Centre for Crop Genetic Improvement, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK.
J Exp Bot. 2011 Jan;62(2):453-67. doi: 10.1093/jxb/erq304. Epub 2010 Oct 27.
Past increases in yield potential of wheat have largely resulted from improvements in harvest index rather than increased biomass. Further large increases in harvest index are unlikely, but an opportunity exists for increasing productive biomass and harvestable grain. Photosynthetic capacity and efficiency are bottlenecks to raising productivity and there is strong evidence that increasing photosynthesis will increase crop yields provided that other constraints do not become limiting. Even small increases in the rate of net photosynthesis can translate into large increases in biomass and hence yield, since carbon assimilation is integrated over the entire growing season and crop canopy. This review discusses the strategies to increase photosynthesis that are being proposed by the wheat yield consortium in order to increase wheat yields. These include: selection for photosynthetic capacity and efficiency, increasing ear photosynthesis, optimizing canopy photosynthesis, introducing chloroplast CO(2) pumps, increasing RuBP regeneration, improving the thermal stability of Rubisco activase, and replacing wheat Rubisco with that from other species with different kinetic properties.
过去小麦产量的提高主要是由于收获指数的提高，而不是生物量的增加。进一步大幅提高收获指数是不太可能的，但增加生产性生物量和可收获谷物的机会是存在的。光合作用能力和效率是提高生产力的瓶颈，有强有力的证据表明，只要其他限制因素不成为限制因素，增加光合作用将提高作物产量。即使光合作用净速率略有增加，也可以转化为生物量和产量的大幅增加，因为碳同化是在整个生长季节和作物冠层中进行的。这篇综述讨论了小麦产量联合体为提高小麦产量而提出的提高光合作用的策略。这些策略包括：选择光合作用能力和效率、增加穗光合作用、优化冠层光合作用、引入叶绿体 CO(2)泵、增加 RuBP 再生、提高 Rubisco 激活酶的热稳定性，以及用具有不同动力学特性的其他物种的小麦 Rubisco 替代。
