铁线莲品种耐热性分析及评价指标筛选

为探讨南方夏季高温对铁线莲生理生化的影响,筛选耐热品种并建立耐热性评价体系,于2015年5-8月,以20个铁线莲品种为试验材料,对其高温半致死温度及高温胁迫下植株热害指数(HII)、相对电导率(REC)、萎蔫程度(WD)等10个生理生化指标性进行测定,并采用主成分、隶属函数、聚类分析和逐步回归等方法对其耐热性进行综合评价。结果表明,20个品种可以分为耐高温、较耐高温、高温较敏感和高温敏感4个类型,其中罗曼蒂克、如古和浪子耐热性较强;高温半致死温度可作为耐热性评价的指标;建立了以HII、REC、叶绿素(CC)和丙二醛(MDA)含量以及超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性等6个指标为变量的铁线莲耐热评价模型。本研究结果为铁线莲品种栽培适应性评价体系的建立和耐热型铁线莲品种选育提供了理论依据。

Evaluation of Heat Tolerance and Screening the Index for the Assessment of Heat Tolerance in Cultivars of Clematis

In order to explore effects of high temperature in summer on physiology and biochemistry of Clematis cultivars, select heat-tolerant varieties and establish a heat-tolerant evaluation system, 10 physiological and biochemical indexes such as HII, REC and WD of 20 Clematis varieties were measured under high temperature stress in May to August 2015. Principal component analysis, membership function, cluster analysis and stepwise regression method were used to evaluate the heat resistance of 20 test samples comprehensively. The results showed that the 20 cultivars of Clematis were classified into 4 types, which were heat tolerance line, moderately heat tolerance line,heat susceptible line,and moderately susceptible line. Romantika, Rooguchi and the Vagabond were the top three with heat-resistance properties. Semi-lethal high temperature could be used as an index for heat tolerance evaluating. The heat resistance evaluation model was established through stepwise regression method based on 6 variables which were HII, REC, chlorophyll content (CC), methane dicarboxylic aldehyde (MDA) content, superoxide dismutase activity (SOD), and ascorbate peroxidase activity (APX). The results of this study provide a theoretical basis for the evaluation of the adaptability of Clematis cultivars and the breeding of heat resistant Clematis varieties.