水稻籼粳亚种间杂种优势利用研究进展

Progress in Research on Utilization of Vigor in Hybrids between Indica and Japonica Rice Subspecies

本文从水稻育种进步的宏观观点,回顾与展望了我国水稻杂种优势利用的历史进程。由早期追求以强大生物优势为主要育种目标的启蒙阶段进入三系法生态远缘优势与理想株型相结合的籼梗杂种优势间接利用阶段,实现了水稻杂种优势利用的第一次飞跃。现在又进入三系法、两系法籼粳有利基因交换与自由配组的籼梗杂种优势直接利用阶段,预期将产生水稻杂种优势利用的第二次飞跃。近年研究表明,双亲遗传距离与经济优势呈二次多项式关系,杂种优势含可利用与非可利用两个方面,广亲和系可以将亚种F_(?)结实率提高到正常水平,但它的稳定性受双亲遗传背景与环境互作影响。因此,采用“籼梗(爪)架桥”,亲缘渐渗,有利基因交换,亲本遗传改良以及因地制宜选择种植区,是籼粳亚种间杂种优势利用的主要方法。

In this paper,from a macroscopic perspective of advances in rice breeding,the course of history of utilization of vigor in hybrids between indica and japonica rice subspecies in China is reviewed,and the prospect for the future is visualized. Hybrid rice breeding has undergone two developmental stages. The transition from the incipient stage,when researchers saught after strong heterosis as their main goal of breeding, to the-stage of indirect utilization of hybrid vigor, in which the advantage of ecological distance was combined with ideal plant morphology by the three-line method,marked the first quantum leap in the utilization of vigor in hybrids of rice. Now we are entering a stage of exchange desirable genes and free combination and direct utilization of hybrid vigor through the two-line method,which will herald the second leap forward. Results of research in recent years showed that the relationship between two parents and hybrid vigor could be expressed by a quadratic polynomial equation,and that hybrid vigor comprised usable and unusable ones. It was also found that wide compatible lines could raise the seed-setting rate in F1 to the normal level, but its stability was subject to the effect of interaction between the parent genetic backgrounds and the environment. Therefore, building a bridge between indica and japonica (or javanica), introgressive hybridization, exchange and recombination of genes, genetic improvement of parents and choosing the region for planting in line with local conditions should be the principal issues in utilization of vigor in hybrids between indica and japonica subspecies.