Variability in mesophyll conductance between barley genotypes, and effects on transpiration efficiency and carbon isotope discrimination

Plant Cell Environ. 2010 Jul;33(7):1176-85. doi: 10.1111/j.1365-3040.2010.02138.x. Epub 2010 Mar 1.


Leaf internal, or mesophyll, conductance to CO(2) (g(m)) is a significant and variable limitation of photosynthesis that also affects leaf transpiration efficiency (TE). Genotypic variation in g(m) and the effect of g(m) on TE were assessed in six barley genotypes (four Hordeum vulgare and two H. bulbosum). Significant variation in g(m) was found between genotypes, and was correlated with photosynthetic rate. The genotype with the highest g(m) also had the highest TE and the lowest carbon isotope discrimination as recorded in leaf tissue (Delta(p)). These results suggest g(m) has unexplored potential to provide TE improvement within crop breeding programmes.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Isotopes / analysis
  • Genetic Variation*
  • Genotype
  • Hordeum / genetics*
  • Hordeum / metabolism
  • Photosynthesis*
  • Plant Leaves / genetics
  • Plant Leaves / metabolism*
  • Plant Transpiration*


  • Carbon Isotopes