Functions and genomic analysis of rice having the high rate of leaf photosynthesis comparable to that of maize

本研究探讨了水稻品种高卡纳里和粳稻品种谷光的回交自交系Pn值极高的原因。与Takanari相比，在叶片含氮量相近的情况下，这些品系的核酮糖1，5-二磷酸羧基/加氧酶(Rubisco)含量和活性都不高，但由于它们的密度较高，叶肉细胞裂片较发达，因此它们确实具有较高的叶肉导度。利用Takanri遗传背景中的39个Koshihikari染色体片段替换系，在Takanri遗传背景的植株中发现了4个提高叶片光合作用速率的数量性状基因座，其中Koshihikari等位基因位于第1染色体、第3染色体和第7染色体上。

We investigated the cause of extremely high values of Pn in the backcrossed inbred lines derived from the indica variety Takanari and the japonica variety Koshihikari. Compared to Takanari, these lines had neither a higher content nor higher activity of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) when the leaf nitrogen contents were similar, but they did have high mesophyll conductance with respect to CO2 flux due to their higher density and more highly developed lobes of mesophyll cells. Using 39 lines of Koshihikari chromosome segment substitution in Takanri genetic background, we found four quantitative trait loci for enhancing the rate of leaf photosynthesis of the plants of Takanari genetic background with a Koshihikari allele on chromosome 1, on chromosome 3 and on chromosome 7. We might increase rates of rice-leaf photosynthesis still further by introducing Koshihikari alleles into the plants of Takanari genetic background.