consistency and Quality in AA5052 Resistance Spot Welding

    Science.gov (United States)

    Luo, Zhen; Ao, Sansan; Chao, Yuh Jin; Cui, Xuetuan; Li, Yang; Lin, Ye

    2015-10-01

    Making consistent resistance spot welds of aluminum alloy with good quality and at high volume has several obstacles in automotive industry. One of the difficult issues arises from the presence of a tough non-conducting oxide film on the aluminum sheet surface. The oxide film develops over time and often is non-uniform across the surface of the aluminum alloy sheet, which makes the contact resistance characteristics irregular at the faying interface during welding. The consistency in quality of the final spot welds is therefore problematic to control. To suppress the effect of the irregular oxide film on the spot weld quality, application of a pre-heating treatment in the welding schedule for aluminum alloy 5052 is investigated in this present work. The current level of the pre-heating required to reduce the scatter of the contact resistance at the W/W (workpiece-to-workpiece) faying interface is quantified experimentally. The results indicate that the contact resistance at the W/W faying interface with a pre-heating treatment becomes much consistent and can be reduced by two orders of magnitude. Having the uncertain variation of the contact resistance at the W/W faying surface virtually reduced or removed, the quality of the spot welds in terms of the peak load and nugget diameter is examined and shows a great improvement. The proposed method may provide a robust method for high-volume spot welding of aluminum alloy sheets in auto industry.

  13. Insulin Resistance in Alzheimer's Disease

    Science.gov (United States)

    Dineley, Kelly T; Jahrling, Jordan B; Denner, Larry

    2014-01-01

    Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD. PMID:25237037

  14. Modeling of electric and heat processes in spot resistance welding of cross-wire steel bars

    Science.gov (United States)

    Iatcheva, Ilona; Darzhanova, Denitsa; Manilova, Marina

    2018-03-01

    The aim of this work is the modeling of coupled electric and heat processes in a system for spot resistance welding of cross-wire reinforced steel bars. The real system geometry, dependences of material properties on the temperature, and changes of contact resistance and released power during the welding process have been taken into account in the study. The 3D analysis of the coupled AC electric and transient thermal field distributions is carried out using the finite element method. The novel feature is that the processes are modeled for several successive time stages, corresponding to the change of contact area, related contact resistance, and reduction of the released power, occurring simultaneously with the creation of contact between the workpieces. The values of contact resistance and power changes have been determined on the basis of preliminary experimental and theoretical investigations. The obtained results present the electric and temperature field distributions in the system. Special attention has been paid to the temperature evolution at specified observation points and lines in the contact area. The obtained information could be useful for clarification of the complicated nature of interrelated electric, thermal, mechanical, and physicochemical welding processes. Adequate modeling is also an opportunity for proper control and improvement of the system.

  15. Biological effects of emissions from resistance spot welding of zinc-coated material after controlled exposure of healthy human subjects.

    Science.gov (United States)

    Gube, Monika; Kraus, Thomas; Lenz, Klaus; Reisgen, Uwe; Brand, Peter

    2014-06-01

    Do emissions from a resistance spot welding process of zinc-coated materials induce systemic inflammation in healthy subjects after exposure for 6 hours? Twelve healthy male subjects were exposed once for 6 hours either to filtered ambient air or to welding fume from resistance spot welding of zinc-coated material (mass concentration approximately 100 μg m). Biological effects were measured before, after, and 24 hours after exposure. At the concentrations used in this study, however, the suspected properties of ultrafine particles did not lead to systemic inflammation as reflected by high-sensitivity C-reactive protein or other endpoint parameters under consideration. Ultrafine particles from a resistance spot welding process of zinc-covered materials with a number concentration of about 10 cm and a mass concentration of about 100 μg m did not induce systemic inflammation.

  16. Using SNP genetic markers to elucidate the linkage of the Co-34/Phg-3 anthracnose and angular leaf spot resistance gene cluster with the Ur-14 resistance gene

    Science.gov (United States)

    The Ouro Negro common bean cultivar contains the Co-34/Phg-3 gene cluster that confers resistance to the anthracnose (ANT) and angular leaf spot (ALS) pathogens. These genes are tightly linked on chromosome 4. Ouro Negro also has the Ur-14 rust resistance gene, reportedly in the vicinity of Co- 34; ...

  17. Multi objective Taguchi optimization approach for resistance spot welding of cold rolled TWIP steel sheets

    Science.gov (United States)

    Tutar, Mumin; Aydin, Hakan; Bayram, Ali

    2017-08-01

    Formability and energy absorption capability of a steel sheet are highly desirable properties in manufacturing components for automotive applications. TWinning Induced Plastisity (TWIP) steels are, new generation high Mn alloyed steels, attractive for the automotive industry due to its outstanding elongation (%40-45) and tensile strength (~1000MPa). So, TWIP steels provide excellent formability and energy absorption capability. Another required property from the steel sheets is suitability for manufacturing methods such as welding. The use of the steel sheets in the automotive applications inevitably involves welding. Considering that there are 3000-5000 welded spots on a vehicle, it can be interpreted that one of the most important manufacturing method is Resistance Spot Welding (RSW) for the automotive industry. In this study; firstly, TWIP steel sheet were cold rolled to 15% reduction in thickness. Then, the cold rolled TWIP steel sheets were welded with RSW method. The welding parameters (welding current, welding time and electrode force) were optimized for maximizing the peak tensile shear load and minimizing the indentation of the joints using a Taguchi L9 orthogonal array. The effect of welding parameters was also evaluated by examining the signal-to-noise ratio and analysis of variance (ANOVA) results.

  18. Cercospora leaf spot in sugar beet. Epidemiology, life cycle components and disease management

    NARCIS (Netherlands)

    Vereijssen, J.

    2004-01-01

    Cercospora beticola, the causal agent of Cercospora 1eaf spot (CLS) in sugar beet, causes I reductions in sugar yield and financial returns. Section I describes the epidemiology of CLS. Two disease severity indices were compared and their relation with sugar yield modelled. A linear curve fitted the

  19. An efficient in vitro test to determine carrot genotypes resistance to cavity spot.

    Science.gov (United States)

    Savelon, S; Vandemoortele, J L

    2001-01-01

    As part of a carrot breeding programme, our objective was to develop a test for determining genotypes resistance against two Pythium species responsible for cavity spot. Ten different media were tested for carrot callus culture, Pythium culture and dual cultures. Carrot callus growth was greater on Murashige and Skoog medium plus 1.25 microM 2.4D plus 2.5 microM BA plus 2.5 microM NAA. Pythium violae was more sensitive to medium composition than Pythium sulcatum. When carrot callus were inoculated by Pythium violae or sulcatum on Murashige and Skoog mineral medium, callus growth of Bolero, an resistant cultivar in the field, was highly inhibited whereas Nanco, a susceptible cultivar was not. Such a medium should be used for screening genotypes resistance to Pythium. A Murashige and Skoog medium supplemented with 1.25 microM 2.4D, 2.5 microM BA and 2.5 microM NAA, where callus growth was highly reduced whatever the genotype used, should be useful for selection of cell lines tolerant to Pythium.

  20. Heat-affected zone liquation crack on resistance spot welded TWIP steels

    International Nuclear Information System (INIS)

    Saha, Dulal Chandra; Chang, InSung; Park, Yeong-Do

    2014-01-01

    In this study, the heat affected zone (HAZ) liquation crack and segregation behavior of the resistance spot welded twinning induced plasticity (TWIP) steel have been reported. Cracks appeared in the post-welded joints that originated at the partially melted zone (PMZ) and propagated from the PMZ through the heat affected zone (HAZ) to the base metal (BM). The crack length and crack opening widths were observed increasing with heat input; and the welding current was identified to be the most influencing parameter for crack formation. Cracks appeared at the PMZ when nugget diameter reached at 4.50 mm or above; and the liquation cracks were found to occur along two sides of the notch tip in the sheet direction rather than in the electrode direction. Cracks were backfilled with the liquid films which has lamellar structure and supposed to be the eutectic constituent. Co-segregation of alloy elements such as, C and Mn were detected on the liquid films by electron-probe microanalysis (EPMA) line scanning and element map which suggests that the liquid film was enrich of Mn and C. The eutectic constituent was identified by analyzing the calculated phase diagram along with thermal temperature history of finite element simulation. Preliminary experimental results showed that cracks have less/no significant effect on the static cross-tensile strength (CTS) and the tensile-shear strength (TSS). In addition, possible ways to avoid cracking were discussed. - Highlights: • The HAZ liquation crack during resistance spot welding of TWIP steel was examined. • Cracks were completely backfilled and healed with divorced eutectic secondary phase. • Co-segregation of C and Mn was detected in the cracked zone. • Heat input was the most influencing factor to initiate liquation crack. • Cracks have less/no significant effect on static tensile properties

  1. Characterizing and Estimating Fungal Disease Severity of Rice Brown Spot with Hyperspectral Reflectance Data

    Directory of Open Access Journals (Sweden)

    Zhan-yu LIU

    2008-09-01

    Full Text Available Large-scale farming of agriculture crops requires real-time detection of disease for field pest management. Hyperspectral remote sensing data generally have high spectral resolution, which could be very useful for detecting disease stress in green vegetation at the leaf and canopy levels. In this study, hyperspectral reflectances of rice in the laboratory and field were measured to characterize the spectral regions and wavebands, which were the most sensitive to rice brown spot infected by Bipolaris oryzae (Helminthosporium oryzae Breda. de Hann. Leaf reflectance increased at the ranges of 450 to 500 nm and 630 to 680 nm with the increasing percentage of infected leaf surface, and decreased at the ranges of 520 to 580 nm, 760 to 790 nm, 1550 to 1750 nm, and 2080 to 2350 nm with the increasing percentage of infected leaf surface respectively. The sensitivity analysis and derivative technique were used to select the sensitive wavebands for the detection of rice brown spot infected by B. oryzae. Ratios of rice leaf reflectance were evaluated as indicators of brown spot. R669/R746 (the reflectance at 669 nm divided by the reflectance at 746 nm, the following ratios may be deduced by analogy, R702/R718, R692/R530, R692/R732, R535/R746, R521/R718, and R569/R718 increased significantly as the incidence of rice brown spot increased regardless of whether it's at the leaf or canopy level. R702/R718, R692/R530, R692/R732 were the best three ratios for estimating the disease severity of rice brown spot at the leaf and canopy levels. This result not only confirms the capability of hyperspectral remote sensing data in characterizing crop disease for precision pest management in the real world, but also testifies that the ratios of crop reflectance is a useful method to estimate crop disease severity.

  2. Identification of two new races of Diplocarpon rosae Wolf, the causal agent of rose black spot disease

    Science.gov (United States)

    The fungal pathogen, Diplocarpon rosae Wolf, infects only roses (Rosa spp.) and leads to rose black spot disease. Rose black spot is the most problematic disease of outdoor grown roses worldwide, due to the potential for rapid leaf yellowing and defoliation. Plants repeatedly defoliated from black ...

  3. Aerosol characterization and pulmonary responses in rats after short-term inhalation of fumes generated during resistance spot welding of galvanized steel

    Directory of Open Access Journals (Sweden)

    James M. Antonini

    Full Text Available Resistance spot welding is a common process to join metals in the automotive industry. Adhesives are often used as sealers to seams of metals that are joined. Anti-spatter compounds sometimes are sprayed onto metals to be welded to improve the weldability. Spot welding produces complex aerosols composed of metal and volatile compounds (VOCs which can cause lung disease in workers. Male Sprague-Dawley rats (n = 12/treatment group were exposed by inhalation to 25 mg/m3 of aerosol for 4 h/day × 8 days during spot welding of galvanized zinc (Zn-coated steel in the presence or absence of a glue or anti-spatter spray. Controls were exposed to filtered air. Particle size distribution and chemical composition of the generated aerosol were determined. At 1 and 7 days after exposure, bronchoalveolar lavage (BAL was performed to assess lung toxicity. The generated particles mostly were in the submicron size range with a significant number of nanometer-sized particles formed. The primary metals present in the fumes were Fe (72.5% and Zn (26.3%. The addition of the anti-spatter spray and glue did affect particle size distribution when spot welding galvanized steel, whereas they had no effect on metal composition. Multiple VOCs (e.g., methyl methacrylate, acetaldehyde, ethanol, acetone, benzene, xylene were identified when spot welding using either the glue or the anti-spatter spray that were not present when welding alone. Markers of lung injury (BAL lactate dehydrogenase and inflammation (total BAL cells/neutrophils and cytokines/chemokines were significantly elevated compared to controls 1 day after exposure to the spot welding fumes. The elevated pulmonary response was transient as lung toxicity mostly returned to control values by 7 days. The VOCs or the concentrations that they were generated during the animal exposures had no measurable effect on the pulmonary responses. Inhalation of galvanized spot welding fumes caused acute lung toxicity

  4. On-line inspection of weld quality based on dynamic resistance curve in resistance spot welding and weldbonding

    Science.gov (United States)

    Sun, Haitao; Zhang, Yansong; Lai, Xinmin; Chen, Guanlong

    2008-12-01

    In order to reduce destructive testing of car sub-assemblies, on-line inspection of weld quality has gained more and more concern in terms of both resistance spot welding (RSW) and weldbonding. Dynamic resistance directly determines the amount of heat generated by current flow and consequently reflects nugget formation and growth, which is one of the most effective technologies for quality inspection. Under the measurements of voltage and current at the secondary circuit of a welding transformer, this paper proposes a method for on-line inspection of weld quality based on two indicators from dynamic resistance curve: time to nugget initiation and durable time to nugget expansion. Firstly, during the welding process of RSW and weldbonding, the proper range of time to nugget initiation and durable time to nugget expansion for good welds is set up. Then on-line inspection of weld quality on the basis of the developed proper range of these two indicators is carried out. The experimental results show the following conclusions: it is clearly able to separate accepted welds without expulsion from the welds of unaccepted nugget size in both RSW and weldbonding; the proper range for good welds, independent of electrode wear, is obtained only for a new electrode.

  5. Fontes de resistência em tomateiro aos begomovírus bissegmentados Tomato yellow spot virus e Tomato severe rugose virus Sources of resistance in tomato to bipartite begomoviruses Tomato yellow spot virus and Tomato severe rugose virus

    Directory of Open Access Journals (Sweden)

    Francisco D Hurtado

    2012-12-01

    Full Text Available Os begomovírus causam doenças de grande importância econômica em diversas culturas, principalmente em regiões tropicais e subtropicais. Juntamente com outras famílias de vírus, os begomovírus têm causado grande prejuízo para os produtores de tomate in natura e para processamento industrial. O objetivo deste trabalho foi avaliar o comportamento de 11 genótipos resistentes ao Tomato yellow leaf curl virus (TYLCV frente à infecção pelos begomovírus Tomato yellow spot virus (ToYSV e Tomato severe rugose virus (ToSRV em condições de casa-vegetação. A inoculação das plantas foi realizada via biobalística no estádio de duas folhas verdadeiras. A infecção viral confirmou-se pelo desenvolvimento dos sintomas e pela técnica de hibridização dot blot. Selecionaram-se como promissores os genótipos STY2, STY5, STY6 e L7, por não apresentarem sintomas e por terem concentrações virais muito baixas para os dois vírus. O espectro de resistência dos genes Ty-1 e Ty-2 não resultaram efetivos ante as espécies virais empregadas no estudo. As linhagens TY52, H24 e CLN2116B, portadoras destes genes, foram suscetíveis aos vírus ToYSV e ToSRV.Begomoviruses cause diseases of major economic importance in many crops, especially in tropical and subtropical regions. Together with other families of viruses, the begomoviruses cause great damage for producers of fresh and processed tomatoes. The objective of this study was to evaluate the behavior of 11 resistant genotypes to Tomato yellow leaf curl virus (TYLCV when infected by the begomoviruses Tomato severe rugose virus (ToSRV and Tomato yellow spot virus (ToYSV under greenhouse conditions. Tomato plants were inoculated by biobalistic method when displaying two true leaves. Viral infection was confirmed by visual observation of symptoms and by dot blot hybridization. Genotypes STY2, STY5, STY6 and L7 were selected as promising due to the absence of symptoms and very low viral

  6. The softened heat-affected zone in resistance spot welded tailor hardened boron steel: a material model for crash simulation

    NARCIS (Netherlands)

    Eller, Tom; Greve, L; Andres, M.T.; Medricky, M; Geijselaers, Hubertus J.M.; Meinders, Vincent T.; van den Boogaard, Antonius H.

    2016-01-01

    A hardness-based model for tailor hardened boron steel is presented that takes into account the softened heat-affected zone of resistance spot welds. The computational model is designed for crashworthiness simulation of fully and partially hardened components obtained by tailored tooling. Five

  7. Microstructure and Mechanical Properties of Resistance Spot Welding Joints of Carbonitrided Low-Carbon Steels

    Science.gov (United States)

    Taweejun, Nipon; Poapongsakorn, Piyamon; Kanchanomai, Chaosuan

    2017-04-01

    Carbonitrided low-carbon steels are resistance welded in various engineering components. However, there are no reports on the microstructure and mechanical properties of their resistance spot welding (RSW) joints. Therefore, various carbonitridings were performed on the low-carbon steel sheets, and then various RSWs were applied to these carbonitrided sheets. The metallurgical and mechanical properties of the welding joint were investigated and discussed. The peak load and failure energy increased with the increases of welding current and fusion zone (FZ) size. At 11 kA welding current, the carbonitrided steel joint had the failure energy of 16 J, i.e., approximately 84 pct of untreated steel joint. FZ of carbonitrided steel joint consisted of ferrite, Widmanstatten ferrite, and untempered martensite, i.e., the solid-state transformation products, while the microstructure at the outer surfaces consisted of untempered martensite and retained austenite. The surface hardening of carbonitrided steel after RSW could be maintained, i.e., approximately 810 HV. The results can be applied to carbonitriding and RSW to achieve a good welding joint.

  8. Joining of Dissimilar alloy Sheets (Al 6063&AISI 304 during Resistance Spot Welding Process: A Feasibility Study for Automotive industry

    Directory of Open Access Journals (Sweden)

    Reddy Sreenivasulu

    2014-12-01

    Full Text Available Present design trends in automotive manufacture have shifted emphasis to alternative lightweight materials in order to achieve higher fuel efficiency and to bring down vehicle emission. Although some other joining techniques are more and more being used, spot welding still remains the primary joining method in automobile manufacturing so far. Spot welds for automotive applications should have a sufficiently large diameter, so that nugget pullout mode is the dominant failure mode. Interfacial mode is unacceptable due to its low load carrying and energy absorption capability. Strength tests with different static loading were performed in, to reveal the failure mechanisms for the lap-shear geometry and the cross-tension geometry. Based on the literature survey performed, venture into this work was amply motivated by the fact that a little research work has been conducted to joining of dissimilar materials like non ferrous to ferrous. Most of the research works concentrated on joining of different materials like steel to steel or aluminium alloy to aluminium alloy by resistance spot welding. In this work, an experimental study on the resistance spot weldability of aluminium alloy (Al 6063 and austenitic stainless steel (AISI304 sheets, which are lap joined by using a pedestal type resistance spot welding machine. Welding was conducted using a 45-deg truncated cone copper electrode with 10-mm face diameter. The weld nugget diameter, force estimation under lap shear test and T – peel test were investigated using digital type tensometer attached with capacitive displacement transducer (Mikrotech, Bangalore, Model: METM2000ER1. The results shows that joining of Al 6063 and AISI 304 thin sheets by RSW method are feasible for automotive structural joints where the loads are below 1000N act on them, it is observed that by increasing the spots per unit length, then the joint with standing strength to oppose failure is also increased linearly incase of

  9. Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus.

    Science.gov (United States)

    López-Gresa, M Pilar; Lisón, Purificación; Yenush, Lynne; Conejero, Vicente; Rodrigo, Ismael; Bellés, José María

    2016-01-01

    Tomato plants expressing the NahG transgene, which prevents accumulation of endogenous salicylic acid (SA), were used to study the importance of the SA signalling pathway in basal defence against Citrus Exocortis Viroid (CEVd) or Tomato Spotted Wilt Virus (TSWV). The lack of SA accumulation in the CEVd- or TSWV-infected NahG tomato plants led to an early and dramatic disease phenotype, as compared to that observed in the corresponding parental Money Maker. Addition of acibenzolar-S-methyl, a benzothiadiazole (BTH), which activates the systemic acquired resistance pathway downstream of SA signalling, improves resistance of NahG tomato plants to CEVd and TSWV. CEVd and TSWV inoculation induced the accumulation of the hydroxycinnamic amides p-coumaroyltyramine, feruloyltyramine, caffeoylputrescine, and feruloylputrescine, and the defence related proteins PR1 and P23 in NahG plants earlier and with more intensity than in Money Maker plants, indicating that SA is not essential for the induction of these plant defence metabolites and proteins. In addition, NahG plants produced very high levels of ethylene upon CEVd or TSWV infection when compared with infected Money Maker plants, indicating that the absence of SA produced additional effects on other metabolic pathways. This is the first report to show that SA is an important component of basal resistance of tomato plants to both CEVd and TSWV, indicating that SA-dependent defence mechanisms play a key role in limiting the severity of symptoms in CEVd- and TSWV-infected NahG tomato plants.

  10. Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus.

    Directory of Open Access Journals (Sweden)

    M Pilar López-Gresa

    Full Text Available Tomato plants expressing the NahG transgene, which prevents accumulation of endogenous salicylic acid (SA, were used to study the importance of the SA signalling pathway in basal defence against Citrus Exocortis Viroid (CEVd or Tomato Spotted Wilt Virus (TSWV. The lack of SA accumulation in the CEVd- or TSWV-infected NahG tomato plants led to an early and dramatic disease phenotype, as compared to that observed in the corresponding parental Money Maker. Addition of acibenzolar-S-methyl, a benzothiadiazole (BTH, which activates the systemic acquired resistance pathway downstream of SA signalling, improves resistance of NahG tomato plants to CEVd and TSWV. CEVd and TSWV inoculation induced the accumulation of the hydroxycinnamic amides p-coumaroyltyramine, feruloyltyramine, caffeoylputrescine, and feruloylputrescine, and the defence related proteins PR1 and P23 in NahG plants earlier and with more intensity than in Money Maker plants, indicating that SA is not essential for the induction of these plant defence metabolites and proteins. In addition, NahG plants produced very high levels of ethylene upon CEVd or TSWV infection when compared with infected Money Maker plants, indicating that the absence of SA produced additional effects on other metabolic pathways. This is the first report to show that SA is an important component of basal resistance of tomato plants to both CEVd and TSWV, indicating that SA-dependent defence mechanisms play a key role in limiting the severity of symptoms in CEVd- and TSWV-infected NahG tomato plants.

  11. Influence of welding current in resistance spot welding on the properties of Zn coated steel DX51D

    OpenAIRE

    Luboš Kaščák; Ján Viňáš; Rudolf Mišičko

    2016-01-01

    The paper deals with the resistance spot welding of three galvanized car body sheets DX51D + Z - EN 10142/2000. The quality of welded joints was evaluated by destructive tests and non-destructive tests. For evaluation of joints quality the shear tension test on spot joints according to DIN 50 124 standard was used. The influence of welding parameters on the structure of a welded joint was observed by metallographic analysis. Influence of welding current from 6.0 to 7.7 kA and infl...

  12. 3D modelling of plug failure in resistance spot welded shear-lab specimens (DP600-steel)

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2008-01-01

    Ductile plug failure of resistance spot welded shear-lab specimens is studied by full 3D finite element analysis, using an elastic-viscoplastic constitutive relation that accounts for nucleation and growth of microvoids to coalescence (The Gurson model). Tensile properties and damage parameters...... it possible to numerically relate the weld diameter to the tensile shear force (TSF) and the associated displacement, u (TSF) , respectively. Main focus in the paper is on modelling the localization of plastic flow and the corresponding damage development in the vicinity of the spot weld, near the HAZ...

  13. Xanthomonas euvesicatoria Causes Bacterial Spot Disease on Pepper Plant in Korea

    Directory of Open Access Journals (Sweden)

    Min-Seong Kyeon

    2016-10-01

    Full Text Available In 2004, bacterial spot-causing xanthomonads (BSX were reclassified into 4 species—Xanthomonas euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Bacterial spot disease on pepper plant in Korea is known to be caused by both X. axonopodis pv. vesicatoria and X. vesicatoria. Here, we reidentified the pathogen causing bacterial spots on pepper plant based on the new classification. Accordingly, 72 pathogenic isolates were obtained from the lesions on pepper plants at 42 different locations. All isolates were negative for pectolytic activity. Five isolates were positive for amylolytic activity. All of the Korean pepper isolates had a 32 kDa-protein unique to X. euvesicatoria and had the same band pattern of the rpoB gene as that of X. euvesicatoria and X. perforans as indicated by PCR-restriction fragment length polymorphism analysis. A phylogenetic tree of 16S rDNA sequences showed that all of the Korean pepper plant isolates fit into the same group as did all the reference strains of X. euvesicatoria and X. perforans. A phylogenetic tree of the nucleotide sequences of 3 housekeeping genes—gapA, gyrB, and lepA showed that all of the Korean pepper plant isolates fit into the same group as did all of the references strains of X. euvesicatoria. Based on the phenotypic and genotypic characteristics, we identified the pathogen as X. euvesicatoria. Neither X. vesicatoria, the known pathogen of pepper bacterial spot, nor X. perforans, the known pathogen of tomato plant, was isolated. Thus, we suggest that the pathogen causing bacterial spot disease of pepper plants in Korea is X. euvesicatoria.

  14. BROWN SPOT CAUSED BY CURVULARIA SPP., A NEW DISEASE OF ASPARAGUS

    Directory of Open Access Journals (Sweden)

    B. SALLEH

    1996-01-01

    Full Text Available The distribution, aetiology and symptomatology of a new disease on asparagus ferns, which we have termed brown spot, is described. Descriptions of and a key to identification of the causal organisms, Curvularia brachyspora, C. eragrostidis, C. lunata and C. pallescens, are also presented. Pathogenicity tests showed that C. lunata was the dominant and most virulent of the four species. Inoculation with conidial suspensions or mycelial transfers through wounded ferns were more effective in inducing the disease than inoculations on unwounded ferns. This is the first record of C. brachyspora in Malaysia and the first report of this disease on asparagus.

  15. Mutation breeding for disease resistance in food bean and cowpea in Kenya

    International Nuclear Information System (INIS)

    Moses Onim, J.F.

    1983-01-01

    Progress is being reported on a project aiming at genetic improvement of cowpea and Phaseolus bean for better disease resistance using induced mutations. The diseases of concern are anthracnose, angular leaf spot, halo blight and bean rust. Selection was effective in M 3 and M 4 generations and provided some lines with different resistance and yield levels, which will have to be examined further. (author)

  16. Controle genético da resistência à mancha-de-Phaeosphaeria em milho Genetic control of resistance to Phaeosphaeria leaf spot in maize

    Directory of Open Access Journals (Sweden)

    Maria Teresa Gomes Lopes

    2007-06-01

    Full Text Available A mancha-de-Phaeosphaeria, de ampla ocorrência no Brasil, tem causado expressiva redução na produtividade da cultura do milho no país. Por isso, o desenvolvimento de híbridos resistentes à doença é um dos principais objetivos dos programas de melhoramento genético da cultura. Informações sobre o controle genético da resistência à doença são necessárias para que os programas de melhoramento sejam eficientes. O objetivo deste estudo foi determinar o controle genético da resistência à mancha-de-Phaeosphaeria em milho a partir da avaliação das médias de gerações oriundas de dois cruzamentos entre linhagens resistentes (DAS95 ou DAS72 com uma suscetível (DAS21, sob condições de infecção natural da doença. Os ensaios foram conduzidos em Indianópolis (MG, em duas épocas de semeadura, outubro e novembro de 2000. Foi utilizado o delineamento experimental blocos ao acaso com três repetições. A avaliação para resistência foi realizada 30 dias após o florescimento com auxílio de uma escala diagramática de porcentagem de tecido foliar total da planta afetado pela doença. As médias da severidade da doença dos genitores e das gerações F1, F2, RCP1 e RCP2 foram analisadas segundo o modelo de MATHER & JINKS (1971. A variação genética devida a efeitos aditivos foi de 73 a 84%, enquanto, devido aos efeitos dominantes, foi de 13 a 23%. Foi evidenciada a predominância dos efeitos gênicos aditivos sobre dominantes em ambas as populações estudadas. Os valores da herdabilidade foram altos, variando de 61 a 88%. Os resultados indicaram condições favoráveis ao melhoramento genético visando àresistência à mancha-de-Phaeospheria nas populações estudadas.The Phaeosphaeria leaf spot, of ample occurrence in Brazil, has been causing an expressive reduction in the corn yield in the country. Thus, the development of resistant hybrids to this disease is one of the main objectives of corn breeding programs. Information

  17. Draft genome sequence of Cercospora sojina isolate S9, a fungus causing frogeye leaf spot (FLS disease of soybean

    Directory of Open Access Journals (Sweden)

    Fanchang Zeng

    2017-06-01

    Full Text Available Fungi are the causal agents of many of the world's most serious plant diseases causing disastrous consequences for large-scale agricultural production. Pathogenicity genomic basis is complex in fungi as multicellular eukaryotic pathogens. The fungus Cercospora sojina is a plant pathogen that threatens global soybean supplies. Here, we report the genome sequence of C. sojina strain S9 and detect genome features and predicted genomic elements. The genome sequence of C. sojina is a valuable resource with potential in studying the fungal pathogenicity and soybean host resistance to frogeye leaf spot (FLS, which is caused by C. sojina. The C. sojina genome sequence has been deposited and available at DDBJ/EMBL/GenBank under the project accession number AHPQ00000000.

  18. Laser welded versus resistance spot welded bone implants: analysis of the thermal increase and strength.

    Science.gov (United States)

    Fornaini, Carlo; Meleti, Marco; Bonanini, Mauro; Lagori, Giuseppe; Vescovi, Paolo; Merigo, Elisabetta; Nammour, Samir

    2014-01-01

    The first aim of this "ex vivo split mouth" study was to compare the thermal elevation during the welding process of titanium bars to titanium implants inserted in pig jaws by a thermal camera and two thermocouples. The second aim was to compare the strength of the joints by a traction test with a dynamometer. Six pigs' jaws were used and three implants were placed on each side of them for a total of 36 fixtures. Twelve bars were connected to the abutments (each bar on three implants) by using, on one side, laser welding and, on the other, resistance spot welding. Temperature variations were recorded by thermocouples and by thermal camera while the strength of the welded joint was analyzed by a traction test. For increasing temperature, means were 36.83 and 37.06, standard deviations 1.234 and 1.187, and P value 0.5763 (not significant). For traction test, means were 195.5 and 159.4, standard deviations 2.00 and 2.254, and P value 0.0001 (very significant). Laser welding was demonstrated to be able to connect titanium implant abutments without the risk of thermal increase into the bone and with good results in terms of mechanical strength.

  19. EFFECTS OF ELECTRODE DEFORMATION OF RESISTANCE SPOT WELDING ON 304 AUSTENITIC STAINLESS STEEL WELD GEOMETRY

    Directory of Open Access Journals (Sweden)

    Nachimani Charde

    2012-12-01

    Full Text Available The resistance spot welding process is accomplished by forcing huge amounts of current flow from the upper electrode tip through the base metals to the lower electrode tip, or vice versa or in both directions. A weld joint is established between the metal sheets through fusion, resulting in a strong bond between the sheets without occupying additional space. The growth of the weld nugget (bond between sheets is therefore determined from the welding current density; sufficient time for current delivery; reasonable electrode pressing force; and the area provided for current delivery (electrode tip. The welding current and weld time control the root penetration, while the electrode pressing force and electrode tips successfully accomplish the connection during the welding process. Although the welding current and weld time cause the heat generation at the areas concerned (electrode tip area, the electrode tips’ diameter and electrode pressing forces also directly influence the welding process. In this research truncated-electrode deformation and mushrooming effects are observed, which result in the welded areas being inconsistent due to the expulsion. The copper to chromium ratio is varied from the tip to the end of the electrode whilst the welding process is repeated. The welding heat affects the electrode and the electrode itself influences the shape of the weld geometry.

  20. Laser Welded versus Resistance Spot Welded Bone Implants: Analysis of the Thermal Increase and Strength

    Directory of Open Access Journals (Sweden)

    Carlo Fornaini

    2014-01-01

    Full Text Available Introduction. The first aim of this “ex vivo split mouth” study was to compare the thermal elevation during the welding process of titanium bars to titanium implants inserted in pig jaws by a thermal camera and two thermocouples. The second aim was to compare the strength of the joints by a traction test with a dynamometer. Materials and Methods. Six pigs’ jaws were used and three implants were placed on each side of them for a total of 36 fixtures. Twelve bars were connected to the abutments (each bar on three implants by using, on one side, laser welding and, on the other, resistance spot welding. Temperature variations were recorded by thermocouples and by thermal camera while the strength of the welded joint was analyzed by a traction test. Results. For increasing temperature, means were 36.83 and 37.06, standard deviations 1.234 and 1.187, and P value 0.5763 (not significant. For traction test, means were 195.5 and 159.4, standard deviations 2.00 and 2.254, and P value 0.0001 (very significant. Conclusion. Laser welding was demonstrated to be able to connect titanium implant abutments without the risk of thermal increase into the bone and with good results in terms of mechanical strength.

  1. Diseases and parasites of laboratory reared and wild population of banded pearl spot Etroplus suratensis (Cichlidae) in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rattan, P.; Parulekar, A.H.

    Banded Pearl spot Etroplus suratensis, the inhabitant of coastal backwaters and lagoons is one among the few finfish species identified for brackishwater farming. Common diseases and parasites from the wild population of Goa and from the laboratory...

  2. Acaricide resistance mechanisms in the two-spotted spider mite Tetranychus urticae and other important Acari: a review.

    Science.gov (United States)

    Van Leeuwen, Thomas; Vontas, John; Tsagkarakou, Anastasia; Dermauw, Wannes; Tirry, Luc

    2010-08-01

    The two-spotted spider mite Tetranychus urticae Koch is one of the economically most important pests in a wide range of outdoor and protected crops worldwide. Its control has been and still is largely based on the use of insecticides and acaricides. However, due to its short life cycle, abundant progeny and arrhenotokous reproduction, it is able to develop resistance to these compounds very rapidly. As a consequence, it has the dubious reputation to be the"most resistant species" in terms of the total number of pesticides to which populations have become resistant, and its control has become problematic in many areas worldwide. Insecticide and acaricide resistance has also been reported in the ectoparasite Sarcoptes scabiei, the causative organism of scabies, and other economically important Acari, such as the Southern cattle tick Rhipicephalus microplus, one of the biggest arthropod threats to livestock, and the parasitic mite Varroa destructor, a major economic burden for beekeepers worldwide. Although resistance research in Acari has not kept pace with that in insects, a number of studies on the molecular mechanisms responsible for the resistant phenotype has been conducted recently. In this review, state-of-the-art information on T. urticae resistance, supplemented with data on other important Acari has been brought together. Considerable attention is given to the underlying resistance mechanisms that have been elucidated at the molecular level. The incidence of bifenazate resistance in T. urticae is expanded as an insecticide resistance evolutionary paradigm in arthropods. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Spot Urine-guided Salt Reduction in Chronic Kidney Disease Patients.

    Science.gov (United States)

    Uchiyama, Kiyotaka; Yanai, Akane; Ishibashi, Yoshitaka

    2017-09-01

    Dietary salt restriction is important in patients with chronic kidney disease (CKD) to reduce hypertension, cardiovascular events, progression of CKD, and mortality. However, recommending salt reduction for patients is difficult without knowing their actual sodium intake. This study evaluated the effectiveness of spot urine-guided salt reduction in CKD outpatients. A prospective cohort study was used. This study included a total of 127 adult outpatients (aged 60 ± 18 years, 80 males) with CKD. Their baseline estimated glomerular filtration rate was 51.4 ± 25.1 (mL/minute/1.73 m 2 ), and 64 (50%) of them were with CKD stage 3a or 3b (both 32 [25%]). We informed the patients of their individual spot urine-estimated salt intake every time they visited the outpatient clinic. Based on the data, the nephrologist encouraged the patients to achieve their salt restriction goal. The primary outcome was the estimated salt excretion, and the secondary outcome was the urinary protein-to-Cr ratio (UPCR). Multiple regression analyses were performed to clarify the contributing factors of changes in both outcomes. Over a follow-up of 12 months, the median number of patients' visits was 7 (5-8). The estimated salt intake was significantly reduced from 7.98 ± 2.49 g/day to 6.77 ± 1.77 g/day (P intake, with borderline significance (P = .08). Providing spot urine-estimated salt intake feedback effectively motivated CKD patients to reduce their salt intake. Spot urine-guided salt reduction may slow CKD progression through decreased urinary protein excretion. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  4. Induced disease resistance signaling in plants

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Loon, L.C. van; Pieterse, C.M.J.

    2006-01-01

    To protect themselves from disease, plants have evolved sophisticated inducible defense mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signaling pathways controlling induced disease resistance is a major objective in

  5. QTL-seq approach identified genomic regions and diagnostic markers for rust and late leaf spot resistance in groundnut (Arachis hypogaea L.).

    Science.gov (United States)

    Pandey, Manish K; Khan, Aamir W; Singh, Vikas K; Vishwakarma, Manish K; Shasidhar, Yaduru; Kumar, Vinay; Garg, Vanika; Bhat, Ramesh S; Chitikineni, Annapurna; Janila, Pasupuleti; Guo, Baozhu; Varshney, Rajeev K

    2017-08-01

    Rust and late leaf spot (LLS) are the two major foliar fungal diseases in groundnut, and their co-occurrence leads to significant yield loss in addition to the deterioration of fodder quality. To identify candidate genomic regions controlling resistance to rust and LLS, whole-genome resequencing (WGRS)-based approach referred as 'QTL-seq' was deployed. A total of 231.67 Gb raw and 192.10 Gb of clean sequence data were generated through WGRS of resistant parent and the resistant and susceptible bulks for rust and LLS. Sequence analysis of bulks for rust and LLS with reference-guided resistant parent assembly identified 3136 single-nucleotide polymorphisms (SNPs) for rust and 66 SNPs for LLS with the read depth of ≥7 in the identified genomic region on pseudomolecule A03. Detailed analysis identified 30 nonsynonymous SNPs affecting 25 candidate genes for rust resistance, while 14 intronic and three synonymous SNPs affecting nine candidate genes for LLS resistance. Subsequently, allele-specific diagnostic markers were identified for three SNPs for rust resistance and one SNP for LLS resistance. Genotyping of one RIL population (TAG 24 × GPBD 4) with these four diagnostic markers revealed higher phenotypic variation for these two diseases. These results suggest usefulness of QTL-seq approach in precise and rapid identification of candidate genomic regions and development of diagnostic markers for breeding applications. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  6. Achieving durable resistance against plant diseases

    NARCIS (Netherlands)

    Lof, Marjolein Elisabeth; Vallavieille-Pope, de Claude; Werf, van der Wopke

    2017-01-01

    Genetic resistance in crops is a cornerstone of disease management in agriculture. Such genetic resistance is often rapidly broken due to selection for virulence in the pathogen population. Here, we ask whether there are strategies that can prolong the useful life of plant resistance genes. In a

  7. Leaf spot disease adversely affects human health-promoting constituents and withanolide biosynthesis in Withania somnifera (L.) Dunal.

    Science.gov (United States)

    Singh, V; Singh, B; Sharma, A; Kaur, K; Gupta, A P; Salar, R K; Hallan, V; Pati, P K

    2017-01-01

    The present work investigates the implication of leaf spot disease on the antioxidant potential and commercial value of pharmaceutically important constituents of Withania somnifera, a high-valued medicinal plant. Leaf spot disease was induced in W. somnifera by inoculating Alternaria alternata (Fr.) Keiss. pathogen. Total polyphenolic content and antioxidant potential showed a significant decrease during leaf spot disease. Evaluation of pharmaceutically active constituents withaferin A, withanone and withanolide A utilizing high-performance liquid chromatography showed a significant decrease in diseased samples as compared to healthy ones. Quantitative expression of major genes involved in withanolide biosynthesis also showed down-regulation in diseased samples. Alterations in the ultra-structure of chloroplasts were also analysed under transmission electron microscopy to get a better insight into the changes of withanolide biosynthesis in leaf during disease infestation. The present work suggests that when the pathogenic fungus invades the host plants, it evokes multiple responses, which could be studied at various levels. The knowledge gained from this work will provide appropriate rationale for controlling the bio-deterioration of the pharmaceutically active metabolites in W. somnifera and development of suitable strategies against leaf spot disease. This is the first study to investigate the effect of leaf spot disease on the human health-promoting constituents and withanolide biosynthesis in this high-valued medicinal plant. © 2016 The Society for Applied Microbiology.

  8. Phage display-selected single-chain antibodies confer high levels of resistance against Tomato spotted wilt virus.

    Science.gov (United States)

    Prins, Marcel; Lohuis, Dick; Schots, Arjen; Goldbach, Rob

    2005-07-01

    Rational design of antibodies targeting essential viral proteins can complement the palette of antiviral resistance strategies. Here, stable and high expression of single-chain monoclonal antibodies targeting the nucleoprotein of the economically important plant virus Tomato spotted wilt virus, a protein that is involved in multiple steps in the viral infection cycle, is reported. High cytoplasmic expression levels of three selected phage display-derived anti-viral single-chain antibodies were established. Of these antibodies, two led to high levels of resistance against this plant virus. Protoplast experiments provided evidence that the two resistance-conferring antibodies may have a different mode of action and could be combined for higher durability of resistance in the field.

  9. Mutation breeding for disease resistance in food beans and cowpea in Kenya

    International Nuclear Information System (INIS)

    Onim, J.F.M.

    1983-01-01

    Ionizing radiation is being used in attempts to obtain more disease resistant variants of bean, cowpea and pigeon pea. In bean M 2 populations large genetic variation for morphological and physiological characters has been observed, but also differences in anthracnose, angular leaf spot and rust. Cowpea appears to be rather resistant to mutagen treatment and although some variation was induced, the number of mutants appears smaller than in Phaseolus vulgaris. (author)

  10. Insights into Tan Spot and Stem Rust Resistance and Susceptibility by Studying the Pre-Green Revolution Global Collection of Wheat

    Directory of Open Access Journals (Sweden)

    Sidrat Abdullah

    2017-04-01

    Full Text Available Tan spot (TS, caused by the fungus Pyrenophora tritici-repentis (Died Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii incorporation of TS susceptibility during development stem rust resistant cultivars led to an increase in TS epidemics globally. Most genotypes were susceptible to stem rust; however, a range of reactions to TS and Ptr ToxA were observed. Four combinations of disease-toxin reactions were observed among the genotypes; TS susceptible-Ptr ToxA sensitive, TS susceptible-Ptr ToxA insensitive, TS resistant-Ptr ToxA insensitive, and TS resistant-Ptr ToxA toxin sensitive. A weak correlation (r = 0.14 for bread wheat and −0.082 for durum was observed between stem rust susceptibility and TS resistance. Even though there were no reported epidemics in the pre-1940s, TS sensitive genotypes were widely grown in that period, suggesting that Ptr ToxA may not be an important factor responsible for enhanced prevalence of TS.

  11. Insights into Tan Spot and Stem Rust Resistance and Susceptibility by Studying the Pre-Green Revolution Global Collection of Wheat.

    Science.gov (United States)

    Abdullah, Sidrat; Sehgal, Sunish Kumar; Jin, Yue; Turnipseed, Brent; Ali, Shaukat

    2017-04-01

    Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii) incorporation of TS susceptibility during development stem rust resistant cultivars led to an increase in TS epidemics globally. Most genotypes were susceptible to stem rust; however, a range of reactions to TS and Ptr ToxA were observed. Four combinations of disease-toxin reactions were observed among the genotypes; TS susceptible-Ptr ToxA sensitive, TS susceptible-Ptr ToxA insensitive, TS resistant-Ptr ToxA insensitive, and TS resistant-Ptr ToxA toxin sensitive. A weak correlation (r = 0.14 for bread wheat and -0.082 for durum) was observed between stem rust susceptibility and TS resistance. Even though there were no reported epidemics in the pre-1940s, TS sensitive genotypes were widely grown in that period, suggesting that Ptr ToxA may not be an important factor responsible for enhanced prevalence of TS.

  12. Natural disease resistance in threatened staghorn corals.

    Directory of Open Access Journals (Sweden)

    Steven V Vollmer

    Full Text Available Disease epidemics have caused extensive damage to tropical coral reefs and to the reef-building corals themselves, yet nothing is known about the abilities of the coral host to resist disease infection. Understanding the potential for natural disease resistance in corals is critically important, especially in the Caribbean where the two ecologically dominant shallow-water corals, Acropora cervicornis and A. palmata, have suffered an unprecedented mass die-off due to White Band Disease (WBD, and are now listed as threatened under the US Threatened Species Act and as critically endangered under the IUCN Red List criteria. Here we examine the potential for natural resistance to WBD in the staghorn coral Acropora cervicornis by combining microsatellite genotype information with in situ transmission assays and field monitoring of WBD on tagged genotypes. We show that six percent of staghorn coral genotypes (3 out of 49 are resistant to WBD. This natural resistance to WBD in staghorn corals represents the first evidence of host disease resistance in scleractinian corals and demonstrates that staghorn corals have an innate ability to resist WBD infection. These resistant staghorn coral genotypes may explain why pockets of Acropora have been able to survive the WBD epidemic. Understanding disease resistance in these corals may be the critical link to restoring populations of these once dominant corals throughout their range.

