Genetic diversity analysis of rice (Oryza sativa) genotypes for seedling characters under saline - alkaline condition

  • K Seetharam, S.Thirumeni, K.Paramasivam, S.Nadaradjan
Keywords: Rice, Salinity, Genetic diversity


Rice is life for Asians as it provides 43 per cent calorie requirement for more than 70 per cent of the population. The
production is often limited by salinity. Understanding of physiological and genetic mechanisms is necessary for a breeding
programme to improve crop performance under environmental stresses. Thirty rice genotypes pre-germinated in salinealkaline
water (pH-9.60; EC-10.0; SAR-54.32; RSC- 11.51) were placed in plastic cups filled with sterile soil and the stress
was imposed upto 21 days. Genetic diversity was estimated based on the observations recorded on germination per centage,
vigor index, shoot length, root length, seedling length, root/shoot ratio, seeding dry weight, Na+/K+ ratio. The genotypes
were grouped in to five clusters based on the Euclidean coefficient which ranged between 2.09(CSR10 X CSR 13) and
76.29 (IWP X Chettiviruppu). Cluster II was largest (22 genotypes) followed by cluster I (4 genotypes). Genotypes grouped
under cluster I showed low Na+/K+ ratio which is an important physiological trait for salinity tolerance. Cluster V (MI 48 &
IWP) grouped the susceptible genotypes which had high Na+/K+ ratio. The hybrids thus developed from the genotypes of
cluster I & V may express high magnitude of transgressive segregants.
Research Article