Abstract

Chickpea is one of the main annual crops in Ethiopia both in terms of its total cultivated area of pulses and its role in direct human consumption. The major problem to increase pulse production is the loss of seed viability and seeds damage from insect infestation particularly Adzuki bean beetle. Research works conducted on diversity study on chickpea varieties grown under different soil fertility levels were scanty. To fill such information gap, hundred chickpea genotypes that were managed under different soil fertility levels for Adzuki bean beetle resistance were screened under laboratory condition at Holetta and Debre Zeit. Cluster analysis was used to group the genotypes into five clusters with and without application of rhizobium and phosphorus, but into six clusters with the application of both rhizobium and phosphorus. Inter-cluster D2 average values of 11.50 (between clusters C4 and C5) to 62.94 (between clusters C2 and C5), 14.85 (between clusters C1 and C2) to 72.12 (between clusters C3 and C5) and 8.61 (between clusters C2 and C3) to 166.25 (between clusters C2 and C6) were found when genotypes grown under neither rhizobium nor phosphorus, only with rhizobium and with rhizobium and phosphorus conditions, respectively. The more divergent the two genotypes are the more will be the probability of improving through selection and hybridization.  The current study showed presence of moderate level of resistance in chickpea genotypes against Adzuki bean beetle regardless of soil fertility levels. In the future, it would be good approach to take up those moderately resistant genotypes in comprehensive breeding programs as a parent for hybridization.

Key words: Adzuki bean beetle, chickpea, cluster, diversity, phosphorus, rhizobium.