Evaluation of Advanced Breeding Lines of Common Bean (Phaseolus vulgaris L.) for Resistance to the Mexican Bean Weevil (Zabrotes subfasciatus) and Yield Potential

Abstract

The study was carried out to select bruchid-resistant advanced lines of common bean with the presence of arceline determination and to evaluate their yield performance under field conditions in Ethiopia. Forty advanced lines and commercial varieties were tested for resistance to Mexican bean weevil (Z. subfasciatus) arranged in randomized complete block design in four replicates of 30 seeds infested with 6 pairs of newly emerged Z. subfasciatus. Data were taken on number of eggs, number of emerged adults, days to adult emergence (DAE) and adult dry weight. The insect bioassay and protein analysis were done at CIAT (Colombia) and the field evaluation was made in Ethiopia. The resistant lines containing Arcelin 1 showed for resistance to the Mexican bean weevil. Among these lines RAZ 4, RAZ 101, RAZ 173, RAZ 44 and RAZ 174 revealed consistently high resistance under all the parameters measured. However, the average yield of susceptible varieties (2.11t/ha, SE = 0.05) was moderately higher than that of the resistant lines (1.8 t/ha, SE = 0.02). The number of days to maturity varied between 78 and 96 without significance difference between susceptible varieties and RAZ lines. Using arcelin protein analysis with 12 highly resistant advanced lines and 10 susceptible varieties plus controls also showed a high level of accuracy. Resistance was associated entirely with the presence of the heavy 35 KDa band representing Arcelin 1.