Genetic Variation And Correltion Among Population Of Betula Platyphylla In Fiber Properties And Molecualr Marker

Five popuplations of Batula platyphylla which grow in natural stands of northeast part of China was taken as the materials, of which the wood fiber characteristics (fiber length, fiber width, ratio of fiber length to width) are analysed by variance analysis. ISSR and RAPD molecular markers are used to detect the genetic diversity of the five populations, and the correlation between the fiber characteristics and the DNA marker are firstly discussed.(1) There were no significant differences among natural birch populations in fiber length of the wood in 18-31 years old, great differences in fiber width and ratio of fiber length to width. The fiber properties in Maoershan population are the best and the worst is Wangqing, but all populations are suitable for paper making.(2) 100 samples from five populations with 20 samples per population are used to study genetic diversity in DNA level. Total of 85 loci (including 68 polymorphic loci ) are amplified by PCR using 11 ISSR primers and total of 78 loci (including 72 polymorphic loci ) are amplified using 11 RAPD primers. The percentage of polymorphic loci is 80% for ISSR and 92.31% for RAPD respectively. The result demonstrates that the percentage of polymorphic loci of Xinbin population from Liaoning is the hightest and the second is Maoershan and Wangqing, while the lowest is Tahe and Jinshantun. Shannon index is used to estimate the genetic variation of five populations, in which the genetic variations of Xinbin population is the highest, while the lowest is Tahe population from Daxinganlin and Jinshantun population from Xiaoxinganling. 10.82% of total genetic variation exists among the populations in ISSR marker, and 12.94% of total genetic variation occurs among the populations in RAPD marker by AMOVA analysis. The result shows that genetic variation of Betula platiphylla mainly occurs within the populations detected by two types of the marker.(3) Five populations are clustered into two groups according to fiber length and width of the wood, in which one group is the populations of Wangqing and Xinbin, and the other is populations of Maoershan, Jinshantun and Tahe. The cluster result of genetic diversity among five populations by ISSR marker is similar to that of the fiber properties, in which Xinbin and Wangqing are firstly clustered, and then clustered with Maoershan, Tahe and Jinshantun in turn. The result indicates that the populations from Maoershan and Wangqing are clustered, the populations from Tahe and Jinshantun are clustered, and finally with Xinbin.(4) By correlation analysis between the fiber properties and the DNA marker, it has 11/ markers to correlate with fiber lengthof the wood, 7 markers in positive and 4 markersin negative, of which OPA09-1 (0.283) and OPX15-2 (-0.286) shows the highest correlation coefficient. 8 markers have close relation to the fiber width, with 4 markers in positive and others in negative, of which OPN08-4 (0.368) and OPX15-5 (-0.257) are the highest in correlation coefficiet. There are 11 markers to correlate with ratio of length to width, of which 6 markers are in positive and 7 markers are in negative,significane level.