Identification of resistant sources and inheritance of Fusarium wilt resistance in garden pea (Pisum sativum ssp. hortense)

Abstract

Wilt caused by Fusarium oxysporum Schlechtend.Fr. f.sp. pisi is a devastating disease of garden pea in India and worldwide. The pathogen being soil-borne fungus is quite difficult to manage by chemical methods and the development of resistant varieties seems to be the only alternative. In the present study 34 garden pea genotypes collected from different sources were evaluated during winter 2012-13 and 2013-14 under wilt sick plot as well as artificial controlled conditions to identify genetic sources of resistance against Fusarium wilt. Three genotypes (GP-6, GP-55 and GP-942) were found to be highly resistant, four genotypes (GP-17, GP-48, GP-473, GP-941) were resistant and identified as new donor source. All the popular cultivated varieties (Arkel, Pusa Pragati, AP-3, VRP-6, VL-7, VL-10 and Arka Ajit) were highly susceptible to wilt. The inheritance of Fusarium resistance gene(s) was also studied using F1, F2, B1 and B2 progenies of three crosses, viz., Pusa Pragati × GP-55, Pusa Pragati × GP-6 and Arkel × GP-17. Chi-square analysis was performed to determine the Mendelian segregation ratios of resistance and susceptibility among the inoculated progenies. The F1 and backcross progenies to the resistant parents segregated in the ratio of 1:0, while the F2 progenies segregated in the ratio of 3:1. The backcross progenies to the susceptible parent segregated in the ratio of 1:1. The results obtained revealed that the resistance to Fusarium wilt in garden pea is governed by monogenic dominant gene. The resistance gene can easily be introgressed by backcross breeding in desired genotype.