Журнал Сибирского федерального университета: Серия Биология (Mar 2009)
Shoot Morphological Structure and Development in 5-Needle Pines of Northern and Eastern Asia: Phylogenetic and Climatic Interpretation
Abstract
Comparative analysis of juvenile and adult shoot structure in 5-needle pine species of Northern and eastern Asia are realized. The more the duration of vegetation period and sum of effective temperatures in natural habitat, the later shoot growth in seedlings begins and terminates. On this point, examined species are neatly divided into 4 groups: (1) subalpine-subarktic P.pumila, (2) boreal- mountain taiga P.sibirica and P.cembra, (3) nemoral species of monsoon forest (P. koraiensis and P.parviflora), (4) subtropical P. armandii. Differences between species by juvenile shoots were not related with climate in its natural range. There are 3 pairs of species were distinguished by duration of juvenile morphogenesis and presence of the mature morphostructures on juvenile shoots: Pinus sibirica + P. cembra, P. koraiensis + P. armandii, P.parviflora + P.pumila. The presented dates adds argument in favor of polyphyletic hypothesis of modern subsection Cembrae origin. The morphological structure of adult shoots in 12 contrasting climatic ecotypes of three Russian Pinus species from Cembrae group (P. sibirica, P. pumila и P. koraiensis) was examined. In all species, male shoots produce one (winter) bud and one (spring) elementary shoot during the growing season. Female shoots were found to initiate two buds and two elementary shoots during the growing season. At the beginning of the season a temporal bud is initiated giving rise to the summer shoot, which is formed during the season without any period of dormancy. Then a winter bud is formed producing the first (spring) elementary shoot in the beginning of the next season. There are short shoots, dormant buds, and lateral long shoots on each elementary shoot. Differences in annual shoot structure between species and ecotypes were showed and discussed.
