不同品种荷花耐盐碱性评价及鉴定指标筛选

为研究不同荷花(Nelumbo nucifera)品种在混合盐碱胁迫下的耐受程度，筛选抗性品种，采用盆栽法，以20个荷花品种为试验材料，对其进行100 mmol·L^-1(NaCl∶NaHCO₃=2∶1)混合盐碱胁迫处理，7 d后测量株高、叶面积、光合色素、叶绿素荧光参数、丙二醛含量、抗氧化物酶活性及渗透调节物质含量，通过耐盐碱系数、相关性分析、主成分分析、隶属函数法、聚类分析等方法对20种荷花耐盐碱性进行综合评价。结果表明：不同荷花品种单项指标的耐盐碱系数变异系数差异较大，除超氧化物歧化酶活性和过氧化物酶活性外，其余单项指标的耐盐碱系数均存在显著或极显著相关性，利用主成分分析将12个单项指标转换为5个综合指标，各综合指标贡献率分别为36.175%、18.709%、13.470%、11.379%、6.610%,累计贡献率达到86.344%。以耐盐碱性综合评价值(D值)为依据进行聚类分析，将20个荷花品种分为4类，第一类为强耐盐碱型，共计4个荷花品种，第二类为耐盐碱型，共计5个荷花品种，第三类为不耐盐碱型，共计8个荷花品种，第四类为敏感型，共计3...

Evaluation of salt-alkali tolerance of different lotus varieties and screening of identification indexes

In order to study the tolerance of different lotus varieties to saline-alkali stress and to screen resistant varieties, using pot culture method, 20 lotus varieties were used as experimental materials, and 100 mmol·L^-1 (NaCl∶NaHCO₃=2∶1) hybrid saline-alkali stress treatment, 7 d after measuring the plant height, leaf area, photosynthetic pigments, chlorophyll fluorescence parameters, content of malondialdehyde, activity of antioxidant enzyme and content of osmotic regulatory substances, the saline-alkali tolerance of 20 lotus species was evaluated comprehensively by means of saline-alkali tolerance coefficient, correlation analysis, principal component analysis, membership function method and cluster analysis. The results showed that there were significant differences in the variation coefficients of saline-alkali tolerance among different lotus varieties. Except superoxide dismutase activity and peroxidase activity, the saline-alkali coefficients of other single indexes were significantly or extremely significantly correlated. The 12 single indexes were converted into 5 comprehensive indexes by using principal component analysis. The contribution rates of each comprehensive index were 36.175%, 18.709%, 13.470%, 11.379%, 6.610%, and the cumulative contribution rate reached 86.344%. With saline resistance value (D value) based on clustering analysis, 20 lotus varieties could be divided into four categories, first, there was strong salt-tolerant type, a total of four lotus varieties, and the second category of salt-tolerant type, a total of five lotus varieties, and the third category was not salt-tolerant type, a total of eight lotus varieties, the fourth category for sensitive type, a total of three varieties of lotus. The optimal evaluation model of salinity and alkali tolerance of lotus was established by stepwise regression analysis, D=0.453+0.148X₁+0.122X₂-0.122X₇-0.033X₈+0.093X₁₁+0.037X₁₂(R²=0.992), and the estimation accuracy was above 95.45%. Plant height, leaf area, malondialdehyde, proline, soluble sugar and soluble protein were selected as evaluation indexes of the saline-alkali tolerance of lotus. The saline-alkali tolerance of lotus could be determined by measuring these 5 indexes under the same conditions.