Seed germination and seedling growth responses of polyembryonic mango (Mangifera indica L.) genotypes to salinity stress

Abstract

Mango (Mangifera indica L.) is a salt sensitive crop particularly at early stages of growth. So, it is essential to study the response of mango seed germination and seedling growth against salinity stress. In this experiment, the effect of salinity (induced by 50 mM NaCl) stress was studied on seed germination, biomass content and growth responses in newly emerged seedlings of sixteen polyembryonic mango genotypes namely EC-95862, Vattam, Vellaikolamban, Nekkare, Mylepelian, Turpentine, Sabre, Manipur, Kitchener, Kensington, Olour, Kurukkan, Bappakkai, Chandrakaran, Muvandan and Deorakhio. Among these genotypes Turpentine (97.50%), Bappakkai (92.50%) and Vattam (80%) showed early and maximum germination after 20 days of sowing while the genotypes, Chandrakaran, Sabre, Kensington and Vellaikolamban depicted 80.00%, 85.00%, 85.00% and 87.50% germination, respectively. Other genotypes had late germination under 50 mM salinity stress (35 days of sowing). The germinated mango seedlings were exhibited significant decline in plant height, numbers of leaf per plant, number seedlings per seed, stem diameter (mm), root length (cm), fresh and dry weight of shoot (g), fresh and dry weight of root (g) under saline conditions, with plant biomass being most sensitive to salinity. With respect to growth behavior, the genotypes Turpentine, Deorakhio and Olour showed a minimum reduction in biomass under salinity and Kitchener, Mylepelian and Chandrakaran, the maximum