楸树无性系叶绿素荧光及生长特性变异研究

对29个楸树无性系的生长性状（树高、地径、胸径、节间距）、叶片性状（叶片长度、宽度、叶柄长度、叶面积、鲜比叶质量、干比叶质量）和叶绿素荧光参数（Fv/Fm）等11个指标进行测定。结果表明:Fv/Fm的日变化曲线呈“V”字型，体现了楸树无性系光能利用率的变化和叶片在高光强下的自我保护机制；29个楸树无性系树高、地径、胸径的平均值分别为4.58 m、50.98 cm、39.31 cm，叶片鲜比叶质量和干比叶质量平均值分别为0.042 和0.014 g/cm2，Fv/Fm平均值为0.836。叶片长度、宽度和叶柄长度平均值均大于20.00 cm，表明楸树无性系叶片较大。方差分析结果表明:各指标差异极显著，其中7个指标表型变异系数大于10%，遗传变异系数与表型变异系数接近；10个指标重复力超过0.800，表明楸树无性系各指标受较强的遗传因素控制。相关分析表明:无性系各生长指标存在显著相关性。主成分分析结果显示:11个性状前3个主成分累积贡献率为71.23%；第1主成分Y1贡献率最高（35.92%），主要包括树高、地径、胸径等生长量指标，第2主成分Y2主要为比叶质量和Fv/Fm等指标；第3主成分Y3则主要代表叶片长度、叶片宽度等叶片性状。利用综合评价法对无性系进行综合评价，当入选率为20%，无性系2-2、008-1、2-8、9-1、1-1和4001入选，这6个无性系的树高和胸径的遗传增益分别为11.23%和9.58%。楸树无性系间生物量各指标与叶绿素荧光参数差异显著，为进一步研究提供基础。 

Variation analysis on chlorophyll fluorescence and growth traits of Catalpa bungei clones

To find the variation characteristics of chlorophyll fluorescence and growth traits of Catalpa bungei clones,29 clones of C.bungei were taken in the research and 11 profiles of the clones were measured and analyzed,including tree height(H),basic diameter(BD),diameter of breast height(DBH),space between burls(SBB),leaf length(LL),leaf width(LW),leaf area(LA),stipe length(SL),fresh leaf mass per area(Flma),leaf mass per area(Lma),and parameters of chlorophyll fluorescence(Fv/Fm).The results showed that the curve of diurnal variation of Fv/Fm shaped "V",reflecting the self-protection mechanisms and variation of solar energy utilization efficiency of C.bungei clones.The average of H,BD,DBH,Flma,Lma and Fv/Fm of C.bungei clones were 4.58 m,50.98 cm,39.31 cm,0.042 g/cm2,0.014 g/cm2 and 0.836 respectively.The averages of LL,LW and SL all exceeded 20.00 cm,indicating that the leaves of C.bungei clones were much bigger.The analysis of variance showed that there was a remarkable difference in 11 characteristics among the clones(sig<0.001).Seven coefficients of variation of phenotype were more than 10%,coefficient of genetic variation was closely to that of phenotype variation.The repeatability of 10 in 11 indices was higher than 0.800,indicating that C.bungei clone variation was strongly controlled by genetic factors.The results of phenotypic correlation showed that there were significant correlations among the growth target.Principal component analysis showed that the cumulative contribution rate of initial three principal components of the 11 characteristics in C.bungei clones was 71.23%.The contribution rate of the first principal components Y1 were the highest(35.92%),including H,BD,DBH,etc.;the second ones Y2 were the trait such as Flma,Lma and Fv/Fm,and the third ones Y3 were about LL and LW,etc.Based on the analysis of colligate evaluated,2-2,008-1,2-8,9-1,1-1 and 4001 were selected as excellent clones when the selection rate was 20%.The genetic gains of three clones on H,DBH were 11.23% and 9.58%.Remarkable difference in characteristics of biomass and chlorophyll fluorescence can provide basis for future research in C.bungei.