  13. Spot urine sodium measurements do not accurately estimate dietary sodium intake in chronic kidney disease12

    Science.gov (United States)

    Dougher, Carly E; Rifkin, Dena E; Anderson, Cheryl AM; Smits, Gerard; Persky, Martha S; Block, Geoffrey A; Ix, Joachim H

    2016-01-01

    Background: Sodium intake influences blood pressure and proteinuria, yet the impact on long-term outcomes is uncertain in chronic kidney disease (CKD). Accurate assessment is essential for clinical and public policy recommendations, but few large-scale studies use 24-h urine collections. Recent studies that used spot urine sodium and associated estimating equations suggest that they may provide a suitable alternative, but their accuracy in patients with CKD is unknown. Objective: We compared the accuracy of 4 equations [the Nerbass, INTERSALT (International Cooperative Study on Salt, Other Factors, and Blood Pressure), Tanaka, and Kawasaki equations] that use spot urine sodium to estimate 24-h sodium excretion in patients with moderate to advanced CKD. Design: We evaluated the accuracy of spot urine sodium to predict mean 24-h urine sodium excretion over 9 mo in 129 participants with stage 3–4 CKD. Spot morning urine sodium was used in 4 estimating equations. Bias, precision, and accuracy were assessed and compared across each equation. Results: The mean age of the participants was 67 y, 52% were female, and the mean estimated glomerular filtration rate was 31 ± 9 mL · min–1 · 1.73 m–2. The mean ± SD number of 24-h urine collections was 3.5 ± 0.8/participant, and the mean 24-h sodium excretion was 168.2 ± 67.5 mmol/d. Although the Tanaka equation demonstrated the least bias (mean: −8.2 mmol/d), all 4 equations had poor precision and accuracy. The INTERSALT equation demonstrated the highest accuracy but derived an estimate only within 30% of mean measured sodium excretion in only 57% of observations. Bland-Altman plots revealed systematic bias with the Nerbass, INTERSALT, and Tanaka equations, underestimating sodium excretion when intake was high. Conclusion: These findings do not support the use of spot urine specimens to estimate dietary sodium intake in patients with CKD and research studies enriched with patients with CKD. The parent data for this

  14. A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity.

    Science.gov (United States)

    Shimamoto, Akira; Yamashita, Keitaro; Inoue, Hirofumi; Yang, Sung-Mo; Iwata, Masahiro; Ike, Natsuko

    2013-04-01

    Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α . The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: R Quota , which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.

  15. High-resolution mapping and characterization of qRgls2, a major quantitative trait locus involved in maize resistance to gray leaf spot.

    Science.gov (United States)

    Xu, Ling; Zhang, Yan; Shao, Siquan; Chen, Wei; Tan, Jing; Zhu, Mang; Zhong, Tao; Fan, Xingming; Xu, Mingliang

    2014-08-31

    Gray leaf spot (GLS) caused by Cercospora zeae-maydis (Czm) or Cercospora zeina (Cz) is a devastating maize disease and results in substantial yield reductions worldwide. GLS resistance is a quantitatively inherited trait. The development and cultivation of GLS-resistant maize hybrids are the most cost-effective and efficient ways to control this disease. We previously detected a major GLS resistance QTL, qRgls2, in bin 5.03-04, which spans the whole centromere of chromosome 5 encompassing a physical distance of ~110-Mb. With advanced backcross populations derived from the cross between the resistant Y32 and susceptible Q11 inbred lines, a sequential recombinant-derived progeny testing strategy was adapted to fine map qRgls2. We narrowed the region of qRgls2 from an initial ~110-Mb to an interval of ~1-Mb, flanked by the markers G346 and DD11. qRgls2 showed predominantly additive genetic effects and significantly increased the resistance percentage by 20.6 to 24.6% across multiple generations. A total of 15 genes were predicted in the mapped region according to the 5b.60 annotation of the maize B73 genome v2. Two pieces of the mapped qRgls2 region shared collinearity with two distant segments on maize chromosome 4. qRgls2, a major QTL involved in GLS resistance, was mapped to a ~1-Mb region close to the centromere of chromosome 5. There are 15 predicted genes in the mapped region. It is assumed that qRgls2 could be widely used to improve maize resistance to GLS.

  16. Resistance Spot Welding of Steel Sheets of the Same and Different Thickness

    Directory of Open Access Journals (Sweden)

    Milan Brožek

    2017-01-01

    Full Text Available Resistance welding ranks among progressive and in practice often used manufacturing techniques of rigid joints. It is applied in single‑part production, short‑run production as well as in mass production. The basis of this method is in the utilization of the Joulean heat, which arises at the passage of current through connected sheets at collective influence of compressive force. The aim of the carried out tests was the determination of the dependence between the rupture force of spot welds made using steel sheets of the same and different thickness for different welding conditions. For carrying out of this aim 360 assemblies were prepared. The sheets (a total of 720 pieces of dimensions 100 × 25 mm and thickness of 0.8 mm, 1.5 mm and 3.0 mm were made from low carbon steel. In the place determined for welding the test specimens were garnet blasted and then degreased with acetone. The welding of two specimens always of the same (0.8+0.8 mm, 1.5+1.5 mm a 3.0+3.0 mm and different (0.8 + 1.5 mm, 0.8+3.0 mm a 1.5+3.0 mm thickness was carried out using the welding machine type BV 2,5.21. At this type the welding current value is constant (Imax = 6.4 kA. The welding time (the time of the passage of the current was changed in the whole entirety, namely 0.10 s, 0.15 s, 0.20 s, 0.25 s, 0.3 s, 0.4 s, 0.6 s, 0.8 s, 1.0 s, 1.3 s, 1.6 s and 2.0 s. The compressive force was chosen according to the thickness of the connected sheets in the range from 0.8 to 2.4 kN. From the results of carried out tests it follows that using the working variables recommended by the producer we obtain the quality welds. But it we use the longer welding times, we can obtain stronger welds, namely up to 21 % compared to welds made using working variables recommended by the producer.

  17. Failure mechanism of resistance-spot-welded specimens impacted on base material by bullets

    Directory of Open Access Journals (Sweden)

    Chunlei Fan

    2018-01-01

    Full Text Available The tests of bullet impact on the base material (BM of a simple specimen with a single resistance-spot-welded (RSW nugget of TRIP800 steel are performed to investigate the response of the RSW specimen to the ballistic debris impact on the RSW specimen. A one-stage gas gun is used to fire the bullets while a laser velocity interferometer system for any reflector (VISAR is used to measure the velocity histories of the free surfaces of the RSW specimen. The recovered RSW specimens are examined with the three-dimensional super depth digital microscope (SDDM and the scanning electro microscope (SEM. For the tests of small multiple-bullet impact, it is revealed that the wave train of the VISAR measured results and the detachment of the base material interfaces in the recovered RSW specimens are directly related to the reflection and refraction of the curved stress waves incoming to the interfaces and the free surfaces in the RSW specimens. The detachment of BM interfaces can lead to the impact failure of the RSW joints for the larger multiple-bullet impact at higher velocity, the mechanism of which is different from the case for normal incidence (spalling. For the tests of single large bullet impact, it is brought to light experimentally that the plastic strain concentration at the “notch tip” spurs either the crack near the RSW joint or the split of the nugget. The numerical simulation shows up the process of splitting the nugget: a crack initiates at the “notch tip”, propagates across the nugget interface and splits the nugget into two parts. It is indicated that the interaction between the stress waves and many interfaces/free surfaces in the RSW specimen under ballistic impact causes variable local stress triaxialities and stress Lode angles, which affects the deformation and fracture mechanism of the RSW specimen including stretching and shearing failure. It is shown that the impact failure of the RSW joints is a mixture of brittle

  18. Failure mechanism of resistance-spot-welded specimens impacted on base material by bullets

    Science.gov (United States)

    Fan, Chunlei; Ma, Bohan; Chen, Danian; Wang, Huanran; Ma, Dongfang

    2018-01-01

    The tests of bullet impact on the base material (BM) of a simple specimen with a single resistance-spot-welded (RSW) nugget of TRIP800 steel are performed to investigate the response of the RSW specimen to the ballistic debris impact on the RSW specimen. A one-stage gas gun is used to fire the bullets while a laser velocity interferometer system for any reflector (VISAR) is used to measure the velocity histories of the free surfaces of the RSW specimen. The recovered RSW specimens are examined with the three-dimensional super depth digital microscope (SDDM) and the scanning electro microscope (SEM). For the tests of small multiple-bullet impact, it is revealed that the wave train of the VISAR measured results and the detachment of the base material interfaces in the recovered RSW specimens are directly related to the reflection and refraction of the curved stress waves incoming to the interfaces and the free surfaces in the RSW specimens. The detachment of BM interfaces can lead to the impact failure of the RSW joints for the larger multiple-bullet impact at higher velocity, the mechanism of which is different from the case for normal incidence (spalling). For the tests of single large bullet impact, it is brought to light experimentally that the plastic strain concentration at the "notch tip" spurs either the crack near the RSW joint or the split of the nugget. The numerical simulation shows up the process of splitting the nugget: a crack initiates at the "notch tip", propagates across the nugget interface and splits the nugget into two parts. It is indicated that the interaction between the stress waves and many interfaces/free surfaces in the RSW specimen under ballistic impact causes variable local stress triaxialities and stress Lode angles, which affects the deformation and fracture mechanism of the RSW specimen including stretching and shearing failure. It is shown that the impact failure of the RSW joints is a mixture of brittle fracture and ductile

  19. Radiation therapy for resistant sternal hydatid disease

    International Nuclear Information System (INIS)

    Ulger, S.; Barut, H.; Tunc, M.; Aydinkarahaliloglu, E.; Aydin, E.; Karaoglanoglu, N.; Gokcek, A.

    2013-01-01

    Hydatid disease is a zoonotic infectious disease for which there are known treatment procedures and effective antibiotics; however, there are resistant cases that do not respond to medication or surgery. We report a case diagnosed as hydatid disease of the chest wall and treated with radiation therapy (RT) after medical and surgical therapy had failed. In conclusion, RT represents an alternative treatment modality in resistant cases. (orig.)

  20. Induced mutations for disease resistance in wheat and field beans

    International Nuclear Information System (INIS)

    Abdel-Hak, T.M.; Kamel, A.H.

    1976-01-01

    Wheat disease in Egypt is reviewed and results of mutation breeding by γ irradiation for disease resistance in wheat and field beans are described. Wheat mutants of the variety Giza 155 resistant to leaf rust, Giza 156 resistant to both leaf and yellow rusts, and Tosson with a reasonable level of combined resistance to the three rusts in addition to mutants of the tetraploid variety Dakar 52 with a good level of stem and yellow rust resistance are required. Their seeds were subjected to 10, 15 and 20 krad. Of 3000-3700 M 2 plants from each variety and dosage, 22 plants from both Giza 155 and Giza 156, although susceptible, showed a lower level of disease development. In 1975, M 3 families of these selected plants and 6000 plants from bulked material were grown from each variety and dosage at two locations. Simultaneously, an additional population consisting of 3000 mutagen-treated seeds was grown to have a reasonable chance of detecting mutants; 2 heads from each plant were harvested. These will be grown next season (1976) to make a population of 25,000-30,000 M 2 plants and screened to composite cultures of specific rusts. Vicia faba seeds of field bean varieties Giza 1, Giza 2 and Rebaya 40, equally susceptible to rust and chocolate spot, were subjected to 3, 5 and 7 krad of 60 Co gamma radiation and 800 M 1 plants were grown in 1972 per variety and dose. Up to this later growing season (M 3 ) no resistance was detected in M 3 plank

  1. Breeding wheat for disease resistance in Kenya

    International Nuclear Information System (INIS)

    Njau, P.N.; Kinyua, M.G.; Karanja, L.; Maling'a, J.

    2001-01-01

    Yellow rust caused by Puccinia striformis and stem rust caused by Puccinia graminis tritici are most destructive diseases in Kenya. In wheat improvement, development of varieties of wheat with resistance to these diseases has been among the foremost contributions in wheat breeding. In breeding programs each disease is considered as a separate problem. Attention has been given to varieties resistant to stem rust, yellow rust and leaf rust among other diseases. In the year 2001 program stem rust and yellow rust were recorded in all the sites where NPT was performed. Breeding for resistance for the two diseases is approached through the Introductions and Hybridisation. The Doubled Haploid Technique is used to quicken the time of homozygous lines production. The introduction and the homozygous lines are then evaluated for yield and disease resistance in the field under preliminary yield trials and the National Performance Trials (NPT) in 2001, 18 lines and 2 check varieties were included in the NPT. The results show that there were some differences in reaction to the three diseases where lines R946, K7972-1 and R899 had the lowest score of the diseases in all sites. In the commercial variety trial the results show that all the varietieshave become susceptible to stem rust and so the need to develop new cultivars which will be resistance to the rusts. Yombi a newly developed variety showed a substantially high level resistance. (author)

  2. Data from: Clarireedia: A new fungal genus comprising four pathogenic species responsible for dollar spot disease of turfgrass

    Science.gov (United States)

    Dollar spot is one of the most destructive globally distributed diseases of turfgrass. The identity of the fungus responsible for the disease has been the subject of debate for more than 75 years. These datasets provide the phylogenetic evidence from three nucleotide sequence markers (CaM, ITS and M...

  3. Unmasking levodopa resistance in Parkinson's disease

    NARCIS (Netherlands)

    Nonnekes, J.H.; Timmer, M.H.M.; Vries, N.M. de; Rascol, O.; Helmich, R.C.G.; Bloem, B.R.

    2016-01-01

    Some motor and nonmotor features associated with Parkinson's disease (PD) do not seem to respond well to levodopa (or other forms of dopaminergic medication) or appear to become resistant to levodopa treatment with disease progression and longer disease duration. In this narrative review, we

  4. Study of Proper Time Range for Current Flow to Resistance Spot Welding Inspected by Mechanical Property and Metallurgy Testing

    International Nuclear Information System (INIS)

    Pearsura, Prachya

    2007-08-01

    Full text: This research used the mechanical property and metallurgy testing to identify the proper time range for current flow. The specimen tested was 1 mm thick mild steel. The welded specimens were tested by Tensile Shear testing following JIS Z 3136: 1999 and Macro Structure testing follow by JIS Z 3139: 1978. Subsequently, the results from analyzing were compared with standard JIS Z 3140. The results show that the suitable current flow is 8 to 10 cycles. This technique can be applied to monitor the process and the quality of resistance spot welding

  5. Influence of welding current in resistance spot welding on the properties of Zn coated steel DX51D

    Directory of Open Access Journals (Sweden)

    Luboš Kaščák

    2016-06-01

    Full Text Available The paper deals with the resistance spot welding of three galvanized car body sheets DX51D + Z - EN 10142/2000. The quality of welded joints was evaluated by destructive tests and non-destructive tests. For evaluation of joints quality the shear tension test on spot joints according to DIN 50 124 standard was used. The influence of welding parameters on the structure of a welded joint was observed by metallographic analysis. Influence of welding current from 6.0 to 7.7 kA and influence of welding time from 10 to 12 periods on weld properties was observed. Increasing the welding current led to increased load-bearing capacity of the welded joints. The spot welded joints without any internal defects occurred in samples welded up to 7.0 kA. Increasing the welding time to 12 periods led to increased load-bearing capacity of the welded joints, within all observed values of welding current.

  6. Grafting on a Non-Transgenic Tolerant Tomato Variety Confers Resistance to the Infection of a Sw5-Breaking Strain of Tomato spotted wilt virus via RNA Silencing.

    Directory of Open Access Journals (Sweden)

    Roberta Spanò

    Full Text Available RNA silencing controls endogenous gene expression and drives defensive reactions against invasive nucleic acids like viruses. In plants, it has been demonstrated that RNA silencing can be transmitted through grafting between scions and silenced rootstocks to attenuate virus and viroid accumulation in the scions. This has been obtained mostly using transgenic plants, which may be a drawback in current agriculture. In the present study, we examined the dynamics of infection of a resistance-breaking strain of Tomato spotted wilt virus (RB-TSWV through the graft between an old Apulian (southern Italy tomato variety, denoted Sl-Ma, used as a rootstock and commercial tomato varieties used as scions. In tests with non-grafted plants, Sl-Ma showed resistance to the RB-TSWV infection as viral RNA accumulated at low levels and plants recovered from disease symptoms by 21 days post inoculation. The resistance trait was transmitted to the otherwise highly susceptible tomato genotypes grafted onto Sl-Ma. The results from the analysis of small RNAs hallmark genes involved in RNA silencing and virus-induced gene silencing suggest that RNA silencing is involved in the resistance showed by Sl-Ma against RB-TSWV and in scions grafted on this rootstock. The results from self-grafted susceptible tomato varieties suggest also that RNA silencing is enhanced by the graft itself. We can foresee interesting practical implications of the approach described in this paper.

  7. Spotting the Primacy of Resistance in the Virtual Encounter of Foucault and Deleuze

    OpenAIRE

    Checchi, Marco

    2014-01-01

    Foucault’s intuition that resistance comes first challenges the theses of the co-originality of power and resistance or the superiority of power over resistance. In order to transform this intuition into the concept of the primacy of resistance, the article uses Deleuze’s ontology and in particular the idea of the virtual. According to Deleuze, resistance displays a privileged relation with the virtual, understood as the ontological region animated by all the potentialities that might be or...

  8. Newborn blood spot screening for sickle cell disease by using tandem mass spectrometry: implementation of a protocol to identify only the disease states of sickle cell disease.

    Science.gov (United States)

    Moat, Stuart J; Rees, Derek; King, Lawrence; Ifederu, Adeboye; Harvey, Katie; Hall, Kate; Lloyd, Geoff; Morrell, Christine; Hillier, Sharon

    2014-02-01

    The currently recommended technologies of HPLC and isoelectric focusing for newborn blood spot screening for sickle cell disease (SCD) identify both the disease and carrier states, resulting in large numbers of infants being followed up unnecessarily. Analysis of blood spot tryptic peptides performed by using tandem mass spectrometry (MS/MS) is an alternative technology to detect hemoglobin (Hb) variant disorders. We analyzed 2154 residual newborn blood spots and 675 newborn blood spots from infants with Hb variants by using MS/MS after trypsin digestion. Screening cutoffs were developed by using the ratio between the variant peptide-to-wild-type peptide abundance for HbS, C, D(Punjab), O(Arab), Lepore, and E peptides. A postanalytical data analysis protocol was developed using these cutoffs to detect only the disease states of SCD and not to identify carrier states. A parallel study of 13 249 newborn blood spots from a high-prevalence SCD area were analyzed by both MS/MS and HPLC. Screening cutoffs developed distinguished the infants with the disease states of SCD, infants who were carriers of SCD, and infants with normal Hb. In the parallel study no false-negative results were identified, and all clinically relevant cases were correctly identified using the MS/MS protocol. Unblinding the data revealed a total of 328 carrier infants that were successfully excluded by the protocol. The screening protocol developed correctly identified infants with the disease states of SCD. Furthermore, large numbers of sickle cell carrier infants were successfully not identified, thereby avoiding unnecessary follow-up testing and referral for genetic counseling.

  9. Diallel analysis of leaf disease resistance in inbred Brazilian popcorn cultivars.

    Science.gov (United States)

    Vieira, R A; Scapim, C A; Moterle, L M; Tessmann, D J; Conrado, T V; Amaral Júnior, A T

    2009-12-01

    We estimated general and specific combining abilities and examined resistance to northern leaf blight (Exserohilum turcicum) and to gray leaf spot (Cercospora zeae-maydis) in a set of nine inbred popcorn lines. These inbreds were crossed in a complete diallel scheme without reciprocals, which produced 36 F(1) hybrids. Two experiments with a square lattice design and three replications were conducted during the 2008/2009 crop season, in Maringá, PR, Brazil. The severity of northern leaf blight and gray leaf spot was assessed under natural infestation conditions. Data were examined by individual and joint analysis of variance. Individual and joint Griffing's diallel analyses were carried out for adjusted means. General combining ability and specific combining ability were significant (P < 0.10) by the F-test for northern leaf blight and gray leaf spot infestation levels. This denotes that additive and non-additive gene effects both contributed to resistance to these diseases, but that the additive gene effects were more important. Among the inbred lines, P(8) and P(9) gave the highest resistance to northern leaf blight, and P(3) and P(4.3) gave the highest resistance to gray leaf spot. The hybrids P(7.4) x P(8) and P(4.3) x P(9) could be exploited by reciprocal recurrent selection to provide genotypes with both northern leaf blight and gray leaf spot resistance. Significant interaction between general combining ability and crop season (P < 0.10) denotes the importance of environment, even though the disease levels in the hybrids were quite consistent.

  10. Identification of Antipathogenic Bacterial Coral Symbionts Against Porites Ulcerative White Spots Disease

    Science.gov (United States)

    Sa’adah, Nor; Sabdono, Agus; Diah Permata Wijayanti, dan

    2018-02-01

    Coral reef ecosystems are ecosystems that are vulnerable and susceptible to damage due to the exploitation of ocean resources. One of the factors that cause coral damage is the disease that attacks the coral. Porites Ulcerative White Spots (PUWS) is a coral disease found in Indonesia and attacks the coral genera Porites allegedly caused by pathogenic microbial attacks. The purpose of this study was to identify the symbiotic bacteria on healthy coral that have antipatogenic potency against PUWS. The method used in this research was descriptive explorative. Sampling was done in Kemujan Island, Karimunjawa. Bacteria were isolated from healthy coral and coral affected by PUWS disease. Streak method was used to purify coral bacteria, while overlay and agar diffusion were used to test antipathogenic activity. Bacterial identification was carried out based on polyphasic approach. The results of this study showed that coral bacterial symbionts have antipathogenic activity against PUWS disease. The selected bacteria NM 1.2, NM 1.3 and KPSH 5. NM1.2 were closely related to Pseudoalteromonas piscicida, Pseudoalteromonas flavipulchra and Bacillus flexus, respectively.

  11. Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

    Directory of Open Access Journals (Sweden)

    Da-Ran Kim

    2016-08-01

    Full Text Available Strawberry bacterial angular leaf spot (ALS disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August, the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%. To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.

  12. Essential oils of Varronia curassavica accessions have different activity against white spot disease in freshwater fish.

    Science.gov (United States)

    de Castro Nizio, Daniela Aparecida; Fujimoto, Rodrigo Yudi; Maria, Alexandre Nizio; Carneiro, Paulo César Falanghe; França, Carina Caroline Silva; da Costa Sousa, Natalino; de Andrade Brito, Fabiany; Sampaio, Taís Santos; de Fátima Arrigoni-Blank, Maria; Blank, Arie Fitzgerald

    2018-01-01

    The aim of this study was to evaluate the antiprotozoal activity of essential oils from Varronia curassavica accessions against different stages of Ichthyophthirius multifiliis. Essential oils from each accession were tested in vitro at the concentrations 0, 10, 25, 50, 75, 100, and 200 mg/L. The VCUR-001, VCUR-202, VCUR-509, and VCUR-601 accessions presented the major compounds α-pinene, germacrene D-4-ol, (E)-caryophyllene and epiglobulol, and sabinene, respectively. These isolated compounds were tested in vitro at a concentration proportional to that found in the essential oil which caused 100% mortality of the parasite. The concentrations of 10 and 50 mg/L of the essential oil of accession VCUR-202 provided 100% mortality of trophonts and tomonts, respectively. For the accession VCUR-509, 100% mortality of trophonts and tomonts was observed at concentrations 75 and 200 mg/L of essential oil, respectively. The same mortality was observed at concentration 200 mg/L in both stages of the parasite for the other accessions. The major compounds α-pinene, sabinene, and the (E)-caryophyllene + epiglobulol mixture caused 100% mortality of trophonts and tomonts. The in vivo assay for white spot disease control was performed in a therapeutic bath of 1 h with the essential oil of accession VCUR-202 at concentrations of 0.5 and 2.0 mg/L. A significant reduction of about 30% of trophonts on infected fish was observed, independent of the oil concentration. The V. curassavica essential oil, especially the VCUR-202 accession, is a potential source of raw material for the formulation and commercialization of bioproducts to control freshwater white spot disease in fish.

  13. Quantitative trait loci associated with resistance to gray leaf spot and grain yield in corn QTLs associados à resistência a cercosporiose e produção de grãos em milho

    Directory of Open Access Journals (Sweden)

    Adriano Delly Veiga

    2012-02-01

    Full Text Available The main objectives of hybrid development programs include incorporating genetic resistance to diseases and increasing grain yield. Identification of Quantitative Trait Loci (QTL through the statistical analysis of molecular markers allows efficient selection of resistant and productive hybrids. The objective of this research was to identify QTL associated with resistance to gray leaf spot and for grain yield in the germplasm of tropical corn. We used two strains with different degrees of reaction to the disease; the genotypes are owned by GENESEEDS Ltda, their F1 hybrid and the F2 population. The plants were evaluated for gray leaf spot resistance, for grain yield and were genotyped with 94 microsatellite markers. Association of the markers with the QTL was performed by single marker analysis using linear regression and maximum likelihood analysis. It was observed that the additive effect was predominant for genetic control of resistance to gray leaf spot, and the dominant effect in that of grain yield. The most promising markers to be used in studies of assisted selection are: umc2082 in bins 4.03 and umc1117 in bins 4.04 for resistance to gray leaf spot; for grain yield umc1042 in bins 2.07 and umc1058 in bins 4.11.A incorporação de resistência genética a doenças e o aumento na produtividade de grãos estão entre os principais objetivos dos programas de desenvolvimento de híbridos. A identificação de locos de caracteres quantitativos (QTL por meio de análises estatísticas associadas a marcadores moleculares possibilita a rápida obtenção de híbridos resistentes e produtivos. Nesta pesquisa, objetivou-se identificar locos de caracteres quantitativos (QTL associados com resistência à cercosporiose e com produção de grãos em germoplasma de milho tropical. Foram utilizadas duas linhagens contrastantes em níveis de reação à doença (genótipos pertencentes à GENESEEDS - Ltda, seu híbrido F1 e a população segregante F2

  14. Effects of colonization of a bacterial endophyte, Azospirillum sp. B510, on disease resistance in tomato.

    Science.gov (United States)

    Fujita, Moeka; Kusajima, Miyuki; Okumura, Yasuko; Nakajima, Masami; Minamisawa, Kiwamu; Nakashita, Hideo

    2017-08-01

    A plant growth-promoting bacteria, Azospirillum sp. B510, isolated from rice, can enhance growth and yield and induce disease resistance against various types of diseases in rice. Because little is known about the interaction between other plant species and this strain, we have investigated the effect of its colonization on disease resistance in tomato plants. Treatment with this strain by soil-drenching method established endophytic colonization in root tissues in tomato plant. The endophytic colonization with this strain-induced disease resistance in tomato plant against bacterial leaf spot caused by Pseudomonas syringae pv. tomato and gray mold caused by Botrytis cinerea. In Azospirillum-treated plants, neither the accumulation of SA nor the expression of defense-related genes was observed. These indicate that endophytic colonization with Azospirillum sp. B510 is able to activate the innate immune system also in tomato, which does not seem to be systemic acquired resistance.

  15. Spotting the earth connection and short circuits between the electric conductors, using D.C. bridges for resistance measurements

    Science.gov (United States)

    Popa, I.; Popa, G. N.; Deaconu, S. I.; Iagăr, A.

    2015-06-01

    The paper establishes the necessary connections meant to spot the earth connections and short circuits between the conductors of a power line, using the DC bridges meant for measuring resistances between conductors at the ends of the power line. Since it is a relative method, it imposes an exact knowledge of the faulty power line setting. For values of the resistances measured between the conductors of the power line having over 1Ω at one end, the measurement will be carried out with a Wheatstone bridge, and for values below 1Ω with a Thomson bridge. In order to accurately determine the place of the fault, it measured the distances from the end of the line up to the fault and then we performed a correction calculation for this distance.

  16. Estimation of daily protein intake based on spot urine urea nitrogen concentration in chronic kidney disease patients.

    Science.gov (United States)

    Kanno, Hiroko; Kanda, Eiichiro; Sato, Asako; Sakamoto, Kaori; Kanno, Yoshihiko

    2016-04-01

    Determination of daily protein intake in the management of chronic kidney disease (CKD) requires precision. Inaccuracies in recording dietary intake occur, and estimation from total urea excretion presents hurdles owing to the difficulty of collecting whole urine for 24 h. Spot urine has been used for measuring daily sodium intake and urinary protein excretion. In this cross-sectional study, we investigated whether urea nitrogen (UN) concentration in spot urine can be used to predict daily protein intake instead of the 24-h urine collection in 193 Japanese CKD patients (Stages G1-G5). After patient randomization into 2 datasets for the development and validation of models, bootstrapping was used to develop protein intake estimation models. The parameters for the candidate multivariate regression models were male gender, age, body mass index (BMI), diabetes mellitus, dyslipidemia, proteinuria, estimated glomerular filtration rate, serum albumin level, spot urinary UN and creatinine level, and spot urinary UN/creatinine levels. The final model contained BMI and spot urinary UN level. The final model was selected because of the higher correlation between the predicted and measured protein intakes r = 0.558 (95 % confidence interval 0.400, 0.683), and the smaller distribution of the difference between the measured and predicted protein intakes than those of the other models. The results suggest that UN concentration in spot urine may be used to estimate daily protein intake and that a prediction formula would be useful for nutritional control in CKD patients.

  17. Disease resistance breeding in rose: current status and potential of biotechnological tools.

    Science.gov (United States)

    Debener, Thomas; Byrne, David H

    2014-11-01

    The cultivated rose is a multispecies complex for which a high level of disease protection is needed due to the low tolerance of blemishes in ornamental plants. The most important fungal diseases are black spot, powdery mildew, botrytis and downy mildew. Rose rosette, a lethal viral pathogen, is emerging as a devastating disease in North America. Currently rose breeders use a recurrent phenotypic selection approach and perform selection for disease resistance for most pathogen issues in a 2-3 year field trial. Marker assisted selection could accelerate this breeding process. Thus far markers have been identified for resistance to black spot (Rdrs) and powdery mildew and with the ability of genotyping by sequencing to generate 1000s of markers our ability to identify markers useful in plant improvement should increase exponentially. Transgenic rose lines with various fungal resistance genes inserted have shown limited success and RNAi technology has potential to provide virus resistance. Roses, as do other plants, have sequences homologous to characterized R-genes in their genomes, some which have been related to specific disease resistance. With improving next generation sequencing technology, our ability to do genomic and transcriptomic studies of the resistance related genes in both the rose and the pathogens to reveal novel gene targets to develop resistant roses will accelerate. Finally, the development of designer nucleases opens up a potentially non-GMO approach to directly modify a rose's DNA to create a disease resistant rose. Although there is much potential, at present rose breeders are not using marker assisted breeding primarily because a good suite of marker/trait associations (MTA) that would ensure a path to stable disease resistance is not available. As our genomic analytical tools improve, so will our ability to identify useful genes and linked markers. Once these MTAs are available, it will be the cost savings, both in time and money, that will

  18. Induced multiple disease resistance in wheat

    International Nuclear Information System (INIS)

    Borojevic, K.; Worland, A.J.

    1990-01-01

    Full text: The existence of genes suppressing resistance to leaf rust, stem rust and yellow rust in hexaploid wheat has been suggested. If such genes are deleted or inactivated, a more resistant variety may be obtained. In mutant lines of the wheat variety San Pastore, selected after treatment with 20,000 rad of gamma-rays, resistance to leaf rust, yellow rust, stem rust, and to some extent to Erysiphe graminis was determined. The mutants responded to infection by producing necrotic flecks in the presence of high level of disease inoculum. Similar flecks develop under stress condition. It is likely that the mother variety San Pastore carries genes for resistance which are masked by suppressor genes. Irradiation inactivates suppressors so that resistance genes which were previously masked are expressed. The first results of monosomic analysis indicate that chromosomes of groups 4 and 5 or possibly 7 may be critical for expression of resistance in the mutant lines. (author)

  19. Mutation breeding for disease resistance in wheat and field beans

    International Nuclear Information System (INIS)

    Abdel-Hak, T.M.; Kamel, A.H.

    1977-01-01

    Wheat and broad-bean diseases cause considerable losses under Egyptian conditions; therefore, an attempt was made to induce useful mutations in both crops resistant to diseases which may be of direct or indirect use in breeding programmes. The methodology of artificial inoculation, evaluation, selection, radiation levels used are reported, in addition to the economic importance of the varieties used. This work passed through two phases, the first started in the 1972/73 crop season with a small population, while the second in 1974/75 with a larger one to have a better chance of detecting resistant mutants. In the first phase, a total of 3563M 1 wheat plants was grown in addition to approximately 3600-44,000M 2 and 77,646M 3 plants. Twenty-two M 2 plants were selected as showing lower level of leaf rust development, but further tests showed these plants are not true mutants since they rusted at the same level of their parent varieties. Out of the M 3 plants none showed good resistance. In the second phase, 36,000, 277,080 and 289,492 plants of M 1 , M 2 and M 3 , respectively, were grown and 73M 2 plants were selected as showing complete resistance to leaf and stem rusts. In field beans out of the first phase, a total of 5760, 37,200 and 33,240M 1 , M 2 and M 3 plants, respectively, was grown and none showed a good level of disease resistance although some were less diseased. These were further tested and proved not true mutants for reduced disease development. In the second phase, 8747, 203,520 and 90,285 plants of M 1 , M 2 and M 3 , respectively, were grown and 27M 2 plants were selected as showing a lower level of chocolate spot and rust development. The paper also discusses the use of single versus composite cultures in mutation breeding for disease resistance. (author)

  20. The Mystery of Spot Blotch Disease Caused by the Fungal Pathogen Bipolaris sorokiniana on Barley (Hordeum vulgare L)

    DEFF Research Database (Denmark)

    Gjendal, Nele

    was investigated. In this PhD work it could be shown that light dependent disease symptoms were associated with less fungal colonization, while suppressing the rate of photosynthesis by keeping plants in darkness made them super-susceptible to B. sorokiniana colonization. Likewise, partial suppression......The fungal pathogen Bipolaris sorokiniana causes a wide spectrum of diseases including spot blotch disease. To achieve a better understanding of the biology of the fungus, the interaction of B. sorokiniana with the host barley (Hordeum vulgare L) and the resulting disease spot blotch...... of photosynthesis with DCMU (3-(3,4-Dichlorophenyl)-1,1-dimethylurea) reduced the formation of necrosis after infection and led to increased susceptibility, strongly implying that active photosynthesis is involved in disease symptom formation and that these symptoms negatively affect fungal colonization...

  1. Characterization of Tomato spotted wilt virus isolates that overcome the Sw-5 resistance gene in tomato and fitness assays

    Directory of Open Access Journals (Sweden)

    Jose ARAMBURU

    2011-01-01

    Full Text Available Resistance-breaking (RB isolates of Tomato spotted wilt virus (TSWV that overcome the resistance conferred by the Sw-5 gene in tomato have had only a limited spread since they were first detected in north-eastern Spain in 2002. Symptom expression, homogeneity, stability and the transmission capacity of RB and non-resistance breaking (NRB isolates were biologically compared. The fitness of both types of isolates infecting tomato plants was determined in competition assays. All TSWV isolates induced similar systemic symptoms in a wide range of plant species, except RB isolates in tomato carrying the Sw-5 resistance gene and pepper carrying the Tsw resistance gene. The mechanical transmission of RB isolates to tomato plants with the Sw-5 gene failed in some trials, although NRB isolates did not differ noticeably in transmission efficiency when tested with the thrips Frankliniella occidentalis. Biological clones from individual local lesions obtained by mechanically inoculating Nicotiana glutinosa in some TSWV field samples showed that they were biologically homogeneous. Mixed infections of RB and wilt-type isolates were not found. The RB isolates were relatively stable because no reversion to NRB isolates was seen after serial passages in susceptible tomato plants. In competition assays between RB and NRB isolates, after serial passages in susceptible tomato plants, the prevalence of a particular isolate was not related to its capacity to overcome Sw-5 gene resistance. The low spread of the RB isolates in Spain does not seem to be related to a loss of fitness in tomato plants or to differences in transmission capacity by thrips, but it could be related to the reduction of the selection pressure of RB isolates as consequence of the gradual replacement of susceptible tomato plants by resistant tomato plants by growers.

  2. Weld nugget formation in resistance spot welding of new lightweight sandwich material

    DEFF Research Database (Denmark)

    Sagüés Tanco, J.; Nielsen, Chris Valentin; Chergui, Azeddine

    2015-01-01

    –metal contact. This is facilitated by the use of a shunt tool and is followed by a second pulse for the actual spot welding and nugget formation. A weldability lobe in the time-current space of the second pulse reveals a process window of acceptable size for automotive assembly lines. Weld growth curves...... are presented together with results of numerical simulations made in the finite element computer program SORPAS® 3D, which is based on an electro-thermo-mechanical formulation. The numerical models are presented together with the specific modeling conditions leading to numerical simulations in good agreement...

  3. Resistance to gray leaf spot of maize: genetic architecture and mechanisms elucidated through nested association mapping and near-isogenic line analysis.

    Science.gov (United States)

    Benson, Jacqueline M; Poland, Jesse A; Benson, Brent M; Stromberg, Erik L; Nelson, Rebecca J

    2015-03-01

    Gray leaf spot (GLS), caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR) loci. Nested association mapping (NAM) was used to identify 16 quantitative trait loci (QTL) for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs) were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis) and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO) gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will facilitate the

  4. Resistance to gray leaf spot of maize: genetic architecture and mechanisms elucidated through nested association mapping and near-isogenic line analysis.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Benson

    2015-03-01

    Full Text Available Gray leaf spot (GLS, caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR loci. Nested association mapping (NAM was used to identify 16 quantitative trait loci (QTL for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will

  5. Creatinine measurement on dry blood spot sample for chronic kidney disease screening.

    Science.gov (United States)

    Silva, Alan Castro Azevedo E; Gómez, Juan Fidel Bencomo; Lugon, Jocemir Ronaldo; Graciano, Miguel Luis

    2016-03-01

    Chronic kidney disease (CKD) screening is advisable due to its high morbidity and mortality and is usually performed by sampling blood and urine. Here we present an innovative and simpler method, by measuring creatinine on a dry blood spot on filter paper. One-hundred and six individuals at high risk for CKD were enrolled. The creatinine values obtained using both tests and the demographic data of each participant allowed us to determinate the eGFR. The adopted cutoff for CKD was an eGFR value 96%, predictive negative value 55% and accuracy 92%. By the CKD-EPI equation the sensitivity was 94%, specificity 55%, predictive positive value 94%, predictive negative value 55% and accuracy 90%. A Bland and Altman analysis showed a relatively narrow range of creatinine values differences (+ 0.68mg/dl to -0.55mg/dl) inside the ± 1.96 SD, without systematic differences. Measurement of creatinine on dry blood sample is an easily feasible non-invasive diagnostic test with good accuracy that may be useful to screen chronic kidney disease.

  6. Disease variation and chemical control of Ramularia leaf spot in sugar beet

    DEFF Research Database (Denmark)

    Thach, Tine; Munk, Lisa; Hansen, Anne Lisbet

    2013-01-01

    in field trials, a semi-field trial and an in vitro test using the compounds pyraclostrobin, epoxiconazole, difenoconazole and propiconazole. Dose response trials with epoxiconazole from two seasons showed both reduced efficacy and yield responses from low doses. They also proved that the optimal input...... preventive and curative effects with 84–100% disease control from epoxiconazole, difenoconazole and pyraclostrobin. In order to optimize an IPM control strategy better forecasting systems are needed along with cultivars providing higher levels of resistance to the disease....

  7. Evaluation of host resistance to Botrytis bunch rot in Vitis spp. and its correlation with Botrytis leaf spot

    Science.gov (United States)

    Botrytis cinerea, the causal agent of Botrytis bunch rot and gray mold, is the number one postharvest disease of fresh grapes in the United States. Fungicide applications are used to manage the disease, but fungicide-resistant isolates are common and postharvest losses occur annually. Host resistanc...

  8. Atypical Celiac Disease Resistant to Thyroxine Replacement

    Directory of Open Access Journals (Sweden)

    Oguzhan Aksu

    2014-08-01

    Full Text Available Celiac disease, an immune-mediated enteropathy that develops in susceptible individuals upon ingestion of gluten containing diet, is closely associated with other autoimmune endocrine disorders, particularly autoimmune thyroid disease. Celiac disease and hypothyroidism ( especially due to Hashimoto disease cooccurence is frequently mentioned in the literature. The relationship between celiac disease and autoimmune thyroid disease was first described three decades ago. Patients usually have the classical presentation of diarrhoea and steatorrhoea but hypothyroidism with weight loss and increased dose requirement of L Thyroxine are two well recognised presentations of celiac disease in hypothyroidism. It is known that these cases are resistant to thyroxine replacement. Herein we presented a 35 year old female patient with atypical celiac disease and needed an extremely high dose of thyroxine such as 1600 mcg/day for treatment.

  9. On Residual Stresses in Resistance Spot-Welded Aluminum Alloy 6061-T6: Experimental and Numerical Analysis

    Science.gov (United States)

    Afshari, D.; Sedighi, M.; Karimi, M. R.; Barsoum, Z.

    2013-12-01

    In this study, an electro-thermal-structural-coupled finite element (FE) model and x-ray diffraction residual stress measurements have been utilized to analyze distribution of residual stresses in an aluminum alloy 6061-T6 resistance spot-welded joint with 2-mm-thickness sheet. Increasing the aluminum sheet thickness to more than 1 mm leads to creating difficulty in spot-welding process and increases the complexity of the FE model. The electrical and thermal contact conductances, as mandatory factors are applied in contact areas of electrode-workpiece and workpiece-workpiece to resolve the complexity of the FE model. The physical and mechanical properties of the material are defined as thermal dependent to improve the accuracy of the model. Furthermore, the electrodes are removed after the holding cycle using the birth-and-death elements method. The results have a good agreement with experimental data obtained from x-ray diffraction residual stress measurements. However, the highest internal tensile residual stress occurs in the center of the nugget zone and decreases toward nugget edge; surface residual stress increases toward the edge of the welding zone and afterward, the area decreases slightly.

  10. Liquid Metal Embrittlement in Resistance Spot Welding and Hot Tensile Tests of Surface-refined TWIP Steels

    Science.gov (United States)

    Barthelmie, J.; Schram, A.; Wesling, V.

    2016-03-01

    Automotive industry strives to reduce vehicle weight and therefore fuel consumption and carbon dioxide emissions. Especially in the auto body, material light weight construction is practiced, but the occupant safety must be ensured. These requirements demand high-strength steels with good forming and crash characteristics. Such an approach is the use of high- manganese-content TWIP steels, which achieve strengths of around 1,000 MPa and fracture strains of more than 60%. Welding surface-refined TWIP steels reduces their elongation at break and produces cracks due to the contact with liquid metal and the subsequent liquid metal embrittlement (LME). The results of resistance spot welds of mixed joints of high-manganese- content steel in combination with micro-alloyed ferritic steel and hot tensile tests are presented. The influence of different welding parameters on the sensitivity to liquid metal embrittlement is investigated by means of spot welding. In a high temperature tensile testing machine, the influence of different parameters is determined regardless of the welding process. Defined strains just below or above the yield point, and at 25% of elongation at break, show the correlation between the applied strain and liquid metal crack initiation. Due to the possibility to carry out tensile tests on a wide range of temperatures, dependencies of different temperatures of the zinc coating to the steel can be identified. Furthermore, the attack time of the zinc on the base material is investigated by defined heating periods.

  11. Vibration analysis of resistance spot welding joint for dissimilar plate structure (mild steel 1010 and stainless steel 304)

    Science.gov (United States)

    Sani, M. S. M.; Nazri, N. A.; Alawi, D. A. J.

    2017-09-01

    Resistance spot welding (RSW) is a proficient joining method commonly used for sheet metal joining and become one of the oldest spot welding processes use in industry especially in the automotive. RSW involves the application of heat and pressure without neglecting time taken when joining two or more metal sheets at a localized area which is claimed as the most efficient welding process in metal fabrication. The purpose of this project is to perform model updating of RSW plate structure between mild steel 1010 and stainless steel 304. In order to do the updating, normal mode finite element analysis (FEA) and experimental modal analysis (EMA) have been carried out. Result shows that the discrepancies of natural frequency between FEA and EMA are below than 10 %. Sensitivity model updating is evaluated in order to make sure which parameters are influences in this structural dynamic modification. Young’s modulus and density both materials are indicate significant parameters to do model updating. As a conclusion, after perform model updating, total average error of dissimilar RSW plate is improved significantly.

  12. Weld Growth Mechanisms and Failure Behavior of Three-Sheet Resistance Spot Welds Made of 5052 Aluminum Alloy

    Science.gov (United States)

    Li, Yang; Yan, Fuyu; Luo, Zhen; Chao, Y. J.; Ao, Sansan; Cui, Xuetuan

    2015-06-01

    This paper investigates the weld nugget formation in three-sheet aluminum alloy resistance spot welding. The nugget formation process in three equal thickness sheets and three unequal thickness sheets of 5052 aluminum alloy were studied. The results showed that the nugget was initially formed at the workpiece/workpiece interfaces (i.e., both upper interface and lower interface). The two small nuggets then grew along the radial direction and axial direction (welding direction) as the welding time increased. Eventually, the two nuggets fused into one large nugget. During the welding process, the Peltier effect between the Cu-Al caused the shift of the nugget in the welding direction. In addition, the mechanical strength and fracture mode of the weld nuggets at the upper and lower interfaces were also studied using tensile shear specimen configuration. Three failure modes were identified, namely interfacial, mixed, and pullout. The critical welding time and critical nugget diameter corresponding to the transitions of these modes were investigated. Finally, an empirical failure load formula for three-sheet weld similar to two-sheet spot weld was developed.

  13. Comparative disease resistance to Newcastle disease in Nigerian ...

    African Journals Online (AJOL)

    A study was conducted to determine the genetic resistance of two Nigerian ecotypes chicken and exotic breed cockerel (black Nera) to Newcastle disease by evaluating their clinical, haematological and humoral responses to experimental Newcastle disease virus infection.. The chicks from the three genotypes were ...

  14. Microstructure and wear resistance of laser cladded composite coatings prepared from pre-alloyed WC-NiCrMo powder with different laser spots

    Science.gov (United States)

    Yao, Jianhua; Zhang, Jie; Wu, Guolong; Wang, Liang; Zhang, Qunli; Liu, Rong

    2018-05-01

    The distribution of WC particles in laser cladded composite coatings can significantly affect the wear resistance of the coatings under aggressive environments. In this study, pre-alloyed WC-NiCrMo powder is deposited on SS316L via laser cladding with circular spot and wide-band spot, respectively. The microstructure and WC distribution of the coatings are investigated with optical microscope (OM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and X-ray diffraction (XRD). The wear behavior of the coatings is investigated under dry sliding-wear test. The experimental results show that the partially dissolved WC particles are uniformly distributed in both coatings produced with circular spot and wide-band spot, respectively, and the microstructures consist of WC and M23C6 carbides and γ-(Ni, Fe) solid solution matrix. However, due to Fe dilution, the two coatings have different microstructural characteristics, resulting in different hardness and wear resistance. The wide-band spot laser prepared coating shows better performance than the circular spot laser prepared coating.

