SHOOT DEVELOPMENT AND STRUCTURE AT THE EARLY STAGES OF ONTOGENY IN EURASIAN SPECIES OF THE GENUS PINUS SECTION STROBUS (PINACEAE) UNDER INTRODUCTION IN TOMSK REGION
The structures and development of juvenile shoots in 6 species of 5-needle pines of the Northern and Eastern Asia has been analyzed. It was found that the longer is the growing season and higher the sum of effective temperatures in its native habitat, the later is beginning and end of the shoot growth in seedlings. The studied species are subdivided into 4 groups by the characters of their seasonal shoot growth: (1) subalpine-subarctic P. pumila, (2) boreal-mountain-taiga P. sibirica and P. cembra, (3) nemoral of monsoon forests P. koraiensis and P. parviflora, and (4) subtropical P. armandii. Differences between species by the pattern of their transition from juvenile to mature morphogenesis did not correlate with a current climate in their native habitats. The species are aragnged into 3 pairs by the duration of their juvenile stage and the presence of the morphostructures of mature type on the juvenile shoot: (1) P. sibirica and P. cembra; (2) P. koraiensis and P. armandii; (3) P. parviflora and P. pumila. This suggests a close relationship in the pairs of species and their common origin.