我国几个板栗品种抗寒性综合评价

Comprehensive evaluation on the cold resistance of several main Chinese chestnut cultivars

关键词:  板栗  抗寒性  指标  综合评价

Key words:  Chinese chestnut  cold resistance  index  comprehensive evaluation

摘要:

以10个中国板栗（Castanea mollissima Bl.）品种休眠期一年生枝条为材料，测定各品种不同低温处理下枝条的相对电导率（REC）、冻害指数、总着色度和丙二醛（MDA）、脯氨酸、可溶性糖含量及枝条结构特征。将REC配合Logistic方程求出枝条低温半致死温度（LT₅₀），通过相关性分析筛选与LT₅₀极显著相关的理化、结构指标，并用隶属函数法求出各抗寒性相关指标平均隶属度，对供试品种进行综合评价和抗寒性排序。结果表明：随处理温度的降低，10个板栗品种枝条REC变化趋势呈近"S"型，基于相对电导率拟合的LT₅₀差异较大，为-26.64~-17.73℃；-20℃处理下枝条REC、冻害指数、总着色度、MDA含量，及枝条木栓层厚度和木栓层比率与其LT₅₀呈极显著相关，可作为板栗枝条抗寒性鉴定的理化和组织结构指标；以6个指标为基础参数的隶属函数法适用于板栗树种枝条的抗寒性准确评价。10个中国板栗主栽品种枝条抗寒性强弱顺序为：‘燕宽’ > ‘燕山早丰’ > ‘燕奎’ > ‘处暑红’ > ‘紫珀’ > ‘粘底板’ > ‘罗田1号’ > ‘红栗’ > ‘燕红’ > ‘杂35’。

Abstract:

Annual dormant branches of 10 chestnut cultivars were taken as the experimental materials.Relative electrical conductivities (REC),freeze injury index,dyeing degree,the contents of malondialdehyde (MDA),proline,and soluble sugar under different low temperature treatments,as well as the anatomical structures indexes of branches were determined in this study.Semi lethal temperature (LT₅₀) was assessed with REC and Logistic equation.The physicochemical and morphological structural indexes,which had significant relationship with LT₅₀,were screened by correlation analysis.The membership function was used to determine the average subordinate level of the indexes,the comprehensive evaluation and cold resistance of main cultivars were sorted by comparing the average subordinative indexes.The results showed that:The relative electrical conductivities of 10 chestnut cultivars were in approximate "S" trend as temperature decreased.The LT₅₀ based on the REC of 10 chestnut varieties (strains) were quite different,ranging from －26.64 to －17.73 ℃.The significant correlations were found between LT₅₀ and the indexes including REC,freeze injury index,dyeing degree,the contents of MDA under －20 ℃ treatment,as well as phellem layer thickness and phellem layer ratio of the branch.These characters could be used as physicochemical and morphological structural indexes.The membership function based on 6 indexes could be used to accurately identify the cold resistance of the chestnut.The order of cold resistance of 10 chestnut cultivars,from the strong to the weak,was Yankuan,Yanshanzaofeng,Yankui,Chushuhong Zipo,Niandiban,Luotian 1,Hongli,Yanhong and Za 35.