TMV RESISTANT TOBACCO PLANT CONTAINING SHORT N INTRODUCED FRAGMENT AND METHOD FOR BREEDING SAME

摘要

A TMV resistant tobacco plant containing a short N introduced fragment and a method for breeding the same. A homozygous tobacco plant containing an N introduced fragment is hybridized with a tobacco plant having a genotype of nn, to obtain an F1 progeny tobacco plant having a genotype of Nn. The F1 progeny tobacco plant is hybridized with the tobacco plant having the genotype of nn, to obtain population materials for screening to obtain the short N introduced fragment. TMV is inoculated at a seedling stage, and Nn genotype plants showing plaques 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 introduced fragment. 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 containing the short N introduced fragment. The number of non-target gene components deleted from plants containing the short N introduced fragment is estimated using TN5.34 and TN5.20 and TN4.99 primer pairs. The obtained short N introduced fragment is applicable to resource formulation and selective breeding of TMV resistant tobacco. The invention is helps to reduce cumbersome linkage with an N gene.