Abstract:

Rice (Oryza sativa L.) eating and cooking quality is mainly influenced by its starch properties. Mapping quantitative trait loci (QTL) for starch properties not only helps us understand their genetic basis leading to acceleration of quality improvement, but also helps us find possible genes participating in the synthesis of starch. A recombinant inbred line (RIL) population consisting of 107 lines, derived from an indica (Zaiyeqing 8, ZYQ 8) and a japonica (Jingxi 17, JX 17) rice, was used to investigate the genetic factors affecting starch quality parameters, such as apparent amylose content (AAC), gel consistency (GC), starch pasting viscosity parameters, gel textural properties, gelatinization temperature (GT) and starch retrogradation properties. A total of 44 QTLs covered chromosomes 2-6, 8, 9 and 11 were detected for the 22 traits, with at least one QTL and as many as four QTLs for each individual trait. The results indicated that two major genes were responsible for most starch property traits. The Wx gene that encodes granule bound starch synthase on chromosome 6 was significant for AAC, GC, starch pasting viscosity parameters, gel textural properties and starch retrogradation properties. The alk gene linked with Wx on chromosome 6 was significant for starch gelatinization temperature characteristics. All other QTLs were minor genes. One QTL on chromosome 9 flanked by RZ404 and G295 was significant for gel hardness (HD), gumminess (GUM), chewiness (CHEW), peak temperature of retrogradated starch (RTp), and percentage retrogradation (R%) and all these traits were not tested before.

利用一个水稻RIL群体定位控制淀粉特性的QTL

包劲松   Harold VORKE   何 平 朱立煌

（1.浙江大学华家池校区核农所， 杭州 310029； 2.香港大学植物系； 3.中国科学院遗传与发育生物研究所， 北京100101）

摘要：利用一个由籼粳(Oryza sativa L.)杂交发展成的重组自交系(RIL)群体研究影响淀粉特性的遗传因子,测定了一系列淀粉特性有关性状,包括直链淀粉含量、胶稠度、淀粉糊粘度、胶的质地、糊化温度、热学特性、回生特性等22个参数.共定位了44个QTL,分布在第2～6、8、9、11染色体上,每个性状所定位的QTL在1到4个不等.其中有2个是主基因,一个是第6染色体上的Wx基因,它控制直链淀粉含量、胶稠度、淀粉糊粘度、胶的质地、回生特性等性状,另一个是第6染色体上的alk基因,它控制糊化温度与热学特性等性状,其他QTL都是微效基因,在第9染色体上RZ404和G295区间系首次检测到,它控制淀粉胶的硬度(hardness)、胶粘性(gumminess)、咀嚼性(chewiness)、回生淀粉的最高糊化温度、回生率等性状,这些性状都未曾研究过.

关健词： alk; 食用与蒸煮品质； 数量性状基因位点；水稻；淀粉； Wx

通讯作者。E-mail: lhzhu @ genetics.ac.cn。