  15. Analysis of Nugget Formation During Resistance Spot Welding on Dissimilar Metal Sheets of Aluminum and Magnesium Alloys

    Science.gov (United States)

    Luo, Yi; Li, Jinglong

    2014-10-01

    The nugget formation of resistance spot welding (RSW) on dissimilar material sheets of aluminum and magnesium alloys was studied, and the element distribution, microstructure, and microhardness distribution near the joint interface were analyzed. It was found that the staggered high regions at the contact interface of aluminum and magnesium alloy sheets, where the dissimilar metal melted together, tended to be the preferred nucleation regions of nugget. The main technical problem of RSW on dissimilar metal sheets of aluminum and magnesium alloys was the brittle-hard Al12Mg17 intermetallic compounds distributed in the nugget, with hardness much higher than either side of the base materials. Microcracks tended to generate at the interface of the nugget and base materials, which affected weld quality and strength.

  16. Microstructure and Tensile-Shear Properties of Resistance Spot Welded 22MnMoB Hot-Stamping Annealed Steel

    Science.gov (United States)

    Li, Yang; Cui, Xuetuan; Luo, Zhen; Ao, Sansan

    2017-01-01

    The present paper deals with the joining of 22MnMoB hot-stamping annealed steel carried out by the spot welding process. Microstructural characterization, microhardness testing and tensile-shear testing were conducted. The effects of the welding parameters, including the electrode tip diameter, welding current, welding time and electrode force upon the tensile-shear properties of the welded joints, were investigated. The results showed that a weld size of 9.6 mm was required to ensure pullout failure for the 1.8 -mm-thick hot-stamping annealed steel sheet. The welding current had the largest influence upon the tensile-shear properties of the 22MnMoB steel welded joint. The bulk resistance should play an important role in the nugget formation. In pullout failure mode, failure was initiated at the heat-affected zone, where softening occurs owing to the tempering of martensite.

  17. Overexpression of BSR1 confers broad-spectrum resistance against two bacterial diseases and two major fungal diseases in rice.

    Science.gov (United States)

    Maeda, Satoru; Hayashi, Nagao; Sasaya, Takahide; Mori, Masaki

    2016-06-01

    Broad-spectrum disease resistance against two or more types of pathogen species is desirable for crop improvement. In rice, Xanthomonas oryzae pv. oryzae (Xoo), the causal bacteria of rice leaf blight, and Magnaporthe oryzae, the fungal pathogen causing rice blast, are two of the most devastating pathogens. We identified the rice BROAD-SPECTRUM RESISTANCE 1 (BSR1) gene for a BIK1-like receptor-like cytoplasmic kinase using the FOX hunting system, and demonstrated that BSR1-overexpressing (OX) rice showed strong resistance to the bacterial pathogen, Xoo and the fungal pathogen, M. oryzae. Here, we report that BSR1-OX rice showed extended resistance against two other different races of Xoo, and to at least one other race of M. oryzae. In addition, the rice showed resistance to another bacterial species, Burkholderia glumae, which causes bacterial seedling rot and bacterial grain rot, and to Cochliobolus miyabeanus, another fungal species causing brown spot. Furthermore, BSR1-OX rice showed slight resistance to rice stripe disease, a major viral disease caused by rice stripe virus. Thus, we demonstrated that BSR1-OX rice shows remarkable broad-spectrum resistance to at least two major bacterial species and two major fungal species, and slight resistance to one viral pathogen.

  18. Contribution of the drought tolerance-related Stress-responsive NAC1 transcription factor to resistance of barley to Ramularia leaf spot

    Science.gov (United States)

    MCGRANN, GRAHAM R D; STEED, ANDREW; BURT, CHRISTOPHER; GODDARD, RACHEL; LACHAUX, CLEA; BANSAL, ANURADHA; CORBITT, MARGARET; GORNIAK, KALINA; NICHOLSON, PAUL; BROWN, JAMES K M

    2015-01-01

    NAC proteins are plant transcription factors that are involved in tolerance to abiotic and biotic stresses, as well as in many developmental processes. Stress-responsive NAC1 (SNAC1) transcription factor is involved in drought tolerance in barley and rice, but has not been shown previously to have a role in disease resistance. Transgenic over-expression of HvSNAC1 in barley cv. Golden Promise reduced the severity of Ramularia leaf spot (RLS), caused by the fungus Ramularia collo-cygni, but had no effect on disease symptoms caused by Fusarium culmorum, Oculimacula yallundae (eyespot), Blumeria graminis f. sp. hordei (powdery mildew) or Magnaporthe oryzae (blast). The HvSNAC1 transcript was weakly induced in the RLS-susceptible cv. Golden Promise during the latter stages of R. collo-cygni symptom development when infected leaves were senescing. Potential mechanisms controlling HvSNAC1-mediated resistance to RLS were investigated. Gene expression analysis revealed no difference in the constitutive levels of antioxidant transcripts in either of the over-expression lines compared with cv. Golden Promise, nor was any difference in stomatal conductance or sensitivity to reactive oxygen species-induced cell death observed. Over-expression of HvSNAC1 delayed dark-induced leaf senescence. It is proposed that mechanisms controlled by HvSNAC1 that are involved in tolerance to abiotic stress and that inhibit senescence also confer resistance to R. collo-cygni and suppress RLS symptoms. This provides further evidence for an association between abiotic stress and senescence in barley and the development of RLS. PMID:25040333

  19. More nutritious bananas resist disease | IDRC - International ...

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

    2010-10-28

    Oct 28, 2010 ... By inserting resistant varieties (like FHIA-17 and FHIA-23) between traditional, susceptible plants, we 'trap' the disease agent and prevent it from spreading. This has a direct impact on food security by restoring the productivity of the traditional varieties." — Abdou Tenkouano, International Institute of ...

  20. SENSITIVE RESPONSE AND RESISTANCE TO BERY DISEASE ...

    African Journals Online (AJOL)

    AISA

    Seedling hypocotyls and attached green coffee berries of 11 Coffea arabica varieties and a Robusta coffee cultivar, with different levels of resistance to coffee berry disease (Colletotrichum kahawae), were examined under a microscope for differences in the development of infections caused by single-conidium isolates of.

  1. Short communication. Inheritance of yield, yield components and resistance to major diseases in Sesamum indicum L

    Energy Technology Data Exchange (ETDEWEB)

    El-Bramaway, M. A. S.; Shaban, W. I.

    2008-07-01

    Field experiments were conducted over 2005 and 2006 to study the gene action associated with yield and ten yield components, as well as resistance Fusarium wilt, charcoal rot and Alternaria leaf spot, in 6x6 half-diallel sesame progenies (F1). Highly significant differences among the 15 F1s and their six parents were detected with respect to all the investigated traits. A preponderance of non-additive genetic variance was seen for all the studied traits, except for days to maturity and resistance to Alternaria leaf spot. Ten traits showed over dominance. Recessive alleles were predominantly involved in fruiting branches plant-1, capsules plant-1 and single plant yield. The distribution of genes with positive and negative effects were symmetrical or nearly symmetrical with respect to 1000-seed weight, charcoal rot disease resistance, fruiting branches plant-1, capsules plant-1, single plant yield, and oil content. The parents possessed mostly negative genes in dominant form with respect to capsules plant-1, 1000-seed weight, oil content, and resistance to charcoal rot and Alternaria leaf spot; positive genes in recessive form were observed for the rest of the studied traits. Given the gene action observed, bi parental mating or diallel selective mating and heterosis breeding is suggested for the improvement of sesame. (Author) 24 refs.

  2. Tan spot susceptibility governed by the Tsn1 locus and race-nonspecific resistance quantitative trait loci in a population derived from the wheat lines Salamouni and Katepwa

    Science.gov (United States)

    Wheat-tan spot interactions are known to have an inverse gene-for-gene relationship where pathogen-produced necrotrophic effectors are recognized by host sensitivity genes to cause susceptibility. However, broad-spectrum non race-specific resistance quantitative trait loci (QTL) that do not conform...

  3. Linkage mapping of the Phg-1 and Co-1(4) genes for resistance to angular leaf spot and anthracnose in the common bean cultivar AND 277.

    Science.gov (United States)

    Gonçalves-Vidigal, Maria Celeste; Cruz, Anelise S; Garcia, Alexandre; Kami, J; Vidigal Filho, Pedro S; Sousa, Lorenna L; McClean, P; Gepts, P; Pastor-Corrales, M A

    2011-03-01

    The Andean common bean AND 277 has the Co-1(4) and the Phg-1 alleles that confer resistance to 21 and eight races, respectively, of the anthracnose (ANT) and angular leaf spot (ALS) pathogens. Because of its broad resistance spectrum, Co-1(4) is one of the main genes used in ANT resistance breeding. Additionally, Phg-1 is used for resistance to ALS. In this study, we elucidate the inheritance of the resistance of AND 277 to both pathogens using F(2) populations from the AND 277 × Rudá and AND 277 × Ouro Negro crosses and F(2:3) families from the AND 277 × Ouro Negro cross. Rudá and Ouro Negro are susceptible to all of the above races of both pathogens. Co-segregation analysis revealed that a single dominant gene in AND 277 confers resistance to races 65, 73, and 2047 of the ANT and to race 63-23 of the ALS pathogens. Co-1(4) and Phg-1 are tightly linked (0.0 cM) on linkage group Pv01. Through synteny mapping between common bean and soybean we also identified two new molecular markers, CV542014(450) and TGA1.1(570), tagging the Co-1(4) and Phg-1 loci. These markers are linked at 0.7 and 1.3 cM, respectively, from the Co-1(4) /Phg-1 locus in coupling phase. The analysis of allele segregation in the BAT 93/Jalo EEP558 and California Dark Red Kidney/Yolano recombinant populations revealed that CV542014(450) and TGA1.1(570) segregated in the expected 1:1 ratio. Due to the physical linkage in cis configuration, Co-1(4) and Phg-1 are inherited together and can be monitored indirectly with the CV542014(450) and TGA1.1(570) markers. These results illustrate the rapid discovery of new markers through synteny mapping. These markers will reduce the time and costs associated with the pyramiding of these two disease resistance genes.

  4. Bell and banana pepper exhibit mature-plant resistance to tomato spotted wilt Tospovirus transmitted by Frankliniella fusca (Thysanoptera: Thripidae).

    Science.gov (United States)

    Beaudoin, A L P; Kahn, N D; Kennedy, G G

    2009-02-01

    Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV) causes annual economic losses in pepper, Capsicum annuum L., across the southern United States and is transmitted by several species of thrips, including the tobacco thrips, Frankliniella fusca (Hinds). Reduced virus transmission and symptom severity as plant age increases is known as mature-plant resistance. TSWV transmission to pepper plants was examined in three and four age classes in field and greenhouse trials, respectively. In the field trial, 'Camelot' bell pepper plants were exposed to potentially viruliferous F. fusca 37, 51, or 65 d postsowing. Two greenhouse trials of Camelot bell and one trial each of 'Bounty' and 'Pageant' banana pepper plants were exposed to potentially viruliferous F. fusca, 43, 57, 71, or 85; 48, 62, 75, or 90; 42, 56, 70, or 84; and 43, 57, 71, or 85 d postsowing, respectively. Linear and hyperbolic regressions of percentage of infected plants per block on days postsowing indicated mature-plant resistance in all trials. All models were significant, but hyperbolic curves better fit the data than linear models. Hyperbolic models were used to calculate the number of days posttransplant at which a 50% decrease from the predicted percentage of infected plants at transplant age (42 d postsowing) was expected. This was referred to as days posttransplant-50 (DPT50). DPRT50 occurred within 9 days posttransplant age for all trials, indicating that early TSWV management in pepper is critical.

  5. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients

    Directory of Open Access Journals (Sweden)

    Juan Pablo Rodriguez-Auad

    2015-01-01

    Full Text Available Monitoring antiretroviral therapy using measurements of viral load (VL and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6% of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings.

  6. Combined effects of elevated CO2 and natural climatic variation on leaf spot diseases of redbud and sweetgum trees.

    Science.gov (United States)

    McElrone, Andrew J; Hamilton, Jason G; Krafnick, Anthony J; Aldea, Mihai; Knepp, Rachel G; DeLucia, Evan H

    2010-01-01

    Atmospheric CO(2) concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. In this study conducted over five years, we assessed how elevated CO(2) and interannual climatic variability affect Cercospora leaf spot diseases of two deciduous trees. Climatic data varied considerably between the five years and altered disease expression. Disease incidence and severity for both species were greater in years with above average rainfall. In years with above average temperatures, disease incidence for Liquidambar styraciflua was decreased significantly. When significant changes did occur, disease incidence and severity always increased under elevated CO(2). Chlorophyll fluorescence imaging of leaves revealed that any visible increase in disease severity induced by elevated CO(2) was mitigated by higher photosynthetic efficiency in the remaining undamaged leaf tissue and in a halo surrounding lesions.

  7. Silicon induces resistance to the brown spot fungus Cochliobolus miyabeanus by preventing the pathogen from hijacking the rice ethylene pathway

    Czech Academy of Sciences Publication Activity Database

    Van Bockhaven, J.; Spíchal, L.; Novák, Ondřej; Strnad, Miroslav; Asano, T.; Kikuchi, S.; Hofte, M.; De Vleesschauwer, D.

    2015-01-01

    Roč. 206, č. 2 (2015), s. 761-773 ISSN 0028-646X R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Bipolaris oryzae * Cochliobolus miyabeanus * disease resistance Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.210, year: 2015

  8. Modified expression of alternative oxidase in transgenic tomato and petunia affects the level of tomato spotted wilt virus resistance

    Directory of Open Access Journals (Sweden)

    Ma Hao

    2011-10-01

    Full Text Available Abstract Background Tomato spotted wilt virus (TSWV has a very wide host range, and is transmitted in a persistent manner by several species of thrips. These characteristics make this virus difficult to control. We show here that the over-expression of the mitochondrial alternative oxidase (AOX in tomato and petunia is related to TSWV resistance. Results The open reading frame and full-length sequence of the tomato AOX gene LeAox1au were cloned and introduced into tomato 'Healani' and petunia 'Sheer Madness' using Agrobacterium-mediated transformation. Highly expressed AOX transgenic tomato and petunia plants were selfed and transgenic R1 seedlings from 10 tomato lines and 12 petunia lines were used for bioassay. For each assayed line, 22 to 32 tomato R1 progeny in three replications and 39 to 128 petunia progeny in 13 replications were challenged with TSWV. Enzyme-Linked Immunosorbent Assays showed that the TSWV levels in transgenic tomato line FKT4-1 was significantly lower than that of wild-type controls after challenge with TSWV. In addition, transgenic petunia line FKP10 showed significantly less lesion number and smaller lesion size than non-transgenic controls after inoculation by TSWV. Conclusion In all assayed transgenic tomato lines, a higher percentage of transgenic progeny had lower TSWV levels than non-transgenic plants after challenge with TSWV, and the significantly increased resistant levels of tomato and petunia lines identified in this study indicate that altered expression levels of AOX in tomato and petunia can affect the levels of TSWV resistance.

  9. Fine mapping of a quantitative resistance gene for gray leaf spot of maize (Zea mays L.) derived from teosinte (Z. mays ssp. parviglumis).

    Science.gov (United States)

    Zhang, Xinye; Yang, Qin; Rucker, Elizabeth; Thomason, Wade; Balint-Kurti, Peter

    2017-06-01

    In this study we mapped the QTL Qgls8 for gray leaf spot (GLS) resistance in maize to a ~130 kb region on chromosome 8 including five predicted genes. In previous work, using near isogenic line (NIL) populations in which segments of the teosinte (Zea mays ssp. parviglumis) genome had been introgressed into the background of the maize line B73, we had identified a QTL on chromosome 8, here called Qgls8, for gray leaf spot (GLS) resistance. We identified alternate teosinte alleles at this QTL, one conferring increased GLS resistance and one increased susceptibility relative to the B73 allele. Using segregating populations derived from NIL parents carrying these contrasting alleles, we were able to delimit the QTL region to a ~130 kb (based on the B73 genome) which encompassed five predicted genes.

  10. AISI/DOE Technology Roadmap Program: Development of Appropriate Resistance Spot Welding Practice for Transformation-Hardened Steels

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Chuko; Jerry Gould

    2002-07-08

    This report describes work accomplished in the project, titled ''Development of Appropriate Resistance Spot Welding Practice for Transformation-Hardened Steels.'' The Phase 1 of the program involved development of in-situ temper diagrams for two gauges of representative dual-phase and martensitic grades of steels. The results showed that tempering is an effective way of reducing hold-time sensitivity (HTS) in hardenable high-strength sheet steels. In Phase 2, post-weld cooling rate techniques, incorporating tempering, were evaluated to reduce HTS for the same four steels. Three alternative methods, viz., post-heating, downsloping, and spike tempering, for HTS reduction were investigated. Downsloping was selected for detailed additional study, as it appeared to be the most promising of the cooling rate control methods. The downsloping maps for each of the candidate steels were used to locate the conditions necessary for the peak response. Three specific downslope conditions (at a fix ed final current for each material, timed for a zero-, medium-, and full-softening response) were chosen for further metallurgical and mechanical testing. Representative samples, were inspected metallographically, examining both local hardness variations and microstructures. The resulting downslope diagrams were found to consist largely of a C-curve. The softening observed in these curves, however, was not supported by subsequent metallography, which showed that all welds made, regardless of material and downslope condition, were essentially martensitic. CCT/TTT diagrams, generated based on microstructural modeling done at Oak Ridge National Laboratories, showed that minimum downslope times of 2 and 10 s for the martensitic and dual-phase grades of steels, respectively, were required to avoid martensite formation. These times, however, were beyond those examined in this study. These results show that downsloping is not an effective means of reducing HTS for

  11. Establishment of Economic Threshold by Evaluation of Yield Component and Yield Damages Caused by Leaf Spot Disease of Soybean

    Directory of Open Access Journals (Sweden)

    Hongsik Shim

    2013-09-01

    Full Text Available This study was carried out to investigate yield loss due to soybean leaf spot disease caused by Cercospora sojina Hara and to determine the economic threshold level. The investigations revealed highly significant correlations between disease severity (diseased leaf area and yield components (pod number per plant, total grain number per plant, total grain weight per plant, percent of ripened grain, weight of hundred seed, and yield. The correlation coefficients between leaf spot severity and each component were −0.90, −0.90, −0.92, −0.99, −0.90 and −0.94, respectively. The yield was inversely proportional to the diseased leaf area increased. The regression equation, yield prediction model, between disease severity (x and yield (y was obtained as y = −3.7213x + 354.99 (R2 = 0.9047. Based on the yield prediction model, economic injury level and economic threshold level could be set as 3.3% and 2.6% of diseased leaf area of soybean.

  12. Physico-chemical characterization of banana varieties resistant to black leaf streak disease for industrial purposes

    Directory of Open Access Journals (Sweden)

    Rossana Catie Bueno de Godoy

    2016-01-01

    Full Text Available ABSTRACT: Cultivated bananas have very low genetic diversity making them vulnerable to diseases such as black-Sigatoka leaf spot. However, the decision to adopt a new banana variety needs to be based on a robust evaluation of agronomical and physical-chemical characteristics. Here, we characterize new banana varieties resistant to black-Sigatoka leaf spot and compare them to the most widely used traditional variety (Grand Naine. Each variety was evaluated for a range of physic-chemical attributes associated with industrial processing and flavor: pH, TTA, TSS/TTA, total sugars, reducing sugars and non-reducing sugars, humidity, total solids and yield. The Thap Maeo variety had the highest potential as a substitute for the Grand Naine variety, having higher levels of total soluble solids, reducing sugars, total sugars and humidity. The Caipira and FHIA 2 varieties also performed well in comparison with the Grand Naine variety. Cluster analysis indicated that the Grand Naine variety was closely associated with varieties from the Gross Michel subgroup (Bucaneiro, Ambrosia and Calipso and the Caipira variety, all of which come from the same AAA genomic group. It was concluded that several of the new resistant varieties could potentially substitute the traditional variety in areas affected by black-Sigatoka leaf spot disease.

  13. Effect of Weld Current on the Microstructure and Mechanical Properties of a Resistance Spot-Welded TWIP Steel Sheet

    Directory of Open Access Journals (Sweden)

    Mumin Tutar

    2017-11-01

    Full Text Available In this study the effect of the weld current on the microstructure and mechanical properties of a resistance spot-welded twinning-induced plasticity (TWIP steel sheet was investigated using optical microscopy, scanning electron microscopy–electron back-scattered diffraction (SEM–EBSD, microhardness measurements, a tensile shear test and fractography. Higher weld currents promoted the formation of a macro expulsion cavity in the fusion zone. Additionally, higher weld currents led to a higher indentation depth, a wider heat-affected zone (HAZ, coarser grain structure and thicker annealing twins in the HAZ, and a relatively equiaxed dendritic structure in the centre of the fusion zone. The hardness values in the weld zone were lower than that of the base metal. The lowest hardness values were observed in the HAZ. No strong relationship was observed between the hardness values in the weld zone and the weld current. A higher joint strength, tensile deformation and failure energy absorption capacity were obtained with a weld current of 12 kA, a welding time of 300 ms and an electrode force of 3 kN. A complex fracture surface with both brittle and limited ductile manner was observed in the joints, while the base metal exhibited a ductile fracture. Joints with a higher tensile shear load (TSL commonly exhibited more brittle fracture characteristics.

  14. Microstructure and mechanical properties of resistance spot welded dissimilar thickness DP780/DP600 dual-phase steel joints

    International Nuclear Information System (INIS)

    Zhang, Hongqiang; Wei, Ajuan; Qiu, Xiaoming; Chen, Jianhe

    2014-01-01

    Highlights: • We examine changes of microstructure of dissimilar thickness DP600/DP780 joints. • The hardness profile of RSW joints can be predicted by the equation. • Failure modes, peak load and energy describes the mechanical properties of joints. • The nugget diameter is the key factor of transition between the failure modes. - Abstract: In this study, resistance spot welding (RSW) experiments were performed in order to evaluate the microstructure and mechanical properties of single-lap joints between DP780 and DP600. The results show that the weld joints consist of three regions including base metal (BM), heat affected zone (HAZ) and fusion zone (FZ). The grain size and martensite volume fractions increase in the order of BM, HAZ and FZ. The hardness in the FZ is significantly higher than hardness of base metals. Tensile properties of the joints were described in terms of the failure modes and static load-carrying capabilities. Two distinct failure modes were observed during the tensile shear test of the joints: interfacial failure (IF) and pullout failure (PF). The FZ size plays a dominate role in failure modes of the joints

  15. The Influence of Welding Parameters on the Nugget Formation of Resistance Spot Welding of Inconel 625 Sheets

    Science.gov (United States)

    Rezaei Ashtiani, Hamid Reza; Zarandooz, Roozbeh

    2015-09-01

    A 2D axisymmetric electro-thermo-mechanical finite element (FE) model is developed to investigate the effect of current intensity, welding time, and electrode tip diameter on temperature distributions and nugget size in resistance spot welding (RSW) process of Inconel 625 superalloy sheets using ABAQUS commercial software package. The coupled electro-thermal analysis and uncoupled thermal-mechanical analysis are used for modeling process. In order to improve accuracy of simulation, material properties including physical, thermal, and mechanical properties have been considered to be temperature dependent. The thickness and diameter of computed weld nuggets are compared with experimental results and good agreement is observed. So, FE model developed in this paper provides prediction of quality and shape of the weld nuggets and temperature distributions with variation of each process parameter, suitably. Utilizing this FE model assists in adjusting RSW parameters, so that expensive experimental process can be avoided. The results show that increasing welding time and current intensity lead to an increase in the nugget size and electrode indentation, whereas increasing electrode tip diameter decreases nugget size and electrode indentation.

  16. Characterization of rust, early and late leaf spot resistance in wild and cultivated peanut germplasm Caracterização da resistência à ferrugem, mancha preta e mancha castanha em germoplasma silvestre e cultivado de amendoim

    Directory of Open Access Journals (Sweden)

    Alessandra Pereira Fávero

    2009-02-01

    Full Text Available Groundnut (Arachis hypogaea has an AB genome and is one of the most important oil crops in the world. The main constraints of crop management in Brazil are fungal diseases. Several species of the genus Arachis are resistant to pests and diseases. The objective of our experiments was to identify wild species belonging to the taxonomic section Arachis with either A or B (or " non-A" genomes that are resistant to early leaf spot (Cercospora arachidicola, late leaf spot (Cercosporidium personatum and rust (Puccinia arachidis. For the identification of genotypes resistant to fungal diseases, bioassays with detached leaves were done in laboratory conditions, with artificial inoculation, a controlled temperature of 25ºC and a photoperiod of 10 h light/14 h dark, for 20-42 days, depending on the fungi species. Most of the accessions of wild species were more resistant than accessions of A. hypogaea for one, two or all three fungi species studied. Arachis monticola, considered to be a possible tetraploid ancestor or a derivative of A. hypogaea, was also more susceptible to Cercosporidium personatum and Puccinia arachidis, as compared to most of the wild species. Therefore, wild germplasm accessions of both genome types are available to be used for the introgression of resistance genes against three fungal diseases of peanut.O amendoim (Arachis hypogaea possui genoma AB e é uma das mais importantes culturas oleaginosas em todo o mundo. Os principais problemas da cultura no Brasil são as doenças fúngicas. Várias espécies do gênero Arachis são resistentes a pragas e doenças. Este trabalho visou a identificar espécies silvestres pertencentes à seção Arachis associadas aos genomas A ou B (ou " não-A" do amendoim que são resistentes à mancha castanha (Cercospora arachidicola, mancha preta (Cercosporidium personatum e ferrugem (Puccinia arachidis. Para a identificação de genótipos resistentes a doenças fúngicas, bioensaios utilizando

  17. Next-generation sequencing of dried blood spot specimens: a novel approach to HIV drug-resistance surveillance.

    Science.gov (United States)

    Ji, Hezhao; Li, Yang; Graham, Morag; Liang, Ben Binhua; Pilon, Richard; Tyson, Shari; Peters, Geoff; Tyler, Shaun; Merks, Harriet; Bertagnolio, Silvia; Soto-Ramirez, Luis; Sandstrom, Paul; Brooks, James

    2011-01-01

    HIV drug-resistance (DR) surveillance in resource-limited settings can be performed using dried blood spots (DBS) because of ease of collection, transportation and storage. Analysis of pooled specimens on next-generation sequencing (NGS)-based platforms, such as the 454 pyrosequencing, is an efficient sequencing method for determining HIV DR rates. In this study, we conducted HIV DR surveillance on DBS using NGS and identified minority variants in individual patients. A total of 48 extracts of DBS from an HIV DR surveillance study in Mexico City were re-amplified using primers tagged with multiplex identifiers, pooled and pyrosequenced. Consensus sequences were generated for each specimen with mixtures identified at positions where >20% of the reads contained a variant. Individual consensus sequences were then analysed for DR mutations and compared with those derived from Sanger sequencing. DBS analysed with tagged pooled pyrosequencing (TPP) were highly concordant with Sanger sequencing genotypes from matching plasma and DBS (99.21% and 99.51%, respectively). An exception was an M184I mutation only detected with TPP of DBS at a frequency of 20.4%. Multiple specimens had minority variant reads below the 20% mixture threshold. TPP using DBS is an effective method for HIV DR surveillance. TPP for genotyping results in cost savings of 40% over conventional in-house methods. The effect of low-abundance DR mutations, undetectable by conventional methods, remains to be determined. This technology might be applied to any HIV specimen (plasma/serum) and can also be used for other diagnostic assays where DNA sequencing is required. © 2011 International Medical Press

  18. Optical Inspection and Morphological Analysis of Diospyros kaki Plant Leaves for the Detection of Circular Leaf Spot Disease

    Directory of Open Access Journals (Sweden)

    Ruchire Eranga Wijesinghe

    2016-08-01

    Full Text Available The feasibility of using the bio-photonic imaging technique to assess symptoms of circular leaf spot (CLS disease in Diospyros kaki (persimmon leaf samples was investigated. Leaf samples were selected from persimmon plantations and were categorized into three groups: healthy leaf samples, infected leaf samples, and healthy-looking leaf samples from infected trees. Visually non-identifiable reduction of the palisade parenchyma cell layer thickness is the main initial symptom, which occurs at the initial stage of the disease. Therefore, we established a non-destructive bio-photonic inspection method using a 1310 nm swept source optical coherence tomography (SS-OCT system. These results confirm that this method is able to identify morphological differences between healthy leaves from infected trees and leaves from healthy and infected trees. In addition, this method has the potential to generate significant cost savings and good control of CLS disease in persimmon fields.

  19. Therapy-resistant symptoms in Parkinson's disease.

    Science.gov (United States)

    Vorovenci, Ruxandra Julia; Biundo, Roberta; Antonini, Angelo

    2016-01-01

    In recent years, the management of Parkinson's disease (PD) has come a long way, leading to an increase in therapeutic options that now include oral and transdermal drug delivery, infusion as well as surgical treatments. Nonetheless, in the evolution of this complex neurodegenerative disorder, several symptoms remain refractory to dopaminergic therapy. It is our aim to review the literature to date and to bring them into focus, as well as emphasizing on pathophysiological mechanisms, profile of risk factors in their development, and therapeutic options. We will focus on freezing of gait, camptocormia, dysphagia and dysphonia, as well as cognitive impairment and dementia because they represent the far end of therapy-resistant symptoms, encompassing poor health-related quality of life and often a more reserved prognosis with either a rapid evolution of the disease, and/or merely a more severe clinical picture. Pathophysiological mechanisms and brain neurotransmitter abnormalities behind these symptoms seem to overlap to some extent, and a better understanding of these correlations is desirable. We believe that further research is paramount to expand our knowledge of the dopamine-resistant symptoms and, consequently, to develop specific therapeutic strategies.

  20. Influences of the disease resistance conferred by the individual ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... If the resistance in the transgenic rice plants with a disease resistance gene is similar to the RPM1 resis- tance in Arabidopsis, that is, negatively correlate with yield or grain quality in rice, we should not only consider the disease resistance of the transgenic rice plants but ignore their yields and grain quality, ...

  1. Influences of the disease resistance conferred by the individual ...

    African Journals Online (AJOL)

    To research possible influences of the disease resistance conferred by different trans-resistance genes on the transgenic rice plants in their yields and grain quality, three transgenic rice lines, including two with the resistance genes Pi-d2 and Pi-d3, respectively, for rice blast, and one with the resistance gene Xa21 for rice ...

  2. Comparisons of protein profiles of beech bark disease resistant and susceptible American beech (Fagus grandifolia

    Directory of Open Access Journals (Sweden)

    Mason Mary E

    2013-01-01

    Full Text Available Abstract Background Beech bark disease is an insect-fungus complex that damages and often kills American beech trees and has major ecological and economic impacts on forests of the northeastern United States and southeastern Canadian forests. The disease begins when exotic beech scale insects feed on the bark of trees, and is followed by infection of damaged bark tissues by one of the Neonectria species of fungi. Proteomic analysis was conducted of beech bark proteins from diseased trees and healthy trees in areas heavily infested with beech bark disease. All of the diseased trees had signs of Neonectria infection such as cankers or fruiting bodies. In previous tests reported elsewhere, all of the diseased trees were demonstrated to be susceptible to the scale insect and all of the healthy trees were demonstrated to be resistant to the scale insect. Sixteen trees were sampled from eight geographically isolated stands, the sample consisting of 10 healthy (scale-resistant and 6 diseased/infested (scale-susceptible trees. Results Proteins were extracted from each tree and analysed in triplicate by isoelectric focusing followed by denaturing gel electrophoresis. Gels were stained and protein spots identified and intensity quantified, then a statistical model was fit to identify significant differences between trees. A subset of BBD differential proteins were analysed by mass spectrometry and matched to known protein sequences for identification. Identified proteins had homology to stress, insect, and pathogen related proteins in other plant systems. Protein spots significantly different in diseased and healthy trees having no stand or disease-by-stand interaction effects were identified. Conclusions Further study of these proteins should help to understand processes critical to resistance to beech bark disease and to develop biomarkers for use in tree breeding programs and for the selection of resistant trees prior to or in early stages of BBD

  3. A Contribution to the Parameters Optimization of a Spot Resistance Welding Transformer from an Aspect of the Working Regimes

    International Nuclear Information System (INIS)

    Chundeva, Snezhana

    2001-01-01

    The main goal of the thesis is to carry out an optimization of a spot resistance welding transformer, by Genetic Algorithm as the most powerful representative of contemporary stochastic optimization tools. Before the optimization process is going to be performed, an extensive and complex investigation of the transformer is required. These include set of experimental investigation, mathematical and numerical modeling of the transformer. An adequate analytical model of the transformer accurately reproducing all the experimentally derived parameters is developed. It is used to calculate the most relevant transformer parameters that can not be derived easily by measurements. Using the most extensively dynamic simulation programs, such as SIMULINK and PSPICE, accurate simulation models of the transformer are derived. Numerical calculation of the electromagnetic field is done by applying finite element method (FEM), while for the thermal analysis the transmission line matrix approach coupled with the FEM results is applied. The various results are verified with the -corresponding experimental and analytically obtained data. In the next step the derived transformer mathematical model is implemented in the Genetic Algorithm suitable for optimization purposes. The optimization process is performed for different electrical and magnetic transformer parameters, different objective functions and various mapping ranges of the design variables. Only the optimized solution which best matches the following criteria: increased duty factor at the nominal position; maintained or slightly decreased secondary current; decreased transformer dimension and thus decreased total weight with maintained transformer efficiency is nominated as optimal, and chosen for detail investigation. The Genetic Algorithm is further used as a tool for optimal designing of concept ally different original mod el of resistance welding transformer - having decreased number of top positions and unique primary

  4. Herança da resistência à mancha-foliar de feosféria em milho Inheritance of the resistance to phaeosphaeria leaf spot in maize

    Directory of Open Access Journals (Sweden)

    Diego Girardi Pegoraro

    2002-03-01

    Full Text Available A mancha-foliar de feosféria tem causado expressiva redução no rendimento de grãos de milho, no Brasil, principalmente, em decorrência da crescente amplitude da data de semeadura, conjugada com o uso de áreas irrigadas e de plantio direto. É importante o desenvolvimento de genótipos resistentes a essa moléstia; porém a realização de uma seleção eficiente depende do entendimento da variabilidade genética e da herança da resistência. Com o objetivo de determinar a capacidade combinatória e o modo de herança do caráter, foram cruzadas sete linhagens de milho, para a realização das análises dialélica e média de gerações. Os experimentos foram conduzidos no Município de Xanxerê, SC, sendo avaliada a porcentagem de tecido foliar afetado pela moléstia 30 dias após o florescimento. Os genótipos apresentaram amplitude de 4,3% a 67,0% de área foliar afetada pela moléstia, na qual a linhagem LA06 e seus híbridos demonstraram elevada resistência. Os resultados indicaram que a seleção de genótipos resistentes à feosféria pode ser realizada com sucesso em programas de melhoramento do milho, visto que a manifestação do caráter é controlada por, pelo menos, dois genes independentes e com uma efetiva participação de efeitos aditivos.Phaeosphaeria leaf spot (PLS has caused an expressive reduction in the corn grain yield in Brazil. The increment in sowing date amplitude, conjugated with the use of irrigated areas and zero tillage, had major contribution in the increase of phaeosphaeria leaf spot (PLS incidence and severity. For this reason, it is important to develop resistant genotypes to this disease; however, an efficient selection depends upon the understanding of the genetic variability and inheritance of the resistance. Aiming to determine combining ability and the mode of inheritance for PLS, seven corn inbreds were crossed for diallel and generation mean analysis. The experiments were conducted in Xanxerê, SC

  5. Future directions in breeding for disease resistance in aquaculture species

    Directory of Open Access Journals (Sweden)

    Ross D. Houston

    Full Text Available ABSTRACT Infectious disease is a major constraint for all species produced via aquaculture. The majority of farmed fish and shellfish production is based on stocks with limited or no selective breeding. Since disease resistance is almost universally heritable, there is huge potential to select for improved resistance to key diseases. This short review discusses the current methods of breeding more resistant aquaculture stocks, with success stories and current bottlenecks highlighted. The current implementation of genomic selection in breeding for disease resistance and routes to wider-scale implementation and improvement in aquaculture are discussed. Future directions are highlighted, including the potential of genome editing tools for mapping causative variation underlying disease resistance traits and for breeding aquaculture animals with enhanced resistance to disease.

  6. Treatment of resistant tattoos using a new generation Q-switched Nd:YAG laser: influence of beam profile and spot size on clearance success.

    Science.gov (United States)

    Karsai, Syrus; Pfirrmann, Gudrun; Hammes, Stefan; Raulin, Christian

    2008-02-01

    Multiple treatments of resistant tattoos often result in fibrosis and visible textural changes that lessen response to subsequent treatments. The aim of this study is to evaluate the influence of beam profile and spot size on clearance rates and side effects in the setting of resistant tattoos. Thirty-six professional, black tattoos (32 patients) were treated unsuccessfully with a Q-switched Nd:YAG laser (MedLite C3, HoyaConBio Inc., Fremont, CA). Because of therapy resistance all tattoos were re-treated using a new generation Nd:YAG laser (MedLite C6, HoyaConBio Inc.). Maximum energy fluence (E (max)), mean energy fluence, mean spot size, level of clearance, side effects and beam profile (irradiance distribution) of both laser systems were assessed and evaluated in a retrospective study. All tattoos were previously treated with the C3 laser at 1,064 nm using a mean E(max) of 5.8+/-0.8 J/cm(2) (range 3.8-7.5 J/cm(2)) as compared with a mean E(max) of 6.4+/-1.6 J/cm(2) (range 3.2-9.0 J/cm(2)) during the C6 treatment course. Corresponding spot sizes were larger during C6 treatments as compared with C3 (5.0+/-0.9 and 3.6+/-0.2 mm, respectively). The C6 laser had a "flat top" and homogenous profile regardless of the spot size. For the C3 laser the beam shape was "Gaussian," and the homogeneity was reduced by numerous micro-spikes and micro-nadirs. After the C6 treatment course 33.3% of the tattoos showed clearance of grade 1 (0-25%), 16.7% of grade 2 (26-50%), 16.7% of grade 3 (51-75%), 30.5% of grade 4 (76-95%), 2.8% of grade 5 (96-100%). The total rate of side effects due to C6 treatment was 8.3% in all tattoos (hyperpigmentation 5.6%, hypopigmentation 2.7%, textural changes/scars 0%). This clinical study documents for the first time the impact of a 1,064-nm Nd:YAG laser with a more homogenous beam profile and a larger spot size on the management of resistant tattoos. Only a few treatment sessions were necessary to achieve an additional clearance with a low rate of

  7. An experimental study on fracture toughness of resistance spot welded galvanized and ungalvanized DP 450 steel sheets used in automotive body

    Energy Technology Data Exchange (ETDEWEB)

    Sevim, I.

    2016-07-01

    The purpose of this study is to determine fracture toughness of Resistance Spot Welded (RSW) Dual Phase (DP) steels. RSW of galvanized and ungalvanized DP 450 steel sheets was carried out on spot welding machine. Fracture toughness of RSW joints of galvanized and ungalvanized DP 450 steel sheets was calculated from tensile-shear tests. New empirical equations were developed using Least Squares Method (LSM) between energy release rate, fracture toughness and critical crack size depending on the relationship between hardness and fracture toughness values. Results indicated that fracture toughness of joints welded by using RSW increased exponentially while the hardness decreased. In addition, fracture toughness and energy release rate of RSW galvanized DP 450 steel sheets were lower compared to RSW ungalvanized DP 450 steel sheets which had approximately the same hardness. (Author)

  8. Experimental consideration on the contact resistance caused by the distribution of contact spots with the contact model using electrolyte bath; Denkai yokuso wo mochiita sesshoku model ni yoru sesshokuten no bunpu to sesshoku teiko tokusei ni kansuru jikkenteki kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Aichi, H. [Daido Institute of Technology, Aichi (Japan); Miyachi, I. [Aichi Institute of Technology, Aichi (Japan)

    1996-09-20

    Electric contact members are classified by the form such as a point, a line, and a plane. Particularly, the point contact member which makes a small circular contact spot is basis of the contact form. Also, the plane contact member will make many contact spots which are different in size and distributing over the contacting portion. Authors have been developing the contact model to measure the contact resistance. In this model, it is available to select the size, the number, and the arrangement of contact spots by the macroscopical contact spots which are formed with some metal electrodes arranged in electrolyte solution of dilute sulfuric acid. In this paper, the fundamental characteristics of the contact resistance caused by the construction of current are investigated with 1 to 3 contact spot models. Then the relations between the contact resistance and the distribution of the contact spots are examined with 2 to 9 multi-contact spot models. As the results, it is cleared that the proposed contact model presents the successful experimental method for the analysis of the contact resistance. 9 refs., 8 tabs.

  9. Microstructure and mechanical properties of weld-bonded and resistance spot welded magnesium-to-steel dissimilar joints

    International Nuclear Information System (INIS)

    Xu, W.; Chen, D.L.; Liu, L.; Mori, H.; Zhou, Y.

    2012-01-01

    Highlights: ► Adhesive reduces shrinkage porosity and stress concentration around the weld nugget. ► Adhesive promotes the formation of intermetallic compounds during weld bonding. ► In Mg/steel joints fusion zone appears only at the Mg side with dendritic structures. ► Weld-bonded Mg/steel joints are considerably stronger than RSW Mg/steel joints. ► Fatigue strength is three-fold higher for weld-bonded joints than for RSW joints. - Abstract: The aim of this study was to evaluate microstructures, tensile and fatigue properties of weld-bonded (WB) magnesium-to-magnesium (Mg/Mg) similar joints and magnesium-to-steel (Mg/steel) dissimilar joints, in comparison with resistance spot welded (RSW) Mg/steel dissimilar joints. In the WB Mg/Mg joints, equiaxed dendritic and divorced eutectic structures formed in the fusion zone (FZ). In the dissimilar joints of RSW and WB Mg/steel, FZ appeared only at Mg side with equiaxed and columnar dendrites. At steel side no microstructure changed in the WB Mg/steel joints, while the microstructure in the RSW Mg/steel joints consisted of lath martensite, bainite, pearlite and retained austenite leading to an increased microhardness. The relatively low cooling rate suppressed the formation of shrinkage porosity but promoted the formation of MgZn 2 and Mg 7 Zn 3 in the WB Mg/steel joints. The added adhesive layer diminished stress concentration around the weld nugget. Both WB Mg/Mg and Mg/steel joints were significantly stronger than RSW Mg/steel joints in terms of the maximum tensile shear load and energy absorption, which also increased with increasing strain rate. Fatigue strength was three-fold higher for WB Mg/Mg and Mg/steel joints than for RSW Mg/steel joints. Fatigue failure in the RSW Mg/steel joints occurred from the heat-affected zone near the notch root at lower load levels, and in the mode of interfacial fracture at higher load levels, while it occurred in the Mg base metal at a maximum cyclic load up to ∼10 kN in

  10. Inheritance of black sigatoka disease resistance in plantain-banana (Musa spp.) hybrids.

    Science.gov (United States)

    Ortiz, R; Vuylsteke, D

    1994-10-01

    Black sigatoka (Mycosphaerella fijiensis Morelet), an airborne fungal leaf-spot disease, is a major constraint to plantain and banana (Musa spp.) production world-wide. Gaining further knowledge of the genetics of host-plant resistance will enhance the development of resistant cultivars, which is considered to be the most appropriate means to achieve stable production. Genetic analysis was conducted on 101 euploid (2x, 3x and 4x) progenies, obtained from crossing two susceptible triploid plantain cultivars with the resistant wild diploid banana 'Calcutta 4'. Segregating progenies, and a susceptible reference plantain cultivar, were evaluated over 2 consecutive years. Three distinct levels of host response to black sigatoka were defined as follows: susceptible ( 10). Segregation ratios for resistance at the 2x level fitted a genetic model having one major recessive resistance allele (bs 1) and two independent alleles with additive effects (bsr 2 and bsr 3). A similar model explains the results at the 4x level assuming that the favourable resistance alleles have a dosage effect when four copies of them are present in their respective loci (bs i (4) ). The proposed model was further validated by segregation data of S 1 progenies. Mechanisms of black sigatoka resistance are discussed in relation to the genetic model.

  11. Genetics and genomics of disease resistance in salmonid species

    Directory of Open Access Journals (Sweden)

    José Manuel Yáñez

    2014-11-01

    Full Text Available Infectious and parasitic diseases generate large economic losses in salmon farming. A feasible and sustainable alternative to prevent disease outbreaks may be represented by genetic improvement for disease resistance. To include disease resistance into the breeding goal, prior knowledge of the levels of genetic variation for these traits is required. Furthermore, the information from the genetic architecture and molecular factors involved in resistance against diseases may be used to accelerate the genetic progress for these traits. In this regard, marker assisted selection and genomic selection are approaches which incorporate molecular information to increase the accuracy when predicting the genetic merit of selection candidates. In this article we review and discuss key aspects related to disease resistance in salmonid species, from both a genetic and genomic perspective, with emphasis in the applicability of disease resistance traits into breeding programs in salmonids.

  12. QTL list: RXopJ4 resistance locus [PGDBj Registered plant list, Marker list, QTL list, Plant DB link and Genome analysis methods[Archive

    Lifescience Database Archive (English)

    Full Text Available QT62244 Solanum lycopersicum Solanaceae RXopJ4 resistance locus resistance to bacterial spot disease resist...ance to bacterial spot disease (Xanthomonas perforans (Xp)) 3 J350 ... Chr06 ... 10.1007/s00122-012-2004-6 23117718

  13. Indução de resistência em feijoeiro a mancha angular por extratos de micélio de Pycnoporus sanguineus Resistance induction in bean plants against angular leaf spot by extracts from Pycnoporus sanguineus mycelium

    Directory of Open Access Journals (Sweden)

    Clair Aparecida Viecelli

    2010-03-01

    Full Text Available O feijoeiro (Phaseolus vulgaris L. está entre as principais culturas da agricultura nacional e pode ser afetada por várias doenças, como a mancha angular causada por Pseudocercospora griseola. Com o objetivo de desenvolver métodos alternativos ao químico para o controle desta doença, verificou-se o potencial de extratos de micélio de Pycnoporus sanguineus para atividade antimicrobiana in vitro contra P. griseola e para indução de resistência e ativação de enzimas de defesa em feijoeiro, como peroxidase, polifenoloxidase e β-1,3-glucanase, além de sua influência nos teores de proteínas e clorofilas. Os experimentos in vitro e em casa de vegetação foram constituídos pelos extratos de micélio de P. sanguineus e dos controles água, acibenzolar-S-metil (ASM: 75 mg i.a./L e fungicida azoxystrobin (40 mg i.a./L. In vitro o extrato de micélio apresentou efeito sobre o crescimento micelial, a esporulação e a germinação de esporos de P. griseola. In vivo a severidade foi reduzida em 93% e 50% em casa de vegetação e a campo respectivamente, em relação ao controle água. A atividade das enzimas peroxidase e polifenoloxidase e os teores de proteínas e clorofilas foram maiores nas plantas tratadas com o extrato. Estes resultados indicam a eficiência de P. sanguineus para o controle alternativo da mancha angular do feijoeiro.Angular leaf spot, caused by the fungus Pseudocercospora griseola, is a major disease of common bean (Phaseolus vulgaris L. in Brazil. The objective of this research was to develop an alternative method for controlling this disease based on an aqueous extract of Pycnoporus sanguineus mycelium. It was evaluated the antimicrobial activity of the aqueous extract against P. griseola as well as its activity of resistance induction against angular leaf spot. The role of the plant defense enzymes peroxidase, polyphenol oxidase and β-1,3-glucanase, and the proteins and chlorophyll content was investigated. The

  14. Molecular characterization of early blight disease resistant and ...

    African Journals Online (AJOL)

    In this study, 20 random amplified polymorphic DNA (RAPD) and 6 simple sequence repeats (SSR) primers were applied to assess the genetic diversity and to identify molecular markers associated with resistance to early blight disease in resistant (Cara, Spunta and Valor), moderately resistant (Hermes and Atlantic) and ...

