Two Trebouxia algae with different physiological performances are ever-present in lichen thalli of Ramalina farinacea. Coexistence versus Competition?
Article first published online: 6 DEC 2010
© 2010 Society for Applied Microbiology and Blackwell Publishing Ltd
Volume 13, Issue 3, pages 806–818, March 2011
How to Cite
Casano, L. M., del Campo, E. M., García-Breijo, F. J., Reig-Armiñana, J., Gasulla, F., del Hoyo, A., Guéra, A. and Barreno, E. (2011), Two Trebouxia algae with different physiological performances are ever-present in lichen thalli of Ramalina farinacea. Coexistence versus Competition?. Environmental Microbiology, 13: 806–818. doi: 10.1111/j.1462-2920.2010.02386.x
- Issue published online: 1 MAR 2011
- Article first published online: 6 DEC 2010
- Received 16 July, 2010; accepted 20 October, 2010.
Ramalina farinacea is an epiphytic fruticose lichen that is relatively abundant in areas with Mediterranean, subtropical or temperate climates. Little is known about photobiont diversity in different lichen populations. The present study examines the phycobiont composition of several geographically distant populations of R. farinacea from the Iberian Peninsula, Canary Islands and California as well as the physiological performance of isolated phycobionts. Based on anatomical observations and molecular analyses, the coexistence of two different taxa of Trebouxia (working names, TR1 and TR9) was determined within each thallus of R. farinacea in all of the analysed populations. Examination of the effects of temperature and light on growth and photosynthesis indicated a superior performance of TR9 under relatively high temperatures and irradiances while TR1 thrived at moderate temperature and irradiance. Ramalina farinacea thalli apparently represent a specific and selective form of symbiotic association involving the same two Trebouxia phycobionts. Strict preservation of this pattern of algal coexistence is likely favoured by the different and probably complementary ecophysiological responses of each phycobiont, thus facilitating the proliferation of this lichen in a wide range of habitats and geographic areas.