实心小麦86-741茎秆的解剖分析及壁厚特性的SSR标记

Microsatellite Markers for Culm Wall Thickness and Anatomical Features of Solid Stem Wheat 86-741

以实心小麦86-741、新疆稻麦及其杂种F1为材料,利用石蜡切片和SSR标记方法对86-741的实心特性进行了分析。结果表明,实心小麦86-741茎内仅有极小髓腔,髓腔中有髓,机械组织中有维管束的分布;杂种F1偏向实心亲本86-741,有髓腔,但髓腔的直径小于新疆稻麦,机械组织所占的比例小于亲本86-741;86-741维管束数最多,F1代其次,新疆稻麦最少。遗传分析与SSR标记结果表明,86-741髓的有无是由双隐性基因控制的;而其壁厚性状由位于3BL染色体上的单显性基因控制,与SSR标记Xgwm-547的遗传距离为5.3cM。暂将该壁厚基因定名为Cwt-1。Xgwm-547可用于辅助转育壁厚特性,提高小麦品种的抗倒伏能力。

Lodging is a big problem in further increasing yield of wheat （Triticum aestivum L.）. Development of variety with thickwall of basal internodes is an effective way to improve lodging resistance in wheat. A solid stem line ＂86-741＂ has been developed from the cross between hexaploid Triticale and common wheat, and acted as parent in lodging resistance breeding. To detect the gene（s） of culm wall thickness in 86-741, we made a cross between 86-741 and a stem hollow wheat line ＂Xinjiang Daomai＂ [Triticum petropavlovskyi Udacz. et Migusch] in 2004-2005 growth season, and developed its F2 population in 2005-2006 growth season. The F2 population was used for bulked segregation analysis （BSA） of the gene related to culm wall thickness by SSR markers. Anatomical analysis revealed that 86-741 had very smaller stem pith cavity with pith, thicker mechanical tissue and more vascular bundles than Xinjiang Daomai. The F1 progeny of the cross showed some tendencies to its parent 86-741： culm with smaller diameters of pith cavity than the parent Xinjiang Daomai. The percentage of mechanical tissue in F1 was smaller than that in 86-741, and the number of vascular bundles in F1 was less than that in 86-741, but more than that in Xinjiang Daomai. Two recessive genes relating to pith and a single dominant gene on 3BL relating to culm wall thickness were detected in 86-741, respectively. The gene controlling culm wall thickness was temporarily designated as Cwt-1. We found 3 microsatellite （SSR） markers Xgwm-247, Xgwm-340, and Xgwm-547 linking to Cwt-1, in which Xgwm-247 was the closest to the gene with genetic distance of 5.3 cM. Our results indicated that Xgwm-247 can be used in marker-assisted selection （MAS） for lodging resistance breeding by selecting culm wall thickness trait in wheat.