Abstract:
Potato is one of the most important tuber crops for food, feed and industrial applications
worldwide. However, not enaph numbers of improved varieties are available due to lack of
adequate characterization, evaluation and genetic analysis works. Therefore twenty five
potato genotypes were tested in a simple lattice design at jimma Zone (Southwest Ethiopia)
with the aim of studying the extent of genetic variation and association among yield and
related traits. Analysis of variance indicated significant difference among the 13 trait with
respect to all the characters except four traits among the tested genotypes studied. Wide
range of variation was observed among all traits. The phenotypic coefficients of variation
values were higher than genotypic coefficients of variation values. Higher heritability
coupled with higher genetic advance as per cent of the mean were noticed for weight of
tuber yield per hectare, date of flowering, plant height tuber diameter and leaf width. This
indicates that there is an opportunity of selection to improve these characters. The
Mahalanobis’s D2 analysis showed that the 25 genotypes were clustered into five clusters.
Maximum inter-cluster distance was recorded between clusters IV and V followed by
clusters III and V clusters II and IV and cluster I and II. In majority of the cases, the
genotypic correlation coefficients were higher than corresponding phenotypic correlation
coefficients.Weight of tuber per hectare was positively and significantly correlated with total
tuber per plant and marketable tuber per plant at genotypic as well as phenotypic level. As
per path analysis, the maximum positive direct effect on tuber yield per hectare was
exhibited by average tuber number, followed by days to flowering could be considered as
selection criteria in potato breeding program. The result of the present investigation may
vary with season since this study was conducted in one season. That means the available
genotypes should be further studied for more seasons over many locations. Furthermore, the
presence of morphological variation between genotypes is not a guarantee for high genetic
variation. Hence, molecular or biochemical studies need to be considered as complementary
to this study.
