实心小麦86-741茎秆的解剖分析及壁厚特性的SSR标记

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5.3 cM。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。

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

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.