30份水稻材料的耐盐性鉴定与评价

以30份耐盐性不同的水稻品种(系)为材料，在苗期对其进行盐胁迫处理（NaCl浓度分别为0，0.3%，0.5%），同时，测定了耐盐相关指标，并运用相关性分析、主成分分析和隶属函数等方法，对水稻耐盐性进行了筛选及评价。结果表明:在盐胁迫条件下，水稻品种的地上部鲜质量(FW)、地上部干质量(DW)、叶片的净光合速率(Pn)、水分利用率(WUE)、叶绿素含量(TC)等与生长相关的指标均呈不同程度的下降。而丙二醛(MDA)含量、可溶性糖(SS)含量、可溶性蛋白(SP)含量、游离脯氨酸(Pro)含量，过氧化物酶(POD)活性等与生理代谢相关的指标都升高。在0.5%NaCl溶液处理下，除Pro含量外，其他指标的耐盐系数的变异系数都大于0.3%盐浓度处理下的变异系数，显示0.5%NaCl处理能更好地展示不同品种(系)之间的耐盐性差异。对0.5%NaCl处理下的各指标，运用相关性分析筛选出各指标间有显著性相关的耐盐指标及用隶属函数综合评价得出D值，显示耐盐性较强的5个品系为14-57，14-6，14-36，W01和14-58-2；耐盐性较弱的5个品系是16-8，50188-2，16-9，15-18-2和14-58-1。逐步回归分析结果显示，利用这3个指标对各水稻品种(系)的耐盐性的估计精度均可达到90%以上。同时发现，叶片的净光合速率(Pn)、水分利用率(WUE)、地上部鲜质量(FW)等是评价水稻耐盐性的最重要的3个指标，根据综合评价结果，使用系统聚类可把30份供试水稻品种(系)分成3类，分别为耐盐型、中间型和盐敏感型。

Identification and Evaluation of Salt Tolerance of 30 Rice Varieties/Lines

Thirty rice varieties/lines with different salt tolerance were treated with NaCl at concentrations of 0 (CK), 0.3% and 0.5% at the seedling stage, and their salt tolerance index was determined, based on which their salt tolerance was analyzed and evaluated by using correlation analysis, principal component analysis and membership function. The results showed that the growth related indexes of the 30 varieties/lines above ground under salt stress, such as fresh weight (FW), dry weight (DW), net photosynthetic rate (Pn), water use efficiency (WUE) and chlorophyll content (TC), declined to some extents, while the indexes related to physiological metabolism, such as malondialdehyde (MDA) content, soluble sugar (SS) content, soluble protein (SP) content, free proline (Pro) content, peroxidase (POD) activity, etc, were elevated. These rice varieties/lines had higher variation in coefficients of salt tolerance of all the indexes, except Pro content, under the 0.5% NaCl treatment than under the 0.3% NaCl treatment, indicating that these varieties/lines under the 0.5% NaCl treatment displayed the highest difference in salt tolerance among all the treatments. All the indexes of the rice under the 0.5% NaCl treatment were used for correlation analysis to select the salt tolerance indexes of high significance from all the indexes for evaluation, based on which D value was calculated by using the membership function. The results showed that 5 lines, 14-57, 14-6, 14-36, W01, and 14-58-2, were highly tolerant of salt and that anther 5 lines, 16-8, 50188-2, 16-9, 15-18-2, and 14- 58-1, were low in salt tolerance. The stepwise regression analysis showed that the net photosynthetic rate (Pn), water use efficiency (WUE) and fresh weight (FW) of the leaves were the three most important indexes for evaluation of the salt tolerance of rice, based on which the estimation accuracy of salt tolerance of each rice variety/line were more than 90%. According to the comprehensive evaluation results, the 30 rice varieties/lines were divided into three categories, salt tolerant, moderately salt tolerant and salt sensitive, by using system clustering.