Person: Vivek, B.
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Vivek
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B.
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Vivek, B.
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0000-0002-2492-6751 8 results
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- Molecular characterization of diverse CIMMYT maize inbred lines from eastern and southern Africa using single nucleotide polymorphic markers(BioMed Central, 2012) Semagn, K.; Magorokosho, C.; Vivek, B.; Makumbi, D.; Beyene, Y.; Mugo, S.N.; Prasanna, B.M.; Warburton, M.Background: Knowledge of germplasm diversity and relationships among elite breeding materials is fundamentally important in crop improvement. We genotyped 450 maize inbred lines developed and/or widely used by CIMMYT breeding programs in both Kenya and Zimbabwe using 1065 SNP markers to (i) investigate population structure and patterns of relationship of the germplasm for better exploitation in breeding programs; (ii) assess the usefulness of SNPs for identifying heterotic groups commonly used by CIMMYT breeding programs; and (iii) identify a subset of highly informative SNP markers for routine and low cost genotyping of CIMMYT germplasm in the region using uniplex assays. Results. Genetic distance for about 94% of the pairs of lines fell between 0.300 and 0.400. Eighty four percent of the pairs of lines also showed relative kinship values ≤ 0.500. Model-based population structure analysis, principal component analysis, neighbor-joining cluster analysis and discriminant analysis revealed the presence of 3 major groups and generally agree with pedigree information. The SNP markers did not show clear separation of heterotic groups A and B that were established based on combining ability tests through diallel and line x tester analyses. Our results demonstrated large differences among the SNP markers in terms of reproducibility, ease of scoring, polymorphism, minor allele frequency and polymorphic information content. About 40% of the SNPs in the multiplexed chip-based GoldenGate assays were found to be uninformative in this study and we recommend 644 of the 1065 for low to medium density genotyping in tropical maize germplasm using uniplex assays. Conclusions. There were high genetic distance and low kinship coefficients among most pairs of lines, clearly indicating the uniqueness of the majority of the inbred lines in these maize breeding programs. The results from this study will be useful to breeders in selecting best parental combinations for new breeding crosses, mapping population development and marker assisted breeding.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2007 regional trials coordinated by CIMMYT(CIMMYT, 2008) Magorokosho, C.; Vivek, B.; McRobert, J.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2005 regional trials coordinated by CIMMYT(CIMMYT, 2006) Magorokosho, C.; Vivek, B.; Banziger, M.; MacRobert, J.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2000 regional trials coordinated by CIMMYT(CIMMYT, 2001) Vivek, B.; Banziger, M.; Pixley, K.V.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2003 regional trials coordinated by CIMMYT(CIMMYT, 2004) Vivek, B.; Banziger, M.; Pixley, K.V.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2002 regional trials coordinated by CIMMYT(CIMMYT, 2003) Vivek, B.; Banziger, M.; Pixley, K.V.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2004 regional trials coordinated by CIMMYT(CIMMYT, 2005) Vivek, B.; Banziger, M.; Pixley, K.V.The Summary Tables present grain yields averaged across sites with significant differences between entries, for each of the five to six environments. Data on agronomic performance such as anthesis date, plant and ear height, ear position, root and stem lodging, husk cover, ear rot, leaf diseases, grain weevil and stem borer damage, grain texture and grain moisture were averaged across all sites that provided results with significant differences between entries. If no data are presented for these traits, no trial data demonstrating significant differences for these traits was available.
Publication - Characterization of maize germplasm grown in Eastern and Southern Africa: results of the 2001 regional trials coordinated by CIMMYT(CIMMYT, 2002) Vivek, B.; Banziger, M.; Pixley, K.V.The Summary Tables present grain yields averaged across sites with significant differences between entries, for each of the five to six environments. Data on agronomic performance such as anthesis date, plant and ear height, ear position, root and stem lodging, husk cover, ear rot, leaf diseases, grain weevil and stem borer damage, grain texture and grain moisture were averaged across all sites that provided results with significant differences between entries. If no data are presented for these traits, no trial data demonstrating significant differences for these traits was available.
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