Taylor, S. H. and Franks, P. J. and Hulme, S. P. and Spriggs, E. and Christin, P. A. and Edwards, E. J. and Woodward, F. I. and Osborne, C. P. (2012) Photosynthetic pathway and ecological adaptation explain stomatal trait diversity amongst grasses. New Phytologist, 193 (2). pp. 387-396. ISSN 0028-646X
Full text not available from this repository.Abstract
• The evolution of C 4 photosynthesis in plants has allowed the maintenance of high CO 2 assimilation rates despite lower stomatal conductances. This underpins the greater water-use efficiency in C 4 species and their tendency to occupy drier, more seasonal environments than their C 3 relatives. • The basis of interspecific variation in maximum stomatal conductance to water (g max), as defined by stomatal density and size, was investigated in a common-environment screening experiment. Stomatal traits were measured in 28 species from seven grass lineages, and comparative methods were used to test for predicted effects of C 3 and C 4 photosynthesis, annual precipitation and habitat wetness on g max. • Novel results were as follows: significant phylogenetic patterns exist in g max and its determinants, stomatal size and stomatal density; C 4 species consistently have lower g max than their C 3 relatives, associated with a shift towards smaller stomata at a given density. A direct relationship between g max and precipitation was not supported. However, we confirmed associations between C 4 photosynthesis and lower precipitation, and showed steeper stomatal size-density relationships and higher g max in wetter habitats. • The observed relationships between stomatal patterning, photosynthetic pathway and habitat provide a clear example of the interplay between anatomical traits, physiological innovation and ecological adaptation in plants.