羊草种质资源耐盐碱性综合评价

Comprehensive Evaluation on Saline-Alkali Tolerance of Leymus chinensis Germplasm Resources

以60份羊草种质资源为对象,采用生长期盐碱溶液灌溉胁迫盆栽试验,盐碱胁迫30d后测定株高、分蘖数、叶长、叶宽、叶片数、地上部干重、地上部鲜重、根干重、根鲜重、SPAD值、光合效率、丙二醛含量、脯氨酸含量等13项指标,运用相关性分析、主成分分析、聚类分析、隶属函数法、灰色关联度分析等方法对羊草种质资源耐盐碱性进行综合评价。结果表明:盐碱胁迫处理下,羊草叶片中SPAD值、脯氨酸和丙二醛含量升高,其余指标平均值均小于对照;除叶片数外,其余指标的变异系数均大于10%;采用主成分分析将盐碱胁迫处理下13个单项指标转换成8个综合指标,累计贡献率达87.56%;根干重、分蘖数、脯氨酸含量与羊草种质资源盐碱胁迫灰色关联度较大,敏感度较高;通过隶属函数分析得到不同地理来源羊草幼苗耐盐碱性综合评价值(D值),采用聚类分析将60份羊草种质划分为5种类型,包括高度耐盐碱型(Ⅰ型)3份、耐盐碱型(Ⅱ型)22份、中等耐盐碱型(Ⅲ型)22份、敏感型(Ⅳ型)12份、高度敏感型(Ⅴ型)1份。

This study was to evaluate the saline-alkali tolerance of Leymus chinensis germplasm resource. A pot experiment was conducted on 60 Leymus chinensis germplasm resources under saline-alkali solution irrigation stress in growing period. After 30 days of saline-alkali stress, 13 indicators, such as the plant height, tiller number, leaf length, leaf width, leaf number, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, SPAD, photosynthetic efficiency, malondialdehyde (MDA) and proline (Pro) content were measured. Correlation analysis, principal component analysis, membership function, cluster analysis and grey correlation analysis were used to comprehensive evaluation on saline-alkaliresistance of Leymus chinensis germplasm resources. The result shows that SPAD value, the content of Pro and MDA in leaves of Leymus chinensis were increased under salt-alkaline stress, and the mean values of the other indicators were lower than those of the control. The variation coefficients of other indicators were greater than 10% except the number of leaves. The 13 single indicators under salt-alkaline stress were converted into eight comprehensive indicators by principal components analysis, and the cumulative contribution rate was 87.56%. Root dry weight, tiller number and Pro were significantly correlated with salt-alkaline tolerance of Leymus chinensis germplasm resources, and were sensitive to salt-alkaline stress. Comprehensive evaluation value (D value) of salt-alkali tolerance of Leymus chinensis seedlings from different geographical sources was obtained by subordinate function analysis. Sixty Leymus chinensis germplasms were classified into five types by cluster analysis, including 3 highly saline-alkali tolerant (type Ⅰ), 22 salt-alkaline-tolerant (type Ⅱ), 22 moderately salt-alkaline-tolerant (type Ⅲ), 12 salt-alkalinesensitive (type Ⅳ), 1 high salt-alkaline-sensitive (type Ⅴ).