中国杂交粳稻的米质及优质达标率研究

根据NY/T 593-2002《食用稻品种品质》标准,分析了中国近8 a(1998—2005)育成的267份杂交粳稻的米质及其达标率。结果表明,杂交粳稻的米质整体较优,各项米质指标的平均值,除垩白米率接近优质3级外,其它全部达到或超过优质3级标准。优质达标率在75%以上的米质指标有糙米率、精米率、透明度、糊化温度、胶稠度、蛋白质含量、直链淀粉含量、整精米率等8项,其中前6项的优质达标率在90%以上。全部10项米质指标均达到优质的组合数占测定总组合数的45.4%。在地域上,北方稻区杂交粳稻的垩白粒率、垩白度的平均值低于南方稻区杂交粳稻。与常规粳稻比较,杂交粳稻各项米质指标的平均值除垩白米率高7个百分点外,其它9项米质指标基本相同。改良垩白性状仍然是杂交粳稻育种的主要目标之一。

Studies on Grain Quality and High Quality Rate of Japonica Hybrid Rice in China

A total of 267 japonica rice hybrids developed in 8 years from 1998 to 2005 in China were studied on their grain quality and high quality rate based on the standard NY/T 593-2002 for cooking rice variety quality.The results showed that the japonica hybrids had a rather good grain quality in whole.Among all of ten quality indexes,i.e.,brown rice rate(BRR),milled rice rate(MRR),head rice rate(HRR),chalky grain percentage(CGP),chalkiness degree(CD),translucency degree(TD),gelatinization temperature(GT),gel consistency(GC),amylose content(AC) and protein content(PC),in terms of the average value,except that CGP was close to the third class of high quality standard,the other nine quality indexes all reached or surpassed the third class of high quality standards.Concerning on the high quality rate,8 indexes including BRR,MRR,TD,GT,GC,PC,AC and HRR had a value of more than 75%,of which 6 indexes more than 90%.The number of hybrids with all ten indexes reaching high quality standard accounted for 45.4% of the total number of tested hybrids.Compared with the japonica hybrids from south China,those from north China showed a lower average value of CGP and CD.Compared with inbred japonica rice,japonica hybrid rice had almost the same average values in all ten indexes except for CGP,which was 7 percentage point higher in hybrid rice than in inbred rice.It was considered that one of the most important breeding objectives would still be the genetic improvement of chalky characters in quality japonica hybrid rice breeding.