Abstract:
Five new improved rice varieties released by Rice Research and Development
Institute, Bathalagoda were screened against salt tolerance for seed germination and early
seedling growth using five different salinity levels (0, 4, 8, 12, and 16 dS/m). Measurements were
taken for root length, shoot length, fresh weight of seedlings, dry weight of seedlings, germination
energy, speed of germination and final germination percentage. All the tested variables, except
dry weight of seedlings, decreased with increasing salinity and had a significant difference
(p<0.05) between salinity levels. Osmotic stress due to increasing salinity and toxic effect due to
high sodium ion concentration interfere water absorption by plants and affect physiological
activities in seeds and seed germination. Among the rice varieties used, Bg 357 rice variety had
a higher root length, shoot length, fresh weight of seedlings, germination energy, speed of
germination and final germination percentage and was considered as tolerant to salt. All the
other rice varieties had different degrees of sensitivity to salinity.