  15. Leading Antimicrobial Drug-Resistant Diseases

    Science.gov (United States)

    ... supporting research on several organisms that have developed resistance to antimicrobial drug treatment. The institute manages a research portfolio of grants aimed at the problem of antimicrobial resistance and hospital-acquired infections. Here is a list ...

  16. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata.

    Science.gov (United States)

    Hou, Yujie; Ma, Xiao; Wan, Wenting; Long, Ni; Zhang, Jing; Tan, Yuntao; Duan, Shengchang; Zeng, Yan; Dong, Yang

    2016-01-01

    The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS) genes and 13 polyketide synthase (PKS) genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs), such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction.

  17. Comparative Genomics of Pathogens Causing Brown Spot Disease of Tobacco: Alternaria longipes and Alternaria alternata.

    Directory of Open Access Journals (Sweden)

    Yujie Hou

    Full Text Available The genus Alternaria is a group of infectious/contagious pathogenic fungi that not only invade a wide range of crops but also induce severe allergic reactions in a part of the human population. In this study, two strains Alternaria longipes cx1 and Alternaria alternata cx2 were isolated from different brown spot lesions on infected tobacco leaves. Their complete genomes were sequenced, de novo assembled, and comparatively analyzed. Phylogenetic analysis revealed that A. longipes cx1 and A. alternata cx2 diverged 3.3 million years ago, indicating a recent event of speciation. Seventeen non-ribosomal peptide synthetase (NRPS genes and 13 polyketide synthase (PKS genes in A. longipes cx1 and 13 NRPS genes and 12 PKS genes in A. alternata cx2 were identified in these two strains. Some of these genes were predicted to participate in the synthesis of non-host specific toxins (non-HSTs, such as tenuazonic acid (TeA, alternariol (AOH and alternariol monomethyl ether (AME. By comparative genome analysis, we uncovered that A. longipes cx1 had more genes putatively involved in pathogen-plant interaction, more carbohydrate-degrading enzymes and more secreted proteins than A. alternata cx2. In summary, our results demonstrate the genomic distinction between A. longipes cx1 and A. altenata cx2. They will not only improve the understanding of the phylogenetic relationship among genus Alternaria, but more importantly provide valuable genomic resources for the investigation of plant-pathogen interaction.

  18. Artificial neural networks for prediction of quality in resistance spot welding; Redes neuronales artificiales para la prediccion de la calidad en soldadura por resistencia por puntos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, O.; Lopez, M.; Martin, F.

    2006-07-01

    An artificial neural network is proposed as a tool for predicting from three parameters (weld time, current intensity and electrode sort) if the quality of a resistance spot weld reaches a certain level or not. The quality is determined by cross tension testing. The fact of reaching this quality level or not is the desired output that goes with each input of the artificial neural network during its supervised learning. The available data set is made up of input/desired output pairs and is split randomly into a training subset (to update synaptic weight values) and a validation subset (to avoid overfitting phenomenon by means of cross validation). (Author) 44 refs.

  19. Transgenic strategies for improving rice disease resistance

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-04

    May 4, 2009 ... proteins of both plant origin and non-plant origin that positively regulates the signaling of systemic acquired resistance, which provides broad-spectrum resistance against viruses, bacteria, and fungi, will be useful sources for genetic engineering of broad-spectrum resistance in rice against multiple types of ...

  20. Defense mechanisms involved in disease resistance of grafted vegetables

    Science.gov (United States)

    Vegetable grafting with resistant rootstocks is an effective strategy to control a variety of soil-borne diseases and root-knot nematodes in the Cucurbitaceae and Solanaceae. In addition, improved resistance to some foliar diseases and viruses has also been reported in grafted plants. Hence, graft...

  1. Biomarkers and mechanisms of natural disease resistance in dairy cows

    NARCIS (Netherlands)

    Altena, van S.E.C.

    2016-01-01

    The aim of this thesis was to define and test biomarkers for disease resistance in dairy cows and to determine the underlying mechanism in natural disease resistance. The health status of the cows is an important issue in dairy farming. Due to the mandatory reduction in the use of antibiotics,

  2. Modeling deployment of Pierce’s disease resistant grapevines

    Science.gov (United States)

    Deployment of Pierce’s disease resistant grapevines is a key solution to mitigating economic losses caused by Xylella fastidiosa. While Pierce’s disease resistant grapevines under development display mild symptoms and have lower bacterial populations than susceptible varieties, all appear to remain ...

  3. Efeito de indutores de resistência em cafeeiro contra a mancha de Phoma Effect of resistance inducers on coffee against Phoma leaf spot

    Directory of Open Access Journals (Sweden)

    Gutemberg Barone Araújo Nojosa

    2009-02-01

    Full Text Available O efeito dos produtos acibenzolar S-metil ester (ASM, Bion®, fosfito de potássio (Hortifós PK® e de um fertilizante foliar (Nutex Axcell® foi avaliado sobre a germinação de esporos e no crescimento micelial de Phoma costarricensis. O efeito desses produtos também foi avaliado na severidade da mancha de Phoma em mudas de cafeeiro. O percentual de germinação dos conídios de P. costarricensis não foi afetado pelas doses de fosfito e ASM, mas reduções no crescimento micelial do fungo foram observadas. A AACPD e a severidade da doença foram menores em todos os tratamentos quando comparados com a testemunha inoculada. Nas plantas tratadas com o fungicida tebuconazole, utilizado como padrão, foi observada redução de 50,9% na severidade da doença. Os menores valores de severidade e de AACPD foram observados nas plantas tratadas com ASM 0,1 g/L; Fosfito 2,5 mL/L; Fosfito 5,0 mL/L e o fertilizante Nutex Axcell® 4,0 mL/L.The effect of acibenzolar S-metil ester (ASM, Bion®, potassium phosfite (Hortifós PK® and of a foliar fertilizer (Nutex Axcell® was assessed on the spore germination and mycelial growth of Phoma costarricensis. The effect of these products on severity of Phoma leaf spot was also assessed on coffee seedlings. The percentage of conidial germination of P. costarricensis was not affected by doses of phosfite and ASM, but reductions on the mycelial growth of the fungus were detected. The area under the disease progress curve (AUDPC and the disease severity were lower in all treatments compared to the inoculated control. There was a reduction of 50.9% on disease severity in plants treated with the standard fungicide tebuconazole. Low values for severity and AUDPC were observed when plants were treated with ASM 0.1 g/L; phosfite 2.5 mL/L; phosfite 5.0 mL/L and the fertilizer Nutex Axcell® at 4.0 mL/L, which differed from other treatments.

  4. Evaluation of certain fungicides for the control of tar spot disease of ...

    African Journals Online (AJOL)

    The present study evaluated the favourable conditions as well as the effectiveness of fungicides in controlling the disease. Ben/ate, Dithane M-45 and Polyram-Combi at the rates of 1.0, 1. 5 and l. 5 gil of water respectively either totally or almost completely controlled the disease when aerial parts of the vines were sprayed ...

  5. Severity of angular leaf spot and rust diseases on common beans in ...

    African Journals Online (AJOL)

    ACSS

    plants has been shown to reduce pest and disease damage (Trenbath, 1993). Boudreau and Mundt (1992) and Fininsa. (1996) reported reduced rust severities for beans intercropped with maize. Fungal disease control in intercrops is believed to result from effects such as host dilution. (reduced numbers of susceptible ...

  6. Effects of tillage operations and plant density on leaf spot disease ...

    African Journals Online (AJOL)

    Two seasons experiments conducted in 2002 and 2003 revealed that Tillage operations significantly influenced leafspot disease severity; Percentage lodging 3.14; 2.08 and Grain yield 3.02; 3.84 in 2002 and 2003 respectively. Plant density also had significant difference on leafspot disease severity; Percentage lodging ...

  7. Gene pyramiding enhances durable blast disease resistance in rice

    OpenAIRE

    Fukuoka, Shuichi; Saka, Norikuni; Mizukami, Yuko; Koga, Hironori; Yamanouchi, Utako; Yoshioka, Yosuke; Hayashi, Nagao; Ebana, Kaworu; Mizobuchi, Ritsuko; Yano, Masahiro

    2015-01-01

    Effective control of blast, a devastating fungal disease of rice, would increase and stabilize worldwide food production. Resistance mediated by quantitative trait loci (QTLs), which usually have smaller individual effects than R-genes but confer broad-spectrum or non-race-specific resistance, is a promising alternative to less durable race-specific resistance for crop improvement, yet evidence that validates the impact of QTL combinations (pyramids) on the durability of plant disease resista...

  8. Atypical Celiac Disease Resistant to Thyroxine Replacement

    OpenAIRE

    Oguzhan Aksu

    2014-01-01

    Celiac disease, an immune-mediated enteropathy that develops in susceptible individuals upon ingestion of gluten containing diet, is closely associated with other autoimmune endocrine disorders, particularly autoimmune thyroid disease. Celiac disease and hypothyroidism ( especially due to Hashimoto disease) cooccurence is frequently mentioned in the literature. The relationship between celiac disease and autoimmune thyroid disease was first described three decades ago. Patients usually have...

  9. Validation of a Multiplex Tandem Mass Spectrometry Method for the Detection of Selected Lysosomal Storage Diseases in Dried Blood Spots

    Directory of Open Access Journals (Sweden)

    Graziela Schmitt Ribas PhD

    2017-02-01

    Full Text Available Background: Interest in screening methods for lysosomal storage diseases (LSDs has increased in recent years, since early diagnosis and treatment are essential to prevent or attenuate the onset of symptoms and the complications of these diseases. In the current work, we evaluated the performance of tandem mass spectrometry (MS/MS for the detection of some LSDs, aiming the future use of this methodology for the screening of these disorders. Methods: Standard curves and quality control dried blood spots were assayed to evaluate the precision, linearity, and accuracy. A total of 150 controls were grouped according to age and subjected to measurement of lysosomal enzymes deficient in Niemann-Pick A/B, Krabbe, Gaucher, Fabry, Pompe, and Mucopolysaccharidosis type I diseases. Samples from 59 affected patients with a diagnosis of LSDs previously confirmed by fluorimetric methods were analyzed. Results: Data from standard calibration demonstrated good linearity and accuracy and the intra- and interassay precisions varied from 1.17% to 11.60% and 5.39% to 31.24%, respectively. Except for galactocerebrosidase and α- l -iduronidase, enzyme activities were significantly higher in newborns compared to children and adult controls. Affected patients presented enzymatic activities significantly lower compared to all control participants. Conclusion: Our results show that MS/MS is a promising methodology, suitable for the screening of LSDs, but accurate diagnoses will depend on its correlation with other biochemical and/or molecular analyses.

  10. Characteristics of contact resistance for Ag, Cu and Al spot contact under DC current flow of 300A; Gin, do oyobi arumi tensesshokushi no chokuryu 300A tsudenji ni okeru sesshoku teiko tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Aichi, H. [Daido Institute of Technology, Nagoya (Japan); Matsumura, T. [Nagoya University, Nagoya (Japan); Miyachi, I. [Aichi Inst. of Technology, Aichi (Japan)

    1997-07-01

    The temperature rise of the contact spot by Joule`s heat under high current flow may result in the softening or welding of the contact materials. Contact resistances of Ag, Cu and Al spot contacts have been observed under the current flow of up to 300A DC. The contact resistances of Ag and Cu with clean surfaces were revealed to be kept constant independent of the magnitude of the applied current flow. On the other hand, contact resistances of Al and Cu with oxidized surfaces were greatly reduced with the increasing current flow. 7 refs., 5 figs., 2 tabs.

  11. Spot Anthracnose Disease Caused by Colletotrichum gloeosporioides on Tulip Tree in Korea.

    Science.gov (United States)

    Choi, Okryun; Choi, Okhee; Kwak, Youn-Sig; Kim, Jinwoo; Kwon, Jin-Hyeuk

    2012-03-01

    The tulip tree (Liriodendron chinense) has been widely cultivated in Korea as a street or garden tree for its large flowers, which have a superficial resemblance to tulips. Occurrence of anthracnose disease on the leaves of tulip trees growing on the campus of Gyeongsang National University, Jinju, Korea, has been observed. Based on mycological characteristics, pathogenicity, and internal transcribed spacer sequence, the causal fungus was identified as Colletotrichum gloeosporioides. This is the first report on anthracnose disease caused by C. gloeosporioides on tulip trees in Korea.

  12. Advances and Challenges in Genomic Selection for Disease Resistance.

    Science.gov (United States)

    Poland, Jesse; Rutkoski, Jessica

    2016-08-04

    Breeding for disease resistance is a central focus of plant breeding programs, as any successful variety must have the complete package of high yield, disease resistance, agronomic performance, and end-use quality. With the need to accelerate the development of improved varieties, genomics-assisted breeding is becoming an important tool in breeding programs. With marker-assisted selection, there has been success in breeding for disease resistance; however, much of this work and research has focused on identifying, mapping, and selecting for major resistance genes that tend to be highly effective but vulnerable to breakdown with rapid changes in pathogen races. In contrast, breeding for minor-gene quantitative resistance tends to produce more durable varieties but is a more challenging breeding objective. As the genetic architecture of resistance shifts from single major R genes to a diffused architecture of many minor genes, the best approach for molecular breeding will shift from marker-assisted selection to genomic selection. Genomics-assisted breeding for quantitative resistance will therefore necessitate whole-genome prediction models and selection methodology as implemented for classical complex traits such as yield. Here, we examine multiple case studies testing whole-genome prediction models and genomic selection for disease resistance. In general, whole-genome models for disease resistance can produce prediction accuracy suitable for application in breeding. These models also largely outperform multiple linear regression as would be applied in marker-assisted selection. With the implementation of genomic selection for yield and other agronomic traits, whole-genome marker profiles will be available for the entire set of breeding lines, enabling genomic selection for disease at no additional direct cost. In this context, the scope of implementing genomics selection for disease resistance, and specifically for quantitative resistance and quarantined pathogens

  13. 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

  14. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  15. Tractor-mounted, GPS-based spot fumigation system manages Prunus replant disease

    Science.gov (United States)

    Our research goal was to use recent advances in global positioning system (GPS) and computer technology to apply just the right amount of fumigant where it is most needed (i.e., in a small target treatment zone in and around each tree replanting site) to control Prunus replant disease (PRD). We deve...

  16. Utilização do inseticida Methomyl na seleção de genótipos de aveia resistentes à helmintosporiose User of Methomyl insecticide for the selection of spot blotch resistant oat genotypes

    Directory of Open Access Journals (Sweden)

    Cristine Luise Handel

    1999-06-01

    Full Text Available A helmintosporiose é uma moléstia que afeta a cultura da aveia, reduzindo seu rendimento e qualidade de grão. A seleção de genótipos resistentes com utilização de filtrados tóxicos do fungo Helminthosporium sativum é eficaz, pois delimita a variabilidade do patógeno e reduz a interferência do ambiente na expressão do genótipo. Contudo, a obtenção dos filtrados tóxicos deste fungo é um processo lento e delicado. Dessa forma, a possibilidade do uso de substâncias sintéticas que simulem seu efeito, inibindo o transporte de elétrons da cadeia respiratória, é de grande interesse. O inseticida Methomyl é eficaz para simular o efeito da toxina do fungo que causa a helmintosporiose em milho, tendo o presente trabalho visado testar sua eficiência na cultura da aveia. Para isso, foi avaliado o crescimento de calos e raízes de aveia expostas ao Methomyl, quando crescimentos maiores indicaram maior resistência ao produto, e possível resistência à moléstia. Os resultados indicam que o Methomyl afeta o crescimento de raízes e calos de aveia e pode ser utilizado para separar os grupos de genótipos com e sem resistência à helmintosporiose. Assim, UFRGS 14, com maior sensibilidade aos filtrados tóxicos de H. sativum em outros estudos, também apresentou crescimento mais afetado pelo Methomyl em todos os experimentos aqui conduzidos.Spot Blotch is a plant disease which causes yield losses in oat and other cereals. Selection for resistant genotypes using Helminthosporium sativum toxic filtrates is an efficient technique, which reduces the pathogen variability and the influence of the environment over the genotype expression. The filtrates extraction is time consuming and a difficult process, and the possibility of using a synthetic product to simulate its action of inhibiting the cell electron transport chain would be useful. The Methomyl insecticide is an efficient product to simulate the effects of the fungus that causes spot

  17. β-Amino-n-butyric Acid Regulates Seedling Growth and Disease Resistance of Kimchi Cabbage.

    Science.gov (United States)

    Kim, Yeong Chae; Kim, Yeon Hwa; Lee, Young Hee; Lee, Sang Woo; Chae, Yun-Soek; Kang, Hyun-Kyung; Yun, Byung-Wook; Hong, Jeum Kyu

    2013-09-01

    Non-protein amino acid, β-amino-n-butyric acid (BABA), has been involved in diverse physiological processes including seedling growth, stress tolerance and disease resistance of many plant species. In the current study, treatment of kimchi cabbage seedlings with BABA significantly reduced primary root elongation and cotyledon development in a dose-dependent manner, which adverse effects were similar to the plant response to exogenous abscisic acid (ABA) application. BABA was synergistically contributing ABA-induced growth arrest during the early seedling development. Kimchi cabbage leaves were highly damaged and seedling growth was delayed by foliar spraying with high concentrations of BABA (10 to 20 mM). BABA played roles differentially in in vitro fungal conidial germination, mycelial growth and conidation of necrotroph Alternaria brassicicola causing black spot disease and hemibiotroph Colletotrichum higginsianum causing anthracnose. Pretreatment with BABA conferred induced resistance of the kimchi cabbage against challenges by the two different classes of fungal pathogens in a dose-dependent manner. These results suggest that BABA is involved in plant development, fungal development as well as induced fungal disease resistance of kimchi cabbage plant.

  18. β-Amino-n-butyric Acid Regulates Seedling Growth and Disease Resistance of Kimchi Cabbage

    Directory of Open Access Journals (Sweden)

    Yeong Chae Kim

    2013-09-01

    Full Text Available Non-protein amino acid, β-amino-n-butyric acid (BABA, has been involved in diverse physiological processes including seedling growth, stress tolerance and disease resistance of many plant species. In the current study, treatment of kimchi cabbage seedlings with BABA significantly reduced primary root elongation and cotyledon development in a dose-dependent manner, which adverse effects were similar to the plant response to exogenous abscisic acid (ABA application. BABA was synergistically contributing ABA-induced growth arrest during the early seedling development. Kimchi cabbage leaves were highly damaged and seedling growth was delayed by foliar spraying with high concentrations of BABA (10 to 20 mM. BABA played roles differentially in in vitro fungal conidial germination, mycelial growth and conidation of necrotroph Alternaria brassicicola causing black spot disease and hemibiotroph Colletotrichum higginsianum causing anthracnose. Pretreatment with BABA conferred induced resistance of the kimchi cabbage against challenges by the two different classes of fungal pathogens in a dose-dependent manner. These results suggest that BABA is involved in plant development, fungal development as well as induced fungal disease resistance of kimchi cabbage plant.

  19. (SSR) markers for screening blue disease resistance in cotton ...

    African Journals Online (AJOL)

    Blue disease of cotton is an economically important disease of the crop first described from the Central African Republic and spread to other countries. Brazil and other South American countries record crop losses of up to 80% from infection but no cases of the disease have been reported in Tanzania. Resistance to the ...

  20. A genetic map of melon (Cucumis melo L.) with RFLP, RAPD, isozyme, disease resistance and morphological markers.

    Science.gov (United States)

    Baudracco-Arnas, S; Pitrat, M

    1996-07-01

    One hundred and ten markers were analysed for linkage in 218 F2 plants derived from two divergent cultivars ('Védrantais' and 'Songwhan Charmi') of Cucumis melo (L.). Thirty-four RFLPs, 64 RAPDs, one isozyme, four disease resistance markers and one morphological marker were used to construct a genetic map spanning 14 linkage groups covering 1390 cM of the melon genome. RAPD and RFLP markers detected similar polymorphism levels. RFLPs were largely due to base substitutions rather than insertion/deletions. Twelve percent of markers showed distorted segregation. Phenotypic markers consisted of two resistance genes against Fusarium wilt (Fom-1 and Fom-2), one gene (nsv) controlling the resistance to melon necrotic spot virus, one gene (Vat) conferring resistance to Aphis gossypii, and a recessive gene for carpel numbers (3 vs 5 carpels: p).

  1. Insights into Tan Spot and Stem Rust Resistance and Susceptibility by Studying the Pre-Green Revolution Global Collection of Wheat

    OpenAIRE

    Abdullah, Sidrat; Sehgal, Sunish Kumar; Jin, Yue; Turnipseed, Brent; Ali, Shaukat

    2017-01-01

    Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii) incorporation of ...

  2. Development and optimization of an internally controlled dried blood spot assay for surveillance of human immunodeficiency virus type-1 drug resistance.

    Science.gov (United States)

    Buckton, Andrew J; Bissett, Sara L; Myers, Richard E; Beddows, Simon; Edwards, Simon; Cane, Patricia A; Pillay, Deenan

    2008-12-01

    We present the evaluation of a methodology for the genotypic assessment of human immunodeficiency virus type-1 (HIV-1) drug resistance, optimized for use with dried blood spots (DBS). The ability to generate HIV-1 protease (PR) and reverse transcriptase (RT) contiguous amplicons and nucleotide sequences from DBS was evaluated. Different collection matrices and extraction methodologies were compared. The relative subtype sensitivity of the amplification strategy was assessed using a comprehensive panel of plasmids representing A-H subtypes. A panel of DBS and plasma specimens was subjected to HIV genotyping. Sequences generated from each sample type were compared. Extensive replicate testing revealed most sensitivity with the use of 903 filter paper and silica/guanidine extraction, which had an estimated 95% inclusivity endpoint of 1542 proviral copies/mL, as compared with 21 573 proviral copies/mL for the FTA system. All HIV-1 group M subtypes analysed-with the exception of subtypes A2, AE, AG, F and H-had a relative sensitivity of /=1000 copies/mL were successfully amplified and sequenced. Twelve specimens had pol genotyping from both plasma and DBS samples. Sequence analysis and drug resistance interpretation revealed that 10 (83%) provided concordant drug resistance interpretation. Our results demonstrate that the technique is appropriate for surveillance of drug resistance in untreated individuals and those with virological failure on therapy.

  3. Effect of foliar fertilizer and fungicidal protection against leaf spot diseases on winter wheat

    Directory of Open Access Journals (Sweden)

    Agnieszka Mączyńska

    2012-12-01

    Full Text Available Field experiments were carried out in the seasons 2000/2001 and 2001/2002 in Plant Protection Institute, Sooenicowice Branch to assess the influence of foliar fertilizers such as Ekolist PK 1, Ekolist Mg, Mikrosol Z and Urea on healthiness of winter wheat. Foliar fertilizers were mixed with fungicides. The fungicides were applied at full or half recommended doses. The effect of the disease on wheat leaves was evaluated three times in each vegetation season. Remaining green leaf area (GLA of leaves was also determined. GLA of the leaves F-1 was not significantly different for each combination with different fertilization and different levels of chemical treatment. The application of foliar fertilizer only had no effect on green leaf area (GLA. The results indicate that foliar fertilization of all experimental plots improved leaf condition and therefore halted the development of wheat leaf diseases. The increases of 1000 grain mass and yield was high for each plot where a fertilizer and a full or half dose of a fungicide was applied. Foliar fertilizing with no chemical control had no proven effect on studied parameters.

  4. Improvement of cross-tension strength using concave electrode in resistance spot welding of high-strength steel sheets

    Science.gov (United States)

    Watanabe, Goro; Amago, Tatsuyuki; Ishii, Yasuhiro; Takao, Hisaaki; Yasui, Toshiaki; Fukumoto, Masahiro

    2016-02-01

    In the spot welding of ultrahigh-strength steel sheets, the generation of expulsion could be suppressed and large-diameter nuggets could be formed by using a concave electrode. The expulsion was suppressed because the clearance for expansion was formed when using the concave electrode. Thus, nuggets with a diameter of ≥4√t (lowest for securing joint strength, t = 1 mm) were obtained without expulsion in a greater welding current range than the range when using a conventional electrode. Furthermore, nuggets with a diameter of approximately 6.5 mm were formed with a large current of 8 kA, which could not be set when using the conventional electrode. In addition, a transition from partial interfacial fracture to pullout fracture occurred as the nugget diameter increased, and the cross-tension strength (CTS) tended to increase. A value of about 8 kN was obtained for a nugget with a diameter of 6.5 mm, which is approximately 1.5 times larger than the value (approximately 5.5 kN) obtained with the conventional electrode. The electrode life test indicated little deterioration in the CTS after 1400 welds. Thus, we propose using a concave electrode to improve the joint strength in the spot welding of high-strength steel sheets.

  5. Micro-Propagation of Disease Resistant Cassava Variety in Rwanda ...

    African Journals Online (AJOL)

    Micro-Propagation of Disease Resistant Cassava Variety in Rwanda. Isidore Mushiyimana, Emmanuel Hakizimana, Gervais Gashaka, Peter Yao Kanze Sallah, Safia Kalisa, Felix Gatunzi, Theodore Asiimwe, Jane Kahia, Daphrose Gahakwa ...

  6. Transgenic approaches for development of disease resistance in banana

    International Nuclear Information System (INIS)

    Shekhawat, Upendra K.S.; Ghag, Siddhesh B.; Ganapathi, Thumballi R.

    2014-01-01

    Banana (Musa spp.) is an important food and cash crop worldwide. Diseases and pests pose the most serious constraint to banana cultivation. Among the diseases, Fusarium wilt and Banana Bunchy Top Virus (BBTV) are the most important economically. We have explored different transgenic approaches for development of efficient resistance in banana against these two diseases. For countering Fusarium wilt, we have over expressed Petunia floral defensins using a strong constitutive promoter in transgenic banana plants. We have also tested a host induced gene silencing strategy targeting two vital fungal genes to obtain Fusarium resistant banana plants. For development of BBTV resistant banana plants also, we have used a host-induced gene silencing approach utilizing the full and partial coding sequence of the viral replication initiation protein. Successful bioassays performed in controlled greenhouse conditions have shown the efficacy of using these strategies to develop disease resistant banana plants. (author)

  7. Molecular detection of disease resistance genes to powdery mildew ...

    African Journals Online (AJOL)

    A study was conducted to detect the presence of disease resistance genes to infection of wheat powdery mildew (Blumeria graminis f. sp. tritici) in selected wheat cultivars from China using molecular markers. Genomic DNA of sixty cultivars was extracted and tested for the presence of selected prominent resistance genes to ...

  8. The molecular basis of disease resistance in higher plants

    African Journals Online (AJOL)

    xxxxxx

    Interactions between disease resistance (R) genes in plants and their corresponding pathogen avirulence (Avr) genes are the key determinants of whether a plant is susceptible or resistance to a pathogen attack. Evidence has emerged that these gene-for-gene interactions in the perception of pathogenic invasions and ...

  9. Selection on resilience improves disease resistance and tolerance to infections

    NARCIS (Netherlands)

    Mulder, H.A.; Rashidi, H.

    2017-01-01

    Response to infection in animals has 2 main mechanisms: resistance (ability to control pathogen burden) and tolerance (ability to maintain performance given the pathogen burden). Selection on disease resistance and tolerance to infections seems a promising avenue to increase productivity of animals

  10. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  11. Effect of Welding Current on the Structure and Properties of Resistance Spot Welded Dissimilar (Austenitic Stainless Steel and Low Carbon Steel) Metal Joints

    Science.gov (United States)

    Shawon, M. R. A.; Gulshan, F.; Kurny, A. S. W.

    2015-04-01

    1.5 mm thick sheet metal coupons of austenitic stainless steel and plain low carbon steel were welded by resistance spot welding technique. The effects of welding current in the range 3-9 kA on the structure and mechanical properties of welded joint were investigated. The structure was studied by macroscopic, microscopic and scanning electron microscopy techniques. Mechanical properties were determined by tensile testing and microhardness measurements. Asymmetrical shape weld nugget was found to have formed in the welded joint which increased in size with an increase in welding current. The fusion zone showed cast structure with coarse columnar grain and dendritic with excess delta ferrite in austenitic matrix. Microhardness of the weld nugget was maximum because of martensite formation. An increase in welding current also increased tensile strength of the weld coupon. An attempt has also been made to relate the mode of fracture with the welding current.

  12. A single point mutation in Tomato spotted wilt virus NSs protein is sufficient to overcome Tsw-gene-mediated resistance in pepper.

    Science.gov (United States)

    Almási, Asztéria; Nemes, Katalin; Csömör, Zsófia; Tóbiás, István; Palkovics, László; Salánki, Katalin

    2017-06-01

    The nonstructural protein (NSs) of Tomato spotted wilt virus (TSWV) was previously identified as an avirulence determinant for Tsw-based resistance on pepper. The NSs of wild-type (WT) and resistance-breaking (RB) TSWV strains isolated in Hungary had only two amino acid substitutions (104, 461). We have analysed the ability of the NSs and their point mutant variants to trigger Tsw-mediated hypersensitive responses and RNA silencing suppressor (RSS) activity in patch assays. We identified a single amino acid change at position 104 (T-A) that was responsible for the necrosis induction or loss, while a significant difference was not detected in the RSS activity of the two parental strains. We have successfully complemented the infection of the WT strain on resistant pepper cultivar with the infectious S RNA transcript of the RB strain and the WT-T104A point mutant. Our work provides direct evidence that a single amino acid change can induce an RB phenotype.

  13. accessions resistants to lethal yellowing disease

    African Journals Online (AJOL)

    Administrator

    2007-02-19

    Feb 19, 2007 ... One of the problems faced in coconut cultivation is the lethal yellowing disease. Experimental trials, conducted in endemic region, showed that the Vanuatu Tall and Sri-Lanka Green Dwarf genotypes were tolerant while the West African Tall appeared susceptible to the lethal yellowing disease. Genetic.

  14. Breeding for disease resistance in cacao

    Science.gov (United States)

    Cacao production must increase in order to meet the projected rise in the demand for chocolate. Approximately one-third of global production is lost annually to diseases and insects. Four diseases account for the greatest losses worldwide: black pod, caused by four Phytophthora spp; witches’ broom...

  15. Use of dried-blood-spot samples and in-house assays to identify antiretroviral drug resistance in HIV-infected children in resource-constrained settings.

    Science.gov (United States)

    Ziemniak, Carrie; Mengistu, Yohannes; Ruff, Andrea; Chen, Ya-Hui; Khaki, Leila; Bedri, Abubaker; Simen, Birgitte B; Palumbo, Paul; Eshleman, Susan H; Persaud, Deborah

    2011-12-01

    Monitoring HIV drug resistance is an important component of the World Health Organization's global HIV program. HIV drug resistance testing is optimal with commercially available clinically validated test kits using plasma; however, that type of testing may not be feasible or affordable in resource-constrained settings. HIV genotyping from dried blood spots (DBS) with noncommercial (in-house) assays may facilitate the capture of HIV drug resistance outcomes in resource-constrained settings but has had varying rates of success. With in-house assays for HIV reverse transcriptase, we evaluated the yield of genotyping DBS samples collected from HIV-infected children who were enrolled in two clinical trials conducted in sub-Saharan Africa (median HIV viral load, 5.88 log(10) HIV RNA copies/ml; range, 4.04 to 6.99). Overall, HIV genotypes were obtained for 94 (89.5%) of 105 samples tested (95% and 84% from clinical trials #1 and #2, respectively); however, successful analysis of 15 (16.1%) of the 94 samples required repeat testing using a different set of primers on previously synthesized cDNA. The yield of genotyping was lower on the DBS that were stored suboptimally from clinical trial #2 (56% versus 88% for optimally stored). Concordance with plasma genotypes derived using a clinically validated, commercial kit-based assay (ViroSeq HIV-1 genotyping system) was also assessed in a subset of children with paired testing. For 34 samples with paired DBS and plasma genotypes, there was 100% concordance for major drug resistance mutations. DBS genotyping using in-house assays provides an alternative for antiretroviral drug resistance testing in children in resource-constrained regions but may require region-specific optimization before widespread use.

  16. Use of Dried-Blood-Spot Samples and In-House Assays To Identify Antiretroviral Drug Resistance in HIV-Infected Children in Resource-Constrained Settings ▿

    Science.gov (United States)

    Ziemniak, Carrie; Mengistu, Yohannes; Ruff, Andrea; Chen, Ya-Hui; Khaki, Leila; Bedri, Abubaker; Simen, Birgitte B.; Palumbo, Paul; Eshleman, Susan H.; Persaud, Deborah

    2011-01-01

    Monitoring HIV drug resistance is an important component of the World Health Organization's global HIV program. HIV drug resistance testing is optimal with commercially available clinically validated test kits using plasma; however, that type of testing may not be feasible or affordable in resource-constrained settings. HIV genotyping from dried blood spots (DBS) with noncommercial (in-house) assays may facilitate the capture of HIV drug resistance outcomes in resource-constrained settings but has had varying rates of success. With in-house assays for HIV reverse transcriptase, we evaluated the yield of genotyping DBS samples collected from HIV-infected children who were enrolled in two clinical trials conducted in sub-Saharan Africa (median HIV viral load, 5.88 log10 HIV RNA copies/ml; range, 4.04 to 6.99). Overall, HIV genotypes were obtained for 94 (89.5%) of 105 samples tested (95% and 84% from clinical trials #1 and #2, respectively); however, successful analysis of 15 (16.1%) of the 94 samples required repeat testing using a different set of primers on previously synthesized cDNA. The yield of genotyping was lower on the DBS that were stored suboptimally from clinical trial #2 (56% versus 88% for optimally stored). Concordance with plasma genotypes derived using a clinically validated, commercial kit-based assay (ViroSeq HIV-1 genotyping system) was also assessed in a subset of children with paired testing. For 34 samples with paired DBS and plasma genotypes, there was 100% concordance for major drug resistance mutations. DBS genotyping using in-house assays provides an alternative for antiretroviral drug resistance testing in children in resource-constrained regions but may require region-specific optimization before widespread use. PMID:21956987

  17. Dark Spots

    Science.gov (United States)

    2006-01-01

    Dark spots (left) and 'fans' appear to scribble dusty hieroglyphics on top of the Martian south polar cap in two high-resolution Mars Global Surveyor, Mars Orbiter Camera images taken in southern spring. Each image is about 3-kilometers wide (2-miles).

  18. Characterization of Coconut cadang-cadang viroid variants from oil palm affected by orange spotting disease in Malaysia.

    Science.gov (United States)

    Wu, Y H; Cheong, L C; Meon, S; Lau, W H; Kong, L L; Joseph, H; Vadamalai, G

    2013-06-01

    A 246-nt variant of Coconut cadang-cadang viroid (CCCVd) has been identified and described from oil palms with orange spotting symptoms in Malaysia. Compared with the 246-nt form of CCCVd from coconut, the oil palm variant substituted C(31)→U in the pathogenicity domain and G(70)→C in the central conserved domain. This is the first sequence reported for a 246-nt variant of CCCVd in oil palms expressing orange spotting symptoms.

  19. Faba Bean Can Adapt to Chocolate Spot Disease by Pretreatment with Shikimic and Salicylic Acids through Osmotic Adjustment, Solutes Allocation and Leaf Turgidity

    Directory of Open Access Journals (Sweden)

    Heshmat S. Aldesuquy

    2014-03-01

    Full Text Available This study investigated the effect of shikimic and salicylic acids at the concentrations of 0.4 and 0.7 mM, respectively, or their combination as phenolic compounds and Ridomil MZ at the concentration of 250 g/100 L as a fungicide on osmotic pressure (OP, solutes allocation, organic acids, inorganic ions and relative water content were quantified in Vicia faba leaves infected by Botrytis fabae. Pathogen induced noticeable decrease in osmotic pressure, total soluble sugar (TSS and inorganic osmolytes (i.e. Na+, K+, Ca2+, Mg2+ and Cl- while caused obvious increase in proline, total soluble nitrogen (TSN and organic acids (i.e. Keto and citric acids in water extract of the leaf of faba bean plants. Furthermore, pathogen caused marked decrease in relative water content (RWC of infected leaves and as a consequence the saturation water deficit (SWD was increased. Exogenous application of shikimic acid, salicylic acid or their combination could counteract the adverse effects of B. fabae on osmotic adjustment by inducing additional increase in proline, total soluble sugars, total soluble nitrogen and organic acids which in turn increase the osmotic pressure as well as relative water content in leaves of infected plants. Recovery of osmotic adjustment as well as leaf turgidity of infected host by using these chemical inducers may encourage the using of them as protective control means. The results of the present study showed also that the application of chemical inducers such as shikimic and salicylic acids or their interaction increased the resistance of Vicia faba against the chocolate spot disease.

  20. traits and resistance to maize streak virus disease in kenya

    African Journals Online (AJOL)

    Maize Streak virus (MSV) disease is a major disease in many parts of Africa, and is the most important viral pathogen of maize in Kenya. A study was conducted in 2004 to evaluate the agronomic performance and maize streak virus (MSV) resistance of maize (Zea mays L.) three-way crosses developed in Kenya. Twenty ...

  1. SSR Markers Assessed for Peanut Smut Disease Resistance

    Science.gov (United States)

    Peanut smut disease, caused by Thecaphora frezii (Carranza & Lindquist), can result in yield losses higher than 50%. Several strategies have been developed for disease management but they are still insufficient. The smut genetic resistance found in wild species and Bolivian landraces is currently th...

  2. Multiple disease resistance in snap bean genotypes in Kenya ...

    African Journals Online (AJOL)

    Snap bean (Phaseolus vulgaris L.) is an important export vegetable crop, produced mainly by small to medium scale farmers under various disease constraints. Disease resistant varieties can reduce reliance on fungicides, and enhance the capacities of smallholder farmers to meet the stringent European export ...

  3. Molecular characterization of early blight disease resistant and ...

    African Journals Online (AJOL)

    Yomi

    2012-01-03

    Jan 3, 2012 ... Potato early blight disease caused by Alternaria solani is one of the major factors limiting potato production worldwide. Developing highly resistant cultivars is the most effective way to control the disease. In this study, 20 random amplified polymorphic DNA (RAPD) and 6 simple sequence repeats.

  4. Molecular detection of disease resistance genes to powdery mildew ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2017-01-04

    Jan 4, 2017 ... 2. State Key Laboratory of Biology for Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of. Agricultural Sciences, Beijing 100193, China. Received 10 October, 2016; Accepted 14 December, 2016. A study was conducted to detect the presence of disease resistance genes to ...

  5. In vitro propagation of the new disease resistant Coffea arabica ...

    African Journals Online (AJOL)

    SAM

    2014-06-11

    Jun 11, 2014 ... Batian is a true breeding commercial coffee variety that was released in Kenya in 2010. It is resistant to coffee berry disease and coffee leaf rust which are the main coffee diseases in Kenya. Coupled with early ripening, good beverage quality and high yields, demand for planting material has surpassed.

  6. Marker-assisted selection for disease resistance in lettuce

    Science.gov (United States)

    Lettuce (Lactuca sativa L.) is the most popular leafy vegetable that is cultivated mainly in moderate climate. Consumers demand lettuce with good visual appearance and free of disease. Improved disease resistance of new cultivars is achieved by combining desirable genes (or alleles) from existing cu...

  7. Thyroid hormone resistance misdiagnosed as Graves' disease

    Directory of Open Access Journals (Sweden)

    Manish Gutch

    2017-01-01

    Full Text Available Resistance to thyroid hormone (RTH syndrome is a very rare disorder characterized by mutations of the thyroid hormone receptor beta and is usually inherited as an autosomal dominant trait. Patients with RTH are usually euthyroid but rarely may present with signs and symptoms consistent with hyperthyroidism. Here, we describe the case of a young girl with goiter who was previously misdiagnosed to have hyperthyroidism and was subsequently diagnosed to be suffering from RTH.

  8. Gene pyramiding enhances durable blast disease resistance in rice.

    Science.gov (United States)

    Fukuoka, Shuichi; Saka, Norikuni; Mizukami, Yuko; Koga, Hironori; Yamanouchi, Utako; Yoshioka, Yosuke; Hayashi, Nagao; Ebana, Kaworu; Mizobuchi, Ritsuko; Yano, Masahiro

    2015-01-14

    Effective control of blast, a devastating fungal disease of rice, would increase and stabilize worldwide food production. Resistance mediated by quantitative trait loci (QTLs), which usually have smaller individual effects than R-genes but confer broad-spectrum or non-race-specific resistance, is a promising alternative to less durable race-specific resistance for crop improvement, yet evidence that validates the impact of QTL combinations (pyramids) on the durability of plant disease resistance has been lacking. Here, we developed near-isogenic experimental lines representing all possible combinations of four QTL alleles from a durably resistant cultivar. These lines enabled us to evaluate the QTLs singly and in combination in a homogeneous genetic background. We present evidence that pyramiding QTL alleles, each controlling a different response to M. oryzae, confers strong, non-race-specific, environmentally stable resistance to blast disease. Our results suggest that this robust defence system provides durable resistance, thus avoiding an evolutionary "arms race" between a crop and its pathogen.

  9. Tay-Sachs and Sandhoff diseases: enzymatic diagnosis in dried blood spots on filter paper: retrospective diagnoses in newborn-screening cards.

    Science.gov (United States)

    Chamoles, Néstor A; Blanco, Mariana; Gaggioli, Daniela; Casentini, Carina

    2002-04-01

    Tay-Sachs disease (TSD), Sandhoff disease (SD) and variants are caused by deficient activity of the lysosomal enzymes hexosaminidase A (HA) and total hexosaminidase (TH) (hexosaminidase A plus B), respectively. For diagnosis, these enzymes are usually measured in plasma or extracts of leukocytes. We describe methods for the assay of hexosaminidase A and total hexosaminidase activities in dried blood spots (DBSs) on filter paper. We studied 163 healthy controls, 9 Tay-Sachs patients, 4 Sandhoff patients, 18 obligate carriers and the newborn-screening cards from two patients with Tay-Sachs and one patient with Sandhoff disease. To tubes containing a 3-mm-diameter blood spot, we added elution liquid and substrate solution. After incubation at 37 degrees C, the amount of hydrolyzed product was compared with a calibrator to allow the quantification of enzyme activity. The described methodology is useful to distinguish patients with Tay-Sachs disease or Sandhoff disease from carriers and controls using samples that are sufficiently stable to be transported to the testing laboratory by mail. The diagnosis of both diseases from a newborn-screening card (NSC) was clearly demonstrated, even after storage for up to 38 months at room temperature. The newborn-screening card has been added to the biological materials that allow the identification of patients with Tay-Sachs disease and Sandhoff disease.

  10. Effect of dietary pigment on growth performance and disease resistance in black tiger shrimp post larva (Penaeus monodon, Fabricius

    Directory of Open Access Journals (Sweden)

    Boonyaratpalin, M.

    2005-02-01

    Full Text Available Effects of dietary pigment on survival and disease (white spot syndrome virus: WSSV resistance in black tiger shrimp post larva (Penaeus monodon, Fabricius (PL15 for a 30-day period were studied. The results showed that not only was mean survival of black tiger shrimp (PL15 fed with supplementation of Lucarotene or Betatene at 125 mg/kg diet significantly higher (P<0.05 but also the body color was increased. There were no effects of dietary pigment on mean weight, percent weight gain and WSSV resistance. However, mean WSSV resistance of black tiger shrimp (PL15 fed diet containing Lucantin pink 50 mg/kg diet, Spirulina 30 g/kg diet or Betatene 125 mg/kg diet was higher than that of control.

  11. Review of aspirin and clopidogrel resistance in peripheral arterial disease.

    Science.gov (United States)

    Guirgis, Mina; Thompson, Peter; Jansen, Shirley

    2017-11-01

    Aspirin resistance (AR) and clopidogrel resistance (CR) are terms used to describe a reduction in the medication's efficacy in inhibiting platelet aggregation despite regular dosing. This review gives context to the clinical role and implications of antiplatelet resistance in peripheral arterial disease (PAD). A review of English-language literature on AR and CR in PAD involving human subjects using PubMed and MEDLINE databases was performed in April 2017. A total of 2075 patients in 22 relevant studies were identified. To give this issue context, a review of the larger, more established literature on antiplatelet resistance in coronary disease was undertaken, identifying significant research associating resistance to major adverse cardiovascular events (MACEs). Studies in the coronary arterial disease literature have strongly associated antiplatelet resistance with increased MACE. Prevalence of AR or CR in coronary disease appears to be >55% for each in some studies. Meta-analyses of >50 studies revealed that AR and CR are significantly associated with MACE (relative risk of 2.09 and 2.8, respectively). This adds further weight to the literature reporting antiplatelet resistance as an independent predictor of and a threefold risk factor for major adverse cardiovascular events. The prevalence of resistance in PAD in this review was comparable to that in the coronary disease literature, with AR and CR prevalence up to 60% and 65%, respectively. There is evidence that the adverse effects of antiplatelet resistance are significant in PAD. In fact, research directly studying stent thrombosis populations with either coronary arterial disease or PAD revealed more significantly impaired platelet responsiveness to clopidogrel and aspirin in PAD compared with similar individuals with coronary disease. AR in PAD was found in studies to be a significant risk factor for iliofemoral stent reocclusion (P = .0093) and stroke in patients with symptomatic carotid disease (P

  12. Harnessing effector-triggered immunity for durable disease resistance

    Science.gov (United States)

    Zhang, Meixiang; Coaker, Gitta

    2018-01-01

    Genetic control of plant diseases has traditionally included the deployment of single immune receptors with nucleotide-binding leucine-rich repeat (NLR) domain architecture. These NLRs recognize corresponding pathogen effector proteins inside plant cells, resulting in effector-triggered immunity (ETI). Although ETI triggers robust resistance, deployment of single NLRs can be rapidly overcome by pathogen populations within a single or a few growing seasons. In order to generate more durable disease resistance against devastating plant pathogens, a multi-tiered strategy that incorporates stacked NLRs combined with other sources of disease resistance is necessary. New genetic and genomic technologies have enabled advancements in identifying conserved pathogen effectors, isolating NLR repertoires from diverse plants, and editing plant genomes to enhance resistance. Significant advancements have also been made in understanding plant immune perception at the receptor level, which has promise for engineering new sources of resistance. Here, we discuss how to utilize recent scientific advancements in a multilayered strategy for developing more durable disease resistance. PMID:28430023

  13. Mutagenesis and breeding for disease resistance in capsicum

    International Nuclear Information System (INIS)

    Saccardo, F.; Sree Ramulu, K.

