A PCR method to detect tomato genotypes with the I-2 gene for resistance to Fusarium oxysporum f. sp. lycopersici race 2

• Published in: Phytopathology Vol. 96; no. 6; pp. S32 - S33
• Main Authors: El-Mohtar, CA, Abou-Jawdah, YA, Atamian, H S, Salus, MS, Maxwell, D P
• Format: Journal Article
• Language: English
• Published: 01.06.2006
• Subjects: Fusarium oxysporum; Lycopersicon esculentum
• ISSN: 0031-949X

Fusarium vascular wilt disease, caused by the soil-borne fungus Fusarium oxysporum f. sp. lycopersici (FOL), is found world-wide. Three races of this fungus are known. Management of this disease is best achieved by development of resistant varieties. Resistance genes to FOL race 1 (I-1 gene) and to FOL race 2 (I-2 gene) are known to be on chromosome 11. The I-2 gene cluster includes one active copy and six non-functional homologs of the I-2 gene. We designed PCR primers to specifically amplify the active copy of this gene. A multiplex PCR protocol was developed that differentiates genotypes with the I-2 gene from those without this gene. Out of 34 genotypes tested with reported reaction to FOL race 2, 33 genotypes gave the expected results. There were no false positives. This method could be used effectively to detect the I-2 gene in a tomato breeding program. Additional keywords: multiplex PCR, Fusarium vascular wilt, marker-assisted selection.