Open AccessA co-dominant molecular marker of fusarium wilt resistance gene <I>I-2</I> derived from gene sequence in tomato
Author(s) -
Yu Shuancang
Publication year - 2008
Publication title -
yichuan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.125
H-Index - 16
ISSN - 0253-9772
DOI - 10.3724/sp.j.1005.2008.00926
Subject(s) - genetics , biology , gene , genotype , locus (genetics) , genotyping , microbiology and biotechnology , primer (cosmetics) , allele , sequence analysis , cleaved amplified polymorphic sequence , restriction fragment length polymorphism , chemistry , organic chemistry
Sequence-specific PCR primers, I-2/5F and I-2/5R were designed according to the sequence from 3 132 bp to 3 765 bp in I-2 gene. With them a 633 bp fragment was amplified from 03F-7 with a genotype of I-2 / I-2, 693 bp fragment from Moneymaker with a genotype of i-2/ i-2, and both fragments from Tebao with heterozygous genotype I-2 / i -2. These two specific fragments were cloned and sequenced. The results from multiple sequence alignment showed that the 633 bp fragment from 03F-7 was identical with the sequence from 3 132 bp to 3 765 bp in I-2 gene. Compared with the sequence of I-2 gene, there were a large number of mutations and a 60 bp fragment inserted in susceptible alleles. The PCR primer combination, I-2/5F and I-2/5R can be used to distinguish homozygous resistant, heterozygous and homozygous susceptible materials, and it is a functional co-dominant marker in I-2 gene selection. Moreover, this marker was employed on 16 major tomato varieties for I-2 locus genotyping, in which half of the varieties contain I-2 gene, and only one variety is homozygous resistant. In addition, simultaneous detection system for I-2 and Tm-2(2) was established by a single PCR and a Hind III digestion. It provides a powerful tool for multiple genes selection in tomato breeding program.