马尾松适应低磷胁迫的生理生化响应

Physiological and Biochemical Responses of Pinus massoniana to Low Phosphorus Stress

采用单因素砂培方法,在温室内通过人工控制磷元素浓度的方法,研究马尾松在低磷胁迫条件下的生理生化响应。结果表明:根冠比提高是马尾松对低磷胁迫的一种主动适应性反应机制;低磷逆境下,马尾松针叶的可溶性糖和脯氨酸含量增加,而叶绿素和可溶性蛋白含量降低;叶绿素和可溶性蛋白含量的降低导致马尾松针叶净光合速率下降;低磷条件下,马尾松针叶的净光合速率和蒸腾速率降低、暗呼吸速率升高是影响其生物量的主要原因之一;马尾松针叶MDA含量、保护酶活性(POD、SOD)增加,这2方面形成一个动态平衡是马尾松适应低磷胁迫的主要生理响应机制之一。

The physiological and biochemical responses of Pinus massoniana to low phosphorus stress were investigated in this study, and the different phosphorus concentrations of the treatments were conducted by using a single factor experiment with sand culture in the green house. Results showed that the increase of root-shoot ratio was an active adaptive response of P. massoniana to low phosphorus stress. Under the situation of low phosphorus stress, the concentrations of soluble sugar and free proline increased whereas the chlorophyll and soluble protein decreased. The decrease of chlorophyll and soluble protein would result in a decrease in net photosynthetic rate of P. massoniana. Thus the major factor affected the biomass of P. massoniana is the decrease of net photosynthetic rate and transpiration rate as well as the increased dark respiration rate. Moreover, the homeostasis established by the increase of MDA concent and protective enzyme （POD, SOD） activity in needles is the mechanism of the adaptive response for P. massoniana to low phosphorus stress.