Comprehensive Evaluation of Salt Tolerance in Rice (Oryza sativa L.) Germplasm at the Germination Stage

Abstract

Salt stress reduces the yield and quality of rice. It is of great significance to screen out salt-tolerant varieties for the development and utilization of saline land. The study was carried out on 114 rice varieties; first, seven varieties were selected and treated with different salt concentrations (0, 50, 85, 120, 155, 190, 225 mM), and seven traits, including germination energy, germination capacity, shoot length, root length, root number, plant fresh weight, and seedling vigor index, were measured. The salt concentration at which the sodium chloride injury index was 50% of the control was considered the optimal salt concentration. Second, 114 rice germplasms were carried out under an optimal salt concentration (120 mM). Then, principal component analysis, fuzzy function analysis, stepwise regression analysis, correlation analysis, and systematic cluster analysis were carried out on each parameter. There was a significant correlation between each parameter and the D-value, and the correlation coefficient between the seedling vigor index and D-value was the highest. D-value = − 0.272 + 1.335 × STI − SVI + 0.549 × STI − RN − 0.617 × STI-RL + 0.073 × STI − GE, R2 = 0.986. Using this equation, the sodium chloride tolerance of rice in the germination experiment could be quickly identified. This study showed that the seedling vigor index was a reliable parameter to identify the salinity tolerance of rice varieties. Five groups were obtained by classification at a Euclidean distance of 5. There were 8 highly salt-tolerant cultivars, 23 salt-tolerant cultivars, 42 cultivars with moderate salt tolerance, 33 salt-sensitive cultivars, and 8 highly salt-sensitive cultivars. In this study, we found that Riguang was the most salt-tolerant rice variety, and Xiangxuejing15 was the most salt-sensitive variety.

Genome-Wide Association Study of Salt Tolerance at the Seed Germination Stage in Flax (Linum usitatissimum L.)

“…Although RGR can well distinguish the salt tolerance of different flax germplasm, it showed a low correlation with RSL or RRL (Figure 1D). This phenomenon has also been reported in some crops (rice [56], chicory [57], sesame [58], etc. ), and different parts of crops have a different sensitivity to salt stress.…”

Effects of foliage-applied exogenous γ-aminobutyric acid on seedling growth of two rice varieties under salt stress

“…The excessive soil salinity inhibits the seed germination, reduces the bud length, slows down the root growth such as its length and number, etc. [ 11 , 12 ]. More damages due to salt stress also include: 1) the inhibition of the leaf elongation and the number of tillers; 2) a prolonged tillering process; 3) a reduction of the total number of flowers; 4) a lower weight per 1,000 grains; and 5) a loss in rice yield and quality [ 13 ].…”

Salinity Stress Response of Rice (Oryza sativa L. cv. Luem Pua) Calli and Seedlings

“…At a salinity of 3.5 dS m −1 , rice yield decreased by 10%, while at 7.2 dS m −1 , rice yield decreased by 50% [ 2 ]. Salt stress has a negative impact on rice development and yield, which varies according to developmental stages, stress severity level and duration, and variety [ 16 ]. Salt stress reduced germination percentage, germination speed, and energy for germination, leading to decreased shoot length, root length, and dry weight in all rice varieties [ 9 ].…”