Effect of Sodium Chloride on Growth, Photosynthesis and Mineral Ions Accumulation of Different Types of Rice (Oryza sativa L.)

Abstract

Growth, photosynthesis and mineral ions accumulation of aromatic small grain, local coarse grain and HYV types of rice were evaluated under saline conditions. Three cultivars from each type were subjected to 0, 50, 100, 150 and 200 mvi NaCl concentrations. After three weeks of 200 mvi NaCl application only Pokkali and Kalobail, both belonging to the local coarse grain type and IPK 37011 of the HYV type were able to survive. Plant height, green leaf area, leaf weight, shoot and root growth were seriously decreased by salinity. However, leaf area was decreased more than other growth parameters. In general aromatic small grain type showed higher salt‐sensitiveness in relation to growth than other types of rice. Photosynthesis (Pn) was decreased by salinity and apparently stomatal resistance was partially responsible for the decreased Pn. Kalijira, an aromatic small grain eultivar, showed serious reduction in Pn, especially at the 150mM NaCl level. Na accumulation was increased while K accumulation was decreased by salinity in all types. Salt tolerant eultivars in all types of rice accumulated less Na and more K than susceptible ones. The K/Na ratio was also higher in tolerant eulti‐vars. Ca and Mg eoncentrations were decreased by salinity although not all the eultivars showed clear accumulation patterns as observed for Na and K. As HYV and local coarse grain types of rice in general showed high salt tolerance, a comprehensive breeding programme should be of value for the improvement of salt tolerance of aromatic small grain rice which has a high demand in rice importing countries.

Effects of Salt and Water Stress on Leaf Production, Sodium and Potassium Ion Accumulation in Soybean

“…The results of the study are in agreement with the earlier reports that the tolerant genotypes accumulate less amounts of Na than susceptible ones ( [15], [17], [2], [25]). The excess amount of Na + creates a toxic effect on plant metabolic processes and therefore, the susceptible cultivars having high amounts of Na + suffer more from the effect than the tolerant cultivars ( [5], [15]).…”

“…As a result, there is a reduction in the supply of photosynthate to the plant, affecting the overall carbon balance necessary to sustain growth [27].The leaf area reduction is a common phenomenon of glycophytes grown under salt stress conditions [20]. The reduction in leaf area due to salinity was reported earlier by Khan et al [17] in rice and Chookhampaeng [6] in pepper plant. Drought stress reduces cell and leaf expansion, stem elongation, and leaf area index ( [34], [4], [10]).…”

“…The leaf dry weight was decreased to 39.72, 38.58 and 39.43% of the control in Galarsum, BD 2331 and BARI Soybean 6, respectively. The reduction in leaf dry weight due to salinity was reported by Karim et al [16] in triticale, Khan et al [17] in rice, Aziz et al [3] in mungbean and Mannan et al [24] in soybean. Leaves dry weight reduced in water stressed cotton plants were reported by Pace et al [29].…”

Morpho-physiological variations in response to NaCl stress during vegetative and reproductive development of rice

“…1; Table 1). This suggests that 150 and 20 mM NaCl are excessive These results are in accordance with data obtained with other rice cultivars using various stress levels (Alam et al 2004;Alamgir and Ali 2006;Khan et al 1997;Welfare et al 1996). During the vegetative growth both cultivars showed a significant decline in chlorophyll content (CCI) and fluorescence (F v /F m ) with increasing NaCl concentrations.…”

Induction and Repression of Gene Expression Mediating Ethylene Biosynthesis and Sodium/Proton Exchange in Rice Seedlings Under Submergence Stress

“…At the seedling stage, salt tolerance causes significant reduction in the germination index and seedling vigor (19,21). Physiological studies of rice suggest that tolerance to salt within leaves can increase the ability to cope with salinity (41).…”