不同发育时期肉苁蓉和梭梭体内氮营养物质变化研究

通过对寄生植物肉苁蓉和寄主梭梭体内不同发育时期硝酸还原酶活性和硝态氮含量的测定，结果表明：寄生肉苁蓉的梭梭的硝酸还原酶活性和硝态氮含量均低于未寄生肉苁蓉的梭梭；与寄主梭梭不同的是，肉苁蓉体内的硝态氮含量高于梭梭同化枝内硝态氮含量，但其硝酸还原酶活性却较梭梭同化枝硝酸还原酶活性低，说明肉苁蓉体内氮素代谢除了以硝酸还原酶为主外，可能还有其他氮代谢途径的参与．肉苁蓉寄生后，将梭梭体内的氮素大量吸收，致使梭梭生长严重受抑制，表现为梭梭同化枝叶绿素含量下降，同化枝生长量严重减少．因此，从寄生关系判断，肉苁蓉对梭梭的寄生为有害寄生．

Study on Variations of Nitrogen Nutrient Substances of Cistanche Deserticola and Haloxylon Ammodendron in Differdent Growth Stages

The activity of nitrate reductase and nitric nitrogen content were determined in different growth stages of parasitic plant, Cistanche deserticolea, and host plant, Haloxylon ammodendron. The results showed that the activity of nitrate reductase and nitric nitrogen content of the parasitic plant and the host plant Were lower than that of the host plant without parasitic plant. Contrasting to the host plant, nitric nitrogen content of Cistanche deserticolea was higher than that of the host plant, but the activity of nitrate reductase was lower, which indicated that the other pathway of nitrogen metabolism might be existed except for the nitrate reductase in Cistanche deserticola. The nitrogen in the host plant was severely absorbed by Cistanche deserticola when they live together that the growth of host was inhibited, which resulted the reducing of the chlorophyll content and the branches growth rate of Haloxylon ammodendron.Therefore, It was concluded that the parasitic plant, Cistanche deserticola had negative effects on host plant, Haloxylon ammodendron.