    1977-01-01

    The principal diseases, for which no sources have so far been found within the cultivars of Capsicum annuum in Italy, are caused by Verticillium dahliae, Phytophthora capsici and cucumber mosaic virus (CMV). The wild species C. pendulum, C. frutescens, C. chinense, C. chacoense, C. pubescens and C. eximium were analysed to find out if the sources for resistance to the three diseases are available. It was observed that particularly the species C. frutescens and C. chinense had good sources of resistance to V. dahliae and Ph. capsici. However, the occurrence of reproductive barriers between the wild and cultivated species appears to be a problem for the transfer of disease-resistant genes. For CMV, none of the wild species showed good resistance; so in this case a screening technique was set up using mutagenic agents to isolate resistant types in the prominent agronomic cultivars of C. annuum. Also, for V. dahliae and Ph. capsici, mutation screening techniques were set up to induce disease resistance character directly in the cultivars of C. annuum, without causing any changes in the most important agronomic characters of the cultivars. (author)

  14. Molecular markers for resistance against infectious diseases of economic importance

    Directory of Open Access Journals (Sweden)

    B. M. Prajapati

    2017-01-01

    Full Text Available Huge livestock population of India is under threat by a large number of endemic infectious (bacterial, viral, and parasitic diseases. These diseases are associated with high rates of morbidity and mortality, particularly in exotic and crossbred cattle. Beside morbidity and mortality, economic losses by these diseases occur through reduced fertility, production losses, etc. Some of the major infectious diseases which have great economic impact on Indian dairy industries are tuberculosis (TB, Johne’s disease (JD, mastitis, tick and tick-borne diseases (TTBDs, foot and mouth disease, etc. The development of effective strategies for the assessment and control of infectious diseases requires a better understanding of pathogen biology, host immune response, and diseases pathogenesis as well as the identification of the associated biomarkers. Indigenous cattle (Bos indicus are reported to be comparatively less affected than exotic and crossbred cattle. However, genetic basis of resistance in indigenous cattle is not well documented. The association studies of few of the genes associated with various diseases, namely, solute carrier family 11 member 1, Toll-like receptors 1, with TB; Caspase associated recruitment domain 15, SP110 with JD; CACNA2D1, CD14 with mastitis and interferon gamma, BoLA -DRB3.2 alleles with TTBDs, etc., are presented. Breeding for genetic resistance is one of the promising ways to control the infectious diseases. High host resistance is the most important method for controlling such diseases, but till today no breed is total immune. Therefore, work may be undertaken under the hypothesis that the different susceptibility to these diseases are exhibited by indigenous and crossbred cattle is due to breed-specific differences in the dealing of infected cells with other immune cel ls, which ultimately influence the immune response responded against infections. Achieving maximum resistance to these diseases is the ultimate goal, is

  15. Pyrosequencing dried blood spots reveals differences in HIV drug resistance between treatment naïve and experienced patients.

    Directory of Open Access Journals (Sweden)

    Hezhao Ji

    Full Text Available Dried blood spots (DBS are an alternative specimen collection format for HIV-1 genotyping. DBS produce HIV genotyping results that are robust and equivalent to plasma when using conventional sequencing methods. However, using tagged, pooled pyrosequencing, we demonstrate that concordance between plasma and DBS is not absolute and varies according to viral load (VL, duration of HIV infection and antiretroviral therapy (ART status. The plasma/DBS concordance is the highest when VL is ≥5,000 copies/ml and/or the patient has no ART exposure and/or when the duration of HIV infection is ≤2 years. Stepwise regression analysis revealed that VL is most important independent predictor for concordance of DBS with plasma genotypes. This is the first study to use next generation sequencing to identify discordance between DBS and plasma genotypes. Consideration should be given to VL, duration of infection, and ART exposure when interpreting DBS genotypes produced using next generation sequencing. These findings are of particular significance when DBS are to be used for clinical monitoring purposes.

  16. Dried blood spot analysis for therapeutic drug monitoring of linezolid in patients with multidrug-resistant tuberculosis

    NARCIS (Netherlands)

    Vu, D H; Bolhuis, M S; Koster, R A; Greijdanus, B; de Lange, W C M; van Altena, R; Brouwers, J R B J; Uges, D R A; Alffenaar, J W C

    2012-01-01

    Linezolid is a promising antimicrobial agent for the treatment of multidrug-resistant tuberculosis (MDR-TB), but its use is limited by toxicity. Therapeutic drug monitoring (TDM) may help to minimize toxicity while adequate drug exposure is maintained. Conventional plasma sampling and monitoring

  17. Cotton-wool spots.

    Science.gov (United States)

    Brown, G C; Brown, M M; Hiller, T; Fischer, D; Benson, W E; Magargal, L E

    1985-01-01

    A series of 24 consecutive patients presenting with a fundus picture characterized by a predominance of cotton-wool spots, or a single cotton-wool spot, is reported. Excluded were patients with known diabetes mellitus. Etiologic conditions found included previously undiagnosed diabetes mellitus in five patients, systemic hypertension in five patients, cardiac valvular disease in two patients, radiation retinopathy in two patients, and severe carotid artery obstruction in two patients. Dermatomyositis, systemic lupus erythematosus, polyarteritis nodosa, leukemia, AIDS, Purtscher's retinopathy, metastatic carcinoma, intravenous drug abuse, partial central retinal artery obstruction, and giant cell arteritis were each found in one patient. In only one patient did a systemic workup fail to reveal an underlying cause. The presence of even one cotton-wool spot in an otherwise normal fundus necessitates an investigation to ascertain systemic etiologic factors.

  18. A comparative study of the microstructure and mechanical properties of HTLA steel welds obtained by the tungsten arc welding and resistance spot welding

    International Nuclear Information System (INIS)

    Ghazanfari, H.; Naderi, M.; Iranmanesh, M.; Seydi, M.; Poshteban, A.

    2012-01-01

    Highlights: ► Hardness mapping is a novel method to identify different phases. ► Surface hardness mapping, tabulates the hardness of a large area of weld. ► Hardness maps can be used to depict the strength map through the specimen. ► Hardness mapping is an easy way to identify the phase fractions within the specimen. - Abstract: Hardness tests are routinely employed as simple and efficient methods to investigate the microstructure and mechanical properties of steels. Each microstructural phase in steel has its own hardness level. Therefore, using surface hardness mapping data over a large area of weld zone would be a reasonable method to identify the present phases in steel. The microstructure distribution and mechanical properties variation through welded structures is inhomogeneous and not suitable for certain applications. So, studying the microstructure of weld zone has a significant importance. 4130 steel is classified in HTLA steels and it is widely used in marine industry due to its superior hardenability, good corrosion resistance and high strength. Gas tungsten arc and resistance spot welding are the most usable processes in joining of 4130 sheets. In this work a series of welds have been fabricated in 4130 steel tube by gas tungsten arc and resistance spot welding. The tube was subjected to quench-tempered heat treatment. Slices from the welds before and after heat treatment were polished and etched and the macrostructure and microstructure were observed. Hardness maps were then determined over the large area of weld zone, including the heat affected zone and base plate. Results show good relations between the various microstructures, strength and hardness values. It is also proved that this method is precise and applicable to estimate phase fraction of each phase in various regions of weld. In the current study some equations were proposed to calculate the ultimate tensile stress and yield stress from the weld. The calculated data were compared

  19. Genetically Engineered Broad-Spectrum Disease Resistance in Tomato

    Science.gov (United States)

    Oldroyd, Giles E. D.; Staskawicz, Brian J.

    1998-08-01

    Resistance in tomato to the bacterial pathogen Pseudomonas syringae pathovar tomato requires Pto and Prf. Mutations that eliminate Prf show a loss of both Pto resistance and sensitivity to the organophosphate insecticide fenthion, suggesting that Prf controls both phenotypes. Herein, we report that the overexpression of Prf leads to enhanced resistance to a number of normally virulent bacterial and viral pathogens and leads to increased sensitivity to fenthion. These plants express levels of salicylic acid comparable to plants induced for systemic acquired resistance (SAR) and constitutively express pathogenesis related genes. These results suggest that the overexpression of Prf activates the Pto and Fen pathways in a pathogen-independent manner and leads to the activation of SAR. Transgene-induced SAR has implications for the generation of broad spectrum disease resistance in agricultural crop plants.

  20. Interplay Between Antibiotic Resistance and Virulence During Disease Promoted by Multidrug-Resistant Bacteria.

    Science.gov (United States)

    Geisinger, Edward; Isberg, Ralph R

    2017-02-15

    Diseases caused by antibiotic-resistant bacteria in hospitals are the outcome of complex relationships between several dynamic factors, including bacterial pathogenicity, the fitness costs of resistance in the human host, and selective forces resulting from interventions such as antibiotic therapy. The emergence and fate of mutations that drive antibiotic resistance are governed by these interactions. In this review, we will examine how different forms of antibiotic resistance modulate bacterial fitness and virulence potential, thus influencing the ability of pathogens to evolve in the context of nosocomial infections. We will focus on 3 important multidrug-resistant pathogens that are notoriously problematic in hospitals: Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. An understanding of how antibiotic resistance mutations shape the pathobiology of multidrug-resistant infections has the potential to drive novel strategies that can control the development and spread of drug resistance. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, email: journals.permissions@oup.com.

  1. Resistant starches for the management of metabolic diseases.

    Science.gov (United States)

    Bindels, Laure B; Walter, Jens; Ramer-Tait, Amanda E

    2015-11-01

    Recent clinical trials and animal studies indicate that resistant starches may be beneficial therapeutic tools for the management of metabolic diseases. The purpose of this review is to summarize these findings and discuss the established and proposed mechanisms by which resistant starches exert their benefits. We also examine open questions regarding how resistant starches improve metabolism and propose future research directions for the field. Data from both humans and animal models clearly support a role for resistant starches in improving a variety of metabolic features; however, discrepancies do exist regarding specific effects. Concomitant improvements in both insulin levels and body fat depots are often reported in rodents fed resistant starches, whereas resistant starch feeding in humans improves insulin sensitivity without having a major impact on fat mass. These differences could be explained by the coexistence of several mechanisms (both gut microbiota-dependent and gut microbiota-independent) underpinning the metabolic benefits of resistant starches. Together, the studies presented in this review offer new insights into the potential pathways by which resistant starches enhance metabolic health, including modulation of the gut microbiota, gut peptides, circulating inflammatory mediators, innate immune cells, and the bile acid cycle.

  2. TP53 hot spot mutations in ovarian cancer: selective resistance to microtubule stabilizers in vitro and differential survival outcomes from The Cancer Genome Atlas.

    Science.gov (United States)

    Seagle, Brandon-Luke L; Yang, Chia-Ping Huang; Eng, Kevin H; Dandapani, Monica; Odunsi-Akanji, Oluwatosin; Goldberg, Gary L; Odunsi, Kunle; Horwitz, Susan Band; Shahabi, Shohreh

    2015-07-01

    To test if TP53 hot spot mutations (HSMs) confer differential chemotherapy resistance or survival outcomes, the effects of microtubule stabilizers on human ovarian carcinoma cells (OCCs) expressing TP53 HSMs were studied in vitro. Survival outcomes of patients with high grade serous epithelial ovarian carcinoma (HGS EOC) expressing matched HSMs were compared using The Cancer Genome Atlas (TCGA) data. Growth inhibition of OCCs transfected with a HSM (m175, m248 or m273) was measured during treatment with paclitaxel, epothilone B (epoB), or ixabepilone. Effects of epoB on p53 expression, phosphorylation, and acetylation, as well as p53-regulated expression of p21 and mdm2 proteins, were determined by Western blot analysis. Expression of p53 target genes P21, GADD45, BAX, PIDD, NF-kB2, PAI-1, and MDR1 was measured by RT-PCR. cBioPortal.org identified patients with codon R175, R248 or R273 HSMs from TCGA data. Survival outcomes were characterized. p53-m248 confers chemoresistance and is not acetylated during epoB treatment. m273 demonstrated high MDR1 expression and resistance to paclitaxel. P21, GADD45 and PAI-1 expression were down-regulated in mutant OCCs. Optimally cytoreduced patients with codon R273 (n=17), R248 (n=13), R175 (n=7) HSMs, or any other TP53 mutation demonstrated median 14.9, 17.6, 17.8 and 16.9months (p=0.806) progression free survival and 84.1, 33.6, 62.1 and 44.5months (p=0.040) overall survival, respectively. Human OCCs harboring different TP53 HSMs were selectively resistant to microtubule stabilizers. Patients with different HSMs had significantly different overall survival. Both in vitro data and clinical experience support further studying the outcomes of particular TP53 HSMs. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Incident Infection and Resistance Mutation Analysis of Dried Blood Spots Collected in a Field Study of HIV Risk Groups, 2007-2010.

    Science.gov (United States)

    Wei, Xierong; Smith, Amanda J; Forrest, David W; Cardenas, Gabriel A; Beck, Dano W; LaLota, Marlene; Metsch, Lisa R; Sionean, Catlainn; Owen, S Michele; Johnson, Jeffrey A

    2016-01-01

    To assess the utility of cost-effective dried blood spot (DBS) field sampling for incidence and drug resistance surveillance of persons at high risk for HIV infection. We evaluated DBS collected in 2007-2010 in non-clinical settings by finger-stick from HIV-positive heterosexuals at increased risk of HIV infection (n = 124), men who have sex with men (MSM, n = 110), and persons who inject drugs (PWID, n = 58). Relative proportions of recent-infection findings among risk groups were assessed at avidity index (AI) cutoffs of ≤25%, ≤30%, and ≤35%, corresponding to an infection mean duration of recency (MDR) of 220.6, 250.4, and 278.3 days, respectively. Drug resistance mutation prevalence was compared among the risk groups and avidity indices. HIV antibody avidity testing of all self-reported ARV-naïve persons (n = 186) resulted in 9.7%, 11.3% and 14.0% with findings within the 221, 250, and 278-day MDRs, respectively. The proportion of ARV-naïve MSM, heterosexuals, and PWID reporting only one risk category who had findings below the suggested 30% AI was 23.1%, 6.9% and 3.6% (pinfection results than did heterosexuals and PWID. The disproportionately higher recent-infection findings for MSM as compared to PWID and heterosexuals increased as the MDR window increased. Unreported ARV use might explain greater recent-infection findings and drug resistance in this MSM population. DBS demonstrated utility in expanded HIV testing; however, optimal field handling is key to accurate recent-infection estimates.

  4. Identificação de marcador RAPD ligado ao gene de resistência à raça 63.39 da mancha-angular do feijoeiro Identification of RAPD marker linked to the resistence gene for the race 63.39 of angular leaf spot in common bean

    Directory of Open Access Journals (Sweden)

    CLAUDIA FORTES FERREIRA

    1999-01-01

    Full Text Available O fungo Phaeoisariopsis griseola é o agente causador da mancha-angular do feijoeiro (Phaseolus vulgaris L., doença que se vem destacando no Estado de Minas Gerais. Com o intuito de identificar marcadores ligados ao gene de resistência à mancha-angular (raça 63.39 de P. griseola, executou-se, previamente, o estudo da herança da resistência. Avaliaram-se, quanto à segregação, as populações derivadas dos cruzamentos entre Rudá (progenitor suscetível - origem mesoamericana e MAR-2 (progenitor resistente - origem mesoamericana. Foi obtida a segregação de 3:1 (plantas resistentes:suscetíveis na geração F2; 1:1, no retrocruzamento com Rudá, e 1:0, no retrocruzamento com MAR-2. Os resultados sugeriram a existência de um alelo dominante governando a resistência. Posteriormente, foram construídos bulks (grupos de DNA, de indivíduos F2 resistentes e suscetíveis à raça 63.39 (origem mesoamericana do patógeno. Esses grupos foram amplificados com 400 iniciadores. Tal amplificação com o iniciador OPE-04 gerou um fragmento de, aproximadamente, 500 pb, o qual co-segregou com o gene de resistência. Na análise de co-segregação, verificou-se que esse marcador está ligado ao gene de resistência à raça 63.39 de P. griseola, a uma distância de 5,8 cM.Phaeoisariopsis griseola is the causal agent of common bean (Phaseolus vulgaris L. angular leaf spot, considered one of the most important bean diseases in the State of Minas Gerais, Brazil. Aiming at identifying RAPD markers closely linked to the angular leaf spot resistance genes (race 63.39 - mesoamerican origin, a previous study of their inheritance was carried out. Populations derived from the cross Rudá (susceptible x MAR-2 (resistant both mesoamerican genetic materials, were evaluated as to disease behaviour. F2 generation presented segregation of 3:1 (resistant: susceptible; 1:1 for the backcross to the susceptible parent (Rudá and 1:0, for the backcross to the resistant

  5. High throughput phenotyping of tomato spotted wilt disease in peanuts using unmanned aerial systems and multispectral imaging

    Science.gov (United States)

    The amount of visible and near infrared light reflected by plants varies depending on their health. In this study, multispectral images were acquired by quadcopter for detecting tomato spot wilt virus amongst twenty genetic varieties of peanuts. The plants were visually assessed to acquire ground ...

  6. Novel Pseudomonas syringae strains associated with leaf spot diseases on watermelon (Citrullus lanatus) and squash (Cucurbita pepo) in California

    Science.gov (United States)

    In 2006 and 2011, bacteria, fluorescent on KMB, were isolated from leaf spots of greenhouse-grown watermelon (Citrullus lanatus) and field-grown squash (Cucurbita pepo) in coastal California. Biochemical characterization of the isolates indicated that they belonged to Pseudomonas syringae. Multilocu...

  7. Melhoramento do feijoeiro comum com grão tipo carioca, visando resistência à antracnose e à mancha angular Breeding of common bean with carioca type grain for the resistance to anthracnose and angular leaf spot

    Directory of Open Access Journals (Sweden)

    Mansuêmia Alves Couto

    2008-10-01

    Full Text Available Objetivou-se no trabalho, selecionar linhagens de feijoeiro comum que reunissem, além da alta produtividade, porte ereto e grãos do tipo Carioca, também a resistência à antracnose e à mancha angular. O material experimental constituiu-se de 143 linhagens oriundas de três famílias segregantes F1:4RC2 {[(G2333 X ESAL 696 X ESAL 696] X CI 140}. Foram conduzidos quatro experimentos em três localidades da região sul de Minas Gerais, avaliando-se a produção, o tipo de grão, o porte e a reação à mancha angular. A reação à antracnose foi determinada a partir de inoculações de plantas jovens de cada linhagem, com as raças 2047 e 1545, mantidas em câmara de nevoeiro por três dias e transferidas para casa de vegetação com irrigação por aspersão, a cada quatro horas. Selecionaram-se quatro linhagens com alta produtividade, porte mais arbustivo, grãos tipo carioca e com resistência à mancha angular (nota até 4. Uma das linhagens selecionada possui o alelo Co-4², outras duas possuem o alelo Co-7 de resistência à antracnose e a última, embora seja suscetível à antracnose, possui resistência à mancha angular (nota 3,97 e maior produtividade de grãos.Aiming to select common bean lines with high grain yield, Carioca grain type, upright plant habit and resistant to anthracnose and angular leaf spot, 143 lines were selected from three families of the cross F1:4RC2 {[(G2333 X ESAL 696 X ESAL 696] X CI 140}. The promising lines were selected based on the agronomical traits in four field experiments, set up in three places in Southern MG State using the square lattice design. The reaction of each line to the anthracnose was evaluated by inoculating the seedlings using the races 1545 and 2047, and kept in humid chamber during three days, and then moved to greenhouse with sprinkle irrigation every four hours. Four lines with high grain yield, upright plant habit, Carioca grain type, and resistance to angular leaf spot (score up

  8. Why is antibiotic resistance a deadly emerging disease?

    Science.gov (United States)

    Courvalin, P

    2016-05-01

    Evolution of bacteria towards resistance to antimicrobial agents, including multidrug resistance, is unavoidable because it represents a particular aspect of the general evolution of bacteria that is unstoppable. Therefore, the only means of dealing with this situation is to delay the emergence and subsequent dissemination of resistant bacteria or resistance genes. In this review, we will consider the biochemical mechanisms and the genetics that bacteria use to offset antibiotic selective pressure. The data provided are mainly, if not exclusively, taken from the work carried out in the laboratory, although there are numerous other examples in the literature. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

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

  10. The role of ethylene perception in plant disease resistance

    NARCIS (Netherlands)

    Geraats, Bart Peter Johan

    2003-01-01

    Ethylene is a plant hormone that is involved in responses of the plant to various stress situations, such as pathogen attack. The role of ethylene in plant-pathogen interactions seems to be diverse. Exposure of plants to ethylene can induce disease resistance, but treatment with ethylene during

  11. resistance of napier grass clones to napier grass stunt disease

    African Journals Online (AJOL)

    ACSS

    Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease. (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.

  12. Evaluating paradox walnut rootstocks for resistance to Armillaria root disease

    Science.gov (United States)

    The most common Juglans regia (English walnut) rootstock in California is Paradox, a hybrid between J. hindsii (Northern California black walnut) and J. regia. Unfortuntely, Paradox rootstock is highly susceptible to Armillaria root disease. The relative resistance of new clonal, Paradox rootstock...

  13. Evaluation of Tomato Culktivar for resistance to wilt disease and ...

    African Journals Online (AJOL)

    ... and 2.7 kg) respectively in both trials. Tomato-Marina recorded statistically the lowest numbers (9.6 and 11.17) and weights (0.23 kg and 0.73 kg) of fruits respectively in both evaluations. Keywords:Meloidogyne incognita Resistance, Tomato, Wilt disease. Nigerian Journal of Horticultural Science Vol. 10 2005: pp. 30-37 ...

  14. Regeneration systems for pyramiding disease resistance into walnut rootstocks

    Science.gov (United States)

    This study was conducted to regenerate selected walnut rootstocks adventitiously. This is an essential step to be able to produce transgenic walnut rootstocks with superior traits, such as disease resistance. A series of plant tissue culture experiments were conducted on RX1 and VX211 rootstocks wit...

  15. Resistance of Napier grass clones to Napier grass Stunt Disease ...

    African Journals Online (AJOL)

    Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.

  16. Resistance training and predicted risk of coronary heart disease in ...

    African Journals Online (AJOL)

    The purpose of this study was to determine the impact of resistance training, designed to prevent the development of coronary heart disease (CHD) based on the Framingham Risk Assessment (FRA) score. Twenty-five healthy sedentary men with low CHD risk were assigned to participate in a 16-week (three days per week) ...

  17. Mongolian spots

    Directory of Open Access Journals (Sweden)

    Divya Gupta

    2013-01-01

    Full Text Available Mongolian spots (MS are birthmarks that are present at birth and their most common location is sacrococcygeal or lumbar area. Lesions may be single or multiple and usually involve < 5% total body surface area. They are macular and round, oval or irregular in shape. The color varies from blue to greenish, gray, black or a combination of any of the above. The size varies from few to more than 20 centimetres. Pigmentation is most intense at the age of one year and gradually fades thereafter. It is rarely seen after the age of 6 years. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although regarded as benign, recent data suggest that MS may be associated with inborn errors of metabolism and neurocristopathies. Mongolian spots usually resolve by early childhood and hence no treatment is generally needed if they are located in the sacral area. However, sometimes it may be required for extrasacral lesions for cosmesis.

  18. Prediction of genetic gain from selection indices for disease resistance in papaya hybrids

    Directory of Open Access Journals (Sweden)

    Marcelo Vivas

    2012-12-01

    Full Text Available In order to select superior hybrids for the concentration of favorable alleles for resistance to papaya black spot, powdery mildew and phoma spot, 67 hybrids were evaluated in two seasons, in 2007, in a randomized block design with two replications. Genetic gains were estimated from the selection indices of Smith & Hazel, Pesek & Baker, Williams, Mulamba & Mock, with selection intensity of 22.39%, corresponding to 15 hybrids. The index of Mulamba & Mock showed gains more suitable for the five traits assessed when it was used the criterion of economic weight tentatively assigned. Together, severity of black spot on leaves and on fruits, characteristics considered most relevant to the selection of resistant materials, expressed percentage gain of -44.15%. In addition, there were gains for other characteristics, with negative predicted selective percentage gain. The results showed that the index of Mulamba & Mock is the most efficient procedure for simultaneous selection of papaya hybrid resistant to black spot, powdery mildew and phoma spot.

  19. Effect of Welding Current and Time on the Microstructure, Mechanical Characterizations, and Fracture Studies of Resistance Spot Welding Joints of AISI 316L Austenitic Stainless Steel

    Science.gov (United States)

    Kianersi, Danial; Mostafaei, Amir; Mohammadi, Javad

    2014-09-01

    This article aims at investigating the effect of welding parameters, namely, welding current and welding time, on resistance spot welding (RSW) of the AISI 316L austenitic stainless steel sheets. The influence of welding current and welding time on the weld properties including the weld nugget diameter or fusion zone, tensile-shear load-bearing capacity of welded materials, failure modes, energy absorption, and microstructure of welded nuggets was precisely considered. Microstructural studies and mechanical properties showed that the region between interfacial to pullout mode transition and expulsion limit is defined as the optimum welding condition. Electron microscopic studies indicated different types of delta ferrite in welded nuggets including skeletal, acicular, and lathy delta ferrite morphologies as a result of nonequilibrium phases, which can be attributed to a fast cooling rate in the RSW process. These morphologies were explained based on Shaeffler, WRC-1992, and pseudo-binary phase diagrams. The optimum microstructure and mechanical properties were achieved with 8-kA welding current and 4-cycle welding time in which maximum tensile-shear load-bearing capacity or peak load of the welded materials was obtained at 8070 N, and the failure mode took place as button pullout with tearing from the base metal. Finally, fracture surface studies indicated that elongated dimples appeared on the surface as a result of ductile fracture in the sample welded in the optimum welding condition.

  20. Nugget formation and its mechanism of resistance spot welded joints in DP600 dual-phase and DC54D ultralow carbon steel

    Science.gov (United States)

    Li, Ci; Yuan, Xinjian; Wu, Kanglong; Wang, Haodong; Hu, Zhan; Pan, Xueyu

    2017-05-01

    Resistance spot welded joints in different configurations of DP600 and DC54D were investigated to elucidate the nugget formation process and mechanical properties of the resultant joints. Results show that, when the welding time was less than 4 cycles, the fusion zone (FZ) was not formed, but the heat-affected zone (HAZ) occurred with a "butterfly" shape. In 4 cycles, the FZ in dissimilar sheets occurred with an "abnormal butterfly" shape because of nugget shift. When the welding time increased to 14 cycles, the FZ exhibited a "bread loaf" shape and the weld shifted to "dog bones." The nugget can be divided into three regions, namely, FZ, HAZ1, and HAZ2, and the FZ consisted of lath martensite. The micro hardness of DP600 FZ was lower than that of HAZ because of the dilution of DC54D. The failure mode of B changed from interfacial failure to plug failure during the nugget formation process. The tensile-shear load of sound weld is 6.375, 6.016, and 19.131 kN.

  1. Insulin Resistance and Alzheimer’s Disease: Bioenergetic Linkages

    Directory of Open Access Journals (Sweden)

    Bryan J. Neth

    2017-10-01

    Full Text Available Metabolic dysfunction is a well-established feature of Alzheimer’s disease (AD, evidenced by brain glucose hypometabolism that can be observed potentially decades prior to the development of AD symptoms. Furthermore, there is mounting support for an association between metabolic disease and the development of AD and related dementias. Individuals with insulin resistance, type 2 diabetes mellitus (T2D, hyperlipidemia, obesity, or other metabolic disease may have increased risk for the development of AD and similar conditions, such as vascular dementia. This association may in part be due to the systemic mitochondrial dysfunction that is common to these pathologies. Accumulating evidence suggests that mitochondrial dysfunction is a significant feature of AD and may play a fundamental role in its pathogenesis. In fact, aging itself presents a unique challenge due to inherent mitochondrial dysfunction and prevalence of chronic metabolic disease. Despite the progress made in understanding the pathogenesis of AD and in the development of potential therapies, at present we remain without a disease-modifying treatment. In this review, we will discuss insulin resistance as a contributing factor to the pathogenesis of AD, as well as the metabolic and bioenergetic disruptions linking insulin resistance and AD. We will also focus on potential neuroimaging tools for the study of the metabolic dysfunction commonly seen in AD with hopes of developing therapeutic and preventative targets.

  2. Animal genomics and infectious disease resistance in poultry.

    Science.gov (United States)

    Smith, J; Gheyas, A; Burt, D W

    2016-04-01

    Avian pathogens are responsible for major costs to society, both in terms of huge economic losses to the poultry industry and their implications for human health. The health and welfare of millions of birds is under continued threat from many infectious diseases, some of which are increasing in virulence and thus becoming harder to control, such as Marek's disease virus and avian influenza viruses. The current era in animal genomics has seen huge developments in both technologies and resources, which means that researchers have never been in a better position to investigate the genetics of disease resistance and determine the underlying genes/mutations which make birds susceptible or resistant to infection. Avian genomics has reached a point where the biological mechanisms of infectious diseases can be investigated and understood in poultry and other avian species. Knowledge of genes conferring disease resistance can be used in selective breeding programmes or to develop vaccines which help to control the effects of these pathogens, which have such a major impact on birds and humans alike.

  3. Insulin Resistance and Alzheimer’s Disease: Bioenergetic Linkages

    Science.gov (United States)

    Neth, Bryan J.; Craft, Suzanne

    2017-01-01

    Metabolic dysfunction is a well-established feature of Alzheimer’s disease (AD), evidenced by brain glucose hypometabolism that can be observed potentially decades prior to the development of AD symptoms. Furthermore, there is mounting support for an association between metabolic disease and the development of AD and related dementias. Individuals with insulin resistance, type 2 diabetes mellitus (T2D), hyperlipidemia, obesity, or other metabolic disease may have increased risk for the development of AD and similar conditions, such as vascular dementia. This association may in part be due to the systemic mitochondrial dysfunction that is common to these pathologies. Accumulating evidence suggests that mitochondrial dysfunction is a significant feature of AD and may play a fundamental role in its pathogenesis. In fact, aging itself presents a unique challenge due to inherent mitochondrial dysfunction and prevalence of chronic metabolic disease. Despite the progress made in understanding the pathogenesis of AD and in the development of potential therapies, at present we remain without a disease-modifying treatment. In this review, we will discuss insulin resistance as a contributing factor to the pathogenesis of AD, as well as the metabolic and bioenergetic disruptions linking insulin resistance and AD. We will also focus on potential neuroimaging tools for the study of the metabolic dysfunction commonly seen in AD with hopes of developing therapeutic and preventative targets. PMID:29163128

  4. Phylogenetic diversity and host specialization of Corynespora cassiicola responsible for emerging target spot disease of cotton and other crops in the southeastern United States.

    Science.gov (United States)

    Sumabat, Leilani; Kemerait, Robert C; Brewer, Marin Talbot

    2018-02-13

    Corynespora cassiicola is a ubiquitous fungus causing emerging plant diseases worldwide, including target spot of cotton, soybean, and tomato, which have rapidly increased in incidence and severity throughout the southeastern United States. The objectives of this study were to understand the causes for the emerging target spot epidemics in the U.S. by comparing phylogenetic relationships of isolates from cotton, tomato, soybean, and other crop plants and ornamental hosts, and through the determination of the host range of isolates from emerging populations. Fifty-three isolates were sampled from plants in the southeastern U.S. and 1,380 nucleotides from four nuclear loci were sequenced. Additionally, sequences of the same loci from twenty-three isolates representing each of the distinct lineages of C. cassiicola described from previous studies were included. Isolates clustered based on host of origin, irrespective of the geographic location of sampling. There was no genetic diversity detected among isolates from cotton, which were genetically distinct from isolates from other host species. Furthermore, pathogenicity and virulence assays of 40 isolates from various hosts onto cotton, soybean, tomato, and cucumber showed that isolates from cotton were more aggressive to cotton than those from other hosts. Soybean and tomato were most susceptible to isolates that originated from the same host, providing evidence of host specialization. These results suggest that emerging target spot epidemics in the U.S. are caused by either the introduction of host-specific isolates or the evolution of more aggressive lineages on each host.

  5. Chocolate spot of Eucalyptus

    OpenAIRE

    Cheewangkoon, R.; Groenewald, J.Z.; Hyde, K.D.; To-anun, C.; Crous, P.W.

    2012-01-01

    Chocolate Spot leaf disease of Eucalyptus is associated with several Heteroconium-like species of hyphomycetes that resemble Heteroconium s.str. in morphology. They differ, however, in their ecology, with the former being plant pathogenic, while Heteroconium s.str. is a genus of sooty moulds. Results of molecular analyses, inferred from DNA sequences of the large subunit (LSU) and internal transcribed spacers (ITS) region of nrDNA, delineated four Heteroconium-like species on Eucalyptus, name...

  6. Epidemiological Features and Trends of Brown Spot of Pear Disease Based on the Diversity of Pathogen Populations and Climate Change Effects.

    Science.gov (United States)

    Moragrega, Concepció; Puig, Mireia; Ruz, Lídia; Montesinos, Emilio; Llorente, Isidre

    2018-02-01

    Brown spot of pear, caused by the fungus Stemphylium vesicarium, is an emerging disease of economic importance in several pear-growing areas in Europe. In recent years, new control strategies combining sanitation practices and fungicide applications according to developed forecasting models have been introduced to manage the disease. However, the pathogenic and saprophytic behavior of this pathogen makes it difficult to manage the disease. In addition, climate change can also result in variations in the severity and geographical distribution of the disease. In this study, ecological and epidemiological aspects of brown spot of pear disease related to inoculum characterization and climate change impact were elucidated. The pathogenic variation in S. vesicarium populations from pear orchards and its relationship to inoculum sources (air samples, leaf debris, and infected host and nonhost tissues) was determined using multivariate analysis. In total, six variables related to infection and disease development on cultivar Conference pear detached leaves of 110 S. vesicarium isolates were analyzed. A high proportion of isolates (42%) were nonpathogenic to pear; 85% of these nonpathogenic isolates were recovered from air samples. Most isolates recovered from lesions (93%) and pseudothecia (83%) were pathogenic to pear. A group of pathogenic isolates rapidly infected cultivar Conference pear leaves resulted in disease increase that followed a monomolecular model, whereas some S. vesicarium isolates required a period of time after inoculation to initiate infection and resulted in disease increase that followed a logistic model. The latter group was mainly composed of isolates recovered from pseudothecia on leaf debris, whereas the former group was mainly composed of isolates recovered from lesions on pear fruit and leaves. The relationship between the source of inoculum and pathogenic/aggressiveness profile was confirmed by principal component analysis. The effect of

  7. A latitudinal cline in disease resistance of a host tree

    Science.gov (United States)

    Hamilton, M G; Williams, D R; Tilyard, P A; Pinkard, E A; Wardlaw, T J; Glen, M; Vaillancourt, R E; Potts, B M

    2013-01-01

    The possible drivers and implications of an observed latitudinal cline in disease resistance of a host tree were examined. Mycosphaerella leaf disease (MLD) damage, caused by Teratosphaeria species, was assessed in five Eucalyptus globulus (Tasmanian blue gum) common garden trials containing open-pollinated progeny from 13 native-forest populations. Significant population and family within population variation in MLD resistance was detected, which was relatively stable across different combinations of trial sites, ages, seasons and epidemics. A distinct genetic-based latitudinal cline in MLD damage among host populations was evident. Two lines of evidence argue that the observed genetic-based latitudinal trend was the result of direct pathogen-imposed selection for MLD resistance. First, MLD damage was positively associated with temperature and negatively associated with a prediction of disease risk in the native environment of these populations; and, second, the quantitative inbreeding coefficient (QST) significantly exceeded neutral marker FST at the trial that exhibited the greatest MLD damage, suggesting that diversifying selection contributed to differentiation in MLD resistance among populations. This study highlights the potential for spatial variation in pathogen risk to drive adaptive differentiation across the geographic range of a foundation host tree species. PMID:23211794

  8. A comparative study between detached leaf and plastic growth pouches techniques on the infection of pseudocercospora leaf spot disease of cowpea cultivars (Vigna unguiculata L. Walp) in northeast Thailand.

    Science.gov (United States)

    Sinsiri, N; Laohasiriwong, S

    2009-03-01

    This glasshouse experiment was carried out in the 2004 at the Department of Agricultural Production, Faculty of Technology, Mahasarakham University, Mahasarakham 4400, Northeast Thailand to compare amounts of infection of Pseudocercospora leaf spot disease in leaves of cowpea cultivars being screened between detached leaf and plastic growth pouches techniques. The experiment was laid in a factorial arranged in a Randomized Complete Block Design (RCBD) with four replications. KVC7, IT81D-1228-14-1 and KKU25 cowpea cultivars were used as factor A, detached leaf and plastic growth pouches techniques were used as factor B and four levels of the concentrations of the spores of the disease, i.e., 0, l x 10(4), 5 x 10(4) and 1 x 10(5) of disease forming units mL(-1) of distilled water were used as factor C. The results showed that KVC7 and IT81D-1228-14-1 cultivars possessed immune and high resistant properties against the disease, respectively, whereas KKU25 cultivar ranked as a susceptible cultivar. Detached leaf technique gave higher amount of infection of the disease than plastic growth pouches technique and the differences were highly significant. A plentiful amount of Infected disease was attained with an inoculation rate of l x 10(5) forming units mL(-1) of distilled water, which was considered too high and the most appropriate concentrations for use lie on both concentrations, i.e., 1 x 10(4) and 5 x 10(4) forming units mL(-1) of distilled water. An interaction among factors AxBxC was severely found with KKU25 cultivar, particularly on day 28 after inoculation, whilst other two cultivars gave a minute amount of disease incidences (%) where detached leaf technique gave much higher disease incidences than plastic growth pouches technique, thus detached leaf technique should be of higher advantages.

  9. Enhanced tomato disease resistance primed by arbuscular mycorrhizal fungus.

    Science.gov (United States)

    Song, Yuanyuan; Chen, Dongmei; Lu, Kai; Sun, Zhongxiang; Zeng, Rensen

    2015-01-01

    Roots of most terrestrial plants form symbiotic associations (mycorrhiza) with soil- borne arbuscular mycorrhizal fungi (AMF). Many studies show that mycorrhizal colonization enhances plant resistance against pathogenic fungi. However, the mechanism of mycorrhiza-induced disease resistance remains equivocal. In this study, we found that mycorrhizal inoculation with AMF Funneliformis mosseae significantly alleviated tomato (Solanum lycopersicum Mill.) early blight disease caused by Alternaria solani Sorauer. AMF pre-inoculation led to significant increases in activities of β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase (PAL) and lipoxygenase (LOX) in tomato leaves upon pathogen inoculation. Mycorrhizal inoculation alone did not influence the transcripts of most genes tested. However, pathogen attack on AMF-inoculated plants provoked strong defense responses of three genes encoding pathogenesis-related proteins, PR1, PR2, and PR3, as well as defense-related genes LOX, AOC, and PAL, in tomato leaves. The induction of defense responses in AMF pre-inoculated plants was much higher and more rapid than that in un-inoculated plants in present of pathogen infection. Three tomato genotypes: a Castlemart wild-type (WT) plant, a jasmonate (JA) biosynthesis mutant (spr2), and a prosystemin-overexpressing 35S::PS plant were used to examine the role of the JA signaling pathway in AMF-primed disease defense. Pathogen infection on mycorrhizal 35S::PS plants led to higher induction of defense-related genes and enzymes relative to WT plants. However, pathogen infection did not induce these genes and enzymes in mycorrhizal spr2 mutant plants. Bioassays showed that 35S::PS plants were more resistant and spr2 plants were more susceptible to early blight compared with WT plants. Our finding indicates that mycorrhizal colonization enhances tomato resistance to early blight by priming systemic defense response, and the JA signaling pathway is essential for mycorrhiza

  10. An experimental study on fracture toughness of resistance spot welded galvanized and ungalvanized DP 450 steel sheets used in automotive body

    Directory of Open Access Journals (Sweden)

    Sevim, Ibrahim

    2016-09-01

    Full Text Available The purpose of this study is to determine fracture toughness of Resistance Spot Welded (RSW Dual Phase (DP steels. RSW of galvanized and ungalvanized DP 450 steel sheets was carried out on spot welding machine. Fracture toughness of RSW joints of galvanized and ungalvanized DP 450 steel sheets was calculated from tensile-shear tests. New empirical equations were developed using Least Squares Method (LSM between energy release rate, fracture toughness and critical crack size depending on the relationship between hardness and fracture toughness values. Results indicated that fracture toughness of joints welded by using RSW increased exponentially while the hardness decreased. In addition, fracture toughness and energy release rate of RSW galvanized DP 450 steel sheets were lower compared to RSW ungalvanized DP 450 steel sheets which had approximately the same hardness.El objetivo de este estudio es determinar la tenacidad de fractura de los aceros dual (DP soldados por puntos de resistencia (RSW. En la máquina de soldadura por puntos se realizó la soldadura de láminas de acero DP 450 galvanizado y sin galvanizar. A partir de los ensayos de tracción-cizallamiento, se calculó la tenacidad a la fractura de las uniones del acero DP 450 galvanizado y sin galvanizar. Aplicando el método de mínimos cuadrados (LSM se desarrollaron nuevas ecuaciones empíricas entre el porcentaje de energía liberada, la tenacidad de fractura y el tamaño de grieta crítica en función de la relación entre los valores de tenacidad de fractura y de dureza. Los resultados indicaron que la tenacidad de fractura de las uniones soldadas por RSW aumentó exponencialmente, mientras que la dureza disminuyó. Además, el porcentaje de energía liberada de las láminas de acero DP 450 galvanizadas y soldadas fueron menores que en el caso de las láminas sin galvanizar a valores iguales de dureza.

  11. An Update on Neurofibromatosis Type 1: Not Just Café-au-Lait Spots, Freckling, and Neurofibromas. An Update. Part I. Dermatological Clinical Criteria Diagnostic of the Disease.

    Science.gov (United States)

    Hernández-Martín, A; Duat-Rodríguez, A

    2016-01-01

    Neurofibromatosis type 1 (NF1) is the most common neurocutaneous syndrome and probably the one best known to dermatologists, who are generally the first physicians to suspect its diagnosis. Although the genetic locus of NF1 was identified on chromosome 17 in 1987, diagnosis of the disease is still mainly based on clinical observations and the diagnostic criteria of the National Institute of Health, dating from 1988. Cutaneous manifestations are particularly important because café-au-lait spots, freckling on flexural areas, and cutaneous neurofibromas comprise 3 of the 7 clinical diagnostic criteria. However, café-au-lait spots and freckling can also be present in other diseases. These manifestations are therefore not pathognomonic and are insufficient for definitive diagnosis in the early years of life. NF1 is a multisystemic disease associated with a predisposition to cancer. A multidisciplinary follow-up is necessary and dermatologists play an important role. Copyright © 2016 AEDV. Published by Elsevier España, S.L.U. All rights reserved.

  12. Mutation breeding for disease resistance in wheat and field beans in Egypt

    International Nuclear Information System (INIS)

    Abdel-Hak, T.M.

    1983-01-01

    Seeds of three varieties of hexaploid wheat and of one variety of tetraploid wheat were treated with gamma rays in order to obtain mutants with improved resistance to stem rust, leaf rust and stripe rust. Mutants with resistance to prevailing races of rusts were selected; however, the race spectrum shifted and made the mutants useless for the time being. Induction of mutations for resistance to chocolate spot and rusts was attempted in Vicia faba. No resistant mutant was found but some mutants with lower levels of infection were. (author)

  13. In Vivo Monitoring on Growth and Spread of Gray Leaf Spot Disease in Capsicum annuum Leaf Using Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Ravichandran

    2016-01-01

    Full Text Available We have demonstrated the application of optical coherence tomography (OCT in diagnosis of growth and spread of the gray leaf spot disease in Capsicum annuum leaf caused by the fungus Stemphylium lycopersici. Using 2D cross-sectional and 3D volumetric images of OCT, in vivo study of layer differences between fungus infected leaves and healthy leaves was observed with distinctive features. We observed that the internal layers of the disease-affected parts of the leaf seem to merge forming a single thick layer. The obtained OCT results verify the noninvasive diagnosis ability of fungal growth and spread in Capsicum annuum leaves and the applicability of this methodology for other plant diseases.

  14. Insulin Resistance and Risk of Cardiovascular Disease in Postmenopausal Women

    DEFF Research Database (Denmark)

    Schmiegelow, Michelle D; Hedlin, Haley; Stefanick, Marcia L

    2015-01-01

    BACKGROUND: Insulin resistance is associated with diabetes mellitus, but it is uncertain whether it improves cardiovascular disease (CVD) risk prediction beyond traditional cardiovascular risk factors. METHODS AND RESULTS: We identified 15,288 women from the Women's Health Initiative Biomarkers...... studies with no history of CVD, atrial fibrillation, or diabetes mellitus at baseline (1993-1998). We assessed the prognostic value of adding fasting serum insulin, HOMA-IR (homeostasis model assessment-insulin resistance), serum-triglyceride-to-serum-high-density lipoprotein-cholesterol ratio TG...... occurred in 894 (5.8%) women. Insulin resistance was associated with CVD risk after adjusting for age and race/ethnicity with hazard ratios (95% confidence interval [CI]) per doubling in insulin of 1.21 (CI, 1.12-1.31), in HOMA-IR of 1.19 (CI, 1.11-1.28), in TG/HDL-C of 1.35 (CI, 1...

