Variability in NaCl tolerance among boro rice (Oryza sativa L.) cultivars from Bangladesh

抄録

A laboratory experiment was conducted with six NaCl levels viz. 0 (control), 4, 8, 12, 16 and 20 dS/m of Electrical Conductivity (EC) to determine the effects of different levels of salinity on seed germination and seedling growth of eight different boro rice cultivars viz. BRRI dhan28, Vajon, Bapi aus, Zia, Kajol lota, Abdul hai, Sharna and Lal sharna. The experiment was laid out in a factorial Completely Randomized Design (CRD) with five replications. Data were collected for final germination percentage (FGP), shoot and root length, shoot and root dry weight, and total dry weight. Based on the dry matter reduction, rice varieties were classified as tolerant (T), moderately tolerant (MT), moderately susceptible (MS) and susceptible (S). There was wide variation in germination and growth parameters among varieties due to different levels of salt applications. Salinity decreased FGP and led to reduction in shoot and root length and dry weight in all varieties and the magnitude of reduction increased with increasing salinity stress. Rice variety Bapi aus exhibited greater salt tolerance during germination (even at 20 dS/m). Sharna and Lal sharna varieties were the inferior regarding germination. However, varieties Vajon and Bapi aus performed better based on the dry matter reduction. The result of the present study suggests that variety Bapi aus might be used for further study of salinity effect on growth processes and physiological consequences at later stages of growth.