Abstract

The diversity among some Nigerian accessions of Cucurbita species was investigated using 19 quantitative and 14 qualitative characters. The result showed that the accessions evaluated differed significantly (p < 0.05) in most of the quantitative characters evaluated. The clustering based on quantitative character, grouped the various accessions into two clusters. However, clustering based on the qualitative variations revealed a more realistic relationship by grouping the accessions into three distinct clusters that appeared to have some bearing with agro-ecology from which the accessions were collected. The variations in qualitative characters showed higher discrimination with some implications on the the genetic diversity and relationship among the accessions of Cucurbita. The Shannon diversity index (HS) was found to be 4.136 suggesting that the evaluated Nigerian Cucurbita accessions are truely diverse. The correlation analyses revealed that the weight of harvested fruits had significant and positive relationships with days to 50% flowering, number of male flowers, number of female flowers, number of fruits per plant, number of healthy fruits, fruit diameter, fruit length, number of seeds per fruit, 100-seed weight  and seed weight. The days to 50% emergence showed negative but significant correlations with days to 50% flowering, number of female flowers, fruit length, seed length and 100-seed weight, suggesting that early crop emergence would imply prolonged vegetative growth  phase and the production of higher number of female flowers that would translate to higher seed yield.

Key words: Diversity, pumpkin, Cucurbita spp., principal component analysis, multivariate statistics.