低温胁迫下二十个杜鹃花品种的抗寒性评价

Comprehensive Evaluation of Cold Resistance of Twenty Rhododendron Cultivars Under Cold Stress

为了明确杜鹃花的抗寒性,以20个杜鹃花品种为试材,进行20d自然低温处理后观测植株形态表现,测定可溶性糖、可溶性蛋白质、丙二醛(MDA)、过氧化氢(H_2O_2)含量及过氧化物酶(POD)和超氧化物歧化酶(SOD)活性等指标,运用隶属函数标准差系数权重法进行抗寒性综合评价,并进行各生理指标与抗寒性综合评价值相关性分析。结果表明:低温胁迫下"红玥"杜鹃形态表现最不明显,抗寒性最强。相关性分析得出可溶性糖含量与抗寒综合评价值极显著正相关(P<0.01),SOD活性显著正相关,MDA含量与抗寒性综合评价呈显著负相关(P<0.05)。POD活性与抗寒性综合评价值呈正相关,可溶性蛋白质含量和H_2O_2含量与抗寒性综合评价值呈负相关。形态观测结果与隶属函数的综合评价基本一致,可鉴定杜鹃花的抗寒性顺序。该研究为不同区域园林应用中杜鹃花品种的选择应用提供参考。

In order to understand the adaptation mechanism of Rhododendronto cold stress,under natural cold treatment for 20 days,20 Rhododendron cultivars were used as the test materials,which cold resistance was evaluated by measuring relative electrical conductivity,soluble sugar content,soluble protein content,MDA content of leaves,H_2O_2 content,POD activity,and SOD activity,and the growth morphology.By the method of subordinate function,comprehensive evaluation on the cold resistance of different Rhododendron cultivars was made.The results showed that the growth change of R.‘Hong Yue＇under cold stress was not obvious,and cold resistance was the best.Using the method of subordinate function weights coefficient of standard deviation,the cold resistence capacity of 20 Rhododendroncultivars was comprehensively evaluated,the cold resistance ability of R.‘Hong Yue＇was the best among 20 Rhododendroncultivars.Correlation analysis demonstrated that integrated assessment value of cold resistance had significant positive correlation with the content of soluble sugar（P0.01）and superoxide dismutase（SOD）activity,had positive correlation with the contents of peroxidase（POD）activity,while had significant negative correlation with malondialdehyde（MDA）content（P0.05）,and had negative correlation with the contents of soluble protein,and hydrogen peroxide（H_2O_2）content.The results indicated that,the comprehensive evaluation results was similar to results observed in morphological characteristics of leaves.The research provided important theoretical basis for the choice of Rhododendron species,which was used in different regions in landscape application.