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The phenotype and adaptability of an individual tree is influenced by genetic and environmental factors. In this study, the genetic parameters of growth traits for 40 poplar clones at three different sites (Lishu, Cuohai, and Fujin) in northeastern China were investigated and analyzed. ANOVAs showed that all effects were significantly different (P

Larix olgensis is one of the most important timber species in Northeast China. Although L. olgensis seed orchards have been established for many years and some progeny tests have been conducted, studies of progeny performance and the selection of superior families are still lacking. These tests are important for upgrading and improvement of seed orchards. Here, we estimate the genetic variation for major economic traits between families to provide selection materials for the establishment of a second-generation seed orchard. This study examined 71 half-sib families and 2 control families of L. olgensis in the Xiyang forest seed orchard in Yongji County, Northeast China. We measured tree height, diameter at breast height, volume, branch angle, stem straightness degree and crown width of 4-year-old progeny. Genetic parameters for the studied traits were determined, and comprehensive analyses of multiple traits and breeding values were used for selection of superior families and individual trees within families. The results show that all these traits are significantly different (P

Rapid growth and high quality have always been important goals pursued for timber forests. Therefore, growth traits and wood properties are the basis of superior materials to select and breed new cultivars. In this study, 42 half-sib families of 31-year-old P. koraiensis trees were used as materials. Nine growth traits (tree height, diameter at breast height, volume, basal diameter, average annual growth of the tree height, under branch height, stem straightness degree, form quotient, and branching angle) and eight wood properties (cellulose contents, hemicellulose contents, holocellulose contents, lignin contents, ash contents, wood density, fiber length and fiber width) were measured and analyzed. The results of an analysis of variance showed that there were extremely significant differences among the families in their growth and wood properties with the exception of the form quotient and wood density; that there were significant differences among block by family for growth traits except for the tree height, basal diameter, under branch height and branching angle; and that there was no significant difference for each growth trait among the blocks. The phenotypic coefficient of variation and heritability of the growth traits ranged from 7.17 to 42.35% and from 0.13 to 0.62, respectively. The phenotypic coefficient of variation and heritability of the wood properties ranged from 10.21 to 50.26% and from 0.67 to 0.92, respectively. There were extremely significantly positive correlations between the tree height, basal diameter, diameter at breast height, volume, under branch height, average annual growth of tree height and form quotient. However, there was no significant correlation between growth traits and wood properties. The result of the principal component analysis indicated that the tree height, diameter at breast height, volume, basal diameter, and cellulose contents, holocellulose contents, and lignin contents could be selected as comprehensive evaluation indices of growth and wood properties, respectively. According to a comprehensive evaluation, when the selection rate was 10%, four families (PK 40, PK 80, PK 42, and PK 71) were selected as elite families based on growth performance; another four families (PK 70, PK 62, PK 52, and PK 44) were selected as elite families based on their wood quality; and finally, four elite families (PK 70, PK 62, PK 61, and PK 40) were selected due to a combination of growth traits and wood properties. This study will provide a theoretical basis for the genetic improvement of fast-growing and high-quality P. koraiensis families.

Growth characteristics have a complex inheritance pattern, and gene–environment interactions make predicting tree responses to environmental change difficult. In this study, we planted 44 Betula platyphylla families at three different sites (Mao er shan forestry center in Shangzhi, Jilin experiment forestry center in Jilin, Lang xiang forestry center in Langxiang) in northeastern China. Variation and stability of genotype–environment interactions of different families were analyzed using additive main effect and multiplicative interaction models. Variation analysis indicated significant differences between site × family interaction mean values for height, diameter at breast height, volume, and stem straight degree, suggesting that most genotypes responded differently according to location. The phenotypic coefficients of variation of different traits ranged from 12.84 % (stem straight degree in Langxiang) to 53.34 % (volume in Langxiang) and heritabilities of the different traits varied from 0.485 (diameter at breast height in Mao er shan) to 0.781 (height in Jilin). Correlation analysis showed a significantly positive association between tree height, diameter at breast height, and volume at the same and different sites, but stem straight degree showing a weaker correlation with other traits. Stability analysis indicated that some families had high tree heights but were sensitive to environmental conditions, whereas others had average tree heights but were resistant to environmental conditions. These results suggest that families should be bred in various habitats to assess growth under favorable and unfavorable environments. Under a selection ratio of 10 %, four families (family 1–7, 4–7, 3–12 and 4–13) were rated as superior families. The average height, diameter at breast height, volume, and stem straight degree of these four families were higher than average of all the families by 12.24, 16.82, 32.28 and 6.28 % in the four test sites, respectively.

Scientists have widely applied transgenic technology to plants. We transferred the TaLEA gene to Populus simonii × P. nigra (Xiaohei Poplar), obtained ten transgenic poplar clones and analyzed these clones in a greenhouse and woodland. The heights (H), basal diameters (BD), and diameter at breast high (DBH) were significantly different (P

The study utilized the offspring of a 5 × 5 diallel cross of Betula platyphylla as the experimental material. Tree height (H), diameter at breast height (DBH) and stem straight degree (SSD) were measured at the fourth and eighth growth year (SSD were measured only in the eighth growth year). ANOVA analyses showed that growth traits in different growth years were significant among families (P