植物数量性状变异的分子基础与QTL克隆研究进展

探讨数量性状变异规律以便对其进行遗传操纵一直是植物遗传学的一个重要领域。DNA分子标记和QTL作图技术的发展以及拟南芥和水稻全基因组测序的完成极大地促进了植物数量性状分子基础的研究。现已克隆了拟南芥ED1、水稻Hdl、玉米Tb1、番茄fw2．2和Brii9-2-5等控制目标数量性状的基因。数量性状表型变异不仅源于多个数量性状基因（QTL）的分离．而且还受到内外环境的修饰。QTL等位基因变异与孟德尔基因变异具有类似的分子基础，即基因表达或蛋白质功能发生改变。通过分析已克隆的植物QTL的变异特征及分子基础，讨论了植物QTL克隆技术策略，并对QTL研究所面临的挑战和应用前景进行了展望。

Research Advances in Molecular Basis of the Variations and QTL Cloning of Quantitative Plant Traits

It is an important field of plant genetics to explore the variation patterns of quantitative traits for genetically manipulating them. The developments of molecular DNA markers,and QTL mapping and the complete sequencings of Arabidopsis and rice genomes greatly enhance the research about molecular basis of the variations of quantitative plant traits. Now,such genes controlling target quantitative traits as ED1 of Arabidopsis,Hdl of rice,Tblof corn,and fw2.2 and Brix9-2-5 of tomato,which are the genes controlling targets can be cloned. The phenotypic variations of quantitative traits not only result from the separations at many quantitative trait loci,but also are modified by external and internal environments. The allelic variations at QTL has similar molecular basis to the variations at simple Mendelian loci and the basis is that gene expressions or protein functions vary. Analyzing the variations and molecular basis of cloned plant QTL,the paper discusses the technical strategies of QTL cloning,and envisages the challenges and application prospects that QTL research will face.