基于代表性植株二次选择和多元统计分析的芦笋芽期苗期耐盐性鉴定及综合评价

Identification and Comprehensive Evaluation for Salt Tolerance of Asparagus Officinalis at Germination and Seedling Stages Based on Secondary Selection of Representative Plants and Multivariate Statistical Analysis

土壤盐渍化是制约农业发展的逆境因素之一,筛选耐盐种质可为芦笋耐盐新品种选育和耐盐机理研究奠定基础。本研究以49个芦笋品种为试验材料,采用二次选择法选择代表性植株,设0 mmol·L^(-1)NaCl(CK)和310 mmol·L^(-1)NaCl(T)2个水培处理,分别测定发芽率、发芽势等4个芽期指标和株高、根长等8个苗期指标,以耐盐系数为基础,运用多元统计分析方法进行耐盐性综合评价。结果表明,盐胁迫极显著影响各项指标(P<0.01),其中,地下部干重和根冠比耐盐系数大于1,其余指标耐盐系数均小于1。相关性分析表明,芽期各指标间均存在极显著相关性(P<0.01),苗期大部分指标间存在显著(P<0.05)或极显著(P<0.01)相关性。芽期基于U值聚类将供试品种划分为强耐盐、中耐盐、弱耐盐和盐敏感4个耐盐级别;苗期通过主成分分析将8个单项指标转换为3个综合指标,反映了全部信息的77.805%,基于D值聚类鉴定出苗期强耐盐品种12个、中耐盐品种20个、弱耐盐品种14个、盐敏感品种3个,其中,冠军和特立龙在芽期和苗期均表现为强耐盐。芽期基于U值和苗期基于D值的耐盐性排序与同时期综合耐盐系数(CSC)和加权耐盐系数(WSC)基本一致。本研究方法较传统鉴定方法更为科学、合理,可大幅减少田间全生育期鉴定工作量,适用于大规模芦笋种质耐盐性评价,对盐渍化土壤的改良利用具有重要意义。

Soil salinization is one of the stress factors that impeding the development of agriculture.Screening of salt-tolerant germplasm of asparagus can lay a foundation for breeding new salt-tolerant asparagus varieties and studying the salt-tolerant mechanism.Forty-nine asparagus varieties were used as experimental materials in this study and the representative plants of each variety were selected by the secondary selection method.The representative plants were cultured in hydroponics supplement with 0(CK)and 310 mmol·L^(-1)NaCl(T)for salt stress,respectively.Four germination indicators and eight seedling indicators,such as germination rate,germination potential,plant height,root length,and so on were measured.Based on the salt tolerance coefficient,multiple statistical analyses were used to comprehensive evaluate the salt tolerance of 49 asparagus varieties.The results showed that salt stress had extremely significant effects on all indicators(P<0.01).Among them,the salt tolerance coefficient of underground dry weight and root-shoot ratio were greater than 1,while the other indicators are less than 1.Correlation analysis showed that there was extremely significant correlation among different germination indicators(P<0.01),and most seedling indicators significantly(P<0.05)or extremely significant(P<0.01)correlated with each other.The tested varieties were clustered into four salt-tolerant grades including strong salt tolerance,medium salt tolerance,weak salt tolerance and salt sensitivity according to U values at germination stage.The eight individual indicators at seedling stage were converted into three separate comprehensive indicators by principal component analysis,representing 77.805%of the total information.According to D value clustering analysis,12 strong salt-tolerant varieties,20 medium salt-tolerant varieties,14 weak salt-tolerant varieties and 3 salt-sensitive varieties were identified at seedling stage.Among them,only Guanjun and Texlong were identified as strong salt tolerance at both germination and seedling stage.The ranking of salt-tolerance based on U value at germination stage and D value at seedling stage was basically consistent with the comprehensive salt tolerance coefficient(CSC)and weighted salt tolerance coefficient(WSC)at the same stage.Compared with the traditional identification method,the method used in this study was more scientific and reasonable,which could greatly reduce the workload of field identification during the whole growth period,and could be suitable for the salt-tolerant evaluation of lots of asparagus germplasms and has important significance for the improvement and utilization of saline soil.