Genetic diversity of commercially cultivated watermelon (Citrullus lanatus) hybrids in Bangladesh

This experiment was carried out to study the genetic variability of watermelon (Citrulluslanatus) genotypes in the southern region of Bangladesh at Regional Horticulture Research Station, BARI, Lebukhali, Patuakhali during Rabi season, 2017–18. Sixteen commercially cultivated hybrids collected from different seed companies as well as from farmers’ collection were used. Significant variations were recorded among the watermelon accessions in terms of different parameters. The genotype World Queen (7.4) and Sugar Kis (4.5) showed the highest performance for fruit weight and fruits number/plant, respectively. The highest genotypic and phenotypic coefficients were recorded for fruit yield/plant (55.14% and 58.69%) followed by single fruit weight/plant (34.51% and 37.65%). The number of male flower, fruit weight, fruit length, fruit diameter, leaf shape, and fruit yield were found to be highly correlated characters among the watermelon genotypes. The number of female flower was negatively correlated with vine length. The number of fruit showed negative correlation with rind thickness and positive correlation with fruit yield. The results of principal component analysis revealed that the important characters responsible for genetic divergence in major axis of differentiations are days to first male flower opening, number of male flower per plant, fruit weight, fruit length, fruit diameter, fruit yield, and leaf shape. Cluster analysis grouped the genotypes into five classes. Larger intercluster distances in all cases than intracluster distances suggested wider genetic diversity where Cluster I had highest vine length with higher internodal length. Cluster II had the highest mean value for number of fruit and fruit yield. Cluster III has the highest number of male flower, highest number of branch, and fruit length. Cluster V produced the largest fruit with highest fruit diameter and rind thickness. It also required maximum days for maleflowering and highest number of female flower. This study shows wide variability among the watermelon genotypes which could be used for future breeding program.