覆盖野生稻基因组的染色体片段替换系的构建及其米质相关数量性状基因座位的鉴定

染色体片段替换系（CSSL）是基因组水平快速初步定位数量性状基因座位（QTL）的良好材料，而水稻的品质性状是多基因控制的数量性状，因此可用替换系鉴定控制水稻品质性状的QTL。本文用分子标记辅助选择技术（MAS）构建了由133个株系组成的以‘特青’（籼稻品种）为轮回亲本，以海南的一种普通野生稻为供体亲本，覆盖绝大部分野生稻基因组的染色体片段替换系。利用这套替换系，初步定位了控制稻米外观和理化品质性状的15个QTL，为今后水稻品质性状QTL的克隆以及稻米品质相关性状的改良提供了依据。

Construction of Chromosome Segment Substitution Lines Carrying Overlapping Chromosome Segments of the Whole Wild Rice Genome and Identification of Quantitative Trait Loci for Rice Quality

Rice is one of the major staple cerea grains. Most of the important traits of crops are complex traits controlled by quantitative trait loc (QTL). Detection and genetic identification o QTLs can provideinsights into molecular and bio logical mechanisms of development and physiology. Chromosome segment substitution lines (CSSLs) have been proposed as a simpleand powerfulway to identify QTLs. The demand for rice grain quality becomes increasingly important. The primary components of rice grain quality include appearance, milling and physico-chemical, cooking and eating quality Mostof these traits are complex and controlled by QTLs, so genetic characterization of these traits is moredifficult than that of traits each controlled by a singular gene such as Waxy, which controls glutinousness of ricegrain. We constructed 133 chromosome segmen substitution lines (CSSLs) from backcross prog enies (BC3F2)derived fromacross between Teqing (an O. sativa L. ssp. indica variety) as the recur rent parent and wild rice (O. rufipogon Griff.) as the donor parent. In this process, we carried ou marker-assisted selection (MAS) by using 118 CAPS or SSR markers covering the whole ricegenome (Figs.1, 2). Because phenotypic values of quality trait weresignificantly different betweencultivarTeqing and wild rice, the CSSLs were used to identify QTLs for ricequalitytraits. Threeappearancequal- ity traits (head rice percentage, HRP; percentage ofchalky ricegrains,PCRG;transparency, TP) and five physico-chemical properties (gelatinization temperature, GT; gel consistency, GC; amylose content, AC; protein content, PC; fat content, FC) were scored using 133 CSSLs which substituted segments covering thewhole genome of wild rice. A total of15 QTLs for five of the eight traits men- tioned above (HRP, PCRG, TP, PC and FC) were identified on ninechromosomes,andseveral QTLs affecting different quality traits were mapped in the same regions (Fig.3, Table 1).