不同地理种源观光木苗期表型性状与生物量比较研究

Phenotypic Traits and Biomass Comparative Analysis of Michelia odora Seedlings from Different Provenances

【目的】种源与家系早期选择是林木育种的重要措施,通过分析不同地理种源观光木的表型性状,以期揭示观光木表型变异程度及变异规律,为观光木优良种质资源的优良选种、保护和开发利用提供理论基础。【方法】本研究以前期收集的11个地理种源1年生实生苗为对象,对不同地理种源观光木苗期生长节律进行初步分析;比较表型性状在种源间的差异和变异系数在种源间的变化以及与种源地理、气候因子的关系,并分析观光木幼苗各器官生物量在种源间的差异,采用聚类分析和模糊隶属函数进行种源综合评价。【结果】观光木在苗期生长过程均呈现明显的“慢—快—慢”的“S”型生长节律,生长速生期在7~10月;不同地理种源观光木表型性状指标、生物量均有显著差异(P<0.01),南宁树木园种源的表型性状指标在11个种源中均处于优势;不同地理种源表型性状平均变异系数为14.11%,苗高、地径的差异明显大于其他指标的差异;从生物量的变异系数上来看,观光木各种源间茎鲜重的变异系数要大于根鲜重,但整体上看,茎鲜重也高于根鲜重,说明观光木各种源间的生物量具有一定的稳定性。绝大部分苗期表型性状与地理因子呈显著负相关关系,观光木在低纬度、温度高、降水充沛的地方生长良好;聚类分析结果和模糊隶属函数评价结果具有一致性,将11个观光木种源划分为3类,初步筛选南宁树木园种源为优良种源。【结论】观光木11个种源苗期表型性状和生物量变异丰富,说明观光木优良种源在苗期就有较大的选择潜力,能够进行基于表型性状的种质资源筛选。

For the early selection of superior provenance for Michelia odora,based on the one-year seedlings of 11 geographical provenances collected previously,the differences in phenotypic traits,the changes in coefficient of variation among provenances,as well as their relationships with geographical and climatic factors were compared,and the differences in biomass of various organs of M.odora seedlings among provenances were analyzed.Taking advantage of the method of cluster analysis and fuzzy membership function,the comprehensive evaluation of the M.odora provenance was carried out.The results showed that the growth increment of M.odora during the seedling stage exhibited significant rhythmicity.The growth rate decreased significantly from July to October,and after November,it reached the lowest point and almost stopped growing.Phenotypic traits and biomass differed significantly among geographical provenances of M.odora(P<0.01).The average coefficient of variation of phenotypic traits from different geographical provenance was 14.11%,and the majority of phenotypic traits at seedling stage correlated negatively with geographical factors significantly.M.odora grew very well in low latitude,high temperature and abundant precipitation areas.The 11 M.odora geographical provenances was divided into 3 groups by the clustering analysis and the fuzzy membership function evaluation,and the M.odora from Nanning Arboretum was identified as the superior one.