Abstract:The differentiae of root anatomical structures of five different rice genotypes(conventional Indica,hybrid Indica,conventional Japonica,hybrid Japonica,upland rice) were studied under inundatory and aerobic conditions.Results showed that there existed genotype difference on the effects of soil moisture on aerenchyma formation and sclerenchymatous cell shape of rice roots among different cultivars.Under inundatory condition aerenchyma in hybrid japonica root (occurred) latest within these five genotypes.Cortex sclerenchymatous cells in conventional indica root were obviously different from those in conventional japonica root in terms of morphological traits.These cells in conventional japonica root(arrayed) tightly and cell walls lignified to a great extent.Whereas those in conventional indica root formed loosely and cell walls lignified less.Under aerobic condition,the formation of root aerenchyma of upland rice was the latest among five rice genotypes.And cortex sclerenchymatous cells in conventional japonica root arranged loosely.Compared with inundatory condition,aerobic condition retarded the formation of aerenchyma of hybrid rice roots and made the cortex sclerenchymatous cells array loosely in conventional japonica root.