江苏省作物遗传生理重点实验室 / 江苏省作物栽培生理重点实验室 / 江苏省粮食作物现代产业技术协同创新中心 / 扬州大学水稻产业工程技术研究院,扬州 225009
Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology/ Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/Research Institute of Rice Industrial Engineering Technology,Yangzhou University,Yangzhou 225009
Jiangsu Agriculture Science and Technology Innovation Fund（CX（21）3111），Jiangsu Province Key Research and Development Program（BE2019343），National Natural Science Foundation of China（32101817），National Science and Technology Support Program（2015BAD01B03）
通过分析水稻在盐胁迫和对照情况下的农艺性状表型差异，筛选出耐盐性强的水稻，为盐碱地的开发利用提供优良种质资源。本研究是水稻全生育期水培耐盐筛选，主要是对国内120个水稻进行耐盐性筛选，设置0%、1.5‰、3‰、4.5‰和6‰5个盐浓度梯度，在成熟期时分别测定各个水稻品种的株高、主茎茎粗、根长、倒1长、倒1宽、倒2长、倒2宽、绿叶数、主茎穗长、茎干重、叶干重、穗干重、根干重、地上部干重、根冠比、穗数、穗粒数、千粒重、结实率和理论产量。首先利用四分位差法确定本研究的最佳筛选盐浓度；其次对最佳筛选盐浓度下的各个耐盐系数进行主成分分析，在主成分分析基础上通过模糊函数法得到隶属函数值和综合评价值（D值），用D值和各个品种的耐盐系数值进行逐步回归分析和相关分析，最后对各个水稻品种的D值用欧式距离和ward法进行系统聚类分析。结果表明6‰盐浓度是最佳筛选盐浓度; 经过主成分分析、隶属函数分析和逐步回归分析得到回归方程: D值=0.152+0.004*LT1+0.005*GDW+0.007*SL-0.027*MST +0.047*WT1。系统聚类分析结果表明在欧式距离为5的地方分类得到11个耐盐性极强的水稻品种、19个耐盐性强的水稻品种，24个耐盐性中等的水稻品种，45个耐盐性弱的水稻品种，21个耐盐性极弱的水稻品种。水培全生育期耐盐筛选最适盐浓度为6‰，通过测定水稻成熟期倒1长、倒1宽、主茎穗长、地上干重和主茎茎粗，利用回归方程可快速鉴定水稻的耐盐性大小。通过筛选得到的高耐盐水稻种质资源可以为进一步挖掘耐盐基因和培育水稻耐盐新品种奠定基础。
Through analyzing the phenotypic differences at agronomic traits under salt stress and control growth conditions, the rice cultivars showing salt-tolerant have been obtained valuable in breeding for new rice varieties adapting to the saline-alkali fields. In this study, we conducted a screening for salt-tolerant elite rice genotypes using 120 rice genotypes in China. This experiment was performed using hydroponic culture using five treatments (salt concentration: 0‰, 1.5‰, 3‰, 4.5‰ and 6‰) in the whole growth period. Dozens of phenotypic traits (Plant height, main stem thickness, root length, the length of top first leaf, the width of top first leaf, the length of top second leaf, the width of top second leaf, green leaf number, spike length of the main stem, stem dry weight, leaf dry weight, panicle dry weight, root dry weight, ground dry weight, root shoot ratio, spike number, spike grain number, thousands seeds weight, seed setting rate and theoretical yield of each rice variety) were quantified at the maturity stage. First, the optimal salt concentration was determined by the quartile difference method. Secondly, principal component analysis was carried out for each salt-tolerant coefficient under the optimal screening salt concentration. Based on the principal component analysis, membership function value and comprehensive evaluation value (D value) was obtained by using fuzzy function method. Stepwise regression analysis and correlation analysis were carried out with D value and salt-tolerant coefficient value of each variety. Finally, the D values of each rice variety were systematically analyzed by the Euclidean distance and Ward method. The results showed that 6‰ salt concentration was the best salt concentration for screening. The regression equation was obtained through principal component analysis, membership function analysis and stepwise regression analysis: D value = 0.152 + 0.004*LT1 + 0.005*GDW + 0.007*SL - 0.027*MST + 0.047*WT1.The results of systematic cluster analysis showed that 11 rice varieties with highly salt-tolerant, 19 salt-tolerant, 24 medium salt-tolerant, 45 salt-sensitive, and 21 highly salt-sensitive were classified (Euclidean distance 5).The optimal salt concentration was 6‰ during the whole growth period of hydroponics. The salt-tolerant of rice could be quickly identified by using the regression equation by measuring the length of top first leaf, the width of top first leaf, main stem spike length, ground dry weight and main stem thickness of rice at maturity. Collectively, this study identified highly salt-tolerant rice germplasm resource which laid a foundation for future exploring salt-tolerant genes and breeding for rice varieties.