以21份水稻(Oryza sativa)种质为材料, 用1.5%NaCl处理种子8天后测定发芽率。在苗期用不同浓度NaCl水培处理10天, 测定叶片死亡率等指标和高亲和性K⁺转运基因(HKT)家族变异。在成株期选3份种质, 用不同浓度NaCl盆栽处理, 在开花期和籽粒蜡熟期测定植株可溶性糖和生物量等指标, 以明确各种质不同生育期的耐盐差异和关键指标。结果表明, 在NaCl胁迫下, 种子发芽率受到显著影响。苗期盐胁迫后, 各种质的平均叶片死亡率变幅最大。在被鉴定的8个耐盐种质中, HKT家族的7个基因除OsHKT2;4外均存在。在≤1 g·kg^-1盐胁迫下植株可溶性糖含量表现出刺激增长效应。CG15R单株生物量与盐浓度呈正相关, 且随盐浓度的增加而缓慢增长。在≤1 g·kg^-1时, 中花9号的生物量随盐浓度的增加而增加。水稻耐盐性具有明显的阶段发育特异性, 且不同发育阶段的耐盐性之间无相关性。叶片死亡率与蜡熟期生物量可分别作为苗期和成株期耐盐鉴定的关键指标。CG15R可作为高耐盐种质进行深入分析和利用。

We used 21 rice (Oryza sativa) germplasm as experimental materials. Dry seeds were treated for 8 d in 1.5% NaCl solution and germination rate was measured. The seedlings with 2 green leaves were cultured by hydroponics in Petri dishes with different NaCl concentrations. After 10 days, relative shoot height, relative root length, leaf mortality, water content and the expression of 7 of 9 high-affinity K⁺ transporter (HKT) gene families were measured. In the adult period (30-d seedling to maturation), 3 representative germplasm were treated at different NaCl concentrations in a pot experiment. We investigated the effects of salt stress at flowering or dough stage of rice, for example, soluble sugar content. The results showed that germination rates of seed were affected significantly, with a wide range of variation, with 1.5% NaCl stress concentration. The variation in leaf mortality was the largest among the measured indicators at seedling stage. Besides OsHKT2;4, 6 members of HKT gene family were detected in the 8 germplasm genome. Soluble sugar content of germplasm showed a growth-stimulation effect with salt content stress ≤1 g∙kg^-1. The biomass of CG15R was positively correlated with salt content and the biomass increased with the addition of salt. Biomass of Zhonghua9 increased with the addition of salt with salt content ≤1 g∙kg^-1. Salt tolerance of rice shows the characteristic of stage development, and salt tolerance at different developmental stages is not correlated. The leaf mortality and biomass of dough stage could be the key indicators of salt tolerance for seedling and adult rice. CG15R represents a germplasm with high salt tolerance and should be further analyzed.