一九五○年以来,美国水稻产量增长近两倍。选育良种为产量的改进作出了显著的贡献。对生理高效品种的选育,过去通常靠经验式的选种方法。而对生理质量性状优势植株的选择和鉴定,则要有更好的方法。人们已从生理上探讨了净同化率、叶面积指数、光合与呼吸比率、同化物运转速率及其作为临时储备下的分布等的测量方法。但对大群体的筛选来说,进行这些项目的测定是困难而费力的。最近,许多植物育种家已把工作转向测定生理效率的谷粒灌浆速率和 Since 1950, the U.S. rice output nearly tripled. Breeding seeds made significant contributions to yield improvement. Breeding physiologically efficient varieties, the past usually by empirical selection method. The quality of physiological traits preferred plants selection and identification, there must be a better way. Physiologically, methods of measurement of net assimilation rate, leaf area index, photosynthetic and respiration rate, assimilate operating rate and its distribution as a temporary reserve have been studied physiologically. However, the screening of large groups, the determination of these items is difficult and laborious. Recently, many plant breeders have turned their attention to assessing physiological efficiency of grain filling rates and