تجزيه باي پلات داده هاي تلاقي دي آلل تيپ آلودگي زنگ زرد گندم

Biplot Analysis of Diallel Cross Data for Infection Type of Wheat Stripe Rust

Diallel crosses have been used in genetic research to determine the inheritance of important traits among a set of genotypes and to identify superior parents for hybrid or cultivars development. Genetic control of infection type of stripe ruts was studied in a half-diallel design using six wheat cultivars, Tiritea (a susceptible check), Tancred, Kotare, Otane, Karamu and Briscard. These cultivars and their 15 Fls_ were evaluated by three stripe rust pathotypes 7E 18A-, 38EOA+ and 134E134A+. For each pathotype a randomized complete block design with three replications was conducted with 21 treatments. The biplot method was arranged by the first two principal component (PCs). Analysis of variance showed significant differences between 21 treatments for infection type. Changing the pathotypes caused reversal of the dominance in most of the crosses. Briscard for the pathotypes 38EOA+ and 134E134A+, and Kotare for the pathotype 7E 18A- had the highest GCA effects for infection type, so they can be used in breeding programs for development of resistant cultivars to stripe rust. The highest negative SCA was observed in crosses of Kotare x Karamu for 7E18A-, Tiritea x Otane for 38EOA+ and Briscard x Kotare for 134E134A+. These SCA values indicate the presence of dominance for the lower infection type. The results indicated that infection type, as a component of resistance is under genetic control and selection for this character would be effective in wheat breeding programs.