Record Details

SSR and Pedigree Analyses of Genetic Diversity among CIMMYT Wheat Lines Targeted to Different Megaenvironments

OAR@ICRISAT

View Archive Info
 
 
Field Value
 
Relation http://oar.icrisat.org/5710/
http://dx.doi.org/10.2135/cropsci2004.3810
 
Title SSR and Pedigree Analyses of Genetic Diversity among CIMMYT Wheat Lines Targeted to Different Megaenvironments
 
Creator Dreisigacker, S
et al, .
 
Subject Genetics and Genomics
 
Description Improved bread wheat (Triticum aestivum L.) cultivars for diverse agroecological environments are important for success in the effort to increase food production. In the 1980s, CIMMYT introduced the megaenvironment (ME) concept to breed wheats specifically adapted to different areas. Our objective was to analyze the genetic diversity among 68 advanced CIMMYT wheat lines targeted to different MEs by using 99 simple sequence repeats (SSRs) and the coefficient of parentage (COP). The average number of alleles detected was higher for the 47 genomic SSRs (5.4) than for the 52 SSRs derived from expressed sequence tags (EST) (3.3), but gene diversity between MEs was similar for both types of markers. No significant differences among the five MEs were observed for the means of SSR-based genetic similarities (GS), calculated as 1 − Rogers' distance, and COP values. Both measures showed a low correlation (r = 0.43). High levels of genetic diversity were found within the germplasm targeted to each ME. However, principle coordinate analysis based on modified Rogers' distances did not separate the genotypes according to their targeted MEs. We conclude that presence of a single core germplasm can reflect large phenotypic differences. A sufficient number of diverse breeding lines for each ME is required because MEs generally combine various production areas. SSRs represent a powerful tool to quantify genetic diversity in wheat, but genotypic differentiation for adaptation to specific MEs in the CIMMYT program could not be proven.
 
Publisher Crop Science Society of America
 
Date 2004
 
Type Article
PeerReviewed
 
Format application/pdf
 
Language en
 
Rights —
 
Identifier http://oar.icrisat.org/5710/1/CropSci_44_381%E2%80%93388_2004.pdf
Dreisigacker, S and et al, . (2004) SSR and Pedigree Analyses of Genetic Diversity among CIMMYT Wheat Lines Targeted to Different Megaenvironments. Crop Science, 44 (2). pp. 381-388. ISSN 0011-183X