水稻亚种间优质米组合的选育初报

Preliminary Studies on Breeding of High Quality Intersubspecific Hybrid Rice

对籼粳交组合及其亲本的稻米品质进行了分析，结果表明：在选育水稻亚种间优质米组合时，亲本中必须有１个优质米亲本，另一个为高产中等米质亲本；配制偏粳组合时，最好选用粳型不育系作母本；反之，配制偏籼组合时，应选用籼型不育系作母本；双亲垩白度都高的亲本不宜选用；另外，在选配偏粳组合时，不宜选用直链淀粉含量高（２４％以上）的籼稻作父本，最好直链淀粉含量在２０％以下。

Twenty-four intersubspecific rice hybrids were studied on their grain quality characters. It has been found that it is not difficult to obtain mid-level quality intersubspecific hybrid rice combinations provided that the parental lines are properly selected, and there also has a good chance to get high quality hybrid rice. The key points are: 1) one of the two parents must be of high quality, the other must be of at least mid-level quality and high yield; 2) indica male sterile (ms) lines should be adopted if indica hybrid rice crosses are expected, and vice versa; 3)parental lines with high chalky rate should not be used; 4) indica male parents with high amylose content (>24%) should not be used if japonica hybrid rice crosses are expected, and amylose content less than 20% is recommended. The rate of hybrid rice (F 2), which achieved the quality standard of elite parents in characters of grain quality, were as follows: 90% (highest) in amylose content, 80% in alkali value, 70% in rate of brown rice, head rice rate and gel consistency value, 60% in rate of milled rice and 40% in chalky and transparency values, and 23% in rate of grain length/width ratio. Hybrid rice (F 2) were found better than both parents in amylose content, brown rice rate, gel consistency value, head rice and milled rice rate.