Progeny Test on the Natural Populations and Selection of Excellent Populations from Fraxinus Mandshurica

Fraxinus mandshurica is one of the ancient relict flora 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, stress 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 smaller, while the coefficients of variance for DBH （41.37%） were larger. On the other hand, there were extremely significant differences in the growth characters among the open-pollinated 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 main evaluation index, which could be widely applied in the advanced generation improvement breeding.

Comparison, Selection and Progeny Test of Natural Populations of White Birch (Betula platyphylla Suk.) in Northern China

[Objectives]This study was conducted to rationally and effectively use natural genetic resources of white birch(Betula platyphylla Suk.),and improve the scientific and technological content of improved varieties.[Methods]With the progeny of the white birch populations naturally distributed in northern China as objects,based on genetic effect analysis and comprehensive evaluation,the genetic variation,heritability and genetic gain of the growth characters in the progeny forest were systematically analyzed,by which populations or individuals with good growth vigor and strong stress resistance and adaptability were finally selected.[Results]There were extremely significant differences in the growth characters between the natural populations of white birch in northern China.The variation was the smallest in tree height,followed by crown width,and largest in DBH,and the average coefficients of variation were 20.56%,32.25%and 33.00%,respectively.The differences in characters between progeny of the same population were also extremely significant.The growth characters of white birch were more controlled by genes,and the genetic gains were larger.The heritability of tree height,DBH and crown width was 0.971,0.816 and 0.576,respectively,and the genetic gains were 15.97%,21.54%and 13.87%,respectively.[Conclusions]With the growth characters as the main evaluation indexes,taking various influencing factors into account,the Shanxi[SX]population,Hebei[HB]population and Liaoning[LN]population were selected to be excellent populations,and LN305,SX516 and HB403 were excellent individuals,which are advised to be widely used in multi-generation genetic improvement breeding.

Genetic Effect Analysis of Quantitative Traits and Selection of Excellent Population in Betula platyphylla var.mandshurica Hara.

Betula platyphylla var. mandshurica Hara. is a geographical variant of B. platyphylla Suk. with strong adaptability, rapid growth, fine texture, wide application and other notable features. In order to investigate the genetic effects of quantitative traits and specificity of different populations of B. platyphylla var. mandshurica Hara. , by permanent sample plot continuous measurement and temporary sample plot random investigation, B. platyphyUa var. mandshurica Hara. populations naturally distributed in Zhangguangcailing Mountain and Laoye Mountain in Changbai Mountain Range were used as experimental materials to systemati- cally analyze the growth dynamic patterns of plant height and diameter at breast height, and comprehensively evaluate the genetic effects of various quantitative traits. According to the results, site conditions suitable for B. platyphylla var. mandshurica Hara. were classified into four grades according to the absolute value of partial correlation coefficients. The growth process of B. platyphylla var. mandshurica Hara. stand generally underwent rapid growth period, steady growth period and slow growth period. The growth of B. platyphylla var. mandshurica Hara. stand at different growth stages varied signitlcantly among various site grades, but the growth trend was basieally the same. Plant height, diameter at breast height, east-west crown diameter and north-south crown diameter varied significantly among B. platyphylla vat. mandshurica Hara. populations, exhibiting extremely significant differences. The heritability of four growth traits was 0. 558,0. 762, 0. 652 and 0. 722, respectively; the genetic gain was 8.09%, 17.67%, 14.56% and 17.53%, respectively. Based on comprehensive evaluation of various indicators, MES （Maoershan） was identified as an excellent population, which exhibited minor variations between individuals within the population, stable growth, strong growth potential and remarkable genetie effects.

Ecological Coupling Analysis and Genetic Effect Evaluation of Quantitative Characters in Lonicera edulis

Lonicera edulis is a perennial berry shrub that prefers the cold and wet climate, with high nutritional and medicinal value. In this study, ecological cou- pling capability of L. edulis with light, heat, water and soil resources in cold regions was investigated to analyze comprehensively ecological effects of quantitative characters and genetic effects of parents, aiming at providing a theoretical basis for the breeding, introduction and domestication of fine varieties of L. edulis in cold regions of China. The results showed that fruit characters in L. edulis exhibited certain variations among different habitat types. To be specific, fruit vertical diame- ter varied slightly, fruit horizontal diameter varied greatly and seed number varied maximally, with the average variance coefficients of 9.38%, 11.92% and 20. 64%, respectively; in addition, fruit characters in L. edtdis exhibited moderate herilability, moderate genetic gain and low level of genetic differentiation; the heritability of fruit vertical diameter, fruit horizontal diameter and seed number was 0.825, 0. 559 and 0. 627, respectively; the genetic gain of these three fruit characters was 7.53%, 5.72% and 11. 94%, respectively, resulting in significant economical benefits.