  15. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Mahadtanapuk, S. [School of Agriculture and Natural Resources, University of Phayao, Phayao 56000 (Thailand); Teraarusiri, W. [Central Laboratory, University of Phayao, Phayao 56000 (Thailand); Phanchaisri, B. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@frnf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Anuntalabhochai, S., E-mail: burinka@hotmail.com [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-15

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10{sup 16}–2 × 10{sup 17} ions/cm{sup 2}. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10{sup 6} spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  16. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    International Nuclear Information System (INIS)

    Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L.D.; Anuntalabhochai, S.

    2013-01-01

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10 16 –2 × 10 17 ions/cm 2 . The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10 6 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  17. Periodontal diseases in patients with vitamin D-resistant rickets.

    Science.gov (United States)

    Japaridze, N V; Margvelashvili, V V; Shengelia, M I; Chigladze, T T; Kalandadze, M N

    2015-02-01

    To define the risk of development of periodontal diseases at vitamin D-resistant rickets. The material for the study was based on the data from 13 children of 0-18 years with vitamin D-resistant rickets (I group), 68 children with vitamin D-dependent rickets (II group), and the control group included 61 children of the same ages. The patients were divided into 3 age groups: I group of 0-5 years (deciduous/milk teeth occlusion), II group of 6-12 of years (mixed bite), III group of 13-18 years (permanent occlusion). For the qualitative data the differences between the groups were detected by using F criteria but for the quantitative data the differences between the groups were detected by Student's t test for independent selection. Mathematical processing was performed using statistical software SPSS-22. In all three groups the gingivitis of mild and moderate forms were fixed, among them acute course was revealed only in the group of vitamin D-resistant rickets. The rate of chronic, local, catarrhal and generalized gingivitis in the group of vitamin D-resistant rickets was reliably higher in comparison with both vitamin D-dependant rickets and control groups. In addition, a mild form of periodontitis with chronic course was revealed in all three groups the rate of which was reliably higher in the group of vitamin D-resistant rickets comparing with the ones of vitamin D-dependant rickets and control groups. the rate of inflammatory periodontal diseases in children with vitamin D-resistant rickets is higher than in children with vitamin D-dependent rickets and the control groups.

  18. Combined effects of elevated CO{sub 2} and natural climatic variation on leaf spot diseases of redbud and sweetgum trees

    Energy Technology Data Exchange (ETDEWEB)

    McElrone, Andrew J., E-mail: ajmcelrone@ucdavis.ed [USDA-ARS, Crops Pathology and Genetics Research Unit, 2154 RMI North, Davis, CA 95616 (United States); Department of Viticulture and Enology, University of California, Davis, CA 95616 (United States); Hamilton, Jason G. [Department of Biology, Ithaca College, Ithaca, NY 14850 (United States); Krafnick, Anthony J. [Department of Biology, Saint Joseph' s University, Philadelphia, PA 19131 (United States); Aldea, Mihai; Knepp, Rachel G.; DeLucia, Evan H. [Department of Plant Biology, University of Illinois, Urbana-Champaign, Urbana-Champaign, IL 61801 (United States)

    2010-01-15

    Atmospheric CO{sub 2} concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. In this study conducted over five years, we assessed how elevated CO{sub 2} and interannual climatic variability affect Cercospora leaf spot diseases of two deciduous trees. Climatic data varied considerably between the five years and altered disease expression. Disease incidence and severity for both species were greater in years with above average rainfall. In years with above average temperatures, disease incidence for Liquidambar styraciflua was decreased significantly. When significant changes did occur, disease incidence and severity always increased under elevated CO{sub 2}. Chlorophyll fluorescence imaging of leaves revealed that any visible increase in disease severity induced by elevated CO{sub 2} was mitigated by higher photosynthetic efficiency in the remaining undamaged leaf tissue and in a halo surrounding lesions. - Climatic variation had a greater impact than elevated CO{sub 2} on Cercospora diseases, especially since leaf photosynthetic efficiency increased under elevated CO{sub 2}.

  19. Resistance to infectious diseases is a heritable trait in rabbits.

    Science.gov (United States)

    Gunia, M; David, I; Hurtaud, J; Maupin, M; Gilbert, H; Garreau, H

    2015-12-01

    Selection for disease resistance is a powerful way to improve the health status of herds and to reduce the use of antibiotics. The objectives of this study were to estimate 1) the genetic parameters for simple visually assessed disease syndromes and for a composite trait of resistance to infectious disease including all syndromes and 2) their genetic correlations with production traits in a rabbit population. Disease symptoms were recorded in the selection herds of 2 commercial paternal rabbit lines during weighing at the end of the test (63 and 70 d of age, respectively). Causes of mortality occurring before these dates were also recorded. Seven disease traits were analyzed: 3 elementary traits visually assessed by technicians on farm (diarrhea, various digestive syndromes, and respiratory syndromes), 2 composite traits (all digestive syndromes and all infectious syndromes), and 2 mortality traits (digestive mortality and infectious mortality). Each animal was assigned only 1 disease trait, corresponding to the main syndrome ( = 153,400). Four production traits were also recorded: live weight the day before the end of test on most animals ( = 137,860) and cold carcass weight, carcass yield, and perirenal fat percentage of the carcass on a subset of slaughtered animals ( = 13,765). Records on both lines were analyzed simultaneously using bivariate linear animal models after validation of consistency with threshold models applied to logit-transformed traits. The heritabilities were low for disease traits, from 0.01 ± 0.002 for various digestive syndromes to 0.04 ± 0.004 for infectious mortality, and moderate to high for production traits. The genetic correlations between digestive syndromes were high and positive, whereas digestive and respiratory syndromes were slightly negatively correlated. The genetic correlations between the composite infectious disease trait and digestive or respiratory syndromes were moderate. Genetic correlations between disease and

  20. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  1. Effects of topical application of fipronil spot-on on dogs against the Chagas disease vector Triatoma infestans

    OpenAIRE

    Gürtler, Ricardo E.; Ceballos, Leonardo A.; Stariolo, Raúl; Kitron, Uriel; Reithinger, Richard

    2008-01-01

    We assessed the insecticidal effects of fipronil spot-on applied to experimental dogs on the blood-feeding success and other vital parameters of the Trypanosoma cruzi vector Triatoma infestans. In the first trial, the cumulative mortality of 30 third or fourth instar nymphs exposed to eight fipronil-treated dogs differed significantly from those exposed to untreated dogs at 1 week post-treatment, but not at baseline or at 2–6 weeks post-treatment. In the second trial, the effects of multiple ...

  2. Role of Dehydrodiferulates in Maize Resistance to Pests and Diseases

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    Rosa A. Malvar

    2010-02-01

    Full Text Available Phenolic esters have attracted considerable interest due to the potential they offer for peroxidase catalysed cross-linking of cell wall polysaccharides. Particularly, feruloyl residues undergo radical coupling reactions that result in cross-linking (intra-/intermolecular between polysaccharides, between polysaccharides and lignin and, between polysaccharides and proteins. This review addresses for the first time different studies in which it is established that cross-linking by dehydrodiferulates contributes to maize’s defences to pests and diseases. Dehydrodiferulate cross-links are involved in maize defence mechanisms against insects such as the European, Mediterranean, and tropical corn borers and, storage pest as the maize weevil. In addition, cross-links are also discussed to be involved in genetic resistance of maize to fungus diseases as Gibberella ear and stalk rot. Resistance against insects and fungus attending dehydrodiferulates could go hand in hand. Quantitative trait loci mapping for these cell wall components could be a useful tool for enhancing resistance to pest and diseases in future breeding programs.

  3. Development of a Loop-Mediated Isothermal Amplification Assay for Rapid and Specific Identification of ACT Producing Alternaria alternata, the Agent of Brown Spot Disease in Tangerine.

    Science.gov (United States)

    Moghimi, Hamid; Moradi, Amir; Hamedi, Javad; Basiri, Mina

    2016-03-01

    Rapid, accurate, and easy identification of pathogenic agents has always been important in medicine, veterinary, and agriculture. The brown spot infection is among the most common diseases in tangerine caused by Alternaria alternata. Due to the existence of seven various pathotypes of A. alternata species, it is challenging and time consuming to detect a pathotype responsible for citrus brown spot. In this study, we were seeking a rapid and specific approach to identify the tangerine pathotype within the A. alternata-pathogenic species, using the loop-mediated isothermal amplification (LAMP) method and actts2 gene as a marker molecule. Nine pathogenic samples were obtained from the region of Ramsar, Iran, and certified as A. alternata-pathogenic isolates. Specific primers were designed for regions coding for Alternaria citri toxin (ACT), and the PCR and LAMP reactions were performed. Our data showed that the primers designed for the tangerine pathotype of A. alternata were specific, and in both reactions, positive results were only observed in desired pathotypes. In the other pathotypes of this species as well as other standard fungal samples as negative controls, no positive result was observed. Therefore, our results suggest the possibility to detect the tangerine-specific A. alternata pathotype from other related species with a high accuracy and in early stages of the disease.

  4. Resistance gene homologues in melon are linked to genetic loci conferring disease and pest resistance.

    Science.gov (United States)

    Brotman, Y.; Silberstein, L.; Kovalski, I.; Perin, C.; Dogimont, C.; Pitrat, M.; Klingler, J.; Thompson, A.; Perl-Treves, R.

    2002-05-01

    Genomic and cDNA fragments with homology to known disease resistance genes (RGH fragments) were cloned from Cucumis melo using degenerate-primer PCR. Fifteen homologues of the NBS-LRR gene family have been isolated. The NBS-LRR homologues show high divergence and, based on the partial NBS-fragment sequences, appear to include members of the two major subfamilies that have been described in dicot plants, one that possesses a TIR-protein element and one that lacks such a domain. Genomic organization of these sequences was explored by DNA gel-blot analysis, and conservation among other Cucurbitaceae was assessed. Two mapping populations that segregate for several disease and pest resistance loci were used to map the RGH probes onto the melon genetic map. Several NBS-LRR related sequences mapped to the vicinity of genetic loci that control resistance to papaya ringspot virus, Fusarium oxysporum race 1, F. oxysporum race 2 and to the insect pest Aphis gossypii. The utility of such markers for breeding resistant melon cultivars and for cloning the respective R-genes is discussed.

  5. Visualization of Spot- welding Resistance

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    Michal Černý

    2016-01-01

    Full Text Available This contribution devotes to monitoring of processes running during joining of steel sheets by incadescent so called point welding using non-destructive trial method – acoustic emission (AE. The joining process is detailed described within experimental measuring from the point of view of metallurgic effects runnig during weld creation (records obtained by means of AE method. It takes into consideration quality of joined steels within welding data of steel producer. Steel welding (determined by chemical composition during mechanical verification and firmness of welds consider results of measurement AE and fracture effect of point joints. The measurement also demonstrates conclusion about connection of metallurgic processes with material wave effects (AE measurement and their impact on firmness of joint at steel with guaranteed welding, difficult welding and at their potential combination.

  6. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  7. Geographical distribution of myrothecium leaf spot disease of momordica charantial L. caused by myrothecium roridum tode in agro-ecological zone of punjab, Pakistan

    International Nuclear Information System (INIS)

    Din, G. M.; Farooq, S.; Khan, S. N.; Imani, J.; Naz, S.

    2017-01-01

    A series of field surveys were carried out during July-October 2012-14 for the development of disease distribution map and updating the index of Myrothecium leaf spot of Momordica charantia (Bitter gourd) in Punjab province. A total of 29 districts were surveyed belonging to 9 sub agro ecological zones of Punjab. The index was calculated on the basis of incidence, prevalence and severity of the disease. The information from stakeholders was gathered through field scouting, formal and informal discussions. Data on socioeconomics was collected by a structured questionnaire. The symptomatic plants and soil specimens were collected form diseased field and transferred to lab for onward studies on host-pathogen characterization and management. Infection development on the plant was investigated on a (0-5) visual severity rating scale. Fungus was isolated, identified on morphological and molecular characteristics as Myrothecium roridum and cultures were deposited to First Fungal Culture Bank of Pakistan (Accession No. FCBP 1155) and Leibniz-institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany (Accession No. DSM 28971). Data gathered highlighted dominance of the disease in mixed cropping zone of Punjab province. Highest disease index (31%) was recorded in mixed cropping zone and lowest (3%) in D.G khan zone. However its severity may vary due to adopted cultural and chemical practices by individual farmers. The investigations strengthen the involvement of irrigation technique, soil type and cropping history in introduction and sporadic occurrence of the disease. (author)

  8. Detection of multi-tomato leaf diseases (late blight, target and bacterial spots) in different stages by using a spectral-based sensor.

    Science.gov (United States)

    Lu, Jinzhu; Ehsani, Reza; Shi, Yeyin; de Castro, Ana Isabel; Wang, Shuang

    2018-02-12

    Several diseases have threatened tomato production in Florida, resulting in large losses, especially in fresh markets. In this study, a high-resolution portable spectral sensor was used to investigate the feasibility of detecting multi-diseased tomato leaves in different stages, including early or asymptomatic stages. One healthy leaf and three diseased tomato leaves (late blight, target and bacterial spots) were defined into four stages (healthy, asymptomatic, early stage and late stage) and collected from a field. Fifty-seven spectral vegetation indices (SVIs) were calculated in accordance with methods published in previous studies and established in this study. Principal component analysis was conducted to evaluate SVIs. Results revealed six principal components (PCs) whose eigenvalues were greater than 1. SVIs with weight coefficients ranking from 1 to 30 in each selected PC were applied to a K-nearest neighbour for classification. Amongst the examined leaves, the healthy ones had the highest accuracy (100%) and the lowest error rate (0) because of their uniform tissues. Late stage leaves could be distinguished more easily than the two other disease categories caused by similar symptoms on the multi-diseased leaves. Further work may incorporate the proposed technique into an image system that can be operated to monitor multi-diseased tomato plants in fields.

  9. Expression of a novel antimicrobial peptide Penaeidin4-1 in creeping bentgrass (Agrostis stolonifera L. enhances plant fungal disease resistance.

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    Man Zhou

    Full Text Available BACKGROUND: Turfgrass species are agriculturally and economically important perennial crops. Turfgrass species are highly susceptible to a wide range of fungal pathogens. Dollar spot and brown patch, two important diseases caused by fungal pathogens Sclerotinia homoecarpa and Rhizoctonia solani, respectively, are among the most severe turfgrass diseases. Currently, turf fungal disease control mainly relies on fungicide treatments, which raises many concerns for human health and the environment. Antimicrobial peptides found in various organisms play an important role in innate immune response. METHODOLOGY/PRINCIPAL FINDINGS: The antimicrobial peptide - Penaeidin4-1 (Pen4-1 from the shrimp, Litopenaeus setiferus has been reported to possess in vitro antifungal and antibacterial activities against various economically important fungal and bacterial pathogens. In this study, we have studied the feasibility of using this novel peptide for engineering enhanced disease resistance into creeping bentgrass plants (Agrostis stolonifera L., cv. Penn A-4. Two DNA constructs were prepared containing either the coding sequence of a single peptide, Pen4-1 or the DNA sequence coding for the transit signal peptide of the secreted tobacco AP24 protein translationally fused to the Pen4-1 coding sequence. A maize ubiquitin promoter was used in both constructs to drive gene expression. Transgenic turfgrass plants containing different DNA constructs were generated by Agrobacterium-mediated transformation and analyzed for transgene insertion and expression. In replicated in vitro and in vivo experiments under controlled environments, transgenic plants exhibited significantly enhanced resistance to dollar spot and brown patch, the two major fungal diseases in turfgrass. The targeting of Pen4-1 to endoplasmic reticulum by the transit peptide of AP24 protein did not significantly impact disease resistance in transgenic plants. CONCLUSION/SIGNIFICANCE: Our results

  10. 'CM 88' - A multiple disease resistant chickpea mutant variety

    International Nuclear Information System (INIS)

    Haq, M.A.; Hassan, Mahmudul; Sadiq, M.

    2001-01-01

    Full text: Chickpea is the most important grain legume crop of Pakistan. Ascochyta blight (Ascochyta rabiei) and Fusarium wilt (Fusarium oxysporum F. sp cicer) are most serious diseases, having the potential to devastate a crop. A multiple disease resistant and high yielding mutant CM 88 has been developed through 100 Gy gamma irradiation treatment of variety 'C 727'. This was once a widely grown and popular variety, which lost its resistance to Ascochyta and was replaced. The selection of mutants was performed in the M2 generation grown in the Ascochyta blight nursery and sixteen mutants were selected. In the subsequent generations CM 88 proved resistant to both Ascochyta blight and Fusarium wilt, and exhibited superiority in agronomic characteristics. CM 88 was also tested for many years in the various yield trials on research stations and farmers fields throughout the country. In these trials it out yielded both the parent and standard varieties. The mutant CM 88 has been approved by the Punjab Seed Council on 27 October 1994 for general cultivation in the Punjab Province, especially the Thal area which accounts for more than 70% of the area under chickpea cultivation. (author)

  11. Omics Approach to Identify Factors Involved in Brassica Disease Resistance.

    Science.gov (United States)

    Francisco, Marta; Soengas, Pilar; Velasco, Pablo; Bhadauria, Vijai; Cartea, Maria E; Rodríguez, Victor M

    2016-01-01

    Understanding plant's defense mechanisms and their response to biotic stresses is of fundamental meaning for the development of resistant crop varieties and more productive agriculture. The Brassica genus involves a large variety of economically important species and cultivars used as vegetable source, oilseeds, forage and ornamental. Damage caused by pathogens attack affects negatively various aspects of plant growth, development, and crop productivity. Over the last few decades, advances in plant physiology, genetics, and molecular biology have greatly improved our understanding of plant responses to biotic stress conditions. In this regard, various 'omics' technologies enable qualitative and quantitative monitoring of the abundance of various biological molecules in a high-throughput manner, and thus allow determination of their variation between different biological states on a genomic scale. In this review, we have described advances in 'omic' tools (genomics, transcriptomics, proteomics and metabolomics) in the view of conventional and modern approaches being used to elucidate the molecular mechanisms that underlie Brassica disease resistance.

  12. Cardiovascular responses of peripheral artery disease patients during resistance exercise

    Directory of Open Access Journals (Sweden)

    Ana Patrícia Ferreira Gomes

    2015-03-01

    Full Text Available BACKGROUND: Resistance training has been used for the treatment of patients with peripheral artery disease (PAD. However, cardiovascular responses during this type of exercise have not been fully elucidated in these patients. OBJECTIVES: To analyze the cardiovascular responses during resistance exercise and to verify whether there are any correlations between these responses and disease severity or blood pressure levels in patients with PAD. METHODS: Seventeen PAD patients performed one set of 10 repetitions of knee extension exercise with an intensity of 50% of one repetition maximum. The responses of systolic blood pressure (SBP, diastolic blood pressure (DBP and heart rate (HR were continuously monitored using the finger photoplethysmography technique. The rate-pressure product (RPP was obtained by multiplication of SBP and HR. RESULTS: During the resistance exercises there were significant increases in SBP (126 ± 14 vs. 184 ± 20 mmHg, p<0.001, DBP (68 ± 8 vs. 104 ± 14 mmHg, p<0.001, HR (76 ± 18 vs. 104 ± 30 bpm, p<0.001 and RPP (9523 ± 2115 vs. 19103 ± 6098 mmHg x bpm, p<0.001. A negative correlation was observed between relative change (Δ in SBP and SBP at rest (r =-0.549, p=0.022. On the other hand, there was no relationship between Δ SBP and the ankle-brachial index (r=0.076, p=0.771. CONCLUSION: Increases in cardiovascular variables were observed during resistance exercise in PAD patients. The highest increases occurred in patients with lower SBP levels at resting.

  13. Resistive index for kidney evaluation in normal and diseased cats.

    Science.gov (United States)

    Tipisca, Vlad; Murino, Carla; Cortese, Laura; Mennonna, Giuseppina; Auletta, Luigi; Vulpe, Vasile; Meomartino, Leonardo

    2016-06-01

    The objectives were to determine the resistive index (RI) in normal cats and in cats with various renal diseases, and to evaluate the effect of age on RI. The subjects were cats that had ultrasonography (US) of the urinary tract and RI measurement at our centre between January 2003 and April 2014. Based on clinical evaluation, biochemical and haematological tests, urinalysis and US, the cats were classified as healthy or diseased. RI measurements were made from the interlobar or arcuate arteries. Data were analysed for differences between the right and the left kidney, the two sexes, different age groups in healthy cats, and between healthy and diseased cats. A total of 116 cats (68 males, 48 females) were included: 24 healthy and 92 diseased. In the healthy cats, RI (mean ± SD) differed significantly (P = 0.02) between the right kidney (0.54 ± 0.07) and the left kidney (0.59 ± 0.08). For the left kidney, RI was significantly higher in cats with chronic kidney disease (0.73 ± 0.12) and acute kidney injury (0.72 ± 0.08) (P = 0.0008). For the right kidney, RI was significantly higher in cats with chronic kidney disease (0.72 ± 0.11), acute kidney injury (0.74 ± 0.08), polycystic kidney disease (0.77 ± 0.11) and renal tumour (0.74 ± 0.001) (P cats, useful in the differential diagnosis of diffuse renal diseases. While it does not change with the age of the cat, ultrasonographers should be aware that RI may differ between the two kidneys. © ISFM and AAFP 2015.

  14. Insulin resistance in clinical and experimental alcoholic liver disease.

    Science.gov (United States)

    Carr, Rotonya M; Correnti, Jason

    2015-09-01

    Alcoholic liver disease (ALD) is the number one cause of liver failure worldwide; its management costs billions of healthcare dollars annually. Since the advent of the obesity epidemic, insulin resistance (IR) and diabetes have become common clinical findings in patients with ALD; and the development of IR predicts the progression from simple steatosis to cirrhosis in ALD patients. Both clinical and experimental data implicate the impairment of several mediators of insulin signaling in ALD, and experimental data suggest that insulin-sensitizing therapies improve liver histology. This review explores the contribution of impaired insulin signaling in ALD and summarizes the current understanding of the synergistic relationship between alcohol and nutrient excess in promoting hepatic inflammation and disease. © 2015 New York Academy of Sciences.

  15. Construction and characterization of a bacterial artificial chromosome library of the causal agent of Black Sigatoka fungal leaf spot disease of banana and plantain, Mycosphaerella fijiensis.

    Science.gov (United States)

    Canto-Canché, Blondy; Guillén-Maldonado, Diana Karina; Peraza-Echeverría, Leticia; Conde-Ferráez, Laura; James-Kay, Andrew

    2007-05-01

    A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain, Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes. After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector). One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9 x genome equivalents, which was supported by hybridization results with homologous and heterologous probes.

  16. PDT in periodontal disease of HAART resistance patients

    Science.gov (United States)

    Giovani, Elcio M.; Noro-Filho, Gilberto A.; Caputo, Bruno V.; Casarin, Renato; Costa, Claudio; Salgado, Daniela; Santos, Camila C.

    2016-03-01

    HIV/Aids patients present a change of microbiota associated with host immunodeficiency. Photodynamic therapy (PDT) showed as a promising and viable alternative in reducing microbiota. Present study evaluate effectiveness of photodynamic therapy in periodontal disease of AIDS patients with highly activity antiretroviral therapy (HAART) failure, measuring the clinical periodontal parameters and periodontal microbiota. Twelve patients with HARRT resistance (R group) divided into two groups (control and PDT) and 12 patients with no HAART resistance (NR group) divided into two groups (control and PDT). The results show the difference in baseline of CD4 cells count, NR group 640.0 +/- 176.2 cells/mm3 R group and 333.3 +/- 205.8 cells / mm3 (pperiodontal parameters (PD and CAL), PDT was more effective than the control group only in the NR group (p periodontal parameters between the both R groups (p>0.05%). Microbiological evaluation in R group presents a general reduction in the Aa at 3 and 6 months. Furthermore, demonstrated a reduction of Pg in all groups at 6 months and in R group at 3 months. The impact assessment of photodynamic therapy in patients with different levels of immunosuppression determined that the combination of mechanical periodontal treatment with photodynamic therapy in patients with HAART failure did not cause additional benefits. Therefore, PDT in this study could not been indicated in HAART resistance patients.

  17. Dystrophin gene expression and intracellular calcium changes in the giant freshwater prawn,Macrobrachium rosenbergii, in response to white spot symptom disease infection.

    Science.gov (United States)

    Noor, Anees Fathima; Soo, Tze Chiew Christie; Ghani, Farhana Mohd; Goh, Zee Hong; Khoo, Li Teng; Bhassu, Subha

    2017-12-01

    Dystrophin, an essential protein functional in the maintenance of muscle structural integrity is known to be responsible for muscle deterioration during white spot syndrome virus (WSSV) infection among prawn species. Previous studies have shown the upregulation of dystrophin protein in Macrobrachium rosenbergii (the giant freshwater prawn) upon white spot syndrome virus (WSSV) infection. The literature has also suggested the important role of calcium ion alterations in causing such muscle diseases. Thus, the interest of this study lies within the linkage between dystrophin functioning, intracellular calcium and white spot syndrome virus (WSSV) infection condition. In this study, the dystrophin gene from M. rosenbergii (MrDys) was first characterised followed by the characterization of dystrophin gene from a closely related shrimp species, Penaeus monodon (PmDys). Dystrophin sequences from different phyla were then used for evolutionary comparison through BLAST analysis, conserved domain analysis and phylogenetic analysis. The changes in mRNA expression levels of dystrophin and the alteration of intracellular calcium concentrations in WSSV infected muscle cells were then studied. A 1246 base pair long dystrophin sequence was identified in the giant freshwater prawn, Macrobrachium rosenbergii ( MrDys ) followed by 1082 base pair long dystrophin sequence in P. monodon ( PmDys ). Four conserved domains were identified from the thirteen dystrophin sequences compared which were classified into 5 different phyla. From the phylogenetic analysis, aside from PmDys, the characterised MrDys was shown to be most similar to the invertebrate phylum of Nematoda. In addition, an initial down-regulation of dystrophin gene expression followed by eventual up-regulation, together with an increase in intracellular calcium concentration [Ca 2+ ] i were shown upon WSSV experimental infection. Both the functionality of the dystrophin protein and the intracellular calcium concentration were

  18. Effects of Microencapsulated Synbiotic Administration at Different Dosages against heavy co-infection of White Spot Disease (WSD and Vibrio harveyi in Pacific White Shrimp (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Yunarty Yunarty

    2016-12-01

    Full Text Available White spot disease (WSD is one of infectious disease in shrimp caused by white spot syndrome virus (WSSV. This study aimed to determine the dosage immunological effects and growth performances of microencapsulated synbiotic (Bacillus NP5 and mannan oligosaccharide at different dosages on Pacific white shrimp.  The microencapsulated synbiotic   was administered as feed supplementation  against the co-infection of   WSSV and Vibrio harveyi. Synbiotic was encapsulated by spray drying method, further feed supplemented to Pacific white shrimp for 30 days at a  dosages of 0.5% (A, 1% (B, 2% (C and control treatments, i.e. without any microencapsulated synbiotic administration as positive control (D and negative control (E. The challenge test was performed on day 30 after feeding supplementation, then the experimental shrimps were injected by WSSV intramuscularly   at the infective dosage of 104 copies.-ml-1. Afterwards,   24 hours after WSSV injection the shrimps were immersed in water contained cells suspension of V. harveyi  at the cells population dosage of 106 CFU-.ml-1. All synbiotic treatments showed better results with the values of Total Haemocyte Count (THC, Phenoloxidase (PO and Respiratory Burst (RB, were higher (P<0.05 compared to positive control. The specific growth rates (SGR of A, B and C showed higher than both controls of D and E. The feed conversion ratio (FCR value of synbiotic treatments were lower (P<0.05 than both controls. However, the administration of microencapsulated synbiotic have not been able to prevent heavy impact of WSSV and V. harveyi co-infection due to lower SR and mortality pattern which continued to increase.   Keywords: Synbiotic, Litopenaeus vannamei, WSSV, Vibrio harveyi, co-infection

  19. Are stomatal responses the key to understanding the cost of fungal disease resistance in plants?

    Science.gov (United States)

    Withers, Catherine M; Gay, Alan P; Mur, Luis A J

    2011-07-01

    Preventing disease in cereal crops is important for maintaining productivity and as the availability and efficacy of chemical control becomes reduced the emphasis on breeding for disease resistance increases. However, there is evidence that disease resistance may be physiologically costly to the plant and we ask if understanding stomatal responses to fungal attack is the key to minimising reductions in growth associated with disease resistance. Copyright © 2011 Society of Chemical Industry.

  20. Resistance to stem canker, frogeye leaf spot and powdery mildew of soybean lines lacking lipoxigenases in the seeds Resistência ao cancro-da-haste, à cercosporiose e ao oídio de linhagens de soja sem lipoxigenases nas sementes

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Osório Martins

    2002-12-01

    Full Text Available The soybean [Glycine max (L. Merrill] crop holds a prominent position in the Brazilian economy because of the extension of the planted area and volume of grain production, but the beany flavor has been a limiting factor for soybean derivatives consumption by western population. This flavor is produced mainly by action of lipoxygenase enzymes (Lox1, Lox2 and Lox3, present in some commercial varieties. The genetic elimination of the alleles that codify these enzymes is the most appropriate way to avoid problems associated to this deleterious flavor. To elucidate the effect of seed lipoxygenase elimination on the resistance to plant pathogens, normal varieties of soybean (FT-Cristalina RCH, Doko RC and IAC-12 and their backcross-derived lines, both with the three lipoxygenases present in their seeds (triple-positive, TP and without the three lipoxygenases (triple-null, TN, were tested for their resistance to stem canker (Diaporthe phaseolorum f.sp. meridionalis, frogeye leaf spot (Cercospora sojina Hara, and powdery mildew (Microsphaera diffusa Cke. & Pk.. All genetic materials studied were resistant to stem canker. FT-Cristalina RCH and Doko-RC and their TP and TN lines were resistant to frogeye leaf spot. IAC-12 and its derived lines not only presented a higher disease index, but also the derived lines, TP and TN, were more susceptible, indicating the loss of genes for disease resistance in the backcrosses. There was no association between the elimination of lipoxygenases from the seeds with the resistance to frogeye leaf spot. In relation to the powdery mildew, TP or TN lines presented similar or higher resistance than their respective recurrent parents whose susceptibility appeared in the following order: IAC-12, less susceptible, Doko-RC, intermediate and FT-Cristalina RCH, more susceptible.A cultura da soja [Glycine max (L. Merrill] ocupa lugar de destaque na economia brasileira, tanto em termos de área plantada, quanto de produção de gr

  1. Quantitative trait loci for resistance to maize streak virus disease in ...

    African Journals Online (AJOL)

    Maize streak virus disease is an important disease of maize in Kenya. In this study, we mapped and characterized quantitative trait loci affecting resistance to maize streak virus in maize populations of S4 families from the cross of one resistant MAL13 and one susceptible MAL9 recombinant inbred lines. Resistance was ...

  2. Insulin Resistance in Patients with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Min-Tser Liao

    2012-01-01

    Full Text Available Metabolic syndrome and its components are associated with chronic kidney disease (CKD development. Insulin resistance (IR plays a central role in the metabolic syndrome and is associated with increased risk for CKD in nondiabetic patients. IR is common in patients with mild-to-moderate stage CKD, even when the glomerular filtration rate is within the normal range. IR, along with oxidative stress and inflammation, also promotes kidney disease. In patients with end stage renal disease, IR is an independent predictor of cardiovascular disease and is linked to protein energy wasting and malnutrition. Systemic inflammation, oxidative stress, elevated serum adipokines and fetuin-A, metabolic acidosis, vitamin D deficiency, depressed serum erythropoietin, endoplasmic reticulum stress, and suppressors of cytokine signaling all cause IR by suppressing insulin receptor-PI3K-Akt pathways in CKD. In addition to adequate renal replacement therapy and correction of uremia-associated factors, thiazolidinedione, ghrelin, protein restriction, and keto-acid supplementation are therapeutic options. Weight control, reduced daily prednisolone dosage, and the use of cyclosporin decrease the risk of developing new-onset diabetes after kidney transplantation. Improved understanding of the pathogenic mechanisms underlying IR in CKD may lead to more effective therapeutic strategies to reduce uremia-associated morbidity and mortality.

  3. Disease Resistant Fish and Shellfish Are within Reach: A Review

    Directory of Open Access Journals (Sweden)

    Trygve Gjedrem

    2015-03-01

    Full Text Available Disease in fish and shellfish is one of the main problems facing aquaculture production. Therefore, all attempts should be made to increase the rate of survival and, thus, reduce economic losses. Much has been done to develop vaccines and medical treatments to reduce mortality; and however, farming of aquatic species has a long way to go to optimize the environmental conditions for the animals and, thus, reduce stress and improve animal welfare. However, the good news is that there is the potential to increase disease resistance by selective breeding. By challenge-testing fingerlings from a number of families per generation, and including the rate of survival in the breeding goal, the results so far are very promising. By focusing on one disease at a time it is possible to increase the rate of survival by at least 12.5% per generation for most diseases studied. Unfortunately, selective breeding is only used to a small degree in aquatic species. In 2010, it was estimated that only 8.2% of aquaculture production was based on genetically improved stocks.

  4. Renal resistive index and mortality in chronic kidney disease.

    Science.gov (United States)

    Toledo, Clarisse; Thomas, George; Schold, Jesse D; Arrigain, Susana; Gornik, Heather L; Nally, Joseph V; Navaneethan, Sankar D

    2015-08-01

    Renal resistive index (RRI) measured by Doppler ultrasonography is associated with cardiovascular events and mortality in hypertensive, diabetic, and elderly patients. We studied the factors associated with high RRI (≥0.70) and its associations with mortality in chronic kidney disease patients without renal artery stenosis. We included 1962 patients with an estimated glomerular filtration rate of 15 to 59 mL/min per 1.73 m(2) who also had RRI measured (January 1, 2005, to October 2011) from an existing chronic kidney disease registry. Participants with renal artery stenosis (60%-99% or renal artery occlusion) were excluded. Multivariable logistic regression model was used to study factors associated with high RRI (≥0.70), and its association with mortality was studied using Kaplan-Meier plots and Cox proportional hazards model. Hypertension was prevalent in >90% of the patients. In the multivariable logistic regression, older age, female sex, diabetes mellitus, coronary artery disease, peripheral vascular disease, higher systolic blood pressure, and the use of β blockers were associated with higher odds of having RRI≥0.70. During a median follow-up of 2.2 years, 428 patients died. After adjusting for covariates, RRI≥0.70 was associated with increased mortality (adjusted hazard ratio, 1.29; 95% confidence interval, 1.02-1.65; Pchronic kidney disease. Noncardiovascular/non-malignancy-related deaths were higher in those with RRI≥0.70. RRI≥0.70 is associated with higher mortality in hypertensive chronic kidney disease patients without clinically significant renal artery stenosis after accounting for other significant risk factors. Its evaluation may allow early identification of those who are at risk thereby potentially preventing or delaying adverse outcomes. © 2015 American Heart Association, Inc.

  5. Dietary Administration of Yeast β 1,3 1,6 Glucan on Immunity and Survival Rate of White Indian Shrimp, Fennerpenaeus indicus Challenged with White Spot Syndrome Disease

    Directory of Open Access Journals (Sweden)

    Babak Ghaednia

    2012-01-01

    Full Text Available The potency of dietary β 1,3 1,6 glucan (BG, derived from Saccharomyces cerevisiae, in stimulating the non-specific immunity of white Indian shrimp, Fennerpenaeus indicus (Milne-Edwards, 1837 and improving its resistance to white spot syndrome disease were investigated. F. indicus (11.32±1.20 g were fed for 20 days on a series of treatment diets containing graded levels of BG (blank control, 0 as control, 2, 10, 20 g kg-1 feed and were then challenged by injection of WSSV virus. Total haemocyte count (THC, total plasma protein (TPP, phagocytic activity (PA and Bacterial Clearance activity (BC were measured at days 0, 7, 14, 21 after BG feeding, and shrimp survival rate was also recorded daily after challenge. THC, TPP, PA and BC of the 10 and 20 g kg-1 BG treatments were significantly higher (P<0.05 by day 14 than control and 2 g kg-1 treatment shrimp. Survival rate of shrimp fed with the diet containing 10 and 20 g kg-1 BG after 21 days, were 53.32±5.77 and 48.32±5.77%, respectively. Accordingly, oral administration of BG at an optimal level of 10 g kg-1 diet for 20 days efficaciously stimulate the immune defense and improve the survival rate of WSV-infected F. indicus.

  6. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... execution within boundaries). Moreover, during the execution of the workload, SpotADAPT suggests a redeployment if the current spot instance gets terminated by Amazon or a better deployment becomes possible due to fluctuations of the spot prices. The approach is evaluated using the actual execution times...

  7. Tagging of resistance gene(s) to rhizomania disease in sugar beet ...

    African Journals Online (AJOL)

    The rhizomania disease is one of the most important diseases in Iran and some other parts of the world which potentially could play a role in decreasing sugar yield in fields. One approach to combat with this disease is the use of resistance varieties. This varieties have been identified which are having resistance genes to ...

  8. Comparison of protein profiles of beech bark disease-resistant or beech bark disease-susceptible American beech

    Science.gov (United States)

    Mary E. Mason; Marek Krasowski; Judy Loo; Jennifer. Koch

    2011-01-01

    Proteomic analysis of beech bark proteins from trees resistant and susceptible to beech bark disease (BBD) was conducted. Sixteen trees from eight geographically isolated stands, 10 resistant (healthy) and 6 susceptible (diseased/infested) trees, were studied. The genetic complexity of the sample unit, the sampling across a wide geographic area, and the complexity of...

  9. Regulatory circuitry governing fungal development, drug resistance, and disease.

    Science.gov (United States)

    Shapiro, Rebecca S; Robbins, Nicole; Cowen, Leah E

    2011-06-01

    Pathogenic fungi have become a leading cause of human mortality due to the increasing frequency of fungal infections in immunocompromised populations and the limited armamentarium of clinically useful antifungal drugs. Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are the leading causes of opportunistic fungal infections. In these diverse pathogenic fungi, complex signal transduction cascades are critical for sensing environmental changes and mediating appropriate cellular responses. For C. albicans, several environmental cues regulate a morphogenetic switch from yeast to filamentous growth, a reversible transition important for virulence. Many of the signaling cascades regulating morphogenesis are also required for cells to adapt and survive the cellular stresses imposed by antifungal drugs. Many of these signaling networks are conserved in C. neoformans and A. fumigatus, which undergo distinct morphogenetic programs during specific phases of their life cycles. Furthermore, the key mechanisms of fungal drug resistance, including alterations of the drug target, overexpression of drug efflux transporters, and alteration of cellular stress responses, are conserved between these species. This review focuses on the circuitry regulating fungal morphogenesis and drug resistance and the impact of these pathways on virulence. Although the three human-pathogenic fungi highlighted in this review are those most frequently encountered in the clinic, they represent a minute fraction of fungal diversity. Exploration of the conservation and divergence of core signal transduction pathways across C. albicans, C. neoformans, and A. fumigatus provides a foundation for the study of a broader diversity of pathogenic fungi and a platform for the development of new therapeutic strategies for fungal disease.

  10. Cognitive reserve, cortical plasticity and resistance to Alzheimer's disease.

    Science.gov (United States)

    Esiri, Margaret M; Chance, Steven A

    2012-03-01

    There are aspects of the ageing brain and cognition that remain poorly understood despite intensive efforts to understand how they are related. Cognitive reserve is the concept that has been developed to explain how it is that some elderly people with extensive neuropathology associated with dementia show little in the way of cognitive decline. Cognitive reserve is intimately related to cortical plasticity but this also, as it relates to ageing, remains poorly understood at the present time. Despite the shortcomings in understanding, we do have some knowledge on which to base efforts to minimise the likelihood of an elderly person developing dementia. For some risks the evidence is far from secure, but resistance to Alzheimer's disease (AD) appears from epidemiological studies to be contributed to by avoiding hypertension in middle life, obesity, depression, smoking and diabetes and head injury and by undertaking extended years of education, physical exercise, and social and intellectual pursuits in middle and late life. Nutritional factors may also promote healthy brain ageing. Resistance to AD is also contributed to by genetic factors, particularly apolipoprotein E2, but some combinations of other genetic polymorphisms as well. Although multiple factors and possible interventions may influence cognitive reserve and susceptibility to dementia, much more work is required on the mechanisms of action in order to determine which, if any, may improve the clinical and epidemiological picture. Understanding of how such factors operate may lead to new initiatives to keep the elderly population in the 21st century able to lead active and fulfilling lives.

  11. Loss of CMD2?mediated resistance to cassava mosaic disease in plants regenerated through somatic embryogenesis

    OpenAIRE

    Beyene, Getu; Chauhan, Raj Deepika; Wagaba, Henry; Moll, Theodore; Alicai, Titus; Miano, Douglas; Carrington, James C.; Taylor, Nigel J.

    2016-01-01

    Summary Cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) are the two most important viral diseases affecting cassava production in Africa. Three sources of resistance are employed to combat CMD: polygenic recessive resistance, termed CMD1, the dominant monogenic type, named CMD2, and the recently characterized CMD3. The farmer?preferred cultivar TME 204 carries inherent resistance to CMD mediated by CMD2, but is highly susceptible to CBSD. Selected plants of TME 204 produc...

  12. multiple disease resistance in snap bean genotypes in kenya

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    fungicide treatments were compared using the. Fisher's protected LSD test at 5% probability level. RESULTS. There were significant (P<0.05) differences among the F4, F6, and backcross populations, and among. HAB lines, SB lines and climbing snap lines in angular leaf spot, rust and anthracnose severity. (Tables 2 - 4).

  13. Low numbers of repeat units in variable number of tandem repeats (VNTR) regions of white spot syndrome virus are correlated with disease outbreaks.

    Science.gov (United States)

    Hoa, T T T; Zwart, M P; Phuong, N T; de Jong, M C M; Vlak, J M

    2012-11-01

    White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable number tandem repeats (VNTR) located in ORF75, ORF94 and ORF125. In the current study, we investigated whether or not the number of repeat units in the VNTRs correlates with virus outbreak status and/or shrimp farming practice. We analysed 662 WSSV samples from individual WSSV-infected Penaeus monodon shrimp from 104 ponds collected from two important shrimp farming regions of the Mekong Delta: Ca Mau and Bac Lieu. Using this large data set and statistical analysis, we found that for ORF94 and ORF125, the mean number of repeat units (RUs) in VNTRs was significantly lower in disease outbreak ponds than in non-outbreak ponds. Although a higher mean RU number was observed in the improved-extensive system than in the rice-shrimp or semi-intensive systems, these differences were not significant. VNTR sequences are thus not only useful markers for studying WSSV genotypes and populations, but specific VNTR variants also correlate with disease outbreaks in shrimp farming systems. © 2012 Blackwell Publishing Ltd.

  14. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H 2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  15. Seleção de famílias de feijoeiro resistente à antracnose e à mancha-angular Selection of common bean families resistant to anthracnose and angular leaf spot

    Directory of Open Access Journals (Sweden)

    Marcelo Geraldo de Morais Silva

    2006-10-01

    Full Text Available O objetivo deste trabalho foi identificar famílias de feijoeiro com resistência a Colletotrichum lindemuthianum e Phaeoisariopsis griseola e com outros fenótipos agronômicos desejáveis. As famílias utilizadas foram obtidas do cruzamento entre a linhagem H91, portadora de três alelos de resistência à antracnose, com três famílias F2:5 resistentes à mancha-angular, derivadas da cultivar Jalo EEP 558. Foi utilizado o delineamento látice quadrado em todos os experimentos. Inicialmente, foram avaliadas 144 famílias F2:3, no inverno de 2004, em Lavras, MG, com base no tipo de grão. Foram selecionadas 80 famílias F2:4 e avaliadas com a testemunha BRSMG Talismã, no período das águas de 2004/2005, no mesmo local. Considerando-se o tipo de grão e a resistência à mancha-angular e antracnose, foram mantidas 48 famílias F2:5, que foram avaliadas na seca de 2005, em Lavras e Lambari, MG. Essas 48 famílias passaram por inoculação das raças 2047, 73 e 1545 de C. lindemuthianum, para verificação da presença dos alelos de resistência Co-4², Co-5 e Co-7, respectivamente. Foram identificados genótipos da maioria das 48 famílias, quanto à reação à antracnose, das quais se destacaram quatro, em relação ao tipo de grão semelhante ao 'Carioca', de porte ereto, produtividade elevada e resistência à mancha-angular.The objective of this work was to select common bean families resistant to Colletotrichum lindemuthianum and Phaeoisariopsis griseola and, also, with superior agronomical traits. Families used were obtained from crosses of H91 lineage, bearer of three alleles resistant to anthracnose, and F2;5 families derived from the cultivar Jalo EEP 558, which is resistant to angular leaf spot. Square lattice design was used in all experiments. Initially the F2:3 families (144 were evaluated in the winter of 2004, in Lavras county, MG, Brazil, based on grain type. Eighty families (F2:4 were selected and evaluated with the check

  16. Dietary ambon lumut banana stem extract Musa cavendishii var. dwarf Paxton as an immunostimulant for white spot disease prevention in Pacific white shrimp Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Afriani Ramadhan

    2017-07-01

    Full Text Available ABSTRACT This study was aimed to evaluate the dietary ambon lumut banana Musa cavendishii var. dwarf Paxton stem extract on the immune responses, growth, and survival rate of Pacific white shrimp against white spot disease. Ambon banana steam extract was obtained by maceration method using ethanol. The shrimps fed by pellet containing ambon banana stem extracts with different dosages for 29 days, i.e designated as 0.1 (A; 0.3 (B, and 0.5 (C g/kg, the diet treatment without ambon banana stem extract without challenged test (K-, and diet treatment without ambon banana stem extract with challenged test (K+. Each treatment consisted of three replications. Feeding was conducted for 29 days of maintenance (four times a day. The results showed that the immune responses (average total hemocyte count: 45.15×106 cells/mL, phenoloxidase activity 1.03±0.08 OD, respiratory burst 0.95±0.04 OD, phagocytic activity 94.33±1.53%, growth (specific growth rate: 7.79±0.06%/day, feed ratio conversion was 52±0.01, and survival of treatment C (survival rate 100% were higher compared with the treatment K+ (total hemocyte count: 3.83×106 cells/mL, phenoloxidase activity 0.04±0.01 OD, respiratory burst 0.18±0.06 OD,  phagocytic activity 5.67±0.58%, specific growth rate: 2.61±0.08%/day, feed conversion ratio 2.11±0.02, survival rate: 50%. Therefore, banana stem extract at a dose of 0.5 g/kg everyday diet can be used to improve growth and nonspecific immune system against white spot disease on Pacific white shrimp. Keywords: Pacific white shrimp, white spot disease, immune response, Ambon banana stem extract  ABSTRAK Penelitian ini bertujuan untuk menguji dosis optimal ekstrak batang pisang ambon melalui pakan dalam meningkatkan respon imun, pertumbuhan dan kelangsungan hidup udang putih terhadap penyakit white spot. Ekstrak batang pisang ambon lumut Musa cavendishii var. dwarf  Paxton menggunakan metode maserasi dengan menggunakan pelarut etanol. Pakan

  17. Inheritance of rainbow trout Oncorhynchus mykiss spleen size and correlation with bacterial cold water disease resistance

    Science.gov (United States)

    Infectious disease causes substantial loss in aquaculture and selective breeding for increased innate resistance offers an attractive strategy for controlling disease. In 2005, the NCCCWA implemented a selective breeding program to increase rainbow trout survival following challenge with Flavobacte...

