Screening of pea germplasm for resistance to powdery mildew

Powdery mildew caused by Erysiphe pisi DC results heavy losses in the yield and quality of pods and seeds of pea crop. Germplasm comprising 701 accessions of garden and field pea originating from 60 countries were screened for powdery mildew resistance under natural epiphytotic conditions and 64 accessions found resistant in field screening for 2 years at one location were further screened both in field at two locations and artificially in laboratory to four isolates. The information was also obtained on the amount of genetic diversity and agronomic superiority in resistant accessions. Fifty-seven accessions showed resistant reaction for 3 consecutive years in field screening but only 14 accessions originating from 10 countries showed resistant reaction in laboratory screening against the four most prevalent isolates of E. pisi collected from different places in the area of experiment. Germplasm lines showed both complete and incomplete levels of resistance and variable reactions to different isolates. There was sufficient genetic diversity and agronomic superiority in the resistant accessions e.g. EC598655, EC598878, EC598704, IC278261, and IC218988, which may serve as useful genetic material to plant breeders for breeding pea varieties for powdery mildew resistance and high yield.