Comparative study on the photosynthetic light response characteristics of Dysosma guangxiensis and D. versipellis
In order to understand the ecophysiological adaptation mechanisms of the endangered plants Dysosma guangx-iensis to light environment, we studied the photosynthetic light response characteristics of D. guangxiensis and the same genera vulnerable species D. versipellis with Li-6400 Portable Photosynthesis(Li-Cor Inc., USA), and then discussed the endangered mechanism of D. guangxiensis. The results showed that the light compensation point of D. guangxiensis and D. versipellis was 440 and 530μmol?m-2?s-1 , the light compensation point was 13.25 and 13.10μmol?m-2?s-1 , the maximum net photosynthetic rate was 3.62 and 6.81μmol?m-2?s-1 , and the apparent quantum yield was 0.065 and 0.042μmol?μmol-1 , respectively. That is to say, the two species are shade herb, but the light compensation point and the saturation point are higher than the general shade herb, and 10%-30% shading forest habitat are conducive to the growth of the two species; compared with D. versipellis, the photosynthetic capacity of D. guangxiensis was weak, the light saturation point was lower, but its quantum efficiency under low light was higher. In comparison, the net photosyn-thetic rate, transpiration rate and stomatal conductance of D. versipellis were higher than those of D. guangxiensis under most light intensities, but the water use efficiency of D. guangxiensis was higher than that of the former, which indicated that the photosynthetic strategy of D. guangxiensis was more conservative, with lower photosynthetic accumulation as the cost to maintain higher water use efficiency, in order to maintain the water balance in body.
Dysosma guangxiensisD. versipellisnet photosynthetic ratetranspiration ratewater use efficiency
国家科技期刊平台
NSTL
万方数据
维普
