两系杂交粳稻的优势潜力和应用前景

The Potentiality and Utilization Prospects of Heterosis in Two-line Japonica Hybrid Rice

两系杂交粳稻与籼杂一样，同样有强大的杂种优势，一般比三系粳杂增产８％，比常规粳稻增产１０％以上。在长江流域双季稻北缘地区，双晚前期的持续高温和９、１０月份连绵低温阴雨天气是影响两系杂交粳稻产量潜力发挥的主要限制因素。为此，提出趋利避害，采取秧田超稀播种，加强后期管理等高产栽培配套技术，达到增穗、增粒、增重、增产的目的。利用粳爪交或粳籼交来选育分蘖期耐高温、穗期耐低温的亚种组合。

The superhigh yielding potentiality in two-line japonica hybrid rice was same as indica hybrid rice. In general, the grain yield of two-line japonica hybrid rice was 8% higher than that of three-line japonica hybrid rice and over 10% higher than that of the local leading variety. The main factors that restricted fully potentialities of superhigh yield of two-line japonica hybrid rice, in fact, were higher temperature in both July and August, and lower temperature and drizzle in both September and October in double season rice regions of the Changjiang River valley. In order to develop the potentialities of superhigh yield, the authors suggested that seeding in low density be applied field management be strengthed in the late stage of growth period and so on. Selection of intersubspecific hybrid rice combinations of japonica javanica or japonica indica,which had high temperature-resisting in tillering stage and lower temperature-resisting in heading stage was favorable for super high yield.