Heritability estimates and response to selection for resistance to mycosphaerella blight in pea

Resistance to Mycosphaerella pinodes in field pea (Pisum sativum L) is a quantitative trait, and expression of resistance is substantially influenced by environment. The disease reaction to mycosphaerella blight of four crosses (F-2:4 and F-2:1 populations) was assessed in field trials at Vegreville, AB, Canada. Broad-sense heritability of resistance was quite high (0.62-0.81). Narrow-sense (realized) heritability was moderate (0.43-0.57), indicating that additive genetic factors contributed substantially to the resistance phenotype. Significant improvement in resistance among the lines developed from selected Individuals indicates that genetic improvement based on progeny testing would be effective. This study demonstrated that resistance to M. pinodes can be improved through progeny selection from crosses of the most resistant lines.