优质籼稻品种黄华占和扬稻6号稻米理化特性和淀粉精细结构比较

Comparative Analysis of Grain Physicochemical Properties and Starch Fine Structure between Indica Rice Cultivars Huanghuazhan and Yangdao 6 with Good Quality

以携带相同Wxb基因的籼稻品种黄华占和扬稻6号为试验材料,系统分析了这2个优质籼稻品种的理化特性和淀粉精细结构。结果表明,黄华占稻米蛋白质含量显著低于扬稻6号,而表观直链淀粉含量高于扬稻6号,其他理化品质如胶稠度、总淀粉含量和碱消值两者无显著差异;黄华占稻米具有较高的糊化温度和热焓值。黄华占和扬稻6号稻米淀粉粘滞曲线较为接近,但黄华占稻米具有较高的崩解值和较小的回复值。扫描电镜分析表明,淀粉粒形态和结构在2个样品间无明显差异;但淀粉精细结构分析表明,黄华占稻米淀粉含有较少的支链淀粉短链以及较多的支链长链和较多的直链淀粉短链;淀粉晶体结构分析表明,黄华占和扬稻6号淀粉均为A型晶体,但黄华占稻米淀粉的长程有序结构较扬稻6号淀粉高,而短程有序结构样品间无显著差异。上述研究为选育优质籼稻提供了参考。

With the high-quality indica rice varieties Huanghuazhan(HHZ)and Yangdao 6(9311)carrying the same Wxb allele as experimental materials,the grain physicochemical properties and starch fine structures of the two varieties were systematically analyzed.The results showed that the protein content of HHZ rice was significantly lower than 9311 rice,and the apparent amylose content was higher than that of 9311.There was no significant difference in other physicochemical properties between the two varieties such as gel consistency,total starch content and alkalinity.The thermal profiles of rice flours were analyzed and rice flours from HHZ exhibited higher gelatinization temperature and gelatinization enthalpy compared with 9311.The pasting properties from RVA analysis showed that both of HHZ and 9311 showed similar RVA curves,however,HHZ rice showed higher breakdown and lower setback than 9311 rice.The morphology of starch granule was observed by using scanning electron microscopy and there were no significant differences between the two varieties.Besides,the starch fine structure were investigated,and we found that HHZ grain starch contained reduced amylopectin short chains and increased longer amylopectin chains.Then the crystalline structure analysis showed that starch from HHZ presented higher level of long-range order structure than that of 9311 while both showed similar short-range order structure.The present data provides useful information for grain improvement in indica rice and also the further application of HHZ and 9311 in rice production.