Breeding tomato for resistance to some prevailing fungal diseases in Iran.

During the collecting and identification of causal agents of most common diseases of tomato , different areas of tomato production in Iran were surveyed and infected fields were identified. Infected plants with fungal wilt,leaf blight and canker symptoms were identified. The samples were cultured on PDA and each isolate was purified by single spore method. The characteristics of isolates was studied and the species of them were determined by using Elllis and Nelson keys. isolates causing wilt of tomato were identified as Fusarium oxysporum by using Nelson key. according to the results of differential host test and comparing of the isolates with the istandard ones which obtain from Amsterdam university, race of isolates causing wilt was determined as race 1. isolates causing leaf blight belonged to Alternaria alternata and Alternaria tenuissima and isolate causing stem canker belonged to Alternaria alternate species. Pathogenesity test of isolates were done in greenhouse with artificial inoculation and aggressive isolates were determined.The reaction of different cultivars and genotypes of tomato were study during the inoculationf of seedlings and plants in greenhouse and fields. Results showed that cultivars King stone , Early orbano VF, FDT 202 and genotype Sunny * Sp-100 to stem canker disease and Super 2270, King stone , Early orbano VF to blight disease were resistant. cultivars and genotypes of tomato with good characters and high yield , were crossed reciprocally with cultivars selected from primary project which had resistance to canker disease in Karaj and Varamin regions. During this procedure about 18 crossed tomato were obtained in F1 generation. The crossed tomatoes with their parents were screened to the most common diseases in the hot spot during the evaluation projects. And thre results showed that crosses including King stone ♂ × Mino ♀ and Soria ♂ × Early Urbano ♀ and cultivars King stone and Early Urbano had the suitable resistance to blight disease, crosses including Soria♂ × Early Urbano♀, Peto Early♀ × Genotype 2♂, Walter♂ × Soria♀, Mino♀ × King stone♂ and Soria♀ × Kallgi♂ and Cultivar "Early Urbano"were resistant to stem canker disease and genotypes including Petomech vf1- 2¡ Petopride III ¡ Redstone¡ Castle rock ,cultivars Kalgi, Early Urbano Shiva and soria had high resistance to the fusarium wilt disease.