A Study On The Comprehensive Selection And Genetic Variation Of Multi-character In Pinus Elliottii Family

Pinus elliottii originated from United States,and is an important timber and lipid-producing tree species.It was introduced in China from the 1930's,and now has became the major afforestation and tapping tree species in South China,for its high quality timber and resin played an important role in the industry.Genetic improvement for P.elliottii in China was focused on a single trait(material or produce fat mass)in the past years.There is less study on the breeding and seedling selection for multiple integrated characters.113 families from Fenshushan forest farm in Jingdezhen and Baiyunshan forest farm in Ji'an were studied.Genetic variation and integrated selection for multiple traits were analyzed.Meanwhile,10 families of P.elliottii,which were newly introduced from United States,were conducted a research on annual seedling growth traits for seedling selection.The aims of this study were to select the optimal families with high-resin yield and large-volume of P.elliottii in those two plantations and the best multiple-traits selecting breeding method for P.elliottii.The results were as follows:(1)The characteristics of the same P.elliottii family have different performance in different sites,as significant differences were found for all the traits of the families in both sites,except for straightness in Fengshushan and canopy shape in Baiyunshan.In Jingdezhen,the variation coefficient for volume was 0.59 and for resin yield was 0.22,as other traits ranged from 0.18 to 0.46.In Baiyunshan,the variation coefficient for volume was 0.41 and for resin yield was 0.24,as other traits ranged from 0.16 to 0.36.(2)In Jingdezhen,there were positive correlations among all traits,except for the correlation between crown width and canopy shape.In Baiyunshan,the correlations between crown width and canopy shape,height under branch and crown surface area were negative,as the correlations among other traits were positive.The correlations between resin-yield,volume and other traits were positive in both two sites,and the correlation coefficients ranged from 0.504 to 0.867 in Jingdezhen,from 0.046 to 0.915 in Baiyunshan.There were high correlations between tree height,diameter at breast height and resin yield,volume in both sites,and thus,ideal results could be taken through multiple-trait selection.(3)23 families were chosen both in Jingdezhen and Baiyunshan through multiple-trait selection,and the selection rate was 20%.5 same families were found in both sites,which accounting for 21.7% in all chosen families.As the selection results were different in different sites,which indicated that genotypes need to be evaluated in the environments where they are deployed.Selection differential for resin-yield and volume were15.18% and46.15% in Jingdezhen,as in Bainyunshan,the resin-yield was16.8% and volume was29.67%.(4)Significant differences were found for all seeding traits among 10 families,and thecoefficients of variation ranged from 8.25% to 34.41%.The relationship among the traits were complex,ranged from 0.068 to 0.886,and growth traits had strong correlations with other traits,indicated that integrated selection can obtain ideal results.No.7,no.5,no.2 and no.8 four families were chosen by multi-factors integrate appraise methods,and selection differential of the traits ranged from 2.07% to 6.32%.(5)The multi-factors integrate appraise method was ideal selection method for high resin-yield and large volume of P.elliottii families.