小麦抗叶锈基因Lr20、Lr28、Lr29的STS、SCAR标记在近等基因系上的特异性验证

Verification of STS and SCAR Molecular Markers for Leaf Rust Resistance Genes Lr20,Lr28 and Lr29in Near-isogenic Lines of Wheat cv. Thatcher

为了把特异性分子标记与抗病性鉴定有效地结合起来,用含有不同抗叶锈基因的54个以Thatcher为遗传背景的近等基因系(Near-isogenic lines,NILs)对与抗叶锈基因Lr20、Lr28和Lr29(Lr29UBC和Lr29OPY)连锁的STS、SCAR标记进行特异性验证,结果分别扩增出片段大小依次为540、378、1 000、900bp的条带,与报道片段大小一致。同时发现与抗病基因Lr20、Lr29连锁的STS分子标记及与Lr29连锁的两个SCAR标记Lr29UBC、Lr29OPY在NILs中特异性较好,但Lr28的PCR-STSLr28扩增产物不仅在其亲本中,而且在其余53个近等基因系中都扩增出与报道大小相同的378 bp的条带。验证结果表明,与抗病基因Lr20、Lr29连锁的STS、SCAR分子标记在NILs中特异性较好,可方便地用于小麦抗叶锈的分子标记辅助选择育种,而Lr28的STS分子标记没有特异性,不能用于分子标记辅助选择育种。

Sequence tag site（STS） and SCAR markers for genes Lr20,Lr28,Lr29（Lr29OPY and Lr29UBC）against Puccinia triticina were used to screen a set of near-isogenic lines（NILs） of wheat cv.Thatcher,which containing in total 54 different Lr genes and their alleles.Polymerase chain reaction（PCR） analysis using STS and SCAR primers specific for these leaf rust resistance genes indicated the marker loci of 540 bp,378 bp,900 bp and 1 000 bp could be obtained as the same as reported previously.The result showed the loci of markers STS Lr20-STS638,SCAR Lr29-UBC and SCAR Lr29-OPY were unique and specific,and could be used for molecular marker-assisted selection.But the locus of the STS Lr28marker for Lr28was detected in all the near-isogenic lines used in this study,which indicated that the locus of marker STS Lr28was not specific,and could not be used for molecular marker-assisted selection.