分子标记辅助改良杂交稻协优57及其父母本的蒸煮食味品质

摘要

Xieyou 57 , an elite indica hybrid between the male-sterile line Xieqingzao A and the restorer line 057 , owns high yield and wide adaptability. The high amylose content ( AC) in the endosperm of both parents relatively results in poor cooking and eating quality of the hybrid. 057( the restorer line, designated as 057 ( GG) ) and XieqingzaoA( the male-sterile line, designated as XA( GG) ) on Wx gene was improved. The AC eating quality and granule-bound starch synthase( GBSS) activity of all the four combinations were analyzed. The results revealed that the AC of the single parent improved hybrids, Xieqingzao A( GG) 057 ( TT) and Xieqingzao A( TT)057( GG) were 19. 9％ and 19. 3％ , respectively. Both were lower than that of original Xieyou 57 ( GG , 26. 2％ ) . Result indicated that the improved line of hybrid with homozygous TT-Wx-Xiepngzao A( TT) × 057( TT) , not only showed a decreased AC ( 12. 5％ ) ,but also had better uniform AC for different seeds and good cooking and eating quality. The GBSS activity was tightly related to AC,and the three Wx genotype showed GG ＞ GT ＞ TT.%协优57是一个产量高和适应性强的杂交中籼组合,但由于其父母本直链淀粉含量(AC)高,导致杂交稻米的AC较高、蒸煮食味品质较差.先前利用PCR-Acc I分子标记辅助选择对协优57的亲本057[恢复系,记作057(GG)]和协青早A[不育系,记作协A(GG)]的Wx基因进行改良.利用改良前、后的各亲本分别配组,分析不同组合的AC、食味品质和颗粒性淀粉结合酶(GBSS)活性.结果表明,改良单亲的GT型组合协A(GG)×057(TT)、协A(TT)×057(GG)杂交稻米的AC由原组合协A(GG)×057(GG)的28%分别降到19.9%和19.3%,但均一性较差.改良双亲的TT纯合型组合协A(TT)×057(GG)的杂交稻米,不仅AC降到中等偏低水平(13.1%),而且AC的均一性也有了很大的提高,蒸煮食味品质明显改善.GBSS活性分析表明:三种Wx基因型的GBSS活性总体表现为GG>GT>TT.