非洲栽培稻基因渗入系的稻米品质鉴定与筛选

稻米品质改良越来越成为现代水稻育种工作的重要目标,探明新选育非洲栽培稻基因渗入系的稻米品质潜力将为其在水稻优质育种工作中的进一步应用奠定基础。对50份非洲栽培稻基因渗入系的12个稻米品质性状进行了考察鉴定,并结合相关性分析、聚类分析和判别分析方法对其综合品质表现进行了分类评价。供试材料均表现较高的糙米率(≥74.19%)、精米率(≥67.83%)、较大的长宽比(≥2.79)和低水分含量(≤13.03%),多数选系具有适宜的直链淀粉含量(17.00-22.00%)。聚类分析将供试材料分为5组,其中第I组的综合米质性状最优;典型判别分析获得2个典型判别函数,分别可解释89.5%和7.2%的方差变异,主要反映垩白粒率和长宽比等指标。新选育的非洲栽培稻基因渗入系在糙米率、精米率、长宽比和直链淀粉含量方面具有优势,垩白粒率和长宽比是非洲栽培稻基因渗入系品质改良的重要指标；本研究将为非洲栽培稻基因渗入系在高产优质水稻新品种选育中的研究应用提供依据。

Identification and Screening of Rice Quality Characteristics of Introgression Lines Carrying African Rice Genes

It is becoming an important goal to improve the rice quality characteristic in the modern rice breeding work. Exploring of the quality potential for the newly bred African rice introgression lines would be an important foundation for their further utilization in the breeding of new rice cultivars with good quality. In this study, 12 rice quality characteristics of 50 African rice introgression lines were investigated, and the integrate quality performance of the tested materials were further assessed and screened with correlation analysis, clustering, and typical discriminant analysis methods. Our results showed that all introgression lines performed high brown rice rate (≥74.19%), high milled rice rate (≥67.83%), high length-width ratio (≥2.79), and low moisture content(≤13.03%); appropriate rice amylose content (17.00-22.00%) were observed for most (26/50) of the introgression lines according to the national standard of good quality in milled rice. The Fifty introgression lines were clustered to 5 groups based on DIST distances calculating with 12 rice quality characteristics, in which group I performed optimal rice quality characteristics. The typical discriminant analysis revealed distinct grouping results which is identical with that of clustering method. Two typical discriminant functions were obtained, and can explain 89.5% and 7.2% of phenotypic variation in all the 12 characteristics, respectively. The appearance quality including chalky rice rate and length-width ratio were highlighted in the two functions, which could be the key traits to be improved in the further study. The newly selected 50 introgression lines of African cultivated rice have good advantages on further research and application potential in terms of brown rice rate, milled rice rate, length-width ratio and amylose content; the chalky grain rate and aspect ratio can be the important indicators for rice quality improvement using introgression lines of African cultivated rice. Our results will provide a basis for the breeding of new rice varieties with high yield and excellent quality.