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作 者 ：林保花^1,2,3;刘金祥¹;肖生鸿¹;杨允菲²

期 刊 ：应用生态学报 2006年 17卷 11期 页码：2041-2045

关键词：香根草；

摘 要 ：在秋季对粤西乡土香根草的光合等生理特性日动态变化进行了测定.结果表明，香根草的净光合速率(P_n)日变化呈双峰型，蒸腾速率(T_r)和气孔导度(G_s)变化趋势与P_n相似，胞间CO₂浓度(C_i)变化方向则与其相反.P_n与光合有效辐射(PAR)、T_r与PAR、T_a和大气相对湿度(RH)的相关程度都达到了极显著水平(P＜0.01)，G_s则与空气温度(T_a)相关程度达到了显著水平(P＜0.05).同一环境因子对P_n、T_r和G_s的影响程度不同，其中PAR是影响香根草光合作用最为强烈的环境因子.T_r是受环境因子控制最为显著的生理参数.

Abstract:The determinations on the photosynthetic parameters of native Vetiveria zizanioides
in Western Guangdong in autumn showed that the net photosynthetic rate (P_n) of
V. zizanioides had a diurnal change with two peaks, transpiration rate (T_r) and
stomatal conductance (G_s) were similar with P_n, while intercellular CO₂ concentration
(C_i) was in adverse. There was a significant positive correlation between P_n and
photosynthetic active radiation (PAR) (P＜0.01), T_r and PAR (P＜0.01), air temperature (T_a) and relative humidity (RH) (P＜0.01), and G_s and T_a (P＜005). Same environmental factors had different effects on P_n, T_r and G_s, and PAR had most intensive effect on the photosynthesis of V. zizanioides. Among the test
photosynthetic parameters, T_r was most sensitive to the environmental factors.

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