Dependence of the level of nitrogenase activity on the water content of the thallus inPeltigera canina, P. evansiana, P. polydactyla, andP. pvaetextata

摘要

The rates of nitrogen fixation and the response to changing levels of thallus moisture have been monitored inPeltigera canina(L.) Willd.,P. evansianaGyel.,P. polydactyla(Neck.) Hoffm., andP. praetextata(Somm.) Vain., using standard vapor-phase chromatography. Maximum levels of fixation range from 2.96ensp;nmol of ethylene evolved/h mg dry weight inP. evansianato 1.31ensp;nmol C2H4/h mg dry weight inP. polydactyla. Each species shows a slightly different pattern of fixation response to changing levels of thallus moisture, and the pattern of fixation correlates with the ecological preferences of each species.