| 摘要: |
| 【目的】筛选小茴香苗期关键耐盐指标及高度耐盐小茴香品种，为促进茴香产业的发展提供参考。【方法】以来自5个不同地区（宁夏海原县、内蒙古托克托县、山西大同市、陕西渭南市和甘肃民勤县）的小茴香为材料，用不同质量浓度（0（CK），3，6，9，12和15 g/L）NaCl胁迫其幼苗20 d后，测定幼苗的形态指标（株高、茎粗、最大叶长、最大叶宽、最大叶面积、根长、根数）和生理指标（相对电导率、丙二醛含量、脯氨酸含量、可溶性糖含量），对以上指标的相关性进行分析,并计算其耐盐系数；在此基础上，对5个不同地区小茴香材料的11个指标进行主成分分析，计算综合评价值（D），对不同地区小茴香幼苗的耐盐性进行综合评价；基于综合评价值，采用组间联接法和平方欧氏距离对不同地区小茴香进行聚类分析；利用逐步回归分析筛选关键耐盐指标，建立小茴香幼苗耐盐性评价的最优回归方程。【结果】①随着NaCl质量浓度的增加，5个地区小茴香幼苗的株高、茎粗、最大叶长、最大叶宽、最大叶面积、根长、根数均呈下降趋势；相对电导率及丙二醛和脯氨酸含量均呈上升趋势；甘肃、内蒙古和山西小茴香幼苗的可溶性糖含量先增加后下降，宁夏和陕西小茴香幼苗的可溶性糖含量均呈上升趋势。②相关性分析表明，NaCl胁迫下小茴香幼苗的各指标之间存在不同程度的相关性，其中株高、茎粗、最大叶宽、最大叶面积和根数之间均呈显著或极显著正相关，相对电导率与丙二醛、脯氨酸和可溶性糖含量呈极显著正相关，相对电导率、脯氨酸和可溶性糖含量与株高、最大叶长、最大叶宽、最大叶面积和根数之间均呈显著或呈极显著负相关。③甘肃地区小茴香材料的D值最大（0.612），其幼苗耐盐性最强；其次为内蒙古（0.545）、山西（0.487）和宁夏（0.429）；陕西地区小茴香材料的的D值最小（0.306），其幼苗耐盐性最弱。④聚类分析结果显示，在欧氏距离8.0处，5个地区的小茴香材料可分为3类，其中第Ⅰ类为甘肃地区小茴香材料，第Ⅱ类为内蒙古、山西和宁夏地区小茴香材料，第Ⅲ类为陕西地区小茴香材料。⑤筛选出最大叶长、最大叶面积、相对电导率、脯氨酸含量4个指标用于小茴香的耐盐性评价，并据此建立了小茴香幼苗耐盐性评价的最优回归方程。【结论】NaCl胁迫对小茴香幼苗生长有抑制作用，不同地区小茴香幼苗对NaCl胁迫的响应程度存在差异。甘肃地区小茴香为耐盐材料，内蒙古、山西和宁夏地区的小茴香为中度耐盐材料，陕西地区小茴香为轻度耐盐材料。 |
| 关键词: 小茴香 耐盐性 综合评价 主成分分析 聚类分析 |
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| 基金项目:宁夏回族自治区农业特色优势产业育种专项（NXNYYZ20200104）；2016 年度教育部春晖计划项目 |
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| Comprehensive evaluation of salt tolerance of fennel at seedling stage in different regions and screening of salt-tolerant indexes |
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ZHAO Xinyue,WANG Xiaomin,ZHAO Yunya,et al
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| Abstract: |
| 【Objective】This study screened key salt-tolerant indexes and highly salt-tolerant varieties of fennel at seedling stage to provide references for promoting fennel industry.【Method】Fennel varieties from 5 different regions (Haiyuan County,Ningxia;Tokto County,Inner Mongolia；Datong City,Shanxi；Weinan City,Shaanxi;Minqin County,Gansu) were selected in this study.After 20 days of NaCl stress at concentrations of 0 (CK),3,6,9,12 and 15 g/L,morphological indexes (plant height,plant stem diameter,maximum leaf length,maximum blade width,maximum leaf area,root length and root number) and physiological indexes (relative electrical conductivity,malondialdehyde content,proline content and soluble sugar content) of seedlings were determined.The correlations between above indexes were analyzed and the salt tolerance coefficients were calculated.Then,principal component analysis was carried out on 11 indexes of fennel materials from 5 different regions and comprehensive evaluation value (D) was calculated to evaluate salt tolerance of fennel seedlings.Cluster analysis was also conducted using inter group connection method and square Euclidean distance.The key indexes of salt tolerance were screened by stepwise regression analysis,and the optimal regression equation of salt tolerance evaluation was established.【Result】① With the increase of NaCl concentration,plant height,plant stem diameter,maximum leaf length,maximum blade width,maximum leaf area,root length and root number of fennel seedlings in 5 regions showed a decreasing trend,while relative electrical conductivity,malondialdehyde content and proline content showed an increasing trend.The soluble sugar contents of fennel seedlings in Gansu,Inner Mongolia and Shanxi increased and then decreased,while those in Ningxia and Shaanxi increased. ② There were different degrees of correlations among the indexes of fennel seedlings under NaCl stress,among which plant height,plant stem diameter,maximum blade width,maximum leaf area and root number had significant or extremely significant positive correlations,and relative electrical conductivity had positive correlations with malondialdehyde,proline and soluble sugar contents.The relative electrical conductivity,proline and soluble sugar contents had significantly negative correlations with plant height,maximum leaf length,maximum blade width, maximum leaf area and root number.③ The D value of fennel from Gansu was the largest (0.612) and its salt tolerance was strongest at seedling stage,followed by varieties from Inner Mongolia (0.545),Shanxi (0.487) and Ningxia (0.429).The D value of fennel from Shaanxi was the lowest (0.306),and its salt tolerance was the weakest at seedling stage.④ The cluster analysis showed that fennel materials from 5 regions were divided into three categories at the Euclidean distance of 8.0,among which class Ⅰ included fennel material from Gansu,class Ⅱ included fennel materials from Inner Mongolia,Shanxi and Ningxia,and class Ⅲ included fennel material from Shaanxi.⑤ Four indexes including maximum leaf length,maximum leaf area,relative electrical conductivity and proline content were selected for salt tolerance evaluation.And based this,the optimal regression equation for evaluating salt tolerance of fennel seedlings was established.【Conclusion】NaCl stress inhibited the growth of fennel seedlings,and fennel seedlings from different regions showed different reponses to NaCl stress.The variety from Gansu was salt-tolerant,the varieties from Inner Mongolia,Shanxi and Ningxia were moderately salt-tolerant,and the variety from Shaanxi was mildly salt tolerant. |
| Key words: fennel salt tolerance comprehensive evaluation principal component analysis cluster analysis |
