Robin S, Pathan M S, Courtois B, Lafitte R, Carandang S, Lanceras S, Amante M, Nguyen H T, Li Z
International Rice Research Institute, MCPO Box 3127, 1271 Makati City, The Philippines.
Theor Appl Genet. 2003 Nov;107(7):1288-96. doi: 10.1007/s00122-003-1360-7. Epub 2003 Aug 12.
Osmotic adjustment is one of several characters putatively associated with drought tolerance in rice. Indica cultivars are known to have a greater capacity for osmotic adjustment than japonica cultivars. We developed an advanced back-cross population using an indica donor, IR62266-42-6-2, to introgress osmotic adjustment into an elite japonica cultivar, IR60080-46A. One hundred and fifty BC(3)F(3) families were genotyped using microsatellites and RFLP markers, and a few candidate genes. We evaluated osmotic adjustment in these lines under greenhouse conditions using the re-hydration technique. Using the composite interval mapping technique, we detected 14 QTLs located on chromosomes 1, 2, 3, 4, 5, 7, 8 and 10 that together explained 58% of the phenotypic variability. Most, but not all, of the alleles with positive effects came from the donor parent. On chromosome 8, two QTLs were associated in repulsion. The QTL locations were in good agreement with previous studies on this trait on rice and in other cereals. Some BC(3)F(3) lines carried the favorable alleles at the two markers flanking up to four QTLs. Intercrossing these lines followed by marker-aided selection in their progenies will be necessary to recover lines with levels of osmotic adjustment equal to the donor parent. The advanced back-cross strategy appeared to be an appropriate method to accelerate the process of introgressing interesting traits into elite material.
渗透调节是水稻中几种被认为与耐旱性相关的特性之一。已知籼稻品种比粳稻品种具有更强的渗透调节能力。我们利用籼稻供体IR62266 - 42 - 6 - 2构建了一个高代回交群体，将渗透调节特性导入优良粳稻品种IR60080 - 46A中。使用微卫星标记、RFLP标记和一些候选基因对150个BC(3)F(3)家系进行了基因分型。我们在温室条件下采用复水技术对这些株系的渗透调节能力进行了评估。利用复合区间作图技术，我们在第1、2、3、4、5、7、8和10号染色体上检测到14个QTL，这些QTL共同解释了58%的表型变异。大多数（但不是全部）具有正向效应的等位基因来自供体亲本。在第8号染色体上，两个QTL呈相斥连锁。这些QTL的位置与之前关于水稻和其他谷类作物该性状的研究结果高度一致。一些BC(3)F(3)株系在多达四个QTL两侧的两个标记位点上携带了有利等位基因。有必要将这些株系进行杂交，然后在其后代中进行分子标记辅助选择，以获得渗透调节水平与供体亲本相当的株系。高代回交策略似乎是一种将优良性状导入优良材料的合适方法，可以加速这一进程。
