白桦半同胞家系苗期生长和光合特性及其选育评价指标筛选

摘要

对6个白桦半同胞家系苗期生长、光合和叶绿素荧光参数进行测定,分析各指标的变异状况,并探讨白桦苗期选育评价的主要因子.结果表明:(1)白桦半同胞家系间生长性状(苗高、地径、叶片长度、叶片宽度、叶片数量、叶片长宽比)和光合指标(Pn、Gs、Gs、E、WUE)差异极显著,除Gi外各光合指标的变异系数和遗传变异系数均超过了10％.(2)白桦半同胞家系间叶绿素荧光参数Fo、Fo'、Fs、Fv'/Fm'、NPQ和Yield差异显著,除NPQ外所有叶绿素荧光参数变异系数和遗传变异系数均不超过10％,表明白桦半同胞家系叶片光合潜在能力差异不大.(3)白桦半同胞家系叶绿素荧光参数各指标遗传力H2均大于0.4,属中度遗传力,而生长指标和光合指标遗传力均大于0.7,属于较高遗传力,表明白桦半同胞家系生长和光合变异主要由遗传因素控制,有利于苗期选择评价.(4)白桦半同胞家系苗高、地径与WUE显著正相关,而与Yield显著负相关；叶片数量和叶片宽度对白桦苗期苗高和地径影响较大,可以作为苗期选择评价的主要因子.%To find the variation of growth and photosynthetic traits and discuss the most important assistant factor for breeding selection of Betula platyphylla,6 half-sib families of were taken in the research,we measured and analyzed 24 profiles of the B.platyphylla half-sib families.The analysis of variance calculation show that:(1)There was a remarkable difference in height (H),basic diameter (BD),leaf length (LL),leaf width (LW),leaf number (LN),the ratio of leaf length to width (L/W),net photosynthesis rate (Pn),stomatal conductance (Gs),intercellular CO2 concentration (Ci),transpiration rate (Tr) and water use efficiency (WUE).The coefficients of variation and genetic variation of H,BD,LL,LW,LN,L/W,Pn,Gs,Tr and WUE were more than 10％.(2)There were also exist remarkable difference in the chlorophyll fluorescence parameters (Fo,Fo ',Fs,Fv' / Fm',NPQ) and Yield.Except parameter NPQ,the coefficients of variation and the genetic variation of chlorophyll fluorescence parameters were less than 10 ％.(3)The heritability of chlorophyll fluorescence parameters of B.platyphylla half-sib families were higher than 0.4,but the photosynthetic and growth parameters were higher than 0.7,indicating that B.platyphylla half-sib families variation was strongly controlled by genetic factors.(4)The results of phenotypic correlation showed that there were significant positive correlation among the growth traits and WUE,but negative correlation with Yield.Regression analysis results showed that LW and LN were the first two variables introduced for H and BD equations,indicating that LW and LN were very important parameters for B.platyphylla seedling selection and evaluation.