July 9, 2010
Source: CropBiotech Update
Major effect genes are used by sorghum breeders and researchers for germplasm identification, for diversity analyses and as selection targets. However, only a small number of morphological characters have been mapped as major effect genes in genetic linkage maps using various kinds of molecular markers in sorghum. Thus, E. S. Mace and D. R. Jordan of Australia's Department of Employment, Economic Development and Innovation conducted a study to consolidate all previously mapped major effect genes onto a complete genome map which is coupled with the whole genome sequence of sorghum. Various linkages between major effect genes and complex genes were discovered such as the linkage of aluminum tolerance gene, the awn gene, and the genetic male sterility gene.
This genome map can be used by sorghum breeders and researchers in studying simple to complex traits and to be aware of the consequences of selecting major effect genes. Furthermore, they could also develop better breeding techniques.
The abstract and the original paper (for subscribers of Theoretical and Applied Genetics journal only) of this study is available here
Location of major effect genes in sorghum (Sorghum bicolor (L.) Moench)
E. S. Mace and D. R. Jordan
Major effect genes are often used for germplasm identification, for diversity analyses and as selection targets in breeding. To date, only a few morphological characters have been mapped as major effect genes across a range of genetic linkage maps based on different types of molecular markers in sorghum (Sorghum bicolor (L.) Moench). This study aims to integrate all available previously mapped major effect genes onto a complete genome map, linked to the whole genome sequence, allowing sorghum breeders and researchers to link this information to QTL studies and to be aware of the consequences of selection for major genes. This provides new opportunities for breeders to take advantage of readily scorable morphological traits and to develop more effective breeding strategies. We also provide examples of the impact of selection for major effect genes on quantitative traits in sorghum. The concepts described in this paper have particular application to breeding programmes in developing countries where molecular markers are expensive or impossible to access.