广西田林种源红椿优树子代苗的早期选择

Early selection for progeny seedlings in elite trees of Toona ciliata in Tianlin,Guangxi

[目的]探讨红椿优树子代苗生长遗传变异规律,并筛选优良家系进行推广应用。[方法]比较广西田林县20个红椿优树子代苗苗高和地径等生长性状,采用方差分析和遗传参数分析对3月龄红椿家系进行综合评价,并通过聚类分析筛选出苗期优良家系。[结果](1)不同苗龄红椿优树子代苗苗高和地径在家系间差异均达极显著水平(P<0.01),苗高遗传力(0.929)大于地径遗传力(0.845);不同家系苗高与地径遗传变异系数均大于15%,说明红椿家系间存在丰富的遗传变异。(2)通过聚类分析,将20个家系分为6类(Ⅰ~Ⅵ),苗高生长量依次为:Ⅰ>Ⅱ>Ⅲ>Ⅳ>Ⅴ>Ⅵ。(3)以20%的入选率选出TL-16、TL-2、TL-15和TL-14等4个优良家系,入选家系的平均苗高、地径分别为38.5 cm、4.95 mm,比参试家系平均苗高(28.3 cm)高36.0%,比平均地径(3.99 mm)高24.1%;苗高与地径的平均遗传增益分别为33.32%、20.39%。[结论]筛选出的4个优良家系具有较高的遗传增益,可作为后续良种选育的种质材料。

[Purpose]The aim of the study was to explore growth genetic variations in seedlings of Toona ciliata superior trees,and to select elite families for promotion and application.[Method]Twenty elite tree progenies from Tianlin,Guangxi were sampled to compare their growth traits in seedling heights and ground diameters.The 3-month-old T.ciliata families were comprehensively evaluated by analysis of variance and genetic parameters.Elite families in seedling stage were selected by cluster analysis.[Result](1)There were significantly different in seedling height and ground diameter among different families of T.ciliata progenies with various seedling ages(P<0.01).The heritability of seedling height(0.929)was higher than that of ground diameter(0.845).Genetic variation coefficient of seedling height and ground diameter of different families were greater than 15%,which indicated there was rich genetic variation among T.ciliata families.(2)20 T.ciliata families were divided into 6 categories(Ⅰ-Ⅵ)by cluster analysis,and the height growth was shown as follow:Ⅰ>Ⅱ>Ⅲ>Ⅳ>Ⅴ>Ⅵ.(3)Based on a selection rate of 20%,TL-16,TL-2,TL-15 and TL-14 were selected as superior families.The average seedling height and ground diameter of superior families were 38.5 cm and 4.95 mm,respectively,which were 36.0%higher than the average seedling height(28.3 cm)and 24.1%greater than the average ground diameter(3.99 mm)of the 20 tested families.The average genetic gain of seedling height and ground diameter of selected families were 33.32%and 20.39%,respectively.[Conclusion]Four excellent T.ciliata families of high genetic gain were selected as germplasm for further breeding processes.