  18. Genetic analysis of resistance to six virus diseases in a multiple virus-resistant maize inbred line.

    Science.gov (United States)

    Zambrano, Jose Luis; Jones, Mark W; Brenner, Eric; Francis, David M; Tomas, Adriana; Redinbaugh, Margaret G

    2014-04-01

    Novel and previously known resistance loci for six phylogenetically diverse viruses were tightly clustered on chromosomes 2, 3, 6 and 10 in the multiply virus-resistant maize inbred line, Oh1VI. Virus diseases in maize can cause severe yield reductions that threaten crop production and food supplies in some regions of the world. Genetic resistance to different viruses has been characterized in maize populations in diverse environments using different screening techniques, and resistance loci have been mapped to all maize chromosomes. The maize inbred line, Oh1VI, is resistant to at least ten viruses, including viruses in five different families. To determine the genes and inheritance mechanisms responsible for the multiple virus resistance in this line, F1 hybrids, F2 progeny and a recombinant inbred line (RIL) population derived from a cross of Oh1VI and the virus-susceptible inbred line Oh28 were evaluated. Progeny were screened for their responses to Maize dwarf mosaic virus, Sugarcane mosaic virus, Wheat streak mosaic virus, Maize chlorotic dwarf virus, Maize fine streak virus, and Maize mosaic virus. Depending on the virus, dominant, recessive, or additive gene effects were responsible for the resistance observed in F1 plants. One to three gene models explained the observed segregation of resistance in the F2 generation for all six viruses. Composite interval mapping in the RIL population identified 17 resistance QTLs associated with the six viruses. Of these, 15 were clustered in specific regions of chr. 2, 3, 6, and 10. It is unknown whether these QTL clusters contain single or multiple virus resistance genes, but the coupling phase linkage of genes conferring resistance to multiple virus diseases in this population could facilitate breeding efforts to develop multi-virus resistant crops.

  19. Elicitors and soil management to induce resistance against fungal plant diseases

    OpenAIRE

    Tamm, L.; Thürig, B.; Fließbach, A.; Goltlieb, A. E.; Karavani, S.; Cohen, Y.

    2011-01-01

    Air-borne foliar diseases as well as soil-borne diseases can cause substantial losses in agricultural production systems. One of the strategies to overcome production losses caused by plant diseases is the targeted use of disease defence mechanisms that are inherent to plants. In this paper, the potential to enhance the plant’s health status either by inducing resistance through optimized soil management techniques or by foliar application of inducers of resistance is explored on the basis of...

  20. White Spot Syndrome Virus infection in Penaeus monodon is ...

    Indian Academy of Sciences (India)

    2013-11-06

    Nov 6, 2013 ... White Spot Syndrome Virus (WSSV) is a major pathogen in shrimp aquaculture, and its rampant spread has resulted in great economic loss. ... has been increasingly hampered by white spot syndrome disease caused by White Spot ..... metabolic proteins have additional roles in immunity and transcriptional ...

  1. Increased Level of IFN-γ and IL-4 Spot-Forming Cells on ELISPOT Assay as Biomarkers for Acute Graft-Versus-Host Disease and Concurrent Infections

    Directory of Open Access Journals (Sweden)

    Yoshihiro Komada

    2012-04-01

    Full Text Available Acute graft-versus-host disease (aGVHD remains a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Infections may coexist and in certain circumstances aggravate aGVHD. It was described that type 1 as well as type 2 cytokines are important mediators of aGVHD. We measured spot-forming cells (SFCs for interferon (IFN-γ, interleukin (IL-4, IL-10, and IL-17 in unstimulated peripheral blood from 80 patients with hematological disorders who underwent allogeneic hematopoietic stem cell transplantation by using the enzyme-linked immunospot (ELISPOT assay that reflects the ongoing in vivo immune status. A serial monitoring showed that both type 1 and type 2 cytokine SFCs were correlated with aGVHD activity. The numbers of IFN-γ and IL-4 SFCs in patients with grade II-IV aGVHD were significantly higher than those in patients with grade 0 and/or I aGVHD. Elevation of IFN-γ and IL-4 SFCs was significantly correlated with the severity of aGVHD, but not with infection itself, e.g., cytomegalovirus infection. Cytokine SFCs are clinically relevant biomarkers for the diagnostic and therapeutic evaluation of aGVHD and concurrent infection.

  2. The renal arterial resistive index and stage of chronic kidney disease in patients with renal allograft

    DEFF Research Database (Denmark)

    Winther, Stine O; Thiesson, Helle C; Poulsen, Lene N

    2012-01-01

    The study investigated the optimal threshold value of renal arterial resistive index as assessed by Doppler ultrasonography determining chronic kidney disease stage 4 or higher in patients with renal allograft.......The study investigated the optimal threshold value of renal arterial resistive index as assessed by Doppler ultrasonography determining chronic kidney disease stage 4 or higher in patients with renal allograft....

  3. Insulin resistance and adipose tissue in the development of vascular diseases in high-risk patients

    NARCIS (Netherlands)

    Gorter, P.M.

    2008-01-01

    The work in this thesis focused on the relationship between presence of insulin resistance and advanced vascular damage in patients with manifest atherosclerotic vascular disease, and on the occurrence of (new) vascular events in insulin resistant patients with and without evident vascular disease.

  4. Spatial Epidemiology and Risk Factor Analysis of White Spot Disease in the Shrimp Farming Industry of Sinaloa, Mexico, from 2005 to 2011.

    Science.gov (United States)

    Muniesa, A; Mardones, F O; Chávez, M C; Montoya, L; Cabanillas, J A; de Blas, I; Martínez-López, B

    2017-10-01

    White spot disease (WSD), caused by the white spot syndrome virus, is currently one of the primary causes of mortality and economic losses in the shrimp farming industry worldwide. In Mexico, shrimp production is one of the most important primary activities generating an annual income of USD 711 million. However, WSD introduction in 1999 had a devastating impact for the Mexican shrimp industry. The aim of this study was to characterize the WSD spatio-temporal patterns and to identify the primary risk factors contributing to WSD occurrence from 2005 to 2011 in Sinaloa, Mexico. We used data collected by the 'Comité Estatal de Sanidad Acuícola de Sinaloa' from 2005 to 2011 regarding WSD outbreaks as well as environmental, production and husbandry factors at farm level. The spatio-temporal patterns of WSD were described using space-time scan statistics. The effect of 52 variables on the time to WSD outbreak occurrence was assessed using a multivariable Cox proportional hazards model. Results reveal that WSD risk and survival time were not homogeneously distributed as suggested by the significant clusters obtained using the space-time permutation model and the space-time exponential model, respectively. The Cox model revealed that the first production cycle [hazard ratio (HR) = 11.31], changes from 1 to 1.4°C of temperature oscillation caused by 'El Niño'/'La Niña' events (HR = 1.44) and high average daily growths (HR = 1.26) were significantly associated with lower survival (i.e. shorter time to WSD outbreak) on farm. Conversely, shrimp weight at the moment of the outbreak (HR = 0.159), changes from -0.9 to -0.5°C of temperature oscillation caused by 'El Niño'/'La Niña' events (HR = 0.540), high superficial water temperature during the pound stocking (HR = 0.823) and high (>100) number of days of culture (HR = 0.830) were factors associated with higher survival. Results are expected to inform the design of risk-based, intervention strategies to

  5. Searching for Factors that Distinguish Disease-Prone and Disease-Resistant Prions via Sequence Analysis

    Directory of Open Access Journals (Sweden)

    Lukasz Kurgan

    2008-01-01

    Full Text Available The exact mechanisms of prion misfolding and factors that predispose an individual to prion diseases are largely unknown. Our approach to identifying candidate factors in-silico relies on contrasting the C-terminal domain of PrPC sequences from two groups of vertebrate species: those that have been found to suffer from prion diseases, and those that have not. We propose that any significant differences between the two groups are candidate factors that may predispose individuals to develop prion disease, which should be further analyzed by wet-lab investigations. Using an array of computational methods we identified possible point mutations that could predispose PrPC to misfold into PrPSc. Our results include confirmatory findings such as the V210I mutation, and new findings including P137M, G142D, G142N, D144P, K185T, V189I, H187Y and T191P mutations, which could impact structural stability. We also propose new hypotheses that give insights into the stability of helix-2 and -3. These include destabilizing effects of Histidine and T188-T193 segment in helix-2 in the disease-prone prions, and a stabilizing effect of Leucine on helix-3 in the disease-resistant prions.

  6. Phase transformation and local mechanical properties of TRIP steel in a simulated and real resistance spot weld process; Phasenumwandlung und lokale mechanische Eigenschaften von TRIP Stahl beim simulierten und realen Widerstandspunktschweissprozess

    Energy Technology Data Exchange (ETDEWEB)

    Brauser, Stephan

    2013-06-01

    TRIP steels give high strength along with good ductility owing to metastable austenite to martensite phase transformation (TRIP effect) caused by mechanical load. Under the extreme process-specific heating and cooling rates of resistance spot welding, these materials may undergo modifications in their austenite portion resulting in changed mechano- technological performance locally. The prime objective of this study was therefore to carry out microstructure analyses of the spot weld area in order to identify the modified portion of austenite and the resulting changes in local mechanical performance with special consideration of the TRIP effect. First, the metastable austenite portion in the unprocessed parent metal was quantified by in-situ diffraction using high energy synchrotron radiation. Next, the basic aspects of temperature dependent austenite transformation in the heating and cooling process were investigated in furnace experiments under defined temperature profiles. Continuative Gleeble tests and furnace experiments were conducted using various temperature profiles with different peaks occurring locally in the spot welding process in order to enable systematic assessment of the influence of temperature and of heating and cooling conditions on the austenite content under real conditions. Correlation experiments between the mechanical characteristics of thermally prepared tensile specimens and the metallographically and roentgenographically determined austenite contents allowed it to ascertain the metastable, i.e. transformable austenite portions. Finally, the results were evaluated concerning their transferability to real resistance spot welds. It was demonstrated that the austenite to martensite phase transformation can come into action only in a strongly localized material area in the transition zone between heat-affected zone and base metal. Consequently, the TRIP effect does not significantly affect the strength and ductility performance in the joining

  7. The perspectives of polygenic resistance in breeding for durable disease resistance

    NARCIS (Netherlands)

    Lindhout, P.

    2002-01-01

    Polygenic resistance is generally quantitative without clear race specific effects. With the onset of molecular markers technologies, the identification of chromosome regions that are involved in quantitative resistance has become feasible. These regions are designated quantitative trait loci

  8. Screening of Soybean Germplasm Collection Resistance to Rust Disease (Phakopsora Pachyrhizi)

    OpenAIRE

    -, Sumartini

    2014-01-01

    Rust disease is an important disease on soybean, it was widely distributed in almost all soybeanproducing countries, the yield losses can be reach 85 %. One of the control measured is planting theresistant varieties. Resistant gens of one character can be obtained from the germplasm collection. Thestudy aiar to evaluate the resistance of soybean germplasm collection against rust diseases. The study wasconducted at Kendalpayak experimental station, Indonesian Legumes and Tuber Crops ResearchIn...

  9. A mutagenesis-derived broad-spectrum disease resistance locus in wheat.

    Science.gov (United States)

    Campbell, Jackie; Zhang, Hongtao; Giroux, Michael J; Feiz, Leila; Jin, Yue; Wang, Meinan; Chen, Xianming; Huang, Li

    2012-07-01

    Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. Breeding durable disease resistance cultivars rely largely on continually introgressing new resistance genes, especially the genes with different defense mechanisms, into adapted varieties. Here, we describe a new resistance gene obtained by mutagenesis. The mutant, MNR220 (mutagenesis-derived new resistance), enhances resistance to three rusts and powdery mildew, with the characteristics of delayed disease development at the seedling stage and completed resistance at the adult plant stage. Genetic analysis demonstrated that the resistance in MNR220 is conferred by a single semidominant gene mapped on the short arm of chromosome 2B. Gene expression profiling of several pathogenesis-related genes indicated that MNR220 has an elevated and rapid pathogen-induced response. In addition to its potential use in breeding for resistance to multiple diseases, high-resolution mapping and cloning of the disease resistance locus in MNR220 may lead to a better understanding of the regulation of defense responses in wheat.

  10. Association mapping of quantitative disease resistance in a natural population of loblolly pine (Pinus taeda L.).

    Science.gov (United States)

    Quesada, Tania; Gopal, Vikneswaran; Cumbie, W Patrick; Eckert, Andrew J; Wegrzyn, Jill L; Neale, David B; Goldfarb, Barry; Huber, Dudley A; Casella, George; Davis, John M

    2010-10-01

    Genetic resistance to disease incited by necrotrophic pathogens is not well understood in plants. Whereas resistance is often quantitative, there is limited information on the genes that underpin quantitative variation in disease resistance. We used a population genomic approach to identify genes in loblolly pine (Pinus taeda) that are associated with resistance to pitch canker, a disease incited by the necrotrophic pathogen Fusarium circinatum. A set of 498 largely unrelated, clonally propagated genotypes were inoculated with F. circinatum microconidia and lesion length, a measure of disease resistance, data were collected 4, 8, and 12 weeks after inoculation. Best linear unbiased prediction was used to adjust for imbalance in number of observations and to identify highly susceptible and highly resistant genotypes ("tails"). The tails were reinoculated to validate the results of the full population screen. Significant associations were detected in 10 single nucleotide polymorphisms (SNPs) (out of 3938 tested). As hypothesized for genes involved in quantitative resistance, the 10 SNPs had small effects and proposed roles in basal resistance, direct defense, and signal transduction. We also discovered associated genes with unknown function, which would have remained undetected in a candidate gene approach constrained by annotation for disease resistance or stress response.

  11. Relevance of hot spots in the evolution and transmission of Tn1546 in glycopeptide-resistant Enterococcus faecium (GREF) from broiler origin

    DEFF Research Database (Denmark)

    Migura, Lourdes Garcia; Hasman, Henrik; Svendsen, Christina Aaby

    2008-01-01

    found in isolates from the UK (n = 150). The first insertion point revealed that 25 isolates harboured Tn1546 positioned in a sequence with 96% homology to a streptomycin adenyltransferase gene (AY604739) from a Staphylococcus intermedius plasmid. At this insertion point, a direct repeat (GTCCT......) was duplicated as previously described, indicating transposition at the target site. Furthermore, this 'hot spot' was also detected in isolates from Norway (2/8) and Denmark (17/20). The second insertion point detected in 45 isolates from the UK revealed integration into an Inc18-like plasmid, most likely...... by a process of target site recombination. Conclusions: The presence of a common insertion point for isolates from different geographical areas could suggest the insertion of Tn1546 by transposition in a plasmid-specific site, followed by genetic rearrangement both inside the transposon and in the flanking...

  12. Plant-pathogen interactions: toward development of next-generation disease-resistant plants.

    Science.gov (United States)

    Nejat, Naghmeh; Rookes, James; Mantri, Nitin L; Cahill, David M

    2017-03-01

    Briskly evolving phytopathogens are dire threats to our food supplies and threaten global food security. From the recent advances made toward high-throughput sequencing technologies, understanding of pathogenesis and effector biology, and plant innate immunity, translation of these means into new control tools is being introduced to develop durable disease resistance. Effectoromics as a powerful genetic tool for uncovering effector-target genes, both susceptibility genes and executor resistance genes in effector-assisted breeding, open up new avenues to improve resistance. TALENs (Transcription Activator-Like Effector Nucleases), engineered nucleases and CRISPR (Clustered Regulatory Interspaced Short Palindromic Repeats)/Cas9 systems are breakthrough and powerful techniques for genome editing, providing efficient mechanisms for targeted crop protection strategies in disease resistance programs. In this review, major advances in plant disease management to confer durable disease resistance and novel strategies for boosting plant innate immunity are highlighted.

  13. Toughing It Out--Disease-Resistant Potato Mutants Have Enhanced Tuber Skin Defenses.

    Science.gov (United States)

    Thangavel, Tamilarasan; Tegg, Robert S; Wilson, Calum R

    2016-05-01

    Common scab, a globally important potato disease, is caused by infection of tubers with pathogenic Streptomyces spp. Previously, disease-resistant potato somaclones were obtained through cell selections against the pathogen's toxin, known to be essential for disease. Further testing revealed that these clones had broad-spectrum resistance to diverse tuber-invading pathogens, and that resistance was restricted to tuber tissues. The mechanism of enhanced disease resistance was not known. Tuber periderm tissues from disease-resistant clones and their susceptible parent were examined histologically following challenge with the pathogen and its purified toxin. Relative expression of genes associated with tuber suberin biosynthesis and innate defense pathways within these tissues were also examined. The disease-resistant somaclones reacted to both pathogen and toxin by producing more phellem cell layers in the tuber periderm, and accumulating greater suberin polyphenols in these tissues. Furthermore, they had greater expression of genes associated with suberin biosynthesis. In contrast, signaling genes associated with innate defense responses were not differentially expressed between resistant and susceptible clones. The resistance phenotype is due to induction of increased periderm cell layers and suberization of the tuber periderm preventing infection. The somaclones provide a valuable resource for further examination of suberization responses and its genetic control.

  14. Response of cotton genotypes to the incidence of Alternaria leaf spot

    Directory of Open Access Journals (Sweden)

    Edivaldo Cia

    Full Text Available ABSTRACT In field experiments and under natural occurrence of the pathogen, 18 cotton genotypes, comprising cultivars and lineages, were evaluated for their reaction to Alternaria leaf spot caused by Alternaria macrospora Zimm. High genetic diversity of resistance to the pathogen was observed, and four groups of reaction to the disease were detected in the environment where the disease showed greater intensity. Differences in the phenotypic stability of resistance were also found, and there were stable genotypes, i.e. of expected performance, both in the resistant and in the susceptible material. It must be emphasized that the existence of unstable genotypes of inconsistent performance, according to the intensity of the disease occurrence, can lead to errors with respect to their resistance degree.

  15. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Science.gov (United States)

    Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L. D.; Anuntalabhochai, S.

    2013-07-01

    Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60-80 keV to a beam fluence range of 2 × 1016-2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11).

  16. Transgenic strategies for improving rice disease resistance | Zhang ...

    African Journals Online (AJOL)

    Improvement of virus resistance can be achieved by generating transgenic rice lines with expression of genes encoding viral coat protein or replication enzymes, expression of RNA interference constructs and suppression of insect vectors. Varieties with improved resistance against fungal and bacterial pathogens can be ...

  17. gene effects for resistance to groundnut rossette disease in exotic ...

    African Journals Online (AJOL)

    ACSS

    2016-02-25

    Feb 25, 2016 ... Opposite and significant signs of dominance [d] and dominance × dominance [l] components indicated the importance of duplicate epitasis in the latter crosses in the control of GRD resistance, which revealed a complex nature of inheritance of GRD resistance. Key Words: Arachis hypogaea, gene effects, ...

  18. Genetic analysis of resistance to soybean rust disease | Kiryowa ...

    African Journals Online (AJOL)

    Soybean rust (Phakopsora pachyrhizi Sydow.) causes the most damage of all the pathogens known to attack soybean (Glycine max. Merril). A study was conducted in Uganda to estimate the magnitude of genetic parameters controlling soybean rust resistance and to estimate narrow sense heritability of the resistance.

  19. Biological changes in Barley mutants resistant to powdery mildew disease

    International Nuclear Information System (INIS)

    Amer, I. M.; Fahim, M. M.; Moustafa, N. A.

    2012-12-01

    physiological studies showed that all kinds of chlorophyll (a), (b) and (a + b) content in infected plant were decreased while, the carotenes pigment were increased. Infection generally reduced total sugars content of all resistant mutants. Infected resistant mutant showed more phenols content and peroxidase, polyphenoloxidase activities than healthy ones of the mutants. (Author)

  20. Genetic analysis of resistance to early blight disease in tomato ...

    African Journals Online (AJOL)

    In this study, the responses of 6 cultivated and 3 wild tomato accessions were tested with 3 isolates of the fungal pathogen. To investigate inheritance of the resistance, resistant plants of NCEBR2 and NCEBR4 genotypes were crossed with susceptible NC84173 tomato line, and their F1, F2 and BC1 populations were ...

  1. Uneven distribution of mating type alleles in Iranian populations of Cercospora beticola, the causal agent of Cercospora leaf spot disease of sugar beet

    Directory of Open Access Journals (Sweden)

    Mounes BAKHSHI

    2011-05-01

    Full Text Available Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Cercospora beticola, the causal agent of Cercospora leaf spot disease on sugar beet, is thought to be exclusively asexual because no teleomorph has yet been found. The possibility of a clandestine sexual cycle in the Iranian population of Cercospora beticola was evaluated by analyzing the distribution and frequency of the mating type alleles on a microspatial and a macrogeographical scale. A total of 89 single-conidial Cercospora beticola isolates were obtained from sugar beet fields in the Moghan, the Talesh and the Khoy regions. The isolates were identifed using a Cercospora beticola-specifc primer set in a PCR assay. A multiplex PCR method using previously designed mating type primers was used to study the distribution and the frequency of the mating type alleles. All isolates showed either the 805-bp fragment or the 442-bp fragment of the MAT1-1 and MAT1-2 genes, but no isolate had both fragments. The distribution of the mating type genes in the sampled areas was uneven. From three sugar beet fields sampled in the Moghan region, two fields had only MAT1-1 isolates; while in the third field all isolates had only the MAT1-2 allele. In the Talesh region only MAT1-1 isolates occurred, and in the Khoy region the mating type alleles were uniformly distributed amongst the isolates. The skewed distribution of mating type alleles in Northwestern Iran was in line with the lack of a sexual cycle for this species and may also indicate that sugar fields in the Moghan region were infected by C. beticola populations of different origins. Normal 0 false false false EN-US X-NONE FA

  2. Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate.

    Science.gov (United States)

    Mahmoud, Amer F; Hassan, Mohamed I; Amein, Karam A

    2015-12-01

    Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 2 rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

  3. Resistência das plantas a moléstias fúngicas Plant resistance to fungal diseases

    Directory of Open Access Journals (Sweden)

    Rodrigo Rodrigues Matiello

    1997-03-01

    Full Text Available As plantas apresentam resistência a moléstias causadas por fungos patogênicos em função da sua constituição genética e de falares do ambiente. Em programas de melhoramento genético, um dos principais objetivos é a obtenção de plantas com alto potencial de rendimento e com resistência às moléstias. Para aumentar a eficiência da seleção, é importante o conhecimento das bases genéticas da resistência. Como a variabilidade dos fungos é bastante ampla, há a necessidade da utilização de estratégias que reduzam a probabilidade de estabelecimento do patógeno nas culturas.Plant resistance to fungic diseases is due to their genetic constitution and environmental factors. In breeding programs, one of the main objectives is to obtain high grainyield potenlial plants with resistance to the prevalent diseases. Knowledge of genetic basis of resistance is importam to increase selection efficiency and due to the wide variability of fungi there is the necessity of using different strategies to reduce the probability of pathogen estabtishment in crops.

  4. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  5. Identification of pyrethroid resistance associated mutations in the para sodium channel of the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Tsagkarakou, A; Van Leeuwen, T; Khajehali, J; Ilias, A; Grispou, M; Williamson, M S; Tirry, L; Vontas, J

    2009-10-01

    We investigated pyrethroid resistance mechanisms in Tetranychus urticae strains from Greece. Combined bioassay, biochemical and synergistic data indicated that although P450 mono-oxygenase activities were associated with the trait, target site insensitivity was the major resistance component. A 3.3 kb cDNA fragment of the T. urticae para sodium channel gene encompassing segment 4 of domain II to segment 6 of domain IV was obtained by a degenerate PCR strategy. The T. urticae sequence showed highest identity (56%) to the scabies mite, Sarcoptes scabiei, and was phylogenetically classified within the divergent group of Arachnida. Comparison of resistant and susceptible strains identified the point mutation F1538I in segment 6 of domain III, which is known to confer strong resistance to pyrethroids, along with a second mutation (A1215D) in the intracellular linker connecting domains II and III with an unknown role. Three transcripts were identified corresponding to the k and l alternative exons. The mode of inheritance of resistance was confirmed as incompletely recessive, which is consistent with a target site mechanism for pyrethroids.

  6. Mutagenesis and haploid culture for disease resistance in Brassica napus

    International Nuclear Information System (INIS)

    MacDonald, M.V.; Ahmad, I.; Ingram, D.S.

    1990-01-01

    Full text: Most winter oilseed rape cultivars share parentage and therefore show little genetic diversity. There is no known resistance to Alternaria spp. in oilseed rape or in any related Brassica species. Experiments with tissue culture yielded only transient, non-genetic resistance. Therefore, mutagenesis may be used to generate heritable resistance to Alternaria spp. Gamma irradiation was applied to seeds of 'Bienvenue', secondary embryoids of cvs 'Primor' and 'Rapora', and buds of cvs 'Primor' and 'Ariana'. Isolated microspores from cv 'Ariana' and rapid cycling B. napus were also treated. The doses used ranged from 0-100 Gy for isolated microspores and buds, up to 600 Gy for seeds and 960 Gy for secondary embryoids. EMS was used to treat seeds of line WRG-42 (supplied by Nickersons RPB) and microspores of cv 'Bienvenue' and rapid cycling B. napus. Seeds were treated with up to 2.0% EMS for 0.2 h. before plating them on the culture medium. Seed irradiation up to 600 Gy did not reduce germination. M 1 and M 2 progenies were tested both in the laboratory and in field trials, and none of these were found to be resistant to Alternaria. However, considerable variation for other characters was observed. Haploid cultures from these plants were extremely difficult to regenerate, and for this reason no regenerant plants have been tested for resistance. For irradiated secondary embryoids the regeneration capacity decreased with increasing dose. Regenerated plants have been tested for resistance to Alternaria, but stable resistance was not observed. Haploid cultures were obtained from irradiated buds, using both anther and microspore culture. Low irradiation treatment was beneficial to developing embryoids. Some regenerants have been obtained from EMS treated microspores and seeds. Four plants have repeatedly given increased levels of resistance to A. brassicicola, and progenies are being tested to determine the genetic nature of the resistance. (author)

  7. Production of homozygous transgenic rainbow trout with enhanced disease resistance

    Science.gov (United States)

    Previous studies conducted in our laboratory showed that transgenic medaka expressing cecropin B transgenes exhibited resistant characteristic to fish bacterial pathogens, Pseudomonas fluorescens and Vibrio anguillarum. To confirm whether antimicrobial peptide gene will also exhibit antibacterial an...

  8. Silicon and plant disease resistance against pathogenic fungi.

    Science.gov (United States)

    Fauteux, François; Rémus-Borel, Wilfried; Menzies, James G; Bélanger, Richard R

    2005-08-01

    Silicon (Si) is a bioactive element associated with beneficial effects on mechanical and physiological properties of plants. Silicon alleviates abiotic and biotic stresses, and increases the resistance of plants to pathogenic fungi. Several studies have suggested that Si activates plant defense mechanisms, yet the exact nature of the interaction between the element and biochemical pathways leading to resistance remains unclear. Silicon possesses unique biochemical properties that may explain its bioactivity as a regulator of plant defense mechanisms. It can act as a modulator influencing the timing and extent of plant defense responses in a manner reminiscent of the role of secondary messengers in induced systemic resistance; it can also bind to hydroxyl groups of proteins strategically involved in signal transduction; or it can interfere with cationic co-factors of enzymes influencing pathogenesis-related events. Silicon may therefore interact with several key components of plant stress signaling systems leading to induced resistance.

  9. Digital Gene Expression Analysis to Screen Disease Resistance-Relevant Genes from Leaves of Herbaceous Peony (Paeonia lactiflora Pall.) Infected by Botrytis cinerea.

    Science.gov (United States)

    Gong, Saijie; Hao, Zhaojun; Meng, Jiasong; Liu, Ding; Wei, Mengran; Tao, Jun

    2015-01-01

    Herbaceous peony (Paeonia lactiflora Pall.) is a well-known traditional flower in China and is widely used for landscaping and garden greening due to its high ornamental value. However, disease spots usually appear after the flowering of the plant and may result in the withering of the plant in severe cases. This study examined the disease incidence in an herbaceous peony field in the Yangzhou region, Jiangsu Province. Based on morphological characteristics and molecular data, the disease in this area was identified as a gray mold caused by Botrytis cinerea. Based on previously obtained transcriptome data, eight libraries generated from two herbaceous peony cultivars 'Zifengyu' and 'Dafugui' with different susceptibilities to the disease were then analyzed using digital gene expression profiling (DGE). Thousands of differentially expressed genes (DEGs) were screened by comparing the eight samples, and these genes were annotated using the Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) database. The pathways related to plant-pathogen interaction, secondary metabolism synthesis and antioxidant system were concentrated, and 51, 76, and 13 disease resistance-relevant candidate genes were identified, respectively. The expression patterns of these candidate genes differed between the two cultivars: their expression of the disease-resistant cultivar 'Zifengyu' sharply increased during the early stages of infection, while it was relatively subdued in the disease-sensitive cultivar 'Dafugui'. A selection of ten candidate genes was evaluated by quantitative real-time PCR (qRT-PCR) to validate the DGE data. These results revealed the transcriptional changes that took place during the interaction of herbaceous peony with B. cinerea, providing insight into the molecular mechanisms of host resistance to gray mold.

  10. Digital Gene Expression Analysis to Screen Disease Resistance-Relevant Genes from Leaves of Herbaceous Peony (Paeonia lactiflora Pall. Infected by Botrytis cinerea.

    Directory of Open Access Journals (Sweden)

    Saijie Gong

    Full Text Available Herbaceous peony (Paeonia lactiflora Pall. is a well-known traditional flower in China and is widely used for landscaping and garden greening due to its high ornamental value. However, disease spots usually appear after the flowering of the plant and may result in the withering of the plant in severe cases. This study examined the disease incidence in an herbaceous peony field in the Yangzhou region, Jiangsu Province. Based on morphological characteristics and molecular data, the disease in this area was identified as a gray mold caused by Botrytis cinerea. Based on previously obtained transcriptome data, eight libraries generated from two herbaceous peony cultivars 'Zifengyu' and 'Dafugui' with different susceptibilities to the disease were then analyzed using digital gene expression profiling (DGE. Thousands of differentially expressed genes (DEGs were screened by comparing the eight samples, and these genes were annotated using the Gene ontology (GO and Kyoto encyclopedia of genes and genomes (KEGG database. The pathways related to plant-pathogen interaction, secondary metabolism synthesis and antioxidant system were concentrated, and 51, 76, and 13 disease resistance-relevant candidate genes were identified, respectively. The expression patterns of these candidate genes differed between the two cultivars: their expression of the disease-resistant cultivar 'Zifengyu' sharply increased during the early stages of infection, while it was relatively subdued in the disease-sensitive cultivar 'Dafugui'. A selection of ten candidate genes was evaluated by quantitative real-time PCR (qRT-PCR to validate the DGE data. These results revealed the transcriptional changes that took place during the interaction of herbaceous peony with B. cinerea, providing insight into the molecular mechanisms of host resistance to gray mold.

  11. Genetic Signature of Resistance to White Band Disease in the Caribbean Staghorn Coral Acropora cervicornis.

    Directory of Open Access Journals (Sweden)

    Silvia Libro

    Full Text Available Coral reefs are declining worldwide due to multiple factors including rising sea surface temperature, ocean acidification, and disease outbreaks. Over the last 30 years, White Band Disease (WBD alone has killed up to 95% of the Caribbean`s dominant shallow-water corals--the staghorn coral Acropora cervicornis and the elkhorn coral A. palmata. Both corals are now listed on the US Endangered Species Act, and while their recovery has been slow, recent transmission surveys indicate that more than 5% of staghorn corals are disease resistant. Here we compared transcriptome-wide gene expression between resistant and susceptible staghorn corals exposed to WBD using in situ transmission assays. We identified constitutive gene expression differences underlying disease resistance that are independent from the immune response associated with disease exposure. Genes involved in RNA interference-mediated gene silencing, including Argonaute were up-regulated in resistant corals, whereas heat shock proteins (HSPs were down-regulated. Up-regulation of Argonaute proteins indicates that post-transcriptional gene silencing plays a key, but previously unsuspected role in coral immunity and disease resistance. Constitutive expression of HSPs has been linked to thermal resilience in other Acropora corals, suggesting that the down-regulation of HSPs in disease resistant staghorn corals may confer a dual benefit of thermal resilience.

  12. Genetic Signature of Resistance to White Band Disease in the Caribbean Staghorn Coral Acropora cervicornis.

    Science.gov (United States)

    Libro, Silvia; Vollmer, Steven V

    2016-01-01

    Coral reefs are declining worldwide due to multiple factors including rising sea surface temperature, ocean acidification, and disease outbreaks. Over the last 30 years, White Band Disease (WBD) alone has killed up to 95% of the Caribbean`s dominant shallow-water corals--the staghorn coral Acropora cervicornis and the elkhorn coral A. palmata. Both corals are now listed on the US Endangered Species Act, and while their recovery has been slow, recent transmission surveys indicate that more than 5% of staghorn corals are disease resistant. Here we compared transcriptome-wide gene expression between resistant and susceptible staghorn corals exposed to WBD using in situ transmission assays. We identified constitutive gene expression differences underlying disease resistance that are independent from the immune response associated with disease exposure. Genes involved in RNA interference-mediated gene silencing, including Argonaute were up-regulated in resistant corals, whereas heat shock proteins (HSPs) were down-regulated. Up-regulation of Argonaute proteins indicates that post-transcriptional gene silencing plays a key, but previously unsuspected role in coral immunity and disease resistance. Constitutive expression of HSPs has been linked to thermal resilience in other Acropora corals, suggesting that the down-regulation of HSPs in disease resistant staghorn corals may confer a dual benefit of thermal resilience.

  13. Identification of molecular targets for selective elimination of TRAIL-resistant leukemia cells. From spots to in vitro assays using TOP15 charts

    Czech Academy of Sciences Publication Activity Database

    Petrák, J.; Toman, O.; Šimonová, T.; Halada, Petr; Čmejla, R.; Klener, P.; Živný, J.

    2009-01-01

    Roč. 9, č. 22 (2009), s. 5006-5015 ISSN 1615-9853 Institutional research plan: CEZ:AV0Z50200510 Keywords : Biomedicine * Drug resistance * HL-60 Subject RIV: CE - Biochemistry Impact factor: 4.426, year: 2009

  14. Differential disease resistance response in the barley necrotic mutant nec1

    Directory of Open Access Journals (Sweden)

    Kunga Laura

    2011-04-01

    Full Text Available Abstract Background Although ion fluxes are considered to be an integral part of signal transduction during responses to pathogens, only a few ion channels are known to participate in the plant response to infection. CNGC4 is a disease resistance-related cyclic nucleotide-gated ion channel. Arabidopsis thaliana CNGC4 mutants hlm1 and dnd2 display an impaired hypersensitive response (HR, retarded growth, a constitutively active salicylic acid (SA-mediated pathogenesis-related response and elevated resistance against bacterial pathogens. Barley CNGC4 shares 67% aa identity with AtCNGC4. The barley mutant nec1 comprising of a frame-shift mutation of CNGC4 displays a necrotic phenotype and constitutively over-expresses PR-1, yet it is not known what effect the nec1 mutation has on barley resistance against different types of pathogens. Results nec1 mutant accumulated high amount of SA and hydrogen peroxide compared to parental cv. Parkland. Experiments investigating nec1 disease resistance demonstrated positive effect of nec1 mutation on non-host resistance against Pseudomonas syringae pv. tomato (Pst at high inoculum density, whereas at normal Pst inoculum concentration nec1 resistance did not differ from wt. In contrast to augmented P. syringae resistance, penetration resistance against biotrophic fungus Blumeria graminis f. sp. hordei (Bgh, the causal agent of powdery mildew, was not altered in nec1. The nec1 mutant significantly over-expressed race non-specific Bgh resistance-related genes BI-1 and MLO. Induction of BI-1 and MLO suggested putative involvement of nec1 in race non-specific Bgh resistance, therefore the effect of nec1on mlo-5-mediated Bgh resistance was assessed. The nec1/mlo-5 double mutant was as resistant to Bgh as Nec1/mlo-5 plants, suggesting that nec1 did not impair mlo-5 race non-specific Bgh resistance. Conclusions Together, the results suggest that nec1 mutation alters activation of systemic acquired resistance

  15. Differential disease resistance response in the barley necrotic mutant nec1

    Science.gov (United States)

    2011-01-01

    Background Although ion fluxes are considered to be an integral part of signal transduction during responses to pathogens, only a few ion channels are known to participate in the plant response to infection. CNGC4 is a disease resistance-related cyclic nucleotide-gated ion channel. Arabidopsis thaliana CNGC4 mutants hlm1 and dnd2 display an impaired hypersensitive response (HR), retarded growth, a constitutively active salicylic acid (SA)-mediated pathogenesis-related response and elevated resistance against bacterial pathogens. Barley CNGC4 shares 67% aa identity with AtCNGC4. The barley mutant nec1 comprising of a frame-shift mutation of CNGC4 displays a necrotic phenotype and constitutively over-expresses PR-1, yet it is not known what effect the nec1 mutation has on barley resistance against different types of pathogens. Results nec1 mutant accumulated high amount of SA and hydrogen peroxide compared to parental cv. Parkland. Experiments investigating nec1 disease resistance demonstrated positive effect of nec1 mutation on non-host resistance against Pseudomonas syringae pv. tomato (Pst) at high inoculum density, whereas at normal Pst inoculum concentration nec1 resistance did not differ from wt. In contrast to augmented P. syringae resistance, penetration resistance against biotrophic fungus Blumeria graminis f. sp. hordei (Bgh), the causal agent of powdery mildew, was not altered in nec1. The nec1 mutant significantly over-expressed race non-specific Bgh resistance-related genes BI-1 and MLO. Induction of BI-1 and MLO suggested putative involvement of nec1 in race non-specific Bgh resistance, therefore the effect of nec1on mlo-5-mediated Bgh resistance was assessed. The nec1/mlo-5 double mutant was as resistant to Bgh as Nec1/mlo-5 plants, suggesting that nec1 did not impair mlo-5 race non-specific Bgh resistance. Conclusions Together, the results suggest that nec1 mutation alters activation of systemic acquired resistance-related physiological markers and

  16. Subthalamic nucleus stimulation and levodopa-resistant postural instability in Parkinson's disease.

    NARCIS (Netherlands)

    Visser, J.E.; Allum, J.H.J.; Carpenter, M.G.; Esselink, R.A.J.; Speelman, J.D.; Borm, G.F.; Bloem, B.R.

    2008-01-01

    We examined the effect of bilateral subthalamic nucleus stimulation on levodopa-resistant balance impairment in 14 patients with Parkinson's disease and 18 matched controls. Instability was quantitatively assessed using standardized multidirectional dynamic posturography. Patients were tested after

  17. Subthalamic nucleus stimulation and levodopa-resistant postural instability in Parkinson's disease

    NARCIS (Netherlands)

    Visser, Jasper E.; Allum, John H. J.; Carpenter, Mark G.; Esselink, Rianne A.; Speelman, Johannes D.; Borm, George F.; Bloem, Bastiaan R.

    2008-01-01

    We examined the effect of bilateral subthalamic nucleus stimulation on levodopa-resistant balance impairment in 14 patients with Parkinson's disease and 18 matched controls. Instability was quantitatively assessed using standardized multidirectional dynamic posturography. Patients were tested after

  18. Resistance to activated protein C is a risk factor for fibrostenosis in Crohn’s disease

    OpenAIRE

    Novacek, Gottfried; Miehsler, Wolfgang; Palkovits, Julia; Reinisch, Walter; Waldhör, Thomas; Kapiotis, Stylianos; Gangl, Alfred; Vogelsang, Harald

    2006-01-01

    AIM: To evaluate the effect of resistance to activated protein C (aPCR), the most common known inherited thrombophilic disorder, on the risk of intestinal operation of fibrostenosis in patients with Crohn’s disease (CD).

  19. Quantitative trait loci for resistance to maize streak virus disease in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... method of controlling the disease is through resistance breeding, since with resistant genotypes, ... Microsatellite markers occur in many plants including maize (Senior and Heun, 1993), soybean ... DNA precipitated out of solution to form white cotton like threads. These were hooked out into1.5 ml micro ...

  20. Genetic characterization of five powdery mildew disease resistance loci in Arabidopsis thaliana.

    Science.gov (United States)

    Adam, L; Somerville, S C

    1996-03-01

    This paper reports on six Arabidopsis accessions that show resistance to a wild isolate of the powdery mildew pathogen, Erysiphe cichoracearum. Resistance at 7 days post-inoculation in these accessions was characterized by limited fungal growth and sporadic development of chlorotic or necrotic lesions at inoculation sites. Three accessions, Wa-1, Kas-1 and SI-0, were highly resistant, while the other accessions permitted some fungal growth and conidiation. Papilla formation was a frequent host response; however, cell death appeared to be neither a rapid nor a common response to infection. To determine the genetic basis of resistance, segregation analyses of progeny from crosses between each of the resistant accessions and Columbia (gl1), which is susceptible to the powdery mildew pathogen, were performed. For all accessions except Sl-0, resistance was conferred by a single locus. Sl-0 was unique in that two unlinked loci controlled the disease reaction phenotype. In accessions Wa-1, Kas-1, Stw-0 and Su-0, powdery mildew resistance was encoded by a semi-dominant allele. However, susceptibility was dominant to resistance in accessions Te-0 and Sl-0. Mapping studies revealed that powdery mildew resistances in Kas-1, Wa-1, Te-0, Su-0 and Stw-0 were controlled by five independent loci. This study suggests that the Arabidopsis powdery mildew disease will be a suitable model system in which to investigate powdery mildew diseases.

  1. Genetic engineering for increasing fungal and bacterial disease resistance in crop plants.

    Science.gov (United States)

    Wally, Owen; Punja, Zamir K

    2010-01-01

    We review the current and future potential of genetic engineering strategies used to make fungal and bacterial pathogen-resistant GM crops, illustrating different examples of the technologies and the potential benefits and short-falls of the strategies. There are well- established procedures for the production of transgenic plants with resistance towards these pathogens and considerable progress has been made using a range of new methodologies. There are no current commercially available transgenic plant species with increased resistance towards fungal and bacterial pathogens; only plants with increased resistance towards viruses are available. With an improved understanding of plant signaling pathways in response to a range of other pathogens, such as fungi, additional candidate genes for achieving resistance are being investigated. The potential for engineering plants for resistance against individual devastating diseases or for plants with resistance towards multiple pathogens is discussed in detail.

  2. Reproductive and developmental costs of deltamethrin resistance in the Chagas disease vector Triatoma infestans.

    Science.gov (United States)

    Germano, Mónica Daniela; Inés Picollo, María

    2015-06-01

    Effective chemical control relies on reducing vector population size. However, insecticide selection pressure is often associated with the development of resistant populations that reduce control success. In treated areas, these resistant individuals present an adaptive advantage due to enhanced survival. Resistance can also lead to negative effects when the insecticide pressure ceases. In this study, the biological effects of deltamethrin resistance were assessed in the Chagas disease vector Triatoma infestans. The length of each developmental stage and complete life cycle, mating rate, and fecundity were evaluated. Susceptible and resistant insects presented similar mating rates. A reproductive cost of resistance was expressed as a lower fecundity in the resistant colony. Developmental costs in the resistant colony were in the form of a shortening of the second and third nymph stage duration and an extension of the fifth stage. A maternal effect of deltamethrin resistance is suggested as these effects were identified in resistant females and their progeny independently of the mated male's deltamethrin response. Our results suggest the presence of pleiotropic effects of deltamethrin resistance. Possible associations of these characters to other traits such as developmental delays and behavioral resistance are discussed. © 2015 The Society for Vector Ecology.

  3. Leaf waxes and thrips resistance in onion

    Science.gov (United States)

    Onion thrips is an important insect pest of onion that damages leaves and bulbs, reduces yields, and transmits important diseases such as iris yellow spot virus and bacterial rots. Growers would benefit from onions resistant to thrips in order to reduce insecticide applications and provide more sust...

  4. Association analysis for disease resistance to Fusarium oxysporum in cape gooseberry (Physalis peruviana L)

    OpenAIRE

    Osorio-Guar?n, Jaime A.; Enciso-Rodr?guez, Felix E.; Gonz?lez, Carolina; Fern?ndez-Pozo, No?; Mueller, Lukas A.; Barrero, Luz Stella

    2016-01-01

    Background Vascular wilt caused by Fusarium oxysporum is the most important disease in cape gooseberry (Physalis peruviana L.) in Colombia. The development of resistant cultivars is considered one of the most cost-effective means to reduce the impact of this disease. In order to do so, it is necessary to provide breeders with molecular markers and promising germplasm for introgression of different resistance loci as part of breeding schemes. Here we described an association mapping study in c...

