Early Selection Of Provenances And Families And Genetic Diversity In C.parthenoxylon(jack.)meissn

Cinnamomum parthenoxylon(Jack.)Meissn is Lauraceae Cinnamomum Multi-purpose native evergreen broad-leaved species,located in north latitude range from10 to 30 degrees,mainly distributed Guangdong,Guangxi,Yunnan,Fujian,Hunan,Jiangxi,Guizhou,Sichuan and other Province in China.With a well-developed canopy,beautiful leaf color,strong resistance and fast growth,it has broad prospects for development.At present,the research on this tree species mainly includes breeding techniques,early growth performance of artificial forests,biomass estimation models,afforestation and landscaping,and chemical components contained in essential oils of plants,While research on early selection of provenances,families and genetic diversity in C.parthenoxylon(Jack.)Meissn has not been reported.In this paper,10 provenances and 144 families from Yunnan,Guangxi,Guangdong and Hunan were selected as the research object,and investigated the growth difference of provenances/families experimental forest in multiple locations and provenances geographical variation,and select excellent provenances and fine families.At the same time,the SSR molecular markers were used to analyse the genetic diversity and genetic structure of the populations of C.parthenoxylon(Jack.)Meissn.The results would provide a theoretical basis for the conservation and development of high quality provenances,development of breeding strategies and sustainable genetic improvement.The main results are as follows:1.There were significant differences in the growth performance of 2-year-old C.parthenoxylon(Jack.)Meissn at test site I(Guangdong Tianjingshan Forest Farm),test site II(Heshan Zhaji town),and test site III(Meizhou Jingnan town).Average height and diameter growth ranked as test site ?(3.19 m,7.18cm)> test site ?(1.8m,3.52cm)> test site ?(0.8m,1.12cm).Different provenances and family tree height and diameter growth have very significant differences,and the growth variation among families is much higher than that among provenances,and the variation coefficient of the ground diameter is higherthan tree height.It shows that provenances and family selection are effective,and the selection potential of families is higher than that of provenances,and the selection potential of the ground diameter is higher than that of tree height.Through provenance/family testing,early elite provenances and families were selected for each of the three experimental sites.The Guangdong Ruyang(RY)provenance had better growth performance of the three pilot sites in Guangdong Province,and Menghai(MH)Provenance had the worst performance.2.The genetic gains of superior families is greater than superior provenances.The analysis of multi-site combined variance of 35 families shared by the three experimental sites showed that family by site interaction was extremely significant,and Eberhart &Russell Joint Regression Analysis for stability evaluation of the ground diameter of 35 Families and They were divided into four types: Unstable Rapid Growth,Unstable Slow Growth,stable Slow Growth,Stable Slow Growth,Stable Rapid Growth,respectively.3.The great majorities of correlation coefficients of provenances` tree heights,ground diameters,and its geography and climatic factors of different provenances did not reach significant levels.There is a very significant positive correlation between ground diameter and longitude of test site ?,a significant positive correlation with frost-free period,and a very significant negative correlation with average annual temperature and extremely low temperature.On the whole,Longitude variation explained the main trend in the ground diameter,and provenance is from west to east,and its ground diameter grows faster.4.Simple sequence repeats(SSRs)were used to investigate genetic diversity of 206 C.parthenoxylon(Jack.)Meissn samples from10 provenances using 11 primer pairs,The results showed that: Shannon information index(I),expected heterozygosity(He)at the level of species and populations were 1.55,0.674 and 1.18,0.60,respectively.It shows that C.parthenoxylon(Jack.)Meissn has a high level of genetic diversity,and the genetic diversity at the species level is higher than the population level.According to the average of He,the genetic diversity of various provenances was YSA> YSO> RY> GC> XA> LC>MH> CS> GY> LY.An ANOVA indicated total variation within provenances of 98%.In the current study,The natural population of C.parthenoxylon(Jack.)Meissn is small and inbreeding(F=0.49),and there was heterozygous deletion(Ho < He),weak genetic differentiation in the population(Fst = 0.108)and relatively high level of gene flowbetween provenances(Nm = 2.067).5.In STRUCTURE analysis,the 10 provenances were divided into two groups.RY is grouped separately,YSO),YSA,GC,XA,GY,LY,CS,MH are grouped into the other group.When the genetic distance D = 0.22,the Nei`s genetic distance clustering is consistent with the Structure genetic structure grouping.The Mantel correlation analysis between Nei's genetic distance and geographic distance shows that there is no geographical isolation pattern between the provenances of C.parthenoxylon(Jack.)Meissn.