Reynolds Matthew, Tuberosa Roberto
International Maize and Wheat Improvement Center CIMMYT, Int. AP 6-641, 06600 México, DF, Mexico.
Curr Opin Plant Biol. 2008 Apr;11(2):171-9. doi: 10.1016/j.pbi.2008.02.005. Epub 2008 Mar 7.
Conventional breeding for drought-prone environments (DPE) has been complemented by using exotic germplasm to extend crop gene pools and physiological approaches that consider water uptake (WU), water-use efficiency (WUE), and harvest index (HI) as drivers of yield. Drivers are associated with proxy genetic markers, such as carbon-isotope discrimination for WUE, canopy temperature for WU, and anthesis-silking interval for HI in maize. Molecular markers associated with relevant quantitative trait loci are being developed. WUE has also been increased through combining understanding of root-to-shoot signaling with deficit irrigation. Impacts in DPE will be accelerated by combining proven technologies with promising new strategies such as marker-assisted selection, and genetic transformation, as well as conservation agriculture that can increase WU while averting soil degradation.
针对易干旱环境(DPE)的传统育种,已通过利用外来种质来扩大作物基因库以及采用生理学方法得到了补充,这些生理学方法将水分吸收(WU)、水分利用效率(WUE)和收获指数(HI)视为产量的驱动因素。驱动因素与代理遗传标记相关联,例如用于WUE的碳同位素判别、用于WU的冠层温度以及用于玉米HI的开花-吐丝间隔。与相关数量性状位点相关的分子标记正在开发中。通过将对根-茎信号传导的理解与亏缺灌溉相结合,WUE也得到了提高。通过将成熟技术与诸如标记辅助选择、遗传转化以及保护性农业等有前景的新策略相结合,可以加速在DPE方面的影响,保护性农业可以增加WU同时避免土壤退化。