生物菌肥不同施用量对鼓节竹发笋末期生长和光合特性的影响

Effects of Bacterial Fertilizer on Growth and Photosynthesis of Bambusa tuldoides in Late Bamboo Shoot-forming Stage

以3年生鼓节竹为材料,研究生物菌肥0、0.3、0.6、0.9、1.2、1.5kg·丛^(-1)共6种施肥量对鼓节竹发笋末期生长及光合特性的影响,测定指标包括叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)和水分利用效率(WUE),以及光合色素含量和成竹率,采用双曲线修正模型对光响应曲线进行模拟。结果表明:双曲线修正模型拟合度>0.99,净光合速率先急剧增长,后趋于稳定,达到光饱和点后呈现一定的下降趋势。各处理间的蒸腾速率、气孔导度和水分利用效率呈现相似的变化趋势,胞间二氧化碳浓度变化趋势则相反。不同菌肥施肥量处理均一定程度上增加了鼓节竹对于强光和弱光的利用,净光合速率和光合参数跟鼓节竹叶片叶绿素含量和成竹率密切相关。综合来看,施生物菌肥0.6kg·丛^(-1)对鼓节竹的生长效果更佳。

Three-year-old Bambusa tuldoides plants were used in the study.A biofertilizer was applied at the rates of 0,0.3,0.6,0.9,1.2 or 1.5 kg per unit to patches of the plants.The photosynthetic properties,including net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),intercellular carbon dioxide concentration(Ci)and chlorophyll content of the leaves,as well asthe water usage efficiency(WUE)andbamboo shoot-forming rateof the plants were determined and fitted to a hyperbolic model for correlating the responses under varied lighting conditions.The correlation coefficients were better than 0.99 on the model fitting.For individual indicators,Pn increased sharply initially,then leveled off,and decreased after reaching the light saturation;and,Tr,Gs,and WUE hada similar response to the treatments,but Ci wasthe opposite.In varying degrees,the fertilizations increased the leaf utilization of high and low light.Thephotosynthetic parameters closely related to the chlorophyll content of the leaves and the shoot-formation of the plant.It was concluded that application of the biofertilizer at a rate of 0.6 kg·patch-1 was optimal for the growth and developmentof B.tuldoides.