The Indian Journal of Genetics and Plant Breeding

Stomata and chloroplast number studies in Zizhyphus species indicated significant differences in the stomatal dimensions, frequency of their occurrence and chloroplast number per two guard cells of the stomata among different ploidy levels. However, non significant differences were observed between pentaploid and octaploid cultivars for these attributes, indicating the deleterious effects of high gene dose beyond pentaploid level. In general, there were non significant differences among the genotypes of diploids with respect to number of chloroplasts in the stomatal guard cells while significant differences were apparent among some of the tetraploid cultivars for these attributes suggesting the role of heterozygosity in the success of spontaneous polyploids. Similarly considerable differences were also observed in respect of pollen diameter of the genotypes with different ploidy levels.