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【目的】土壤盐渍化是危害水稻生产的重要非生物胁迫之一。鉴定水稻种质资源发芽期耐盐性,筛选耐盐指标,培育耐盐品种,对水稻生产的发展具有重要意义。【方法】利用125 mmol/L Na Cl溶液对64份粳稻种质资源进行盐胁迫,于胁迫后3 d测定发芽数;胁迫5 d、10 d后,测定发芽数、芽长和根长,并计算相对芽长、根长、发芽势、发芽率、盐害率,发芽指数和活力指数。运用多种统计学方法对各种质资源的芽期耐盐性进行综合评价,分析典型耐盐和盐敏感种质盐胁迫条件下的发芽特征。【结果】相对盐害率与相对根长、相对发芽势、相对发芽率、发芽指数和活力指数均极显著负相关;除相对芽长外各指标间的相关性均达到极显著水平。通过聚类分析将64份粳稻种质资源划分成4个类群。第Ⅰ、Ⅰ类群分别为典型的盐敏感和耐盐类群,第Ⅱ类群为弱耐盐种质为主的混合类群,第Ⅲ类群主要由耐盐种质组成。通过主成分分析将7个评价指标转换为3个主成分,应用隶属函数和权重,获得了客观评价粳稻种质资源耐盐性的综合评价值D。分别选取D值最高和最低的5份种质资源进行芽期耐盐指标的差异显著性分析,结果表明,两组种质资源盐胁迫5 d的各评价指标差异均达到极显著水平,10 d的评价指标除相对芽长外,均达到了显著差异水平。【结论】水稻芽期对盐胁迫较为敏感,且耐盐性不同的种质间差异显著。利用逐步回归和主成分分析获得发芽指数、相对根长和相对盐害率3个指标,可作为快速鉴定粳稻种质资源芽期耐盐性的重要指标,若采用多元统计方法评价可靠性更高。
【Objective】 Soil salinization is one of the most important abiotic stresses that endanger rice production. Identification of rice germplasm resources of salt tolerance, screening of salt tolerance indicators, cultivating salt-tolerant varieties of rice production is of great significance. 【Method】 Sixty-four japonica rice germplasm resources were subjected to salt stress with 125 mmol / L NaCl solution. The number of germination was determined 3 days after stress. Germination number, shoot length and root length were measured after 5 d and 10 d of stress Relative bud length, root length, germination potential, germination rate, salt damage rate, germination index and vigor index were calculated. A variety of statistical methods were used to evaluate the salt-tolerance of germplasm resources at various budgets, and the germination characteristics of typical salt-tolerant and salt-sensitive germplasm under salt stress were analyzed. 【Result】 The results showed that the relative salt damage rate was significantly and negatively correlated with the relative root length, relative germination potential, relative germination rate, germination index and vigor index. The correlations among the indexes except the relative bud length reached extremely significant levels. According to cluster analysis, 64 japonica germplasm resources were divided into 4 groups. The first and the first group are typical salt sensitive and salt tolerant groups, the second group is a weak salt tolerant germplasm mixed group, the third group mainly composed of salt-tolerant germplasm. Through the principal component analysis, the seven evaluation indexes were transformed into three principal components, and the membership function and weight were applied to obtain the comprehensive evaluation value D for objectively evaluating the salt tolerance of japonica germplasm resources. Five high and low D germplasm resources were selected to analyze the significant difference of salt tolerance index at bud stage. The results showed that the difference of each evaluation index of two germplasm resources at 5 d reached extremely significant level, and on the 10th Of the evaluation index except relative bud length, reached a significant level of difference. 【Conclusion】 The rice bud stage is sensitive to salt stress, and the difference of salt tolerance is significant. The three indicators of germination index, relative root length and relative salt damage rate were obtained by stepwise regression and principal component analysis, which could be used as an important index to rapidly identify the salt tolerance of japonica germplasm bud at budding stage. Multivariate statistical method was more reliable .