Poster Abstract

In order to determine the genetic parameters, number of genes and gene action, for resistance genes to yellow rust, F1, F2, F3, BC1, BC2, BC1S1, BC2S1 generations derived from a cross made between MV17 (resistant) and Bolani (susceptible) were grown and evaluated using Randomized Complete Blocks Design with three replications in Field Research Station, Seed and Plant Improvement Institute, Karaj, Iran. These generations were inoculated in different stages by mixture of pathogen, 134E134A+ race, and talk powder. Following the diseases establishment; infection severity and infection type on flag leaves of single plants, in three times with 7 days intervals, were recorded. Using these records, coefficient of infections (CI) for each interval were calculated, and then final coefficient of infections (FCI) and areas under diseases progress curve (AUDPC) and relative areas under diseases progress curve (rAUDPC) were estimated and used in statistical analyses for estimation of genetic components, means and variances. Generation mean analysis using joint scaling test revealed that additive, dominance and epistasis effects, particularly, additive x dominance and additive x additive interactions, significantly affected reduction in FCI, AUDPC and rAUDPC. Finally, considering all three traits, five parameters model m, [d], [h], [i], [j] was determined as suitable model. Dominance degree for all traits was complete dominance but negative which indicates that dominance is inclined towards parents with lower AUDPC, FCI and rAUDPC. Broad sense heritability for different resistance components was high, but narrow heritability was intermediate.

Global Wheat Program

Text in English

INT3505

CIMMYT Staff Publications Collection