多倍体水稻优良回复二倍体品系的米质分析

Analysis of the Grain Quality of Elite Diploid Rice Lines Reverted from Polyploid Rice

摘要: 水稻是我国第一大粮食作物，在粮食安全中发挥着重要作用，优质高产水稻新品种的选育对社会稳定和经济发展具有重要意义。前期通过多倍体水稻品系的花药培养，获得了多个农艺性状优良的回复二倍体品系。为详细掌握回复二倍体的米质状况，分析其应用前景，并为其遗传改良提供参考，本研究以15份回复二倍体品系为材料，对其加工品质、外观品质、蒸煮和食味品质等相关指标进行测定并分析。加工品质方面，15份材料的糙米率和精米率差异不大，其中糙米率均接近80%，精米率均在70%左右；但整精米率有较大差异，最高可达68.2%，而最低只有42.2%。外观品质方面，15份材料的粒长除WH20ST218外，均超过6 mm，最长可达6.8 mm；长宽比除WH20ST218外均超过3.0，最大为3.3；垩白粒率和垩白度上不同材料变化较大，但表现均较好，其中垩白粒率最小9%，最大25%，垩白度最小2.5%，最大8.1%；由于垩白粒率和垩白度较小，透明度均表现为1级或2级。蒸煮和食味品质方面，15份材料均属于低直链淀粉稻米，直链淀粉含量在14%左右，最小13.5%，最大15.4%；15份材料均属于软胶稠度稻米，且多在75 mm左右，最小65 mm，最大89 mm；碱消值方面，9份材料为3~4级，6份材料为6~7级。综合全部指标，依据NY/T593-2013优质米评判标准，15份材料中有2份为二级优质米，1份为三级优质米，其余为普通米。

Abstract: Rice is the main food crop in China and plays an important role in food security. The breeding of new rice varieties with high-quality and high-yield is of great significance to social stability and economic development. In the previous study, several elite diploid rice lines with excellent agronomic traits were obtained by anther culture from polyploid rice lines. In order to master the grain quality of the reverted diploid in detail, analyze its application prospects, and provide references for its genetic improvement, the indexes of processing quality, exterior quality, cooking and eating quality of fifteen elite reverted diploid rice lines were measured and analyzed in this study. For processing quality, there was little difference on brown rice rate and milled rice rate of the 15 materials. The brown rice rate was close to 80%, and the milled rice rate was about 70%. However, the head rice rate had great difference among the 15 materials, the highest was 68.2%, and the lowest was only 42.2%. For exterior quality, the grain length of the 15 materials was more than 6 mm except for WH20ST218, and the longest grain could reach 6.8 mm; length-width ratios were more than 3.0 except for WH20ST218, and the maximum was 3.3; the chalkiness rate and chalkiness degree of different materials varied greatly, but they all performed well. Among them, the minimum and maximum chalkiness rates were 9% and 25%, respectively. The minimum and maximum chalkiness degrees were 2.5% and 8.1%, respectively. Because both the chalkiness rate and chalkiness degree were low, the transparency was grade 1 or 2. For cooking and eating quality, all the 15 materials were low amylose content rice (about 14%). The minimum and maximum of amylose contents were 13.5% and 15.4%, respectively. The 15 materials were all of the soft gel consistency rice, and the gel consistency was about 75 mm. The minimum and maximum gel consistencies were 65 mm and 89 mm, respectively. For alkali digestion value, 9 materials were grade 3 to 4, and 6 materials were grade 6 to 7. Base on all the indicators as well as the high-quality rice evaluation standard (NY/T 593-2013), among the 15 materials, 2 were grade 2, 1 was grade 3, and other materials were common rice.