Identification of Mycosphaerella Blight Resistance in Wild Pisum Species for Use in Pea Breeding

Abstract

ABSTRACTMycosphaerella blight caused by Mycosphaerella pinodes (Berk. and Blox.) Vestergren is the most important disease of pea (Pisum sativum L.) in the world. It reduces seed yield and quality and limits the areas where field pea can effectively be grown. Extensive studies have failed to identify high levels of resistance. However, some accessions of Pisum fulvum Sm., a wild relative of field pea, may be a source of new resistance genes. The objective of this study was to identify mycosphaerella blight‐resistant wild pea accessions for use in introgression breeding in Canada. Twenty‐six P. fulvum accessions and 18 accessions of wild subspecies of P. sativum {subsp. elatius (Steven ex M. Bieb.) Asch. & Graebn., subsp. transcaucasicum Govorov, subsp. asiaticum Govorov, subsp. sativum var. arvense (L.) Poir., and Pisum abyssinicum A. Braun [syn. P. sativum subsp. abyssinicum (A. Braun) Govorov]} were evaluated along with the check cultivars CDC Striker (moderate resistance) and Alfetta (poor resistance). Among the 44 wild accessions tested under greenhouse condition, 12 accessions had significantly lower disease scores than CDC Striker (P < 0.0001). The 18 most promising accessions along with checks including ‘Radley’ (moderate resistance), CDC Striker, and Alfetta were evaluated for disease resistance under field conditions. None of these accessions had significantly lower disease scores than Radley and CDC Striker. Pisum fulvum accessions PI595937, P651, W615017, and PI560061 and P. sativum subsp. elatius accession PI344538 were considered the most promising for resistance breeding.