Analysis Of Genetic Diversity In Linzhi Spruce In Tibet

Picea likiangensis var.linzhiensis is one of the most important indigenous tree species used for the production of pulp wood and timber,and it distributes universally in western-southern Tibet.Most of natural stands were felled in history,some gene resources had been lost.In order to conserve the remainders scientifically and utilize rationally,it was necessary to make clear population differentiation within the species.This study could provide the theoretical references and basic data for the gene resources conservation and genetic improvement in this species.Based on field investigations and analysis of the natural distribution of linzhi spruce in Tibet China,6-30 trees from each of 13 populations in Tibet were selected to study genetic diversity in linzhi spruce in Tibet.The genetic diversity of linzhi spruce were evaluated and compared at three levels of phenotype,element concentration and isozyme by the same experimental materials.The results were obtained as follows:(1)The result showed that it was conducted to determine phenotypic diversity of natural populations and found out the relation between phenotypic variation of natural populations and different distribution areas in linzhi spruce.Based on field investigations and analysis of the natural distribution of linzhi spruce in Tibet China,three cone characters,three needle traits and three seed wing characters in 6-30 trees from each of 13 populations in Tibet were selected and investigated.Morphological diversity among /within populations were discussed on the basis of 9 phenotypic traits analysis.The method of novon analysis,multi-comparison,related analysis and hierarchical cluster analysis were used for analysis of experimental results,the results showed that there was significantly difference in genetic variation among populations and among individuals within populations.Three phenotypic traits about needle,cone,and seed wing in different individuals within populations the CV were 20.40%,15.41%,and 10.68%respectively;the R' were 60.06%,55.61%,and 54.90%respectively;the L_s were 44.52%,33.35%,and 36.35%respectively.The traits diversity of needle Was higher than that of other traits.The Vst of needle,cone,and seed wing ranged from 12.25%to 55.21 %.The mean phenotypic differentiation coefficient Vst among populations Was 30.06%, which was greatly smaller than that within populations(69.94%).The pst of needle,cone,and seed wing ranged from 6.20%to 20.70%.The mean phenotypic multiplicity analysis pst among populations was 13.75%,which was greatly smaller than that within populations(86.25%).The phenotypic diversity of natural populations within linzhi spruce species is afected mainly by latitude and Longitude in spatial distribution.The 13 populations of linzhi spruce investigated could be divided into three groups according to the UPGMA cluster analysis.(2)We examined 11 kinds of element concentration of the needle in linzhi spruce.The needle samples were collected from 13 linzhi spruce populations in Tibet,china,and we chose 6 healthy trees from per population.ICP-AES was used to examine concentrations of P,K,Ca,Mg,Cu, Fe,Zn,Mn in needle samples of linzhi spruce.Instrument of element analysis(EA)that was made in Germany was used to examine concentrations of C,H,N in needle samples of linzhi spruce. Needles samples would be dried and skived in order to turn to dust before we examined them.Then we analyzed for geographic variation by the method of variance analysis,calculating variation coefficients and related analysis.The results showed that concentrations of C,H,N,Ca,Mg,Cu and Mn varied significantly among 13 populations.But concentrations of P,K,Fe and Zn varied insignificantly among 13 populations.Extent of microelement variation is greatly abroad among/of 13 populations.Extent of microelement variation exceeds extent of micro-element variation.We analyzed correlations for mean value and variation coefficients of element concentration between location respectively.We found that correlation of P between latitude was significant,but other correlations were all insignificant.So variable model of element concentration of the needle in linzhi spruce is random.(3)The genetic diversity of twelve populations of linzhi spruce in Tibet of China was assessed using allozyme analysis by horizontal sliceable starch gel electrophoresis.We obtained 20 clear locus(27 alleles)Of 10 enzyme systems.Analysis of 20 clear locus showed:In species level of natural populations of linzhi spruce,Means of alleles(Na)was 1.900;Observed number of alleles(Ne)was 1.6093;Effective number of alleles(Ne)was 1.6093;Observed heterozygosity(Ho)was 0.2291; Expected heterozygosity(He)was 0.2648;Shannon's information index(Ⅰ)was 0.4168.Means of 12 populations was lower than species level.By researching genetic differentiation of 12 population structure,we found that the coefficient of gene differentiation(Gst)was 7.4065%and there was 92.5935%differentiation within populations;Differentiation coefficient(Fst)was 8.4247%and the other 91.5357%was within populations'.Gene flow(Nm=7.0119＞4)could replace of genetic random variation to stopping differentiation among populations.By studying genetic distance between populations,we obtained that changing range of genetic identity(1)was 0.9450-0.9979 and means was 0.9801;changing range of genetic distance(D)was 0.0021-0.0540 and means was 0.0191.(4)By phenotypic traits,element concentration and allozyme marker coupling studying,we found it was abundance of linzhi spruce diversity among populations and within ppulations.By correlation studying to between diversity and geographic zoology factors,we obtained that linzhi spruce diversity increasingly became great from west area to east area in tibet.So it was preliminary to cinfirm that the populations in east of tibet were adaptable to be prioritized for conservation. Moreover,collect of individual couldn't neglect.