Understanding the variation of leaf anatomy and its influence on photosynthesis is very important for yield improvement.
Xiong et al. found that leaf mass per area (LMA) varies greatly among rice genotypes, and the variation is mainly determined by leaf density rather than leaf thickness. Moreover, the responses of LMA and photosynthesis to nitrogen supplement are genotype dependent and are also mainly determined by leaf density. The results highlight the importance of leaf density in leaf anatomy and photosynthesis.