Susceptibility response of varieties and local populations of lupines to Bruchus rufimanus (Coleoptera: Chrysomelidae)

Abstract

This study aimed to evaluate the susceptibility response of varieties and local populations of lupines to Bruchus rufimanus in multi-environment field tests. Seed damaged rate and susceptibility index were assessed in each environment and subjected to a heritability-adjusted genotype and genotype x environment biplot analysis. It was found that the susceptibility index of damaged seeds was positively related to precipitation amounts and humidity, and inversely to min and max temperatures. The seed damaged rate was positively related to temperatures but negatively to rain and humidity. The local polish population WAT and cultivars Pink Mutant, Solnechnii, and Bezimenii 1 had the lowest seed damaged rate and stable position across environments. Meanwhile, these cultivars showed a low susceptibility index and low variability. The discrepancy between the early phenological development of ‘Pink Mutant’, ‘Solnechnii’, and ‘Bezimenii 1’ and the life cycle of B. rufimanus was one of the reasons for manifested tolerance. Correlations between damaged seed and susceptibility index as well as the mass of 1000 seeds and sensitivity index were strongly positive and negative, respectively. ‘WAT’, ‘Pink Mutant’, ‘Solnechnii’, and ‘Bezimenii 1’ had a clear advantage in defending itself from B. rufimanus attack, which makes them particularly interesting for breeding purposes.