|Klein, Robert - Bob|
Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2000
Publication Date: 2/1/2001
Citation: Klein, R.R., Rodriguez-Herrera, R., Schlueter, J.A., Klein, P.E., Yu, J., Rooney, W.L. 2001. Identification of genomic regions that affect grain mould incidence and other traits of agronomic importance in sorghum. Journal of Theoretical and Applied Genetics. 102:307-319. Interpretive Summary: Grain sorghum is a very important crop worldwide that is used both as a human food and in animal feeds. Under some circumstances, grain sorghum can become moldy, which reduces its quality as a foodstuff or feedstuff. Some varieties of grain sorghum have the ability to resist becoming moldy, and one of the goals of plant breeders is to develop varieties that are mold resistant. We have conducted research using very sophisticated techniques of molecular biology that allow us to determine the mold resistance status of grain sorghum. These techniques also allow us to evaluate other important traits of grain sorghum, including plant height, grain quality, and the ability of the plants to resist diseases. The molecular tools we have developed will be very useful to sorghum breeders in developing better varieties of grain sorghum for growth under many different conditions found worldwide.
Technical Abstract: Here, our objective was to use genome mapping to improve our knowledge of genetic variation and co-variation for grain mold incidence and other inter-related agronomic traits. Grain mold incidence, kernel milling hardness, grain density, plant height, panicle peduncle length, foliar disease incidence, and plant color were measured on 125 genotypes derived from a cross of Sureno and RTx430. Quantitative trait loci were detected by means of 130 mapped markers distributed among ten linkage groups. One to five quantitative trait loci affected each trait, with the exception of grain density for which no locus was detected. Grain mold incidence was affected by five trait loci each accounting for between 10% and 23% of the phenotypic variance. The effects and relative positions of trait loci for grain mold incidence were in accordance with the loci distribution of several inter-related agronomic traits including plant height and peduncle length and with the correlation between these phenotypic traits and grain mold incidence. The detection of trait loci for grain mold incidence was dependent on the environment, which is consistent with heritable estimates that show strong environmental and genotype-by-environment effects. Several genomic regions affected multiple traits including one region that affected grain mold incidence, plant height, panicle peduncle length, and grain milling hardness and a second region that influenced grain mold and plant height.