| Eucalyptus is an important tree species for the development of forestry in Guangxi,but there is a phenomenon of large-scale afforestation of single clones,which has affected the further development of the eucalyptus industry.To lay the foundation for the selection of eucalyptus clones suitable for afforestation in the San Men Jiang Forest Farm in Guangxi,and to spread the radiation to the entire central region of Guangxi.In this paper,15 five-year-old Eucalyptus spp clones were used as research objects to measure the growth of successive years.Combining the physical properties of wood anatomy and wood density,the genetic variation of multiple traits was determined,and the correlation between traits was carried out.Sexual analysis and research on comprehensive selection of multiple traits.The main findings are as follows:(1)The differences in DBH,tree height and plant volume of 15 eucalyptus clones reached extremely significant levels(p<0.01),and the coefficients of variation were 19.58%,14.92%and 43.96%,respectively,and showed CV plants.Volume>CV DBH>CV tree height,the genetic variability of single plant volume is high.Among them,the No.8 clone showed the best performance,and the DBH,tree height and single plant volume were the best.The average values reached 17.30cm,20.71m and 0.2312 m3 respectively,followed by the 14th DBH,tree height and single plant volume respectively reaching 15.53.Cm,20.69m and 0.1965 m3.The clones No.8 and No.14 can better exert the fast-growing potential in the Liuzhou area and can produce a large amount of wood in a short time.(2)The wood traits of 15 eucalyptus clones were not significantly different except for the density of the raw materials,and the differences of other traits between different clones reached extremely significant levels.The coefficient of variation is CV wall-to-cavity ratio(36.35%)>CV double,,wall thickness(20.73%)>CV cavity diameter(20.16%)>CV aspect ratio(17.00%)>CV basic density(14.37%)>CV width(13.50%)>CV cavity diameter ratio(12.19%)>CV length(12.00%)>CV green material density(8.31%),it can be seen that the wall cavity ratio is the best between the clones,and the raw material density is the weakest.Among the clones,the basic density of the clone No.11(0.609 g·cm-3)and the density of the green material(1.001 g·cm-3)were the highest,and the fiber length of the clone No.14(847.53 ?m)and the fiber width(18.18 ?m)and fiber cavity diameter(12.32?m)were the highest,fiber length ratio(55.41)and cavity diameter ratio(0.73)of No.2 clone were the highest,and fiber double wall thickness(6.60?m)of No.12 clone was the highest,No.7 The wall cavity ratio of the clones was the highest(1.01).(3)Based on growth traits and material traits,15 clones can be divided into four categories.The first type is characterized by growth characteristics such as DBH,tree height,and individual plant volume,fiber length and fiber width.Excellent,but the basic density is low;the second type is characterized by poor growth traits and wood traits;the third type is breast diameter,single plant volume and basic density are better,but fiber length and fiber width are shorter;fourth The characteristic of the class is that a certain indicator of the clones performs better,but other indicators perform relatively moderately or perform poorly.Through analysis,it was found that in the case of small coefficient of variation of wood,the growth traits and fiber characteristics of clones 14 and 8 were superior,and the performance of other clones was different,and there were short plates.(4)Principal component analysis of 3 growth traits and 3 wood traits of 15 clones,and comprehensive sorting and evaluation.The first score of comprehensive score was clone 14 with a comprehensive score of 2.19.It is a clone with high fiber length and fiber width,high tree height and single plant volume,and good growth traits and woody traits.The second rank is clone No.8,which is characterized by breast diameter and single plant volume.The highest among the 15 clones,the clonal with more prominent growth traits.In addition,the top five are the No.9,No.2 and No.6 clones.(5)Analysis of comprehensive growth shape,fiber characteristics,basic density and other traits.No.14 and No.8 clones can not only exert the potential of fast-growing and high-yield,but also have good fiber characteristics,which can be considered as the asexual development of San Men Jiang Forest Farm. |
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