关键词: 大血藤, 叶生长, 叶绿素含量, 硝酸还原酶活力, 净光合速率

Abstract: Studys on characteristics of leaves growth and photosynthesis physio ecology of Sargentodoxa cuneata showed that there were same increasing tendency among leaves length、area and dry weight of Sargentodoxa cuneata. They increased rapidly in early growth phase, but increased slowly after then. Leaves length and leaves area was maximum in the middle of July. Leaves dry weight was maximum at the beginning of August. The increasing of chlorophyll content and nitrate reducase activity with leaves growth lasted to August, reversed after then. The light compensation point in spring and summer was lower than in autumn, but the light saturation point was opposite. The diurnal variation of Pn was "single-peak" curve in spring, which was "twin-peak" curve showing obvious "noon-rest" in summer and autumn. The increasing of daily average of Pn in whole growing seasons lasted to the beginning of August, reversed after then. In summer, daily average Pn of Sargentodoxa cuneata was lower than evergreen broad-leaf species, which was higher than deciduous broad-leaf species.

Key words: Sargentodoxa cuneata, leaf growth, chlorophyll content, nitrate reducase activity, net photosynthetic rate