Biomass allocation and allometry of Pinus yunnanensis seedlings from different provenances

ObjectiveThere are abundant genetic variations of the Pinus yunnanensis among geographical provenances. However, genetic variation in biomass allocation and allometric relationships among biomass components were rarely addressed in this tree. Biomass allocation and allometry of P. yunnanensis seedlings from different provenances were studied to understand genetic variations in biomass allocation among provenances of P. yunnanensis seedlings.

MethodP. yunnanensis seedlings in containers from nine geographical provenances were designed by single-factor randomized block and then were selected to compare their biomass allocation and allometric relationships, and the correlations between geo-climatic parameters and biomass allocation were analyzed. Allometric relationships among seedling components were analyzed using standardized major axis regression.

ResultThere were significant differences in biomass and its allocation among provenances. The highest biomass of stem, leaf, total biomass and the lowest root biomass appeared in Yongren provenance, while Yunlong provenance, Yunnan Province of Southwestern China had the lower total biomass but the highest leaf biomass ratio. Biomass allocation was influenced variously by geographical and climatic factors, of which main influencing factors were altitude and mean annual temperature. The allometric scaling exponents among biomass components varied significantly in different provenances, the similar phenomenon occurred between each organ and plant size.

ConclusionDespite the same species, there are no collaborative change characteristics in both organs ’ growth rates and biomass partition among provenances of P. yunnanensis, reflecting the genetic variation in the biomass distribution pattern of P. yunnanensis seedlings due to the long-term influence of geographical and climatic factors in each provenance.