| The article take Sichuan Local poplar seeds which contain artificial hybridization offspring and cutting propagation clone as research objects, and study the heritable variation of hybrid and clone growth trait, and discuss the variation of hybrid and clone growth trait, branch trait and photosynthetic trait, and provide theoretical basis and instruction for Sichuan Local poplar crossbreeding and clonal selection. Main results as follows:(1)The growth trait among hybridized combination exist significant differences, and two years growth presents major variable coefficient, and hybrid has abundant variation. The estimation to genetic parameter, the family heritability of tree height and ground diameter is 0.787 and 0.741; and the heritable variation coefficient is 12.48% and 13.21%; the growth trait of tree height and ground diameter is controlled by strongly hereditary, which contains abundant heritable variation, and providing material basis for family selection. The two years growth Relevance between tree height and ground diameter is positive correlation in extremely remarkable level, and correlation index are all above 0.7.(2)On the basis of hybrid branching habit analysis result, the features of SD combination crown are narrow and small, and thick; the features of EC combination crown are oval and more branches; which could be used for timberland cultivation or farmland shelterbelt. The crown feature of ED combination, SC combination, CD combination and TD combination is open type, which could be used for landscaping.(3)According to two years growth trait performance, ED combination and EC combination are better families that grow fast and big year increment.(4)The tree height of clone current year cutting seedling and ground diameter growth trait exist large variation, and Repeatability are 0.757 and 0.540, and heritable variation coefficient are 15.14% and 13.99%. The tree height and ground diameter heritability of stump seedling are 0.862 and 0.720, greater thanl-year-old cuttings heritability. The clone growth express more stable after stumping.(5)Transform clonal eleven traits to four main factor by Utilizing PCA, and cumulative reaches 79.522%, which could explain different trait features, divide twenty-four clone into five sorts by combining Hierarchical Cluster Analysis and method of the longest distance,Ⅰ、Ⅱ、Ⅲ sorts each contains one clone, Ⅳ sort has five clones and V sort has sixteen clones. According to the performance of the height and ground diameter growth traits,106、1011、1015、1017 and 1018 are selected as excellent clones with fast growth.(6)The clone annual growth rhythm presents "slow-fast-slow" sigmoid growth curve. Simulate the growth equation of clone tree height and ground diameter by using logistic growth model, the correlation coefficient R-value are all above 0.94, and the correlation reaches extreme significant level (p<0.01). According to growth equation to Determine Growth time point, and divide one year growth into three stages:pre-growing-stage, fast-growing-stage and late-growth-stage. Ground diameter’s fast-growing stage is longer than tree height’s.(7)Different clonal photosynthetic physiology indexes have certain differences, which all have large heritability and under strong genetic control. The growth trait and net photosynthetic rate of tree height and ground diameter have extremely significant correlation, and the correlation coefficient is 0.534 and 0.562 respectively, whose correlation are insignificant to other photosynthetic physiology indexes. There is significant positive correlation or negative correlation between photosynthetic physiology indexes. There are differences in different clones by using the range of light intensity; the capacity utilization of 1017 clone is better to strong light, and 1028 to weak light. The Photosynthesis ability of the leaves in the middle is greater than the upper leaves and bottom leaves in the clone main trunk, which is the main area for photosynthesis of plant. |
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