Progeny Test on the Natural Populations and Selection of Excellent Populations fro/Fraxinus Mandshurica.

Fraxinus mandshurica is one of the ancient relict fora species originated from the Tertiary period, which is mainly produced in the eastern mountains in Northeast China. It has an important scientific value for studying the Tertiary flora and the Quaternary glacial climate. In order to make rational use of the natural genetic resources of F. mandshurica, and to increase the scientific and technological added value of improved varieties, this study used the method of positional observation of fixed standard fields to discuss the genetic variations of tree height and DBH of the natural populations and its open-pollinated progenies, systematically analyze the heritability and genetic gains in growth characters based on the analysis of progeny test, growth dynamic and heredity effects. The populations with good growth, strees resistance and adaptability were selected. The results showed that there were extremely significant difference in the growth characters among the natural populations, and the coefficients of variance for tree height (22. 99%) were smaHer, while the coefficients of variance for DBH (41.37%) were larger. On the other hand, there were extremely significant diferences in the growth characters among the open-poHinated progenies, and the interaction between these progenies and the blocks was significant. Meanwhile, the growth characters had strong heritability, high genetic gain, and remarkable heredity effects. The heritability of tree height and DBH were 0. 825 and 0. 781, and the genetic gains were 15.16% and 25. 85%, respectively. Therefore, Shanhetun (SHT) and Xinglong (XIL) were determined to be excellent natural populations both in the growth, resistance and adaptation with growth traits as the min evaluation index, which could be widely applied in the advanced generation improvement breeding. [ABSTRACT FROM AUTHOR]