割手密光合特性及其与原生长地海拔关系

Relations between Photosynthesis Characteristics of Saccharum spontaneum and Altitude of Its Native Area

测定了144份不同原生长地甘蔗割手密无性系的净光合速率、蒸腾速率、气孔导度、叶绿素a含量、叶绿素b含量等生理指标。结果表明:不同割手密无性系光合特性差异较大;原生长地海拔与蒸腾速率呈显著线性关系与其它光合特性无相关性;原生长地海拔与割手密无性系叶绿素a含量、叶绿素b含量和叶绿素a+b含量呈反抛物的线性关系,与叶绿素a/b值呈显著正相关;在割手密无性系各光合特性间,气孔导度与蒸腾速率、净光合速率、细胞间隙CO2浓度呈显著的直线关系,其余各光合特性之间无显著关系。由此认为:原生长地不同的割手密无性系间在光合特性方面存在丰富的多样性特征;其光合特性与海拔密切相关;海拔一方面影响叶绿素的含量,另一方面调节气孔和蒸腾速率,进而影响光合速率。

Net photosynthesis rate （Pn）, transpiration rate （E）, stomatal conductance （C）, intercellular CO2 concentration （Ci）, and chlorophyll content （Chl） of 144 clones of Saccharum spontaneum L. collected from different areas in China were determined. The results showed： there are rich variations on photosynthesis characteristics of S. spontaneum in different native area. There are significantly positive correlations （P〈0.05） between altitude of its native area and E, but no correlation with other parameters. There is a reverse parabola change direction between the altitude of and Chla, Chlb, Chla＋b, and there is a significantly positive correlation between altitude and Chla/b. There are significant positive correlations between C and E, Pn, Ci, and no significant correlation between other parameters. So, there could be rich variations on photosynthesis characteristics of S. spontaneum clones in their different native area, and there is closely relationship with the altitude. The altitude impacts on not only chlorophyll content but also stomatal conductance and transpiration rate so as to affect on photosynthesis rate of S. spontaneum.