Genetic Variability Studies in Ethiopian Shallot (Allium cepa L. var. ascalonicum Backer) Genotypes

Abstract

Field experiments were conducted on forty-nine shallot genotypes to estimate the nature and magnitude of variability for bulb yield and other related characteristics at Sirinka and Girana trial sites in northeastern Ethiopia. The experimental design was simple lattice with two replications. Observations were made on ten plant samples. A wide range of genetic variability was obtained for all the traits, except for leaf diameter at Girana and the number of lateral branches and maturity date at Sirinka. Highly significant genetic differences
were recorded for plant height, leaves per plant, bulb splits, bulb diameter, total, marketable and biological yields, harvest index, total soluble solids, bulb dry weight and pungency. The PCV values ranged from 5.91% for days to maturity at Sirinka to 41.57% for total yield per plant at Girana. At both locations, wide PCV and GCV as well as phenotypic ( 2p) and genotypic ( 2g) variances were observed for biological, total and marketable yields, bulb dry weight and leaf number per plant. The lowest PCV and GCV levels were observed in days to maturity and harvest index. Similarly, lower phenotypic and genotypic variances were observed for lateral branches per plant and bulb splits, bulb diameter, total soluble solids and the pungency of the bulbs. At both locations, moderate to
high heritability estimates coupled with moderate to high genetic advances as a percentage of the mean were recorded for bulb yield and related traits considered. This study demonstrates the existence of adequate genetic variability in Ethiopian shallot genotypes for further exploitation through breeding. Selection for biological, total and marketable yields, bulb dry weight, bulb splits and pungency characteristics is likely to be effective for
improvement of the crop as high heritability values have been associated with high genetic advance.

Keywords: Shallot; Bulb Yield; Genetic Variability; Heritability; Genetic Advance

East African Journal of Sciences Vol. 2 (2) 2008: pp. 130-134