失水-吸水过程中微鞘藻光合活性的特性

RECOVERY OF PHOTOSYNTHETIC ACTICITY OF MICROCOLEUS VAGINATUS AFTER WATER LOSS AND REHYDRATION

雨季来临时,干藻重新吸收水分,光合活性恢复,迅速生长。微鞘藻(Microcoleus vaginatus)藻体在失水过程中,光合活性降低;而干藻接种到流沙后,恢复生长,在生长后期,生物量可达27μg/cm2土壤。在重吸水中,离子对光合活性的恢复具有重要作用,相对于去离子水来说,BG-11培养液处理后活性恢复较高;K+和Mg2+的缺失,对光合活性有抑制作用,而Ca2+的缺失,造成光合活性恢复的延缓;较高浓度的胞外多糖(Extracellular polymeric substances,EPS)和热水溶性多糖(500mg/L),较低浓度的蔗糖(100mg/L),对光合活性的恢复和保持具有促进作用。结果表明,在光合重吸水过程中,离子在促进光合恢复中起重要作用,而糖类在保持细胞形态上具有重要的作用,这对于利用干藻进行流沙接种试验具有非常重要的意义。

Desiccated filaments restore photosynthetic activity and grow rapidly after rehydration when the rainy season comes. Photosynthetic activity off Microcoleus vaginatus decreased during the process of water loss, and the biomass of man-made algal crust reached maximum about 27μg Chl a/cm^2 after inoculated onto unconsolidated sand. It is important for ion concentration in the recovery of photosynthetic activity in rehydration process. Compared with distilled water, photosynthetic activity recovered high after wetted with BG -11 medium. Compared with the recovery of BG-11, photosynthetic activity were inhibited by the deficiency of K^＋ and Mg^2＋ , and it was retarded by the deficient of Ca^2＋, while N and A5 didn＇t have a significant change. The recovery of photosynthetic activity was enhanced by the addition of 500mg/L EPS, HWP and 100mg/L sucrose. It indicated that some ion contents （K, P, Mg, Ca^2＋） played an important role in the recovery of photosynthetic activity, and EPS, HWP and sucrose may play an important role in keeping cell morphology.