| Casuarinais one of the most successful tree species introduced to the coastal areas of Southern China,which isfast-growing,wind-broken,sand-fixation and high tolerances on degraded land.It is commonly used in agroforestry systems,wood forests,multipule purposes of forests,and in coastal protection and rehabilitation.During the past years,considerable progress hasbeen made: breeding research of casuarina,and the introduction of germplasm resources,but which has been lacked research on wood breeding.In order to screen out superior provenance and individual trees for further cross-breeding,inter-provenances genetic variations in terms of wind-resistance,growth,form traits and wood properties were released,evluated and discussed in this context due to a trial of C.equisetifolia,C.glauca,C.cunninghamianaand Casuarinajunghuhniana.The results about this research as followings:(1)There were significant differences among provenances in the survival of the four species at 2,5 and 7 years old after planting,except for the survival of C.cunninghamiana was not significant among provenances at 2 years old after planting.The highest survival of provenance is C.equisetifolia,and C.junghuhniana is the lowest survival of provenance at 2 years old after planting.C.glaucais in the highest survival and C.equisetifolia is in the lowest survival at 5 years old after planting.After typhoon was over,the provenance of Dongfang,Ledong,Huianfrom C.equisetifolia at7 years old after planting were generally good,with survival exceeding 80%;The provenance 13143,13139,13146 and 16363 from C.glauca at7 years old after planting were generally good,with survival exceeding 85%,The provenance 15004,15574 and CK from C.cunninghamiana at7 years old after planting were generally good,with survival exceeding 75%;The provenance 18844,18846,18849 and 19489 from C.junghuhniana at7 years old after planting were generally good,with survival exceeding 70%.The result indicate that significant differences in survival among casuarina species,and the ability of order C.equisetifolia,C.junghuhniana,C.glauca,C.cunninghamiana.The provenance heritability and thecoefficients of genetic variations for wind-resistance(RES)of four casuarina species were ranging from 0 ~ 0.108 and 0.05% ~ 4.17%.Comparing to other species,C.equisetifolia were highest and C.glauca were lowest at 2,5 and 7 years old after planting.When the selection rate was 20%,the wind-resistance of C.cunninghamiana was the highest,with the genetic gains 2.33%,the second was C.equisetifolia(0.75%),the genetic gains for wind-resistance of C.glauca and C.junghuhniana were near zero.(2)The results showed that significant differences(P<0.05 or P<0.01)in tree height,DBH,volumes of the four species were detected among provenances at 2,5 and 7 years after planting.The mean for the growth traits which from 5 provenances of C.equisetifolia(Yangxi,Dianbai,Ledong,Dongshan and 18244),5 provenances of C.glauca(13139,13144,15218,15939 and 16361),2 provenances of C.cunninghamiana(14005 and 20477)and 3 provenances of C.junghuhniana(19489,19490 and 17877)were higher than the their relative overall mean.The provenance heritability and thecoefficients of genetic variations for the growth traits of C.glaucawere obviously lower than other 3 casuarina species at 2,5 and 7 years old after planting.The provenance heritability and thecoefficients of genetic variations for volume of C.cunninghamianaat 7 years old after planting were the highest,0.403 and 68.07%.Except for C.glauca,the coefficients of genetic variations for volume of other 3 casuarina species were higher than thecoefficients of genetic variations for height and DBH.When the selection rate was 20%,the genetic gains for the growth traits of C.glauca were less than 0.21% at 7 years old after planting,and the genetic gains for height,DBH and volume of 3 casuarina species at 7 years old after planting were ranging from 1.28% to 6.59%,from 0.92% to 12.63% and from 1.93% to 39.86%,respectively.C.equisetifolia has the highest tree height,followed by C.junghuhniana and C.glauca,the lowest was C.cunninghamiana at 7 years old after planting.The maximum DBH and volume was C.equisetifolia and the minimum DBH and volume was C.glauca.(3)The significant differences(P<0.05)were detected among provenances in thickness of permanent branches(TPB),angle of permanent branches(APB),length of permanent branches(LPB),length of deciduous branchlets(LDP),axis persistence(AP)and stem straightness(SFS)of C.equisetifolia,and the provenance heritability and thecoefficients of genetic variations for these trait were ranging from 0.004 to 0.242 and 0.48% to 5.79%.The genetic gains for these form traits of C.equisetifolia were ranging from 0.01% to 3.72% when the selection rate was 20%.There were significant differences(P<0.05)were detected among provenances in LDB and SFS of C.glauca,and the provenance heritability and thecoefficients of genetic variations for these trait were ranging from 0.042 to 0.283 and 2.72% to 5.69%.The genetic gains for these form traits of C.glauca were ranging from 0.68% to 5.13% when the selection rate was 20%,.The significant differences(P<0.05)were detected among provenances in density of permanent branches(DPB),TPB,APB and SFS of C.cunninghamiana,and the provenance heritability and thecoefficients of genetic variations for these trait were ranging from 0.021 to 0.247 and 2.01% to 3.49%.The genetic gains for these form traits of C.cunninghamiana were ranging from 0.25% to 2.03% when the selection rate was 20%.The significant differences(P<0.05)were detected among provenances in TPB,APB,LDB,AP and SFS of C.junghuhniana,and the provenance heritability and thecoefficients of genetic variations for these trait were ranging from 0.007 to 0.088 and 0.93% to 5.56%.The genetic gains for these form traits of C.junghuhniana were ranging from 0.07% to 2.45% when the selection rate was 20%.