Abstract: Chinese rice scientists increased rice varietal yields during the 1950s and 1960s by improving the plant type and since the 1970s by exploiting the phenomenon of heterosis in developing F₁ hybrid cultivars. Both approaches seem to have reached a plateau, with yields of 8～9 t/ha. If still higher yields are to be achieved, total biomass yield has to be increased while maintaining a reasonable gram straw ratio. Research efforts should aim at:(1) increasing leaf area; (2) increasing photosynthetic efficiency per unit leaf area and (3) improving fertilizer responsiveness and lodging resistance. This would require combining ideal plant morphology with favorable vigor, Indica—japonica hybridization should meet this objectives. High stomata frequency of indicas could be combined with japonica traits of compact plant type, higher specificleaf weight, higher chlorophyll content per unit leaf area, and higher nitrogen and RUBPC content. All these characteristics are advantageous to close planting and to increasing photosynthetic efficiency of leaves and total biomass yield. Indtca japonica crossing would also result in ideal plant morphology and in increased growth vigor.

Key words: Indica-japonica hybridization, Ideotype, Photosynthetic efficiency

摘要： 中国的水稻科学家在50和60年代改善了水稻的株型而提高了水稻的产量。70年代以来则利用_1杂种优势,兴起了杂交稻,两方面似乎都达到了每公顷8～9吨产量的平台倘要达到更高的单产,将在保持合理的谷草比率之下提高生长量,研究工作应该着重于:(1)增加叶面积;(2)提高单位叶面积的光合效率;和(3)改进耐肥抗倒性。这就需要理想株形与有利优热相组合籼粳稻杂交育种将有可能适应这一目的。籼稻叶片的高密度气孔有可能与粳稻的紧凑株型、较高的比叶重、较高的单位叶面积的叶绿素含量和较高的含氮量及RUBPC含量结合,所有这些性状都有利于密植和有利于提高叶片的光合效率及生长量。籼粳稻杂交育种将可能育成理想株形并同时提高生长优势。

关键词: 籼粳稻杂交, 理想株型, 光合效率