Abstract: To understand reproductive allocation and floral traits of alpine plants in response to elevation and to clarify reproductive strategies of Sausserua plants at high elevation, we investigated the reproductive allocation and floral characteristic of Saussurea katochaete Maxim at different elevations along Tibetan Plateau. The results showed that there was a significantly negative correlation between the individual size, vegetative organ biomass, the number of tubular flowers, capitulum biomass and elevation (P<0.01). The length of filaments and the number of pollen were negatively correlated with elevation (P<0.01), while the anther length, style length, and style branch length were significantly and positively correlated with elevation (P<0.01). Reproductive organ biomass and reproductive allocation depended on individual size, with the former showing a positive correlation with individual size (P=0.024) but the latter showing a negative correlation with individual size (P<0.01). There was significantly negative correlations between the number of tubular florets and the weight of capitulum (P<0.01), between the number of tubular florets and single tubular floret weight (P<0.01), and between the pistil weight and stamen weight(P=0.024). Our results indicated that elevation had a great impact on the biomass of S. katochaete. The individual size was closely related to plant reproductive allocation strategy. As the elevation increased, S. katochaete adapted to the environment and improved its own fitness through the trade-offs of the flower number versus weight and pistil weight versus stamen weight.

Key words: Paenibacillus sp., heavy metal-tolerance, phytate phosphate, rice