Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA.
Donald Danforth Plant Science Center, Saint Louis, MO 63132, USA
J Exp Bot. 2014 Jun;65(11):2825-34. doi: 10.1093/jxb/eru221. Epub 2014 May 27.
The successful commercialization of bioenergy grasses as lignocellulosic feedstocks requires that they be produced, processed, and transported efficiently. Intensive breeding for higher yields in food crops has resulted in varieties that perform optimally under high-density planting but often with high input costs. This is particularly true of maize, where most yield gains in the past have come through increased planting densities and an abundance of fertilizer. For lignocellulosic feedstocks, biomass rather than grain yield and digestibility of cell walls are two of the major targets for improvement. Breeding for high-density performance of lignocellulosic crops has been much less intense and thus provides an opportunity for improving the feedstock potential of these grasses. In this review, we discuss the role of vegetative shade on growth and development and suggest targets for manipulating this response to increase harvestable biomass under high-density planting. To engineer grass architecture and modify biomass properties at increasing planting densities, we argue that new model systems are needed and recommend Setaria viridis, a panicoid grass, closely related to major fuel and bioenergy grasses as a model genetic system.
生物能源草作为木质纤维素饲料的成功商业化需要高效地生产、加工和运输。为了在粮食作物中获得更高的产量而进行的密集选育，导致了一些品种在高密度种植下表现最佳，但往往投入成本较高。玉米就是一个典型的例子，过去玉米的大部分产量增长都是通过增加种植密度和大量施肥实现的。对于木质纤维素饲料来说，生物量而不是谷物产量和细胞壁的消化率是两个主要的改良目标。木质纤维素作物高密度性能的选育要少得多，因此为提高这些草的饲料潜力提供了机会。在这篇综述中，我们讨论了营养体遮荫对生长和发育的作用，并提出了操纵这种反应的目标，以在高密度种植下增加可收获的生物量。为了在不断增加的种植密度下构建草的结构并改变生物量特性，我们认为需要新的模式系统，并推荐与主要燃料和生物能源草密切相关的panicoid 草属 Setaria viridis 作为一个模式遗传系统。
