Study On The Adaptability And Genetic Differences Of 15 Hybrid Eucalyptus

In this paper,growth traits,wind damage,high yield and stability analysis,related genetic parameter estimation,genetic and environmental interaction and environmental interaction of 15 hybrid eucalyptus clones from different locations were studied.The main conclusions were as follows:(1)The two of the best growth performances were showed in a 3.5-year-old hybrid eucalyptus clones in Leizhou,followed the one in Dongmen.In contrast,the worst performance was showed in Wuzhou.The volume of the top two clones at Dongmen Y9 and Y15 were 29.83%and 15.17%higher than the comparative variety;while the top two clones in Wuzhou(Y9 and Y10)were32.22%and 9.16%higher than the comparative variety.Seven clones of Leizhou were superior to the control,the best clone of them was Y9 with a volume gain of 63.72%.(2)The growth performance of each clone was quite different.Y9 has showed the best growth performance among these three points.Whether it was tree height,breast diameter or volume,it was ranked in the forefront and had the potential for further genetic improving.Each clone has a large difference with the production ranking.In production and application,the preservation rate of the strain needs to be considered.(3)The clones Y9 and Y12 showed good adaptability to all of three sites.Clone Y15 was very suitable for planting in Leizhou and Zhangzhou,while Y8showed poor adaptation to these locations and was eliminated in the first round of selection.(4)According to the comprehensive analysis,the average values of DBH,tree height and volume were 10.6cm,15.4m and 0.0731m~3;the heritabilities were 0.4806,0.5857 and 0.4647;the genetic variation coefficients were 11.16%,13.26%and 27.37%;and the coefficient of variation of the type was 16.09%,17.32%,and 40.15%,respectively.These data indicated a medium genetic strength was existed to control this population,and the clonal growth was greatly affected by the environment.(5)There are some differences in the effects of wind damage on each clone.Y7,Y9,Y6 and Y15 were the best wind-resistant clones all over the three locations.The overall wind damage situation of each clone is the best in Leizhou,followed by Wuzhou and Dongmen.In the coastal typhoon area,Y7,Y9,Y6and Y15 clones were recommended,while the Y8,Y10,Y1,etc.were recommended to be planted in inland areas with less typhoon.(6)The environmental effects in Dongmen,Zhangzhou and Leizhou were0.46,-0.80 and 1.26 of the breast diameter,0.92,-1.94 and 1.01 of the tree height,-0.0023,-0.0200 and 0.0224 of the volume,respectively.The clonal genotypes and environmental interactions have different strengths.The intensity and direction of interactions vary from clones to locations,while the same clonal growth traits and environmental interactions are consistent in the same location.