RM-9475 / 08 Program of Study : Plant Breeding Title : Evaluation of Chickpea ( Cicer arietinum L . ) Genotypes Managed under Different Soil Fertility for Adzuki bean beetle ( Callosobruchus chinensis L . ) Resistance in Ethiopia

Chickpea is one of the main annual crop 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 screening resistant host chickpea varieties grown under different soil fertility levels were scanty. To fill such information gap, hundred chickpea genotypes that managed under different soil fertility levels for Adzuki bean beetle resistance were screened under laboratory condition at Holetta and Debre Zeit. The combined ANOVA over the two locations indicated that the difference between locations was significant (P<0.05) for most traits regardless of the soil fertility levels, except for thousand seed weight and proportion of seed coat weight. Management levels showed significant (P < 0.05) differences for a number of different characters including total number of eggs, days to adult emergence, number of adults emerged, mean number of holes per seed, proportion of seed coat weight, percent seed weight loss and susceptibility index, but non-significantly differed for adult recovery, seed size and percentage of damage seeds The relative susceptibility of different genotypes to bruchids attack was somewhat varied under the three soil fertility levels. In general, under the three soil management levels detecting a complete level of resistance against the bettele was not possible. However desi types (209035, 41290, 225874, 231328, 41021, 41029, 41303, 207661, 41027, 41174, 207151, 41291, 207745, DZ-2012-CK-0039 DZ-2012-CK-0038, DZ-2012-CK0033, Dalota, Fetenech, and Kutaye) showed relatively least level of infestation against the beetle. Genotype by location interaction effects significantly differed for most traits, but non-significant for days to adult emergence, percentage of damage seeds and percent seed weight loss. Similarly, genotype by management interaction effects significantly differed for most traits, but non-significant for total number of adults, days to adult emergence, adult recovery, proportion of seed coat weight and percentage of damage seeds. The three way interaction among genotype by management by location interaction effects were non-significant for all characters. Cluster analysis grouped 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 principal component analysis showed the first three principal components explained more than 76.7%, 82.1% and 81.0% of the total variation among genotypes managed with neither rhizobium nor phosphorus, only with rhizobium, and with rhizobium and phosphorus condition, respectively. Index of susceptibility showed highly significant positive correlation with total number of eggs, number of adults emerged, adult recovery, mean number of holes per seed, thousand seed weight, percentage of damaged seeds and percent weight loss. In contrast, index of susceptibility exhibited significant negative association with days to adult emergence and proportion of seed coat weight. Under the three soil management levels, high heritability, gain from selection and gains as a percentage of the mean were recorded for thousand seed weight, proportion of seed coat weight and percent weight loss. 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 take up those moderately resistant genotypes in a comprehensive breeding programs as a parent for hybridization.