Study On Genetic Diversity Of Provenances And Clones Of Larix Gmelinii(Rupr.) Rupr

In this study takes the clones of Larix gmelinii(Rwpr.)Rupr which are in collection areas of Heilongjiang province Qingshan forestry centre as the experiment material.,using ISSR and RAPD molecular markers and combining to phenotypic growth traits to analysis of genetic diversity in Larix gmelinii(Rupr.)Rupr.It can be a true reflection of genetic situation in original source of different species,but also to understand the interaction effects between growth traits and gene.Thus it can precisionly,truly and objectively assessment the geographical provenance The conclusion had a certain instruction:action for the afforestation,introduction,seed distribution,preservation of genetic resources and so on,which will establish a basis for further studying relative relations of among provenances and identify clones,as well as provide a theoretical basis for constructing the genetic maps of Larix gmelinii.The main findings are as follows:1 The orthogonal design was used to optimize RAPD amplification system of Larix gmelinii(Rupr.)Rupr.Through the deep analyze,a suitable RAPD-PCR reaction system was established,namely 20μL reaction system containing 1.0U Taq DNA polymerase,2.5 mmol·L^-1 Mg²⁺,0.25 mmol·L^-1 dNTP,0.5μmol·L^-1 primer,1×PCR buffer,90 ng DNA template.The temperature profile used forRAPD-PCR was 94℃for 3 min;followed by 40 cycles of 94℃for 1 min;38.5℃for 1 min;and 72℃for1.5min;and was terminated with a 7 min DNA extension step at 72℃.2 There was larger variation in the growth traits of the provenance and clones of Larix gmelinii(Rupr.)Rupr,and there was a significant difference.At the level of Provenance:tree height,diameter at breast height and volume coefficients of variation were 12.69～17.38%, 18.03～28.25%,41.67～55.27%;the greater genetic variation of Provenance was Youhao,whose tree height,diameter at breast height and volume coefficients of variation were 14.73%,28.25%,55.27%,the smaller genetic variation of provenance was Kudu'er,whose tree height, diameter at breast height and volume coefficients of variation were 12.69%,18.03%,41.67%;tree height,diameter at breast height and volume coefficients of variation at the Clonal level were 1.25～26.69%,3.74～59.56%,10.21～94.25%,and the larger genetic variation of clones were 1555,1007,1031,1570 and 1439,whose tree height,diameter at breast height and volume coefficients of variation were 25.39%,59.56%,94.25%; 19.64%,38.95%,89.27%;24.41%,35.38%,74.00%;25.27%,46.43%,68.90%; 23.84%,36.70%,65.43%respectively。3 ISSR and RAPD markers has proved the provenance of Larix gmelinii(Rupr.)Rupr has a wealth of genetic diversity from the molecular level,and the two markers both indicate that the genetic variation mainly exists within populations,smaller variation exists among populations.21 ISSR primers detected a total of 171 sites,in which the percentage of polymorphic loci was 169,and the percentage of polymorphic loci as high as 98.83%.23 RAPD primers detected a total of 189 sites,in which the percentage of polymorphic loci was 184 loci,the percentage of polymorphic loci as high as 97.35%.At the same time,two markers both indicate that the genetic variation mainly exists within populations,smaller variation exists among populations.4 There was a significant difference in the growth traits of the provenance and clones of Larix gmelinii(Rupr.)Rupr.The better provenance was Youhao and Kudu'er,the average tree height,diameter at breast height and volume were 12.34m,18.73cm,0.1818m³ and 12.16m,17.92cm,0.1753m³ respectively.It exceeded the average than 7.49%,6.56%, 16.67%and 5.92%,1.99%,12.18%,exceeding the worst provenance Aershan 15.33%,13.79%, 41.15%and 13.64%,8.87%,36.10%respectively.The better clones of Youhao provenance were 1566,1556,1666,the the average tree height,diameter at breast height and volume were 13.75m,20.93cm,0.251m³;13.22m,21.14cm,0.248m³;13.50m,20.32cm,0.242m³ respectively。The clones of A'ersan provenance were 1036,1037,1007,the average tree height,diameter at breast height and volume were 8.80m,14.08cm,0.081m³;10.00m,14.45cm,0.092m³;9.37m,14.68cm,0.103m³ respectively.5 The height,breast and diameter of Larix gmelinii(Rupr.)Rupr with latitude,elevation was negatively correlated with longitude was positively correlated;the longitude and height of the correlation was significant;two markers showed that the percentage of polymorphic loci and latitude,elevation was negatively correlated with longitude was a positive correlation;and with the July temperature and annual precipitation was significantly positively correlated,so it illustrated that hydrothermal factors are the major climatic factors for the impact of the percentage of polymorphic loci.6 The analysis of genetic identity(I:0.9219～0.9563 for ISSR;0.9137～0.9601 for RAPD)and genetic distance(D:0.0447～0.0814 for ISSR;0.0408⁰.0903 for RAPD)showed high genetic identity among seven populations and a certain genetic differentiation.7 By cluster analysis on the genetic distance ISSR Clustering Results:the genetic distance 0.065,seven provenances were divided four groups,of which the first group included A'ersan, Nenjiangzhongyang and Kudu'er provenances;the second was,Mo'erdaoga,Ganheyuanjiang, the third was Wuyiling and the last group was Youhao provenances.RAPD clustering results: the genetic distance in 0.08,seven provenances were divided into two groups,A'ersan,Kudu'er, Ganheyuanjiang,Mo'erdaoga for the first group;Nenjiangzhongyang,Youhao,Wuyiling for the second group.The clustering results of the two types of molecular markers have been the result of similar genetic clustering,but there are some differences.The genetic distance in 0.07, seven provenances were also divided into three groups,A'ersan for the first group,Kudu'er, Ganheyuanjiang,Mo'erdaoga for the second group;Youhao,Wuyiling for the third group.