  5. Pyrethroid resistance in Aedes aegypti and Aedes albopictus: Important mosquito vectors of human diseases.

    Science.gov (United States)

    Smith, Letícia B; Kasai, Shinji; Scott, Jeffrey G

    2016-10-01

    Aedes aegypti and A. albopictus mosquitoes are vectors of important human disease viruses, including dengue, yellow fever, chikungunya and Zika. Pyrethroid insecticides are widely used to control adult Aedes mosquitoes, especially during disease outbreaks. Herein, we review the status of pyrethroid resistance in A. aegypti and A. albopictus, mechanisms of resistance, fitness costs associated with resistance alleles and provide suggestions for future research. The widespread use of pyrethroids has given rise to many populations with varying levels of resistance worldwide, albeit with substantial geographical variation. In adult A. aegypti and A. albopictus, resistance levels are generally lower in Asia, Africa and the USA, and higher in Latin America, although there are exceptions. Susceptible populations still exist in several areas of the world, particularly in Asia and South America. Resistance to pyrethroids in larvae is also geographically widespread. The two major mechanisms of pyrethroid resistance are increased detoxification due to P450-monooxygenases, and mutations in the voltage sensitive sodium channel (Vssc) gene. Several P450s have been putatively associated with insecticide resistance, but the specific P450s involved are not fully elucidated. Pyrethroid resistance can be due to single mutations or combinations of mutations in Vssc. The presence of multiple Vssc mutations can lead to extremely high levels of resistance. Suggestions for future research needs are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Low numbers of repeat units in variable number of tandem repeats (VNTR) regions of white spot syndrome virus are correlated with disease outbreaks

    NARCIS (Netherlands)

    Tran Thi Tuyet, H.; Zwart, M.P.; Phuong, N.T.; Jong, de M.C.M.; Vlak, J.M.

    2012-01-01

    White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable

  7. Quantitative genetics of disease resistance in vaccinated and unvaccinated Atlantic salmon (Salmo salar L.).

    Science.gov (United States)

    Drangsholt, T M K; Gjerde, B; Ødegård, J; Finne-Fridell, F; Evensen, Ø; Bentsen, H B

    2011-10-01

    Furunculosis (Aeromonoas salmonicida) is an important disease in Atlantic salmon (Salmo salar) farming. Vaccination and selective breeding for increased resistance to the disease on the basis of challenge tests of unvaccinated fish are used as complementary prophylactic methods. An important issue is whether genetic predisposition to infection is consistent across vaccinated and unvaccinated fish. Hence, the main objective of this study was to determine the magnitude of the genetic associations (correlations) between resistance to furunculosis in vaccinated and unvaccinated fish, and to estimate the magnitude of the correlation of resistance to furunculosis with resistance to the viral diseases infectious pancreatic necrosis (IPN) and infectious salmon anaemia (ISA). Sub-samples of unvaccinated and vaccinated salmon from 150 full-sib families were subjected to separate cohabitation challenge tests. Substantial genetic variation was found in resistance to furunculosis in both the unvaccinated (heritabilities of 0.51 ± 0.05) and vaccinated (0.39 ± 0.06) fish. However, the genetic correlation between resistance to furunculosis in the two groups was low (0.32 ± 0.13), indicating a weak genetic association between resistance in the two groups. Hence, the current selection strategy on the basis of challenge tests of unvaccinated fish is likely to produce low genetic improvement in resistance to furunculosis under field conditions, where fish are vaccinated with an effective vaccine. Evidence was found of significantly favourable genetic associations of resistance to furunculosis in unvaccinated (but less so for vaccinated) fish with resistance to both IPN and ISA (unvaccinated fish), indicating that vaccination 'mask' genetic associations between resistance to different diseases.

  8. RESISTANCE TO ANTIPLATELET DRUGS IN PATIENTS WITH ISCHEMIC HEART DISEASE

    Directory of Open Access Journals (Sweden)

    D. H. Aynetdinova

    2007-01-01

    Full Text Available The clinical, cell and genetic factors are distinguished among reasons for resistance to antiplatelet drugs. There are many methods to detect sensitivity to antiplatelet drugs, but they all have disadvantages. Moreover, there is no unified approach for interpretation of received results, and no recommendations for their practical use. It is necessary to work out unified procedure to assess platelet function, to define indications for its usage and to work out unified criteria of resistance. Individualized approach and each patient’s peculiarities consideration are essential when prescribing antiplatelet therapy.

  9. Alternaria leaf spot of sugar beet: factors associated with risk

    Science.gov (United States)

    Recently, increased incidence and severity of Alternaria leaf spot has been observed in Michigan and other growing regions. In the past, Alternaria leaf spot in sugar beet has been a minor foliar disease issue in the United States and management of this disease usually has not been required. If seve...

  10. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  11. Summary of Results of Tests Made by Aluminum Research Laboratories of Spot-welded Joints and Structural Elements

    Science.gov (United States)

    HARTMANN E C; Stickley, G W

    1942-01-01

    Available information concerning spot welding as a means of joining aluminum-alloy parts has been summarized and comparisons have been made of the relative merits of spot-welded and riveted aluminum-alloy structural elements. The results indicated that spot welding was as satisfactory as riveting insofar as resistance to static loads is concerned. Spot welds showed slightly lower resistance to impact loads but definitely lower resistance to repeated loads than rivets.

  12. Evaluation and delivery of disease-resistant and micronutrient ...

    African Journals Online (AJOL)

    ACSS

    farmers and consumers for both food and other uses. To date nine OFSP varieties have been released and disseminated to farmers.Generally, most of the released OFSP varieties are susceptible to weevils (Cylas spp.), but moderately resistant to both SPVD and Alternaria blight. Key words: Alternaria blight, Vitamin A, ...

  13. Applied disease screening and selection program for resistance to ...

    African Journals Online (AJOL)

    Landowners are reluctant to consider A. koa for reforestation and restoration in many areas due to the threat of FOXY. Producing seeds or propagules with genetic resistance to FOXY is vital to successful A. koa reforestation and restoration. Virulent FOXY isolates were used in seedling inoculation trials to evaluate ...

  14. Sensitive response and resistance to bery disease ( Colletotrichum ...

    African Journals Online (AJOL)

    As compared to susceptibility, resistance was characterised by fewer infection sites, slower and distorted fungal growth, as well as cytoplasmic changes in host cells. This resulted in plant cell death, hypersensitive reaction, pathogen death and the formation of scabs and cork barriers of various appearances.

  15. Testing of disease-resistance of pokeweed antiviral protein gene ...

    African Journals Online (AJOL)

    Transformation of pokeweed antiviral protein gene (PAP) into plants was shown to improve plant resistance to several viruses or fungi pathogens with no much negative effect on plant growth. The non-virulent defective PAP inhibits only the virus but does not interfere with the host. A non-virulent defective PAP gene ...

  16. Breeding for Improved Disease Resistance in Organic Farming – Possibilities and Constraints

    Directory of Open Access Journals (Sweden)

    Magnusson Ulf

    2002-03-01

    Full Text Available Lowered incidences of disease may be reached in several ways: management and rearing measures, vaccination programmes and preventive medications as well as breeding for improved disease resistance. Here the focus is on breeding for improved resistance to infectious diseases. In comparison to conventional farming, one has to acknowledge that the spectrum of diseases in animals reared under organic conditions is different and that the proportion of the breeding stock of animals in organic farming is considerably smaller. There are at least four different approaches that may be used in breeding towards resistance to infectious diseases. The most obvious is to record disease incidence in the progeny and select those parents that produce the progeny with the lowest incidences of disease. Another approach is to use breeders possessing certain major histo-compatibility complex antigens suggested being associated with resistance to certain infections. A third approach is to analyse the heritability of a set of immune functions or related traits crucial for resistance to infections and then use the traits with high heritability in breeding programmes. Finally, one may genetically select animals for high immune response using an index that combines estimated breeding values for several immunological traits. Examples of these various approaches are given and the feasibility for using these in organic farming are discussed.

  17. Prospects of Understanding the Molecular Biology of Disease Resistance in Rice

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Singh

    2018-04-01

    Full Text Available Rice is one of the important crops grown worldwide and is considered as an important crop for global food security. Rice is being affected by various fungal, bacterial and viral diseases resulting in huge yield losses every year. Deployment of resistance genes in various crops is one of the important methods of disease management. However, identification, cloning and characterization of disease resistance genes is a very tedious effort. To increase the life span of resistant cultivars, it is important to understand the molecular basis of plant host–pathogen interaction. With the advancement in rice genetics and genomics, several rice varieties resistant to fungal, bacterial and viral pathogens have been developed. However, resistance response of these varieties break down very frequently because of the emergence of more virulent races of the pathogen in nature. To increase the durability of resistance genes under field conditions, understanding the mechanismof resistance response and its molecular basis should be well understood. Some emerging concepts like interspecies transfer of pattern recognition receptors (PRRs and transgenerational plant immunitycan be employed to develop sustainable broad spectrum resistant varieties of rice.

  18. Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Ana Teresa P. Carvalho

    2014-01-01

    Full Text Available OBJECTIVES: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro. METHODS: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn's disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations. RESULTS: No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn's disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn's disease than in ulcerative colitis (p = 0.047. A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn's disease (OR: 4.13; p = 0.009, whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094. In Crohn's disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010. However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories. CONCLUSION: The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn's disease. This association with Crohn's disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut

  19. A novel Capsicum gene inhibits host-specific disease resistance to Phytophthora capsici.

    Science.gov (United States)

    Reeves, Gregory; Monroy-Barbosa, Ariadna; Bosland, Paul W

    2013-05-01

    A novel disease resistance inhibitor gene (inhibitor of P. capsici resistance [Ipcr]), found in the chile pepper (Capsicum annuum) variety 'New Mexico Capsicum Accession 10399' (NMCA10399), inhibits resistance to Phytophthora capsici but not to other species of Phytophthora. When a highly P. capsici-resistant variety was hybridized with NMCA10399, the resultant F1 populations, when screened, were completely susceptible to P. capsici for root rot and foliar blight disease syndromes, despite the dominance inheritance of P. capsici resistance in chile pepper. The F2 population displayed a 3:13 resistant-to-susceptible (R:S) ratio. The testcross population displayed a 1:1 R:S ratio, and a backcross population to NMCA10399 displayed complete susceptibility. These results demonstrate the presence of a single dominant inhibitor gene affecting P. capsici resistance in chile pepper. Moreover, when lines carrying the Ipcr gene were challenged against six Phytophthora spp., the nonhost resistance was not overcome. Therefore, the Ipcr gene is interfering with host-specific resistance but not the pathogen- or microbe-associated molecular pattern nonhost responses.

  20. Standard method for detecting Bombyx mori nucleopolyhedrovirus disease-resistant silkworm varieties

    Directory of Open Access Journals (Sweden)

    Yang Qiong

    Full Text Available ABSTRACT Bombyx mori nucleopolyhedrovirus (BmNPV disease is one of the most serious silkworm diseases, and it has caused great economic losses to the sericulture industry. So far, the disease has not been controlled effectively by therapeutic agents. Breeding resistant silkworm varieties breeding may be an effective way to improve resistance to BmNPV and reduce economic losses. A precise resistance-detection method will help to accelerate the breeding process. For this purpose, here we described the individual inoculation method (IIM. Details of the IIM include pathogen BmNPV preparation, mulberry leaf size, pathogen volume, rearing conditions, course of infection, and breeding conditions. Finally, a resistance comparison experiment was performed using the IIM and the traditional group inoculation method (GIM. The incidence of BmNPV infection and the within-group variance results showed that the IIM was more precise and reliable than the GIM.

  1. genetics of resistance to groundnut rosette virus disease abstract

    African Journals Online (AJOL)

    ACSS

    Groundnut Rosette Virus disease (GRD) has long been regarded a major limiting biotic constraint to groundnut production in Sub-Saharan Africa (SSA). The disease is caused by a complex of three viral components that interact in a synergistic fashion resulting into severe crop losses. A study was conducted to better ...

  2. Genetics of resistance to groundnut rosette virus disease. | Kayondo ...

    African Journals Online (AJOL)

    Groundnut Rosette Virus disease (GRD) has long been regarded a major limiting biotic constraint to groundnut production in Sub-Saharan Africa (SSA). The disease is caused by a complex of three viral components that interact in a synergistic fashion resulting into severe crop losses. A study was conducted to better ...

  3. Breeding for cotton leaf curl disease (CLCuD) resistance

    Science.gov (United States)

    Cotton leaf curl disease (CLCuD) is caused by a whitefly (Bemisia tabaci) transmitted geminivirus. It is a major disease of cotton in Africa and South Asia, and has spread to other countries through ornamental plants. It can potentially devastate U.S. cotton where commercial varieties have no resi...

  4. Sources of resistance to cassava anthracnose disease | Owolade ...

    African Journals Online (AJOL)

    A total of 436 African landraces and 497 improved cassava genotypes were planted in 1996, 1997, 1998 and 1999 growing seasons.. These were evaluated for their reactions to cassava anthracnose disease (CAD) under natural infection conditions at Ibadan (a high infection zone). The severity of the disease was ...

  5. Trade-Offs in Arbuscular Mycorrhizal Symbiosis: Disease Resistance, Growth Responses and Perspectives for Crop Breeding

    Directory of Open Access Journals (Sweden)

    Catherine N. Jacott

    2017-11-01

    Full Text Available There is an increasing need to develop high-yielding, disease-resistant crops and reduce fertilizer usage. Combining disease resistance with efficient nutrient assimilation through improved associations with symbiotic microorganisms would help to address this. Arbuscular mycorrhizal fungi (AMF form symbiotic relationships with most terrestrial plants, resulting in nutritional benefits and the enhancement of stress tolerance and disease resistance. Despite these advantages, arbuscular mycorrhizal (AM interactions are not normally directly considered in plant breeding. Much of our understanding of the mechanisms of AM symbiosis comes from model plants, which typically exhibit positive growth responses. However, applying this knowledge to crops has not been straightforward. In many crop plants, phosphate uptake and growth responses in AM-colonized plants are variable, with AM plants exhibiting sometimes zero or negative growth responses and lower levels of phosphate acquisition. Host plants must also balance the ability to host AMF with the ability to resist pathogens. Advances in understanding the plant immune system have revealed similarities between pathogen infection and AM colonization that may lead to trade-offs between symbiosis and disease resistance. This review considers the potential trade-offs between AM colonization, agronomic traits and disease resistance and highlights the need for translational research to apply fundamental knowledge to crop improvement.

  6. Rapid cloning of disease-resistance genes in plants using mutagenesis and sequence capture

    Science.gov (United States)

    Genetic solutions to protect crops against pests and pathogens are preferable to agrichemicals 1. Wild crop relatives carry immense diversity of disease resistance (R) genes that could enable more sustainable disease control. However, recruiting R genes for crop improvement typically involves long b...

  7. Application of hordothionins and cecropin B for engineering bacterial disease resistance into plants

    NARCIS (Netherlands)

    Florack, D.

    1994-01-01

    Bacterial diseases can cause a drastic decrease of yield in certain crops. Breeding for bacterial disease resistance therefore is of utmost necessity. Up to now, traditional plant breeding was the only method to reach this goal. Recent developments in genetic engineering technology however

  8. Selection for immunoresponsiveness in chickens : effects of the major histocompatibility complex and resistance to Marek's disease

    NARCIS (Netherlands)

    Pinard, M.H.

    1992-01-01

    Improving genetic disease resistance may be an attractive preventive measure in the control of infectious diseases in livestock production. Chickens were selected for high and low antibody response to sheep red blood cells for ten generations. Divergent selection was successfully achieved

  9. Overexpression of a citrus NDR1 ortholog increases disease resistance in Arabidopsis

    Science.gov (United States)

    Emerging devastating diseases, such as Huanglongbing (HLB) and citrus canker, have caused tremendous losses to the citrus industry worldwide. Genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. The key to the success of this approach r...

  10. Overexpression of a modified plant thionin enhances disease resistance to citrus canker and Huanglongbing (HLB)

    Science.gov (United States)

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an ec...

  11. Toward The identification Of candidate genes involved in black pod disease resistance in Theobroma cacao L.

    Science.gov (United States)

    Increasing yield, quality and disease resistance are important objectives for cacao breeding programs. Some of the diseases, such as black pod rot (Phytophtora spp), frosty pod (Moniliophthora roreri) and witches’ broom (M. perniciosa), produce significant losses in all or in some of the various pro...

  12. An assessment of antimicrobial resistant disease threats in Canada.

    Science.gov (United States)

    Garner, Michael J; Carson, Carolee; Lingohr, Erika J; Fazil, Aamir; Edge, Victoria L; Trumble Waddell, Jan

    2015-01-01

    Antimicrobial resistance (AMR) of infectious agents is a growing concern for public health organizations. Given the complexity of this issue and how widespread the problem has become, resources are often insufficient to address all concerns, thus prioritization of AMR pathogens is essential for the optimal allocation of risk management attention. Since the epidemiology of AMR pathogens differs between countries, country-specific assessments are important for the determination of national priorities. To develop a systematic and transparent approach to AMR risk prioritization in Canada. Relevant AMR pathogens in Canada were selected through a transparent multi-step consensus process (n=32). Each pathogen was assessed using ten criteria: incidence, mortality, case-fatality, communicability, treatability, clinical impact, public/political attention, ten-year projection of incidence, economic impact, and preventability. For each pathogen, each criterion was assigned a numerical score of 0, 1, or 2, and multiplied by criteria-specific weighting determined through researcher consensus of importance. The scores for each AMR pathogen were summed and ranked by total score, where a higher score indicated greater importance. A sensitivity analysis was conducted to determine the effects of changing the criteria-specific weights. The AMR pathogen with the highest total weighted score was extended spectrum B-lactamase-producing (ESBL) Enterobacteriaceae (score=77). When grouped by percentile, ESBL Enterobacteriaceae, Clostridium difficile, carbapenem-resistant Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus were in the 80-100th percentile. This assessment provides useful information for prioritising public health strategies regarding AMR resistance at the national level in Canada. As the AMR environment and challenges change over time and space, this systematic and transparent approach can be adapted for use by other stakeholders domestically and

  13. An assessment of antimicrobial resistant disease threats in Canada.

    Directory of Open Access Journals (Sweden)

    Michael J Garner

    Full Text Available Antimicrobial resistance (AMR of infectious agents is a growing concern for public health organizations. Given the complexity of this issue and how widespread the problem has become, resources are often insufficient to address all concerns, thus prioritization of AMR pathogens is essential for the optimal allocation of risk management attention. Since the epidemiology of AMR pathogens differs between countries, country-specific assessments are important for the determination of national priorities.To develop a systematic and transparent approach to AMR risk prioritization in Canada.Relevant AMR pathogens in Canada were selected through a transparent multi-step consensus process (n=32. Each pathogen was assessed using ten criteria: incidence, mortality, case-fatality, communicability, treatability, clinical impact, public/political attention, ten-year projection of incidence, economic impact, and preventability. For each pathogen, each criterion was assigned a numerical score of 0, 1, or 2, and multiplied by criteria-specific weighting determined through researcher consensus of importance. The scores for each AMR pathogen were summed and ranked by total score, where a higher score indicated greater importance. A sensitivity analysis was conducted to determine the effects of changing the criteria-specific weights.The AMR pathogen with the highest total weighted score was extended spectrum B-lactamase-producing (ESBL Enterobacteriaceae (score=77. When grouped by percentile, ESBL Enterobacteriaceae, Clostridium difficile, carbapenem-resistant Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus were in the 80-100th percentile.This assessment provides useful information for prioritising public health strategies regarding AMR resistance at the national level in Canada. As the AMR environment and challenges change over time and space, this systematic and transparent approach can be adapted for use by other stakeholders domestically and

  14. 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.

  15. Evaluation of lettuce germplasm resistance to gray mold disease for organic cultivations.

    Science.gov (United States)

    Shim, Chang Ki; Kim, Min Jeong; Kim, Yong Ki; Jee, Hyeong Jin

    2014-03-01

    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 (3×10(7) 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.

  16. Characterization of a tailless white spot syndrome virus from ...

    African Journals Online (AJOL)

    WSSV) but without tail-like extension was identified and characterized from diseased Penaeus vannamei and moribund Procambarus clarkia. Contrary to previous reports, white spots were not observed on the carapace of the diseased P.

  17. Antimicrobial resistance in Salmonella that caused foodborne disease outbreaks: United States, 2003–2012

    Science.gov (United States)

    BROWN, A. C.; GRASS, J. E.; RICHARDSON, L. C.; NISLER, A. L.; BICKNESE, A. S.; GOULD, L. H.

    2016-01-01

    SUMMARY Although most non-typhoidal Salmonella illnesses are self-limiting, antimicrobial treatment is critical for invasive infections. To describe resistance in Salmonella that caused foodborne outbreaks in the United States, we linked outbreaks submitted to the Foodborne Disease Outbreak Surveillance System to isolate susceptibility data in the National Antimicrobial Resistance Monitoring System. Resistant outbreaks were defined as those linked to one or more isolates with resistance to at least one antimicrobial drug. Multidrug resistant (MDR) outbreaks had at least one isolate resistant to three or more antimicrobial classes. Twenty-one per cent (37/176) of linked outbreaks were resistant. In outbreaks attributed to a single food group, 73% (16/22) of resistant outbreaks and 46% (31/68) of non-resistant outbreaks were attributed to foods from land animals (P outbreaks from land animals and 8% (3/40) of outbreaks from plant products (P outbreaks attributed to foods from land animals than outbreaks from foods from plants or aquatic animals. Antimicrobial susceptibility data on isolates from foodborne Salmonella outbreaks can help determine which foods are associated with resistant infections. PMID:27919296

  18. Antimicrobial resistance in Salmonella that caused foodborne disease outbreaks: United States, 2003-2012.

    Science.gov (United States)

    Brown, A C; Grass, J E; Richardson, L C; Nisler, A L; Bicknese, A S; Gould, L H

    2017-03-01

    Although most non-typhoidal Salmonella illnesses are self-limiting, antimicrobial treatment is critical for invasive infections. To describe resistance in Salmonella that caused foodborne outbreaks in the United States, we linked outbreaks submitted to the Foodborne Disease Outbreak Surveillance System to isolate susceptibility data in the National Antimicrobial Resistance Monitoring System. Resistant outbreaks were defined as those linked to one or more isolates with resistance to at least one antimicrobial drug. Multidrug resistant (MDR) outbreaks had at least one isolate resistant to three or more antimicrobial classes. Twenty-one per cent (37/176) of linked outbreaks were resistant. In outbreaks attributed to a single food group, 73% (16/22) of resistant outbreaks and 46% (31/68) of non-resistant outbreaks were attributed to foods from land animals (P outbreaks from land animals and 8% (3/40) of outbreaks from plant products (P outbreaks attributed to foods from land animals than outbreaks from foods from plants or aquatic animals. Antimicrobial susceptibility data on isolates from foodborne Salmonella outbreaks can help determine which foods are associated with resistant infections.

  19. Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate

    Directory of Open Access Journals (Sweden)

    Amer F. Mahmoud

    2015-12-01

    Full Text Available Yellow rust (stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F₈ recombinant inbred lines (RILs derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant and Sakha-69 (susceptible were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 2 <6. However, only 7 RILs showed RRI value <2. Five RILs expressed hypersensitive type of resistance (R against the pathogen and showed the lowest Average Coefficient of Infection (ACI. Bulked segregant analysis (BSA with eight simple sequence repeat (SSR, eight sequence-related amplified polymorphism (SRAP and sixteen random amplified polymorphic DNA (RAPD markers revealed that three SSR, three SRAP and six RAPD markers were found to be associated with the resistance to yellow rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

  20. Cardiovascular Disease Susceptibility and Resistance in Circumpolar Inuit Populations

    DEFF Research Database (Denmark)

    Tvermosegaard, Maria; Dahl-Petersen, Inger K; Nielsen, Nina Odgaard

    2015-01-01

    Cardiovascular disease (CVD) is a major public health issue in indigenous populations in the Arctic. These diseases have emerged concomitantly with profound social changes over the past 60 years. The aim of this study was to summarize the literature on CVD risk among Arctic Inuit. Literature...... on prevalence, incidence, and time trends for CVD and its risk factors in Arctic Inuit populations was reviewed. Most evidence supports a similar incidence of coronary heart disease and a higher incidence of cerebrovascular disease among Arctic Inuit than seen in western populations. Factors that may increase...... intake (at least documented in Greenland), and contaminant levels are declining. Although there have been marked socioeconomic and dietary changes, it remains unsolved and to some extent controversial how this may have influenced cardiovascular risk among Arctic Inuit. The increase in life expectancy...

  1. Application of infrared and Raman spectroscopy for the identification of disease resistant trees

    Directory of Open Access Journals (Sweden)

    Anna O. Conrad

    2016-01-01

    Full Text Available New approaches for identifying disease resistant trees are needed, as the incidence of diseases caused by non-native and invasive pathogens increases. These approaches must be rapid, reliable, cost-effective, and should have the potential to be adapted for high-throughput screening or phenotyping. Within the context of trees and tree diseases, we summarize vibrational spectroscopic and chemometric methods that have been used to distinguish between groups of trees which vary in disease susceptibility or other important characteristics based on chemical fingerprint data. We also provide specific examples from the literature of where these approaches have been used successfully. Finally, we discuss future application of these approaches for wide-scale screening and phenotyping efforts aimed at identifying disease resistant trees and managing forest diseases.

  2. The genetic architecture of disease resistance in plants and the maintenance of recombination by parasites.

    Science.gov (United States)

    Kover, P X; Caicedo, A L

    2001-01-01

    Parasites represent strong selection on host populations because they are ubiquitous and can drastically reduce host fitness. It has been hypothesized that parasite selection could explain the widespread occurrence of recombination because it is a coevolving force that favours new genetic combinations in the host. A review of deterministic models for the maintenance of recombination reveals that for recombination to be favoured, multiple genes that interact with each other must be under selection. To evaluate whether parasite selection can explain the maintenance of recombination, we review 85 studies that investigated the genetic architecture of plant disease resistance and discuss whether they conform to the requirements that emerge from theoretical models. General characteristics of disease resistance in plants and problems in evaluating resistance experimentally are also discussed. We found strong evidence that disease resistance in plants is determined by multiple loci. Furthermore, in most cases where loci were tested for interactions, epistasis between loci that affect resistance was found. However, we found weak support for the idea that specific allelic combinations determine resistance to different host genotypes and there was little data on whether epistasis between resistance genes is negative or positive. Thus, the current data indicate that it is possible that parasite selection can favour recombination, but more studies in natural populations that specifically address the nature of the interactions between resistance genes are necessary. The data summarized here suggest that disease resistance is a complex trait and that environmental effects and fitness trade-offs should be considered in future models of the coevolutionary dynamics of host and parasites.

  3. Genome-Wide Association and Genomic Selection for Resistance to Amoebic Gill Disease in Atlantic Salmon.

    Science.gov (United States)

    Robledo, Diego; Matika, Oswald; Hamilton, Alastair; Houston, Ross D

    2018-03-28

    Amoebic gill disease (AGD) is one of the largest threats to salmon aquaculture, causing serious economic and animal welfare burden. Treatments can be expensive and environmentally damaging, hence the need for alternative strategies. Breeding for disease resistance can contribute to prevention and control of AGD, providing long-term cumulative benefits in selected stocks. The use of genomic selection can expedite selection for disease resistance due to improved accuracy compared to pedigree-based approaches. The aim of this work was to quantify and characterize genetic variation in AGD resistance in salmon, the genetic architecture of the trait, and the potential of genomic selection to contribute to disease control. An AGD challenge was performed in ∼1,500 Atlantic salmon, using gill damage and amoebic load as indicator traits for host resistance. Both traits are heritable (h 2 ∼0.25-0.30) and show high positive correlation, indicating they may be good measurements of host resistance to AGD. While the genetic architecture of resistance appeared to be largely polygenic in nature, two regions on chromosome 18 showed suggestive association with both AGD resistance traits. Using a cross-validation approach, genomic prediction accuracy was up to 18% higher than that obtained using pedigree, and a reduction in marker density to ∼2,000 SNPs was sufficient to obtain accuracies similar to those obtained using the whole dataset. This study indicates that resistance to AGD is a suitable trait for genomic selection, and the addition of this trait to Atlantic salmon breeding programs can lead to more resistant stocks. Copyright © 2018 Robledo et al.

  4. Review of insecticide resistance and behavioral avoidance of vectors of human diseases in Thailand

    Science.gov (United States)

    2013-01-01

    Physiological resistance and behavioral responses of mosquito vectors to insecticides are critical aspects of the chemical-based disease control equation. The complex interaction between lethal, sub-lethal and excitation/repellent ('excito-repellent’) properties of chemicals is typically overlooked in vector management and control programs. The development of “physiological” resistance, metabolic and/or target site modifications, to insecticides has been well documented in many insect groups and disease vectors around the world. In Thailand, resistance in many mosquito populations has developed to all three classes of insecticidal active ingredients currently used for vector control with a majority being synthetic-derived pyrethroids. Evidence of low-grade insecticide resistance requires immediate countermeasures to mitigate further intensification and spread of the genetic mechanisms responsible for resistance. This can take the form of rotation of a different class of chemical, addition of a synergist, mixtures of chemicals or concurrent mosaic application of different classes of chemicals. From the gathered evidence, the distribution and degree of physiological resistance has been restricted in specific areas of Thailand in spite of long-term use of chemicals to control insect pests and disease vectors throughout the country. Most surprisingly, there have been no reported cases of pyrethroid resistance in anopheline populations in the country from 2000 to 2011. The precise reasons for this are unclear but we assume that behavioral avoidance to insecticides may play a significant role in reducing the selection pressure and thus occurrence and spread of insecticide resistance. The review herein provides information regarding the status of physiological resistance and behavioral avoidance of the primary mosquito vectors of human diseases to insecticides in Thailand from 2000 to 2011. PMID:24294938

  5. Retention of acetylcarnitine in chronic kidney disease causes insulin resistance in skeletal muscle.

    Science.gov (United States)

    Miyamoto, Yasunori; Miyazaki, Teruo; Honda, Akira; Shimohata, Homare; Hirayama, Kouichi; Kobayashi, Masaki

    2016-11-01

    Insulin resistance occurs frequently in patients with chronic kidney disease. However, the mechanisms of insulin resistance associated with chronic kidney disease are unclear. It is known that an increase in the mitochondrial acetyl-CoA (AcCoA)/CoA ratio causes insulin resistance in skeletal muscle, and this ratio is regulated by carnitine acetyltransferase that exchanges acetyl moiety between CoA and carnitine. Because excess acetyl moiety of AcCoA is excreted in urine as acetylcarnitine, we hypothesized that retention of acetylcarnitine might be a cause of insulin resistance in chronic kidney disease patients. Serum acetylcarnitine concentrations were measured in chronic kidney disease patients, and were significantly increased with reduction of renal function. The effects of excess extracellular acetylcarnitine on insulin resistance were studied in cultured skeletal muscle cells (C2C12 and human myotubes), and insulin-dependent glucose uptake was significantly and dose-dependently inhibited by addition of acetylcarnitine. The added acetylcarnitine was converted to carnitine via reverse carnitine acetyltransferase reaction, and thus the AcCoA concentration and AcCoA/CoA ratio in mitochondria were significantly elevated. The results suggest that increased serum acetylcarnitine in CKD patients causes AcCoA accumulation in mitochondria by stimulating reverse carnitine acetyltransferase reaction, which leads to insulin resistance in skeletal muscle.

  6. Multiple insecticide resistances in the disease vector Culex p. quinquefasciatus from Western Indian Ocean.

    Science.gov (United States)

    Pocquet, Nicolas; Milesi, Pascal; Makoundou, Patrick; Unal, Sandra; Zumbo, Betty; Atyame, Célestine; Darriet, Frédéric; Dehecq, Jean-Sébastien; Thiria, Julien; Bheecarry, Ambicadutt; Iyaloo, Diana P; Weill, Mylène; Chandre, Fabrice; Labbé, Pierrick

    2013-01-01

    Several mosquito-borne diseases affect the Western Indian Ocean islands. Culex pipiens quinquefasciatus is one of these vectors and transmits filariasis, Rift Valley and West Nile viruses and the Japanese encephalitis. To limit the impact of these diseases on public health, considerable vector control efforts have been implemented since the 50s, mainly through the use of neurotoxic insecticides belonging to Organochlorines (OC), Organophosphates (OP) and pyrethroids (PYR) families. However, mosquito control failures have been reported on site, and they were probably due to the selection of resistant individuals in response to insecticide exposure. In this study, we used different approaches to establish a first regional assessment of the levels and mechanisms of resistance to various insecticides. Bioassays were used to evaluate resistance to various insecticides, enzyme activity was measured to assess the presence of metabolic resistances through elevated detoxification, and molecular identification of known resistance alleles was investigated to determine the frequency of target-site mutations. These complementary approaches showed that resistance to the most used insecticides families (OC, OP and PYR) is widespread at a regional scale. However, the distribution of the different resistance genes is quite heterogeneous among the islands, some being found at high frequencies everywhere, others being frequent in some islands and absent in others. Moreover, two resistance alleles displayed clinal distributions in Mayotte and La Réunion, probably as a result of a heterogeneous selection due to local treatment practices. These widespread and diverse resistance mechanisms reduce the capacity of resistance management through classical strategies (e.g. insecticide rotation). In case of a disease outbreak, it could undermine the efforts of the vector control services, as only few compounds could be used. It thus becomes urgent to find alternatives to control populations

  7. Multiple insecticide resistances in the disease vector Culex p. quinquefasciatus from Western Indian Ocean.

    Directory of Open Access Journals (Sweden)

    Nicolas Pocquet

    Full Text Available Several mosquito-borne diseases affect the Western Indian Ocean islands. Culex pipiens quinquefasciatus is one of these vectors and transmits filariasis, Rift Valley and West Nile viruses and the Japanese encephalitis. To limit the impact of these diseases on public health, considerable vector control efforts have been implemented since the 50s, mainly through the use of neurotoxic insecticides belonging to Organochlorines (OC, Organophosphates (OP and pyrethroids (PYR families. However, mosquito control failures have been reported on site, and they were probably due to the selection of resistant individuals in response to insecticide exposure. In this study, we used different approaches to establish a first regional assessment of the levels and mechanisms of resistance to various insecticides. Bioassays were used to evaluate resistance to various insecticides, enzyme activity was measured to assess the presence of metabolic resistances through elevated detoxification, and molecular identification of known resistance alleles was investigated to determine the frequency of target-site mutations. These complementary approaches showed that resistance to the most used insecticides families (OC, OP and PYR is widespread at a regional scale. However, the distribution of the different resistance genes is quite heterogeneous among the islands, some being found at high frequencies everywhere, others being frequent in some islands and absent in others. Moreover, two resistance alleles displayed clinal distributions in Mayotte and La Réunion, probably as a result of a heterogeneous selection due to local treatment practices. These widespread and diverse resistance mechanisms reduce the capacity of resistance management through classical strategies (e.g. insecticide rotation. In case of a disease outbreak, it could undermine the efforts of the vector control services, as only few compounds could be used. It thus becomes urgent to find alternatives to

  8. Definition, identification and treatment of resistant hypertension in chronic kidney disease patients.

    Science.gov (United States)

    Drexler, Yelena R; Bomback, Andrew S

    2014-07-01

    Resistant hypertension, the inability to achieve goal blood pressure despite the use of three or more appropriately dosed antihypertensive drugs (including a diuretic), remains a common clinical problem, especially in patients with chronic kidney disease (CKD). While the exact prevalence and prognosis of resistant hypertension in CKD patients remain unknown, resistant hypertension likely contributes significantly to increased cardiovascular risk and progression of kidney disease in this population. We review the identification and evaluation of patients with resistant hypertension, including the importance of 24-h ambulatory blood pressure monitoring in the identification of 'white-coat', 'masked' and 'non-dipper' hypertension, the latter of which has particular clinical and therapeutic importance in patients with resistant hypertension and CKD. We then discuss treatment strategies for resistant hypertension that target the pathophysiologic mechanisms underlying resistance to treatment, including persistent volume excess, incomplete renin-angiotensin-aldosterone system blockade and inadequate nocturnal blood pressure control. Finally, we propose a treatment algorithm for evaluation and treatment of resistant hypertension in patients with CKD. © The Author 2013. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  9. HOPM1 mediated disease resistance to Pseudomonas syringae in Arabidopsis

    Science.gov (United States)

    He, Sheng Yang [Okemos, MI; Nomura, Kinya [East Lansing, MI

    2011-11-15

    The present invention relates to compositions and methods for enhancing plant defenses against pathogens. More particularly, the invention relates to enhancing plant immunity against bacterial pathogens, wherein HopM1.sub.1-300 mediated protection is enhanced, such as increased protection to Pseudomonas syringae pv. tomato DC3000 HopM1 and/or there is an increase in activity of an ATMIN associated plant protection protein, such as ATMIN7. Reagents of the present invention further provide a means of studying cellular trafficking while formulations of the present inventions provide increased pathogen resistance in plants.

  10. Identification of potential hot spots in the carboxy-terminal part of the Epstein-Barr virus (EBV) BNLF-1 gene in both malignant and benign EBV-associated diseases

    DEFF Research Database (Denmark)

    Sandvej, K; Peh, S C; Andresen, B S

    1994-01-01

    In this study, we have sequenced the C-terminal part of the Epstein-Barr virus (EBV)-BNLF-1 gene encoding for the latent membrane protein-1 from tissues of EBV-positive Danish Hodgkin's disease (HD) and of Danish and Malaysian peripheral T-cell lymphomas (PTLs) and from tonsils of Danish infectio...... of the CAO-BNLF-1 gene do not characterize a new EBV type A substrain. Rather, some of the positions of single base mutations and the 30-bp deletion are hot spots that may have mutated independently through the evolution of EBV strains....

  11. Bier’s spots with onset in childhood*

    Science.gov (United States)

    Portocarrero, Larissa Karine Leite; Saraiva, Maria Isabel Ramos; Barbosa, Marcella Amaral Horta; Veronez, Isis Suga; Swiczar, Bethania Cabral Cavalli; Valente, Neusa Yuriko Sakai

    2016-01-01

    Bier spots are small, irregular, hypopigmented macules that are usually found on the arms and legs. The macules disappear when the limb is raised. Bier spots have been reported in association with a number of conditions but there is no consistent association to specific desease. Although they usually affect young adults, we report a case of Bier spots that began in childhood. As an asymptomatic and possibly transitional condition, the disease does not require treatment. PMID:28300906

  12. Insecticide resistance in disease vectors from Mayotte: an opportunity for integrated vector management.

    Science.gov (United States)

    Pocquet, Nicolas; Darriet, Frédéric; Zumbo, Betty; Milesi, Pascal; Thiria, Julien; Bernard, Vincent; Toty, Céline; Labbé, Pierrick; Chandre, Fabrice

    2014-07-01

    Mayotte, a small island in the Indian Ocean, has been affected for many years by vector-borne diseases. Malaria, Bancroftian filariasis, dengue, chikungunya and Rift Valley fever have circulated or still circulate on the island. They are all transmitted by Culicidae mosquitoes. To limit the impact of these diseases on human health, vector control has been implemented for more than 60 years on Mayotte. In this study, we assessed the resistance levels of four major vector species (Anopheles gambiae, Culex pipiens quinquefasciatus, Aedes aegypti and Aedes albopictus) to two types of insecticides: i) the locally currently-used insecticides (organophosphates, pyrethroids) and ii) alternative molecules that are promising for vector control and come from different insecticide families (bacterial toxins or insect growth regulators). When some resistance was found to one of these insecticides, we characterized the mechanisms involved. Larval and adult bioassays were used to evaluate the level of resistance. When resistance was found, we tested for the presence of metabolic resistance through detoxifying enzyme activity assays, or for target-site mutations through molecular identification of known resistance alleles. Resistance to currently-used insecticides varied greatly between the four vector species. While no resistance to any insecticides was found in the two Aedes species, bioassays confirmed multiple resistance in Cx. p. quinquefasciatus (temephos: ~ 20 fold and deltamethrin: only 10% mortality after 24 hours). In An. gambiae, resistance was scarce: only a moderate resistance to temephos was found (~5 fold). This resistance appears to be due only to carboxyl-esterase overexpression and not to target modification. Finally, and comfortingly, none of the four species showed resistance to any of the new insecticides. The low resistance observed in Mayotte's main disease vectors is particularly interesting, because it leaves a range of tools useable by vector control

  13. Strategies for resistance to bacterial wilt disease of bananas through ...

    African Journals Online (AJOL)

    The livelihoods of millions of Ugandan farmers have been threatened by current outbreak of a banana bacterial wilt disease caused by Xanthomonas campestris pv. musacearum, which is very destructive and rapidly spreading in Uganda. Bananas are the highest value staple food and source of income for millions of ...

  14. Cisgenic Approach for improved disease resistance in apple

    NARCIS (Netherlands)

    Broggini, G.A.L.; Durel, C.E.; Vergne, E.; Chevreau, E.; Fahrentrapp, J.; Vanblaere, T.; Peil, A.; Flachowsky, H.; Hanke, M.V.; Krens, F.A.; Schouten, H.J.; Gessler, C.

    2013-01-01

    Swiss and more generally European apple (Malus × domestica) production is hampered by several diseases, the most destructive being fire blight, caused by Erwinia amylovora. On the other hand, there are apple scab, caused by Venturia inaequalis and powdery mildew, caused by Podosphaera leucotricha,

  15. genetics of resistance to groundnut rosette virus disease abstract ...

    African Journals Online (AJOL)

    ACSS

    2014-02-03

    Feb 3, 2014 ... Groundnut rosette virus disease is caused by synergyistic interaction of three viral agents, namely, groundnut rosette virus (GRV), its satelitte RNA (Sat RNA) and groundnut rosette assistor virus (GRAV). GRAV plays an important role in aiding aphid transmission, alongside the other two viral components.

  16. Genetic anaylsis of a disease resistance gene from loblolly pine

    Science.gov (United States)

    Yinghua Huang; Nili Jin; Alex Diner; Chuck Tauer; Yan Zhang; John Damicone

    2003-01-01

    Rapid advances in molecular genetics provide great opportunities for studies of host defense mechanisms. Examination of plant responses to disease at the cellular and molecular level permits both discovery of changes in gene expression in the tissues attacked by pathogens, and identification of genetic components involved in the interaction between host and pathogens....

  17. Conserved allosteric hot spots in the transmembrane domains of cystic fibrosis transmembrane conductance regulator (CFTR) channels and multidrug resistance protein (MRP) pumps.

    Science.gov (United States)

    Wei, Shipeng; Roessler, Bryan C; Chauvet, Sylvain; Guo, Jingyu; Hartman, John L; Kirk, Kevin L

    2014-07-18

    ATP-binding cassette (ABC) transporters are an ancient family of transmembrane proteins that utilize ATPase activity to move substrates across cell membranes. The ABCC subfamily of the ABC transporters includes active drug exporters (the multidrug resistance proteins (MRPs)) and a unique ATP-gated ion channel (cystic fibrosis transmembrane conductance regulator (CFTR)). The CFTR channel shares gating principles with conventional ligand-gated ion channels, but the allosteric network that couples ATP binding at its nucleotide binding domains (NBDs) with conformational changes in its transmembrane helices (TMs) is poorly defined. It is also unclear whether the mechanisms that govern CFTR gating are conserved with the thermodynamically distinct MRPs. Here we report a new class of gain of function (GOF) mutation of a conserved proline at the base of the pore-lining TM6. Multiple substitutions of this proline promoted ATP-free CFTR activity and activation by the weak agonist, 5'-adenylyl-β,γ-imidodiphosphate (AMP-PNP). TM6 proline mutations exhibited additive GOF effects when combined with a previously reported GOF mutation located in an outer collar of TMs that surrounds the pore-lining TMs. Each TM substitution allosterically rescued the ATP sensitivity of CFTR gating when introduced into an NBD mutant with defective ATP binding. Both classes of GOF mutations also rescued defective drug export by a yeast MRP (Yor1p) with ATP binding defects in its NBDs. We conclude that the conserved TM6 proline helps set the energy barrier to both CFTR channel opening and MRP-mediated drug efflux and that CFTR channels and MRP pumps utilize similar allosteric mechanisms for coupling conformational changes in their translocation pathways to ATP binding at their NBDs. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Insulin Signaling, Resistance, and the Metabolic Syndrome: Insights from Mouse Models to Disease Mechanisms

    OpenAIRE

    Guo, Shaodong

    2014-01-01

    Insulin resistance is a major underlying mechanism for the “metabolic syndrome”, which is also known as insulin resistance syndrome. Metabolic syndrome is increasing at an alarming rate, becoming a major public and clinical problem worldwide. Metabolic syndrome is represented by a group of interrelated disorders, including obesity, hyperglycemia, hyperlipidemia, and hypertension. It is also a significant risk factor for cardiovascular disease and increased morbidity and mortality. Animal stud...

  19. Improving food and agricultural production. Thailand. Breeding for soybean resistance to anthracnose disease

    International Nuclear Information System (INIS)

    Backman, P.A.

    1992-01-01

    This is the report of a mission to evaluate projects using mutation breeding techniques to develop resistance in soybeans to anthracnose disease. The project to date is generally successful in that training has been provided to numerous scientists in Thailand, and this will lead to improved University teaching and better research. Several changes in experimental procedure are suggested to increase the chances of finding anthracnose resistance in soybean

  20. Loss of CMD2-mediated resistance to cassava mosaic disease in plants regenerated through somatic embryogenesis.

    Science.gov (United States)

    Beyene, Getu; Chauhan, Raj Deepika; Wagaba, Henry; Moll, Theodore; Alicai, Titus; Miano, Douglas; Carrington, James C; Taylor, Nigel J

    2016-09-01

    Cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) are the two most important viral diseases affecting cassava production in Africa. Three sources of resistance are employed to combat CMD: polygenic recessive resistance, termed CMD1, the dominant monogenic type, named CMD2, and the recently characterized CMD3. The farmer-preferred cultivar TME 204 carries inherent resistance to CMD mediated by CMD2, but is highly susceptible to CBSD. Selected plants of TME 204 produced for RNA interference (RNAi)-mediated resistance to CBSD were regenerated via somatic embryogenesis and tested in confined field trials in East Africa. Although micropropagated, wild-type TME 204 plants exhibited the expected levels of resistance, all plants regenerated via somatic embryogenesis were found to be highly susceptible to CMD. Glasshouse studies using infectious clones of East African cassava mosaic virus conclusively demonstrated that the process of somatic embryogenesis used to regenerate cassava caused the resulting plants to become susceptible to CMD. This phenomenon could be replicated in the two additional CMD2-type varieties TME 3 and TME 7, but the CMD1-type cultivar TMS 30572 and the CMD3-type cultivar TMS 98/0505 maintained resistance to CMD after passage through somatic embryogenesis. Data are presented to define the specific tissue culture step at which the loss of CMD resistance occurs and to show that the loss of CMD2-mediated resistance is maintained across vegetative generations. These findings reveal new aspects of the widely used technique of somatic embryogenesis, and the stability of field-level resistance in CMD2-type cultivars presently grown by farmers in East Africa, where CMD pressure is high. © 2015 The Authors Molecular Plant Pathology Published by British Society for Plant Pathology and John Wiley & Sons Ltd.