Landcare Research, PO Box 40, Lincoln 7640, New Zealand.
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.
叶片内部或叶肉的二氧化碳（CO2）导度（g(m)）是光合作用的一个重要且可变的限制因素，也会影响叶片蒸腾效率（TE）。本研究在六个大麦基因型（四个普通大麦和两个球大麦）中评估了 g(m)的基因型变异及其对 TE 的影响。在基因型之间发现了 g(m)的显著差异，并且与光合速率相关。g(m)最高的基因型也具有最高的 TE 和叶片组织中最低的碳同位素分馏（Delta(p)）。这些结果表明，g(m)在作物育种计划中具有尚未开发的潜力，可以提高 TE。
