Marker‐assisted selection (MAS) can speed up the plant breeding process and reduce the labour and field costs. The sequence‐characterized amplified region (SCAR) marker allows the elimination of the restriction digestion step. Hence, it is more efficient and reliable than the cleaved amplified polymorphic sequence (CAPS) marker in gel‐based screening. But we still only have CAPS marker for many tomato disease resistance genes. By comparing the coding region and its flanking sequences of the disease‐resistant genes between the resistant and the susceptible varieties, we designed primers that can amplify fragments with different sizes from these varieties for the Pto, Tm2², Sw5 and I3 genes conferring resistance to bacterial speck (BS), Tomato mosaic virus (ToMV), tomato spotted wilt virus (TSWV) and Fusarium wilt (FW) race 3, respectively in tomato. We tested these new markers using our tomato breeding lines and hybrids. All the new SCAR markers worked as expected. The fragments' sizes were amplified from the resistant variety, and the susceptible variety is 1,512 and 450 bp for Pto, 885 and 583 bp for Tm2², 521 and 451 bp for Sw5 and 673 and 480 bp for I3 genes. All the new markers are tightly‐linked to the resistant genes; the markers of Pto, Tm2², Sw5 and I3 are 3,306, 4,888, 0 and 8,310 bp from their corresponding coding sequences, respectively. These new markers may be useful for MAS in tomato breeding.

中文翻译：

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开发共价SCAR标记以检测番茄（Solanum lycopersicum）中的Pto，Tm22，I3和Sw5基因

标记辅助选择（MAS）可以加快植物育种过程并降低人工和田间成本。序列鉴定的扩增区（SCAR）标记可消除限制性酶切步骤。因此，在基于凝胶的筛选中，它比裂解的扩增多态性序列（CAPS）标记更为有效和可靠。但是我们仍然只有CAPS标记可用于许多番茄抗病基因。通过比较抗病和易感品种之间抗病基因的编码区及其侧翼序列，我们设计了引物，可扩增出这些品种中不同大小的Pto，Tm2 ²，Sw5和I3片段分别赋予番茄抗细菌斑点（BS），番茄花叶病毒（ToMV），番茄斑萎病病毒（TSWV）和镰刀菌枯萎病（FW）第3种抗性的基因。我们使用番茄育种系和杂种测试了这些新标记。所有新的SCAR标记器均按预期工作。从抗性品种中扩增出片段的大小，Pto的易感品种分别为1,512和450 bp，Tm2 ²的敏感品种为885和583 bp，Sw5和I3基因的敏感品种分别为521和451 bp和673和480 bp 。所有这些新标记都与抗性基因紧密相连。Pto，Tm2 ²，Sw5和I3的标记分别从其相应的编码序列开始分别为3,306、4,888、0和8,310 bp。这些新标记可能对MAS在番茄育种中很有用。