The genetic resistance to angular leaf spot （ALS） caused by Phaeoisariopsis griseola in the common bean cultivar Mexico 54 was investigated on disease reactions in parental, F1, F2 and backcross generations derived ...The genetic resistance to angular leaf spot （ALS） caused by Phaeoisariopsis griseola in the common bean cultivar Mexico 54 was investigated on disease reactions in parental, F1, F2 and backcross generations derived from crosses between a resistant cultivar Mexico 54 and a susceptible cultivar Kablanketi under screen house conditions. The heritability （h2） estimate was as high as 0.719 indicating a successful transfer of ALS resistance among progenies and thus selection can be performed in early generation. High heritability coupled with high expected genetic advance of 39.5% is considered to be more useful in predicting the outcome of selecting the best individuals. Chi-square values were computed to determine whether the observed ratios for disease reactions deviated from expected Mendelian ratios for a single, dominant gene controlling resistance to angular leaf spot in common bean. Based on the resistance of the F2, and the backcross generation to the resistant parent, a 3 resistant： 1 susceptible segregation ratio in the F2 and a 1 resistant： 1 susceptible segregation ratio in the backcross generation to the susceptible parent was obtained implying that resistance to the isolate ofPhaeoisariopsis griseola is governed by a single, dominant gene.展开更多
文摘The genetic resistance to angular leaf spot （ALS） caused by Phaeoisariopsis griseola in the common bean cultivar Mexico 54 was investigated on disease reactions in parental, F1, F2 and backcross generations derived from crosses between a resistant cultivar Mexico 54 and a susceptible cultivar Kablanketi under screen house conditions. The heritability （h2） estimate was as high as 0.719 indicating a successful transfer of ALS resistance among progenies and thus selection can be performed in early generation. High heritability coupled with high expected genetic advance of 39.5% is considered to be more useful in predicting the outcome of selecting the best individuals. Chi-square values were computed to determine whether the observed ratios for disease reactions deviated from expected Mendelian ratios for a single, dominant gene controlling resistance to angular leaf spot in common bean. Based on the resistance of the F2, and the backcross generation to the resistant parent, a 3 resistant： 1 susceptible segregation ratio in the F2 and a 1 resistant： 1 susceptible segregation ratio in the backcross generation to the susceptible parent was obtained implying that resistance to the isolate ofPhaeoisariopsis griseola is governed by a single, dominant gene.
