水分对发状念珠藻生理活性的影响

研究了水分对发状念珠藻(Nostor flagelliforme Born.et Flah.)生理活性的影响作用。结果表明：干藻体在湿润的过程中，呼吸、光合和固氮活性依次恢复；且随水分含量的增加，光合活性和固氮活性逐渐增强，呼吸作用缓慢减弱并在一定水平上保持相对稳定，自由水是束缚水8倍左右时发菜生理活性全面恢复。吸水饱和的藻体在干燥过程中，光合、呼吸、固氮作用依次停止；呼吸作用随水分的丧失逐渐下降；固氮活性、光合活性在水分丧失20％～40％时有一定程度的增强，出现活性高峰；此后，生理活性下降，水分完全丧失时，光合作用终止，呼吸和固氮作用极其微弱。试验证明，水分是发状念珠藻生理活性的重要限制因子，适宜的水分有助于发菜维持正常的生理代谢和生长。

Effect of Water on Physiological Activity of Nostoc flagelliforme

This paper was conducted to study the effect of water on physiological activity of Nostoc flagelliforme Born.et Flah. Results indicated that: Respiration, photosynthesis and nitrogen fixation were recovery in turn. Following water content increasing, photosynthesis and nitrogen fixation increased and respiration decreased. Physiological activity was recovery thoroughly when content of free water was 8 times of bound water. During rewetting samples kept in dessicator to lose water, respiration decreased following water loss, but photosynthesis and nitrogenase activity increased at the time that water lose rate was under 40%, then decreased with water loss. The results proved water is a limiting factor to N. flagelliforme and optimal water will help to normal physiological activity and growth.