模拟微重力对植物幼苗光合特性的影响

目的：研究模拟微重力对植物幼苗光合特性的影响。方法：采用1π回转器模拟微重力并处理植物样品120h。结果：1）株高和叶片数有所增加。2）草莓的叶绿素含量降低47．5％，香石竹叶绿素含量增加4．3％，3）回转后两种幼苗的叶绿素主要吸收峰位不变，而每个峰位吸收强度有所增加；4）两种幼苗的叶片快速荧光动力学参数，回转后除CA／Fo外，Fv/Fo,Fv/FM和T1／2均有提高；5）对照和处理的叶绿体的两个光系统间的激发能分配有差异。结论：微重力对叶绿体的正常光合功能没有显著影响，故植物幼苗在微重力条件下可以正常生长。

Effects of Simulated Microgravity on Characteristics of Photosynthesis in Plant Seedling

Objective: To study the effects of simulated microgravity on the characteristics of photosynthesis in some plant seedlings. Method: Plant samples were treated on a 1 pi clinostat rotated at 2 gamma/min for 120 h. Then chlorophyll absorption and chlorophyll fast fluorescence induction kinetics were determined. Result: After treatment on the clinostat: 1) there were some increase in height and number of leaves per plant; 2) the strawberry seedlings contained 47.5% less chlorophyll and the carnation seedlings contained 4.3% more; 3) there was no change in position of the main absorption peaks of chlorophyll in both seedlings after the rotation, but their intensity was increased; 4) there were significant increase in the parameters of fluorescence induction kinetics in the leaves of both seedlings: there was an increase in Fv/Fo, Fv/Fm and T1/2, except CA/Fo; 5) there were some differences in excitation energy distribution between the two photosystems in the chloroplasts of control and treated samples. Conclusion: Simulated microgravity does not have a significant effect on normal photosynthetic function in chloroplasts, so plant seedlings can grow up normally under microgravity.