Resistance of Pea Cultivars and Lines (Pisum sativum L.) to Pseudomonas syringae pv. pisi

I. Kiryakov, M. Koleva

Abstract: Breeding and using of resistant cultivars is a main strategy for control of diseases in the legume crops. The aim of this investigation was to determine the disease response of pea accessions (Pisum sativum) to the cause agent of bacterial blight (P. s. pv. pisi) with a view of their using as donors of resistance in the breeding program. The investigation involved 70 accessions of spring fodder and garden pea. The accessions were inoculated twice: at phenophase budding (petioles) and at grain filling (pod) with bacterial suspension in concentration 108 CFU/ml from isolates Bz4 and NCPPB 2585, using 1 ml syringe. The response of the accessions was read 10 days after inoculation according to a 9-degree scale. The mean diseases index (MDI) was calculated and the accessions were divided into five groups: immune (I), resistant (R), moderately resistant (MR), susceptible (S) and very susceptible (VS). Variations were found in the response of the leaves and the pods of some of the accessions to both strains of P. s. pv. pisi. Five of the 70 investigated accessions had a resistant to moderately resistant phenotype after inoculation with strain Bz4. Thirty-eight accessions had immune to moderately resistant reaction of leaves and pods to strain NCPPB. Four of the investigated accessions had immune to moderately resistant reaction of leaves and pods to the two strains of P. s. pv. pisi; this allowed including them in the breeding program for resistance to bacterial blight on pea.

Keywords: bacterial blight; P. s. pv. pisi; P. sativum; peas

Date published: 2017-02-13