Genetic Variation And Selection Of Provenances, Families And Clones Of Platycladus Orientalis (Linn.) Franco In Jiaxian, Henan Province

Investigating the variations of growth,form and adaptability traits for adult tree in each genetic levels of Platycladus orientalis(Linn.) Franco would be helpful to understand the genetics variation, structure of sources,as well as to performance selections for its improvement.Based on field trails of provenance,forest stand,family and clone of P.orientalis in Jiaxian,Henan Province,variations of 9 traits were evaluated and the trend of geographic variations of provenance was analysised.The results were as follows:(1) Significant variations were showed in many traits among provenances.The height,ground diameter and crown had higher genetic components on provenance effect than others,which were 14.938%,10.802%and 14.097%,they were the main traits for provenance selection.The genetic components of form and branch traits were less than 10%.(2) There were no significant correlation showed between traits and the geographical locations of seed source tested provenances which could be divided into 3 zones,according to main trunk growth and crown.There had no obviously geographic cluster trend in each zone among provenances.(3) For the purpose of combining timber production and ecological application,the height,ground diameter,crown width and survival ratio were used as criteria for comprehensive provenance selection. The results showed that the relative value of 10 provenances exceeded one standard deviation of provenance average,Xichuan and Zunhua had good performance,which were superior provenances, selected for Jiaxian and the hilly regions of same climate and site conditions in southern Henan province.(4) Significant variations were showed in the height and crown form of adult trees,between superior foerest stands within each provenance in Henan province of P.orientalis.Among them the two provenances Yiyang and Luoyang,have better performance in stem growth,They should be the first choice for provenance application.(5) There were 8 traits significant variation found among families,except the trait of branch diameter/diameter.Using index selection,24 families for timber production and 21 families for ecological application were selected.(6) Variance components of individual tree for the investigated traits were more than 80%in general. Using the stem height and ground diameter as the main traits,49 individual trees of second generation were selected by comprehensive selection,The evaluation values of expected genetic gain of the height, ground diameter for individual tree selection were 16.3%and 20.6%respectively.(7) Significant variances of all the tested traits were revealed among clones.Based on combine selection index integrated both relative performances of clone and family from each plus tree,using the stem height and ground diameter as the main traits,30 better clones were selected,which combine selection index are exceed 8.60%of the average.The trends of provanance variation,the applications of selected meterials were discussed.The results of the research could be helpful for management and ulitilization of genetic meterials,which also could provide a reference on genetic variation and improvement in P.orientalis.