Variability and association of some characters with yield in shallot (Allium cepa var. Aggregatum Don.)

Abstract

Shallot is used to be and indispensable crop used as condiment, cash source, and medicinal plant.Information about genetic variability and knowledge of quantitative characters with yield and among themselves is important for improvement of the crop through breeding; however, there is little information for genetic variability of different shallot accessions in Ethiopia using quantitative and qualitative traits. Forty nine shallot accessions were tested in a 7x7 simple lattice design at Debre-Zeit Agricultural Research Center in 2009/10. The over all objective was to study the extent of genetic variation and association among bulb yield and bulb yield related traits. The accessions differ significantly for most of the characters and relatively wide range of the mean for most of characters indicated the existence of variation among the tested accessions. High phenotypic coefficient of variation (PCV) and genotypic coefficient variation (GCV) were recorded for leaf diameter and percentage of bulb sprouting. High GCV along with high heritability and genetic advance was obtained from leaf diameter and percentage of bulb sprouting. Bulb yield was positively and significantly associated with plant height, leaf length, leaf sheath length, leaf sheath diameter, bulb length, bulb diameter, bulb dry weight, biological yield per plant, and marketable yield per plant at both phenotypic and genotypic levels. Path-coefficient analysis revealed that bulb dry weight exerted maximum positive direct effect on bulb yield followed by leaf length, leaf sheath diameter, and number of bulb splits per plant. D 2 analysis showed the 49 shallot accessions grouped into six clusters. This makes the accessions to become moderately divergent. Principal component analysis showed that the first six principal components explained about 76.15% of the total variation. The phenotypic diversity index for qualitative traits were (H’=0.58) for leaf color, (H’=0.47) for foliage attitude, (H’=0.36) for both leaf cross section and bulb skin color each revealed high diversity. Whereas, bulb shape (H’=0.07) showed the lowest diversity. From the result of this study, it could be concluded that BDW and LL can be considered for selection.