Abstract:

Measurement and analysis of wood basic density (BD) and fiber length (FL) of 282 wood cores,which sampled from seven year-old provenance plantations of two species of Liriodendron,Chinese Tuliptree (Liriodendron chinense (Hemsl.) Sarg) and Tuliptree (Liriodendron tulipifera L.),in Jiangxi,Fujian and Hubei province respectively,were conducted.The samples were divided into groups and the frequency of each group was counted and normally imitated.The result showed that the wood core samples were abided by the normal distribution at two characteristics.The precision analysis showed that the 6 trees sampled from each provenance were of higher precision (P>90%),and 1～2 trees sampled from each provenance were of lower precision (P<80%) which could not be taken in the variance analysis but only used for calculating the average of provenance. T-test proved that there were not significant differences in the BD and FL between Chinese Tuliptree and Tuliptree. The BD and FL average of Liriodendron,including Chinese Tuliptree and Tuliptree,was 0.397g/cm³ and 1.603mm,respectively.Liriodendron was the species with long-fiber and middle-low-density according to wood classification criterion by Cheng Junqing. The variance analysis indicated that the differeneces of BD and FL Among provenances in Chinese Tuliptree were both significant at 0.05 level,and those of Tuliptree were not significant.The difference among sites and the mutual actions of G (provenances) and E(sites) were both not significant.BD's hereditability in broad sense was 0.654 and Fl's was 0.29,which indicated that BD was strongly controlled by genetic factors,while FL was weakly controlled by genetic factors.Characteristic coorrelation between BD and FL was very weak (r=0.157) and relationship between BD,FL and growth traits was also very weak,which impressed the independent selection of each characteristics could be conducted.Age-age genetic correlations of BD and FL were analyzed and all age-age correlation coefficients only except that one between 1 a and 5 a were significantly at 0.05 level. At the base of the analysis above,the provenance selection of wood character combined two species in Liriodendron was conducted according to different selection criteria so that the selection results could meet the different breeding demands.The results showed the most excellent provenances of WD were Lushan in Jiangxi Province and Sangzhi in Hunan Province,and the most excellent provenances of FL were Liuyang in Hunan Province and Ganwuyi in Jiangxi Province.Although the hybrid clones (CK) were beyond the average,it did not reach at the top provenance.The tuliptree provenances were not selected as the excellent provenance because they were slightly varied around the average line.

Key words: Liriodendron, Basic density, Fiber length, Genetic variation, Provenance selection of wood character