A TMV resistant tobacco plant containing a short N introgressed segment and a method for breeding the same. A homozygous tobacco plant containing an N introgressed segment is hybridized with a tobacco plant of genotype nn to obtain an F1 progeny tobacco plant of genotype Nn. The F1 progeny tobacco plant is hybridized with the tobacco plant of genotype nn, to obtain population materials for screening to obtain the short N introgressed segment. TMV is inoculated at a seedling stage, and Nn genotype plants showing necrotic lesion are obtained by screening the population materials. The Nn genotype plants are genotyped using a molecular marker TN5.51 primer pair and an N gene-specific molecular marker N1N2 at the right end of the N introgressed segment. A plant found to be negative when tested by the TN5.51 primer pair and to be positive when tested by the N1N2 molecular marker is a plant comprising the short N introgressed segment. The size of non-target genomic components deleted from plants containing the short N introgressed segment is estimated using TN5.34 and TN5.20 and TN4.99 primer pairs. The obtained short N introgressed segment is applicable to germplasma innovation and breeding of TMV resistant tobacco. The invention is helps to reduce linkage drag with the N gene.
一种含有短 N 导入片段的抗 TMV 烟草植株及其育种方法。将含有 N 导入片段的同源烟草植株与
基因型为 nn 的烟草植株杂交,获得
基因型为 Nn 的 F1 后代烟草植株。将 F1 后代烟草植株与
基因型为 nn 的烟草植株杂交,获得用于筛选的群体材料,以获得短 N 导入片段。在幼苗期接种 TMV,通过筛选群体材料获得出现坏死病变的 Nn
基因型植株。使用分子标记 TN5.51 引物对 Nn
基因型植株进行
基因分型,并在 N 导入片段的右端使用 N
基因特异性分子标记 N1N2。在使用 TN5.51 引物对检测时发现为阴性,而使用 N1N2 分子标记检测时发现为阳性的植株就是含有短 N 导入片段的植株。使用 TN5.34、TN5.20 和 TN4.99 引物对估算从含有短 N 导入片段的植株中删除的非目标
基因组成分的大小。所获得的短 N 导入片段可用于抗 TMV 烟草的种质创新和育种。本发明有助于减少 N
基因的连锁阻力。