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Shaina Gupta Sukhjit Kaur Sunish Sehgal Achla Sharma Parveen Chhuneja Navtej S. Bains 《Euphytica》2010,175(3):373-381
Corn leaf aphids (Rhopalosiphum maidis Fitch) are found throughout the year on maize in Hawaii and occasionally cause yield loss. Sweet corn inbred Hi38-71 was
observed to have high field resistance to aphids and was chosen for this genetic study. An artificial infestation technique
was developed using hair-pin clip cages (2.2 cm diameter) which we devised and built. The cages were applied to field-grown
plants into which three wingless viviparous adults were placed. Aphid populations were classified on a 1–10 rating scale after
about 2 weeks based on digital images of the cages. Mean aphid coverage ratings were 2.97 for the resistant parent and 7.28
for the susceptible parent (representing >200 insects per cage). The F1 hybrids showed similar susceptibility (6.72), showing resistance to be recessive in nature. Six generations of the cross
between Hi38-71 and susceptible inbred Hi27 were artificially infested to provide a generation mean analysis of 360 treated
plants over two growing seasons. A joint scaling test showed that the fit to a 3-parameter additive-dominance model satisfactorily
explained the observed variability with no assumed linkage or epistasis. We conclude that resistance to corn leaf aphid in
Hi38-71 is conferred by a single recessive gene labeled aph. These results concur with a previous study under uncontrolled natural infestation in a single environment. The hair-pin
clip cage method was most effective in distinguishing resistant and susceptible genotypes under diverse natural growing conditions
in Hawaii. 相似文献
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Rupinder Pal Singh Puja Srivastava Achla Sharma N. S. Bains 《Journal of Crop Improvement》2017,31(2):183-191
With continuous outbreaks of stripe rust (Puccinia striiformis f. sp. tritici) epidemics and rapid breakdown of deployed resistance in bread wheat (Triticum aestivum L.) cultivars in North West Plains Zone (NWPZ) in India warrant knowledge and deployment of new and durable sources of resistance to stripe rust. Bread wheat cultivar PBW 343, until recently the most widely cultivated wheat variety in India, is now highly susceptible to stripe rust (score 9 on a 1–9 scale), whereas PBW 621 (score 5.05–5.65) and HD 2967 (score 5.40–6.20) show low levels of resistance. We conducted an experiment, spanning three crop seasons (2013–2014 to 2015–2016), in which parental lines, F1 and F2 populations, F3 and F4 families from two bread wheat crosses, PBW 621/PBW 343 and HD 2967/PBW 343 were generated and evaluated for stripe rust resistance against a virulent pathotype. While the F1 revealed partial dominance, the segregation pattern for stripe rust resistance in F2 and F3 showed transgressive segregation for resistance in both crosses. Chi-square analysis indicated that resistant segregants possessed two genes, one contributed by PBW 621 or HD 2967 (depending on the cross) and the other, unexpectedly but obviously, came from the most susceptible cultivar, PBW 343. Possible genetic mechanisms for this residual resistance and implications for breeding programs are discussed. 相似文献
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Prashant Vikram Jorge Franco Juan Burgueo Huihui Li Deepmala Sehgal Carolina Saint‐Pierre Cynthia Ortiz Vaibhav Kumar Singh Clay Sneller Achla Sharma Maria Tattaris Carlos Guzman Javier Pena Carolina Paola Sansaloni Jaime Amador Campos Serna Karthikeyan Thiyagarajan Guillermo Fuentes Davila Matthew Reynolds Kai Sonder Velu Govindan Marc Ellis Sridhar Bhavani Mohammad R. Jalal Kamali Mozaffar Roosatei Sanjay Singh Daisy Basandrai Navtej Singh Bains Ashwani Basandrai Thomas Payne Jos Crossa Sukhwinder Singh 《Plant Breeding》2021,140(1):87-99
Iranian wheat landrace accessions (IWAs) were collected from country‐wide farm fields and market places in 1935 by a professor at the University of Tehran and shared with University of California at Davis, California. IWAs were further submitted to the genebank of International Maize and Wheat Improvement Center (CIMMYT), Mexico. 2,403 IWAs from CIMMYT’s genebank were assayed by DArT‐seq technology to assess genetic diversity. No apparent ecogeographic patterns related to genetic diversity were detected, probably due to long‐term transport and frequent interchange of landraces among farmers. A multivariate clustering procedure combining genotypic and phenotypic information was used in selecting a core‐set, which represented 15% of the hexaploid wheat accessions included in this study. This subset captured an estimated 93% of rare (frequency <0.05) alleles. Multisite phenotypic data (India, Mexico) validated the ability of the core‐set in detecting useful variants. Potential donor accessions for multiple traits (disease resistance, zinc concentration) were identified from the core‐set for wheat‐breeding. This report illustrates a breeder friendly robust core‐set formulation strategy for harnessing the useful genetic variation stored in the genebanks. 相似文献
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Shalini Jhanji N. K. Sekhon U. S. Sadana Achla Sharma A. K. Shukla 《Journal of plant nutrition》2015,38(6):938-958
Wheat genotypes display differential tolerance to manganese (Mn) deficiency. Growing Mn-efficient cultivars in Mn deficient soil could be effective in improving yields. A pot experiment was conducted with eight genotypes grown in Mn deficient soil treated with 0 (no Mn fertilizer) and 50 ppm (50 mg Mn kg?1soil applied as mangansese sulfate monohydrate (MnSO4.H2O) Mn. The genotypes were classified on the basis of grain yield and grain physiological efficiency as efficient and responsive (SAMNYT 410, GLUPRO 200, PBW 621, and BW 9178), efficient and nonresponsive, inefficient and responsive (HD 2967), and inefficient and nonresponsive (PDW 314, PDW 291, and PBW 636). The genotypes in different groups differed in morphophysiological characteristics; efficient and responsive genotypes recorded more leaf area, higher SPAD index, higher Fv/Fm ratio, and longer roots than inefficient and nonresponsive. Efficient and responsive genotypes are desirable by farmers, whereas inefficient and responsive genotypes in a breeding program for their Mn-responsive characteristics. 相似文献
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Kumar Antul Sharma Achla Sharma Rajni Choudhary Anuj Srivastava Puja Kaur Harmanjot Padhy Asish Kumar 《Genetic Resources and Crop Evolution》2022,69(1):411-430
Genetic Resources and Crop Evolution - Gradual deterioration in water resources and unpredictable distribution pattern of annual precipitation amount are major threats having drastic effects on... 相似文献
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