Objective Pinus sibirica is a precious tree species with excellent wood and fruit. It is mainly distributed in the cold and temperate zone of Russia, with rich intraspecific variation. The introduction experiments of different provenances were carried out to select excellent provenances, so as to provide basis for large-scale introduction and afforestation in China in the later stage.
Method According to the provenance division of the tree species, seeds were collected at 7 seed collection points in the main provenance area. The seedling raising and afforestation were designed according to the completely randomized block experiment. We investigated the tree height of 7 years old and 9−18 years old, and the DBH of 7, 15 and 18 years old. What’s more, the 18-year-old preservation rate was also investigated. For the investigated characters, the analysis of variance and multiple comparative analysis among provenances were carried out. The generalized heritability of each character was estimated. The correlation analysis between the characters and the temperature and precipitation factors of afforestation site was carried out, and the tree height growth curve model fitting analysis of different provenances was carried out.
Result The results of variance analysis showed that the differences of growth traits among various provenances mostly reached a very significant level, and the coefficient of variation was between 17% – 65%, mostly about 25%. The coefficient of variation of tree height traits basically showed a trend of gradually decreasing with the increase of age. The broad heritability of all traits was high, most of which were more than 70%. The correlation analysis between the height growth in the current year and the temperature and precipitation of the afforestation site showed that the temperature of afforestation site was the main factor affecting the height growth. The higher annual average temperature, March and July average temperature not only promoted the height growth of Pinus sibirica in the current year, but also significantly promoted the height growth in the second year. The fitting analysis of tree height curve model and multiple comparative analysis showed that among the introduced Pinus sibirica provenances, Tomsk provenance and Ulanude provenance were outstanding and determined as excellent provenances. The genetic gains of tree height and DBH were 6.73% and 3.09%, 4.68% and 9.50% respectively.
Conclusion The growth characters of Pinus sibirica provenances showed obvious variation, the temperature of afforestation site is the main factor affecting height growth. Higher temperature is not only beneficial to height growth in the current year, but also significantly promotes height growth in the second year. Based on the tree height curves and multiple comparisons of various provenances, Tomsk provenance and Ulanude provenance are selected as excellent provenances.