基于主成分分析和通径分析法对萼距花耐盐性的综合评价

Comprehensive Evaluation of Salt Tolerance in Cuphea hookeriana Based on Principal Component Analysis and Pathway Analysis

为探究萼距花对土壤盐渍化的耐受能力,以萼距花扦插苗为试验材料,采用盆栽法模拟盐胁迫,共分为0、25、50、75、100 mmol/L 5个浓度梯度处理,测定各项生理指标的变化。研究结果发现萼距花的相对电导率、脯氨酸含量、丙二醛含量与盐胁迫浓度呈正相关;相对含水量与之呈负相关;叶绿素a和类胡萝卜素在盐胁迫条件下都呈现出先降后升的变化,而叶绿素b在盐胁迫条件下表现出先降后升再降的变化。由此发现,萼距花针对不同浓度的胁迫环境存在不同程度的生理响应,胁迫环境浓度越高,对幼苗生理特性的影响越大;而且萼距花可以通过降低相对含水量、增加丙二醛和脯氨酸含量响应盐胁迫;此外,叶绿素a、叶绿素b、类胡萝卜素含量在下降后可通过一定程度的回升以降低因盐胁迫带来的生理紊乱。通过主成分分析发现,对萼距花生理特性的影响由大到小依次为100、75、50、25、0 mmol/L;通径分析发现盐胁迫下影响萼距花脯氨酸含量的最重要因素为相对含水量。本研究探究了萼距花在NaCl盐胁迫下的生理响应机制,对提升萼距花的耐盐性和更大范围的引种栽培具有重要的意义。

In order to investigate the tolerance of Cuphea hookeriana to soil salinization,C.hookeriana cuttings were used as experimental materials to simulate salt stress by the potting method,which was divided into five concentration gradient treatments,namely,0,25,50,75,and 100 mmol/L,and the changes of various physiological indexes were determined.The results of the study revealed that relative conductivity,proline content,and malondialdehyde content of C.hookeriana were positively correlated with salt stress concentration;relative water content was negatively correlated with it;and both chlorophyll a and carotenoids showed a decrease followed by an increase in salt stress conditions,while chlorophyll b showed a decrease followed by an increase followed by a decrease in salt stress conditions.It was found that C.hookeriana had different physiological responses to different concentrations of stress,and the higher the concentration of stress,the greater the effect on acteristics of seedlings;C.hookeriana could respond to salt stress by decreasing the relative water content and increasing the content of malondialdehyde and proline;furthermore,the content of chlorophyll a,chlorophyll b,and carotenoids could be rebounded to a certain extent after a decrease to reduce physiological disorders caused by salt stress.The effects on the physiological characteristics of C.hookeriana were found to be 100,75,25,50,and 0 mmol/L in descending order by principal component analysis,and the most important factor affecting the proline content of C.hookeriana under salt stress was found to be the relative water content by pass-through analysis.The present study investigated the physiological response mechanism of C.hookeriana under NaCl salt stress,which is of great significance for the enhancement of salt tolerance and wider introduction of C.hookeriana into cultivation.