A comparative study of morphological characteristics in diploid and tetraploid (auto and allotetraploids) Citrullus genotypes

In this study, ploidy levels were determined by stomatal observations and flow cytometry analysis of plants polyploidised by the application of 0.05% colchicine to seedlings at the first true leaf stage. In the study of developing polyploid watermelon rootstocks, the survival rate of the plants was 77%, and the polyploidisation rates were 11% and 3% according to stomatal observations and flow cytometry analysis, respectively. According to the results of flow cytometry, 22 polyploid genotypes were determined. Auto- (12) and allotetraploids (10) of genotypes were developed, and their plant growth performance was determined in hydroponic culture in comparison with diploids, commercial rootstocks (RS841, ‘Argentario’) and watermelon cultivar (‘Crimson Tide’). Putative tetraploids and their diploid controls were grown in hydroponic culture for 21 days, and their vegetative growth performances were determined. The results showed that the increases in plant biomass depending on polyploidisation were 100% in autotetraploids and 156% in allotetraploids as compared to diploid controls.