| The systematic study of provenance in Larix gmelinii (Rupr.) Rupr, come of 1980s, up to now, has obtained great results. This study was conducted by using population genetics and quantity genetics principles at four provenances trials of Larix gmelinii (Rupr.) Rupr. The growth characteristics, wood properties, and ISSR diversity among the provenances firstly were detected, the genetic diversity of Larix gmelini were studied, and selection and division of provenance of Larix gmelini were also discussed. The main results are as follows:There are significant differences in growth characteristics among the filial generation of different provenances of Larix gmelini, and these variations showed a dual continuous geographic variation model on level and uprightness, of which longitude and altitude were main effect factors, and latitude was; assisted factor. There is strong correlation for the growth characteristics between the early and the late stages. By cluster analysis on growth characteristics and dominant geographic variation factors, Larix gmelinii (Rupr.) Rupr have been divided into three provenance groups, that is the Daxing'an Mountains provenance group; the intermediate provenance group of Daxing'an Mountains and Xiaoxing'an Mountains; the provenance group in the southeast part of Xiaoxing'an Mountains. Youhao and Wuyiling were selected as superior provenances primarily by LSD multiple comparing analysis. By the analysis of genetic stability of provenance, the result showed that Youhao and Wuyiling provenances were the provenances with high yield and genetic stability. By the estimation for heritability, the result showed that the growth characteristics of Larix gmelinii (Rupr.) Rupr had higher heritability, and this tiee species had better improved potential in the growth characteristics.The principal wood characteristics of the 17-year-old provenance of Larix gmelini were measured. The results showed that there exists significant variation among the wood characteristics. There are correlations between growth and wood characteristics, as well as among wood characteristics in a certain extent, which provided a theoretical basis for comprehensive selection of this species as pulpwood. Wuyiling, Youhao, Tahe and Hebei provenances were decided as good pulpwood provenances primarily by comprehensive valuation.ISSR marker about the provenances of Larix gmelinii (Rupr.) Rupr has been conducted. The results showed that there were higher genetic variations among the provenances. The changes in percentage of polymorphic loci among 17 provenances were in range of 25.26%-44.21%. Genetic diversities for the provenances of Larix gmelinii (Rupr.) Rupr. were estimated by Shannon's Information Index and Nei's Gene Diversity Index. The results had almost the same varying trends for these indexes among provenances. The variation degree of Ganhe provenance was the lowest (I * = 0.1310), and that of Hebei was the highest (I * = 0.2118). There existed higher genetic identities among the provenances, varying from 0.8225to 0.9546. On the base of cluster analysis of genetic distance, between the genetic distance of 0.8 and 1.2, seventeen provenances were divided four groups, of which the first group included A'ersan and Chao'er provenances, the second was Kudu'er, Genhe, Mangui, Mo'erdaoga, Ganhe, Xinlin, Zhanhe, Shibazhan and Tahe provenances, the third was Zhongyangzhan, Sanzhan and Huapiyao provenances, and the last group contained Wuyiling, Youhao and Hebei provenances. The relationship between the genetic distance and the geographical distance among provenances were also studied by correlation analysis. The results showed that there was a significantly positive correlation between the genetic distance and the geographical distance among provenances (r=0.53). By cluster analysis on the genetic distance and the geographical distance among provenances, four groups were classified in three ranges, which are: (1) A'ershan, Chao'er. (2) Kudu'er, Genhe, Mangui, Mo'erdaoga, Shibazhan, Tahe, Xinlin, Ganhe, Zhongyangzhan, Sanzhan and Huapiyhao. (3) Youhao, Wuyiling and Hebei. (4) Zhanhe.Based on growth characteristics, wood properties, some information of genetic diversity and dominant geographic factors at DNA level, the seventeen provenances were divided into two groups by cluster analysis, that is: (1) A'ershan, Chao'er, Kudu'er, Genhe, Mo'erdaoga, Mangui, Shibazhan, Tahe, Xinlin, Ganhe, Huapiyao, Zhongyangzhan, and Sanzhan. (2) Wuyiling, Youhao, and Hebei.In this study, genetic diversity of different geographic provenances of Larix gmelini was entirely studied according to the growth characteristics, wood properties, and DNA maker. 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 constructing the genetic maps of Larix gmelini, and provide a theoretical basis for the early selection of growth characteristics and cross breeding.
|
PDF Full Text Request