Development Of Snp For Leaf Mould Resistance Gene CF-9in Tomato And Screen Of Germplasm Resources

Tomato leaf mold, caused by the fungus Cladosporium fulvum, which can develop new physiological races of the pathogen very rapidly, is one of the most economically significant diseases of the tomato industry. A resistant cultivar will become susceptible soon once be used in the production. Consequently, breeding to obtain resistant cultivars is an efficient method to control leaf mold outbreaks. SNP is a DNA molecular technique with ideal diversity which has just been applied in breeding. Compare with conventional artificial inoculation, the method of molecular marker assisted screening (MAS) was highly sensitive and specific for finding target resistant germplasm.This study identified the SNP molecular marker linked to C.fulvum resistant gene Cf-9in tomato.63cultivars of germplasm resource were screened using the SNP markers we identified. These resistant cultivars we obtained could be used in C.fulvum resistant breeding practice. The results as follows:1) Material of tomato resistance to leaf mould provided by our research group.455individuals of F2segregating population were derived from Dongnong712(F1), the inoculation results showed that the resistance of tomato material was controlled by a single dominant gene(Cf-9) and that fits the monogenic Mendelian inheritance law completely.2) Two primer conbinations for Cf-9gene were designed, and we obtained three SNPs(S918, S1040、 S2690) and one Indel (1910) through the comparation amone Cf-9sequence of all6materials and the Cf-9gene in the GenBank.3) AS-PCR primer were designed according to the SNPs we obtained, the primer combination S918-1/CP-1(based on S918) was selected to be used in germplasm resource screening.And the AS-PCR pair S918-1/S918-2(with common sense primer CP-1)were used for genotyping of partitial F2population.4) We obtained16germplasm resistant resources carrying C/-9gene in the screening of63germplasm resources by using the S918-1/CP-1SNP marker we developed, but14Cf-9carried germplasm resources were resistant in inoculation.There were12resistant germplasm showed the same identification result in both SNP marker identification and inoculation.