(4)There were significant differences among provenance of 4 Casuarina species in wood density(BD),fiber length(FL)and fiber length-width ratio(LTW),but fiber width(FW)was only significant in C.equisetifolia at 7 years old after planting.The means of BD which from 5 provenances of C.equisetifolia(Maoming,Dongfang,18015,18244 and 18122)and 1 provenances of C.junghuhniana(19490)were over 0.70 g?cm-3 and the means of BDwhich from4 provenances of C.glauca(15932,15938,15941 and 19242)and 1 provenance of C.cunninghamiana(14005)were more than 0.60 g?cm-3;Fiber lengths which from 1 provenance of C.equisetifolia(18298),1 provenance of C.glauca(CK),2 provenances of C.cunninghamiana(14005 and 20477)and 4 provenances of C.junghuhniana(18849,17877,19239 and 17877)were over 0.85 mm.The provenance heritability for wood density,fiber length and fiber length-width ratio of 4 casuarina species were ranging from 0.155 to 0.519,from 0.143 to 0.504,and from 0.094 to 0.489,respectively.The scope of its genetic variation coefficient were ranging from 2.82% to 10.16%,from 4.67% to 10.64% and from 3.90% to 10.64%,respectively.The provenance heritability and genetic variation coefficients of C.cunninghamiana were maximum.The provenance genetic gain for wood density,fiber length and fiber length-width ratio of C.equisetifolia and C.junghuhniana were less than 2% when the selected ratio was 20%,only near 5% of the genetic gain for wood density of C.junghuhniana,but it was all over 5% about C.cunninghamiana.(5)Correlationships of inter-growth traits of four species showed that very significantly positive genetic and phenotypic correlations(P< 0.01)among the tree heights,DBH and volumes at 2,5 and 7 years after planting.The relationship of inter-growth traits can be used as indicator for early selection.Correlationships among RES and form trait,wood properties showed as follows: the correlations of RES with all form trait and wood properties of C.glauca were not significant(P<0.01);the correlations of RES with TPB,AP,BD of C.equisetifolia were significant positive genetic correlationships(P< 0.01),RES with APB of C.equisetifolia were significant negative genetic correlationships(P< 0.01).This indexes,TPB,AP,BD and APB,should be focused when selecting best provenance with wind-resistance of C.equisetifolia.The correlations of RES with SFS,BD,FL of C.cunninghamiana were significant positive genetic and phenotypic correlationships(P< 0.01 or P< 0.05).The indexes SFS,BD and FL,should be focused when selecting best provenance with wind-resistance of C.cunninghamiana.The correlations of RES with SFS,FL of C.junghuhniana were significant positive genetic and phenotypic correlationships(P< 0.01 or P< 0.05).The indexes,SFS and FL,should be focused when selecting best provenance with wind-resistance of C.junghuhniana.Correlationsamong growth traits and form traits,wood properties showed as follows: the correlations of growth traits with FL were significant positive genetic correlationships(P< 0.01),with LTW were not significant correlationship(P?0.05).So growth traits and LTW can be alone used as index to select best wood property on C.equisetifolia and C.cunninghamiana.When long fiber as select target,fast-growing provenance should be considered.(6)Comprehensive index selection is a great measure for union provenance selection on growth traits,form traits and wood properties.Comprehensive index equation which based on using H(X1),DBH(X2),RES(X3),TPB(X4),SFS(X5),BD(X6),FL(X7),FW(X8)and LTW(X9),in sum of 9 characteristics.The provenances were selected by the comprehensive index equation emphasized on the equal emphasis weights,the result showed that the excellentprovenances of C.equisetifolia were Dongshan,Lingao,Ledongand 18127,C.glauca 13141,13987,13142 and 15939,C.cunninghamiana 20477 and 15574,and C.junghuhniana 17877,19490,19489 and 18849.The provenances were selected by the comprehensive index equation emphasized on growth traits,the result showed that the excellent provenances of C.equisetifolia were Dongshan,Lingao,Ledongand 18127,C.glauca 13141,13987,13142 and 15939,C.cunninghamiana 14005 and 20477,and C.junghuhniana 19490,19489,17877 and 18950.The provenances were selected by the comprehensive index equation emphasized on wood properties,the result showed that the excellent provenances were C.equisetifolia18269,Dongshan,Lingaoand Huian,C.glauca 13141,13987,13142 and 15939,C.cunninghamiana 20477 and 13519,and C.junghuhniana 17877,19490,19489 and 18849. |
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