Submitted to: Journal of Plant Science and Molecular Breeding
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/31/2013
Publication Date: 6/11/2013
Citation: Egamberdiev, S.S., Ulloa, M., Saha, S., Salakhudinov, I.B., Abdullaev, A., Glukhova, L.A., Adylova, A.T., Scheffler, B.E., Jenkins, J.N., Abdurakhmonov, I.Y. 2013. Molecular characterization of Uzbekistan isolates of fusarium oxysporum f. sp. vasinfectum. Journal of Plant Science and Molecular Breeding. 2:3. Interpretive Summary: Fusarium wilt is an important disease of many crops that is caused by a fungus that can survive for long periods in the soil, making it impossible to eliminate. This disease reduces yield in cotton. The cotton host-specific forms of this fungus are comprised of different genotypes called races. These races significantly differ in the way they affect and infect cotton cultivars. A collection of isolates with unknown race identification of the Fusarium fungus from infected cotton in Uzbekistan was characterized based on DNA candidate-gene sequencing approach. Results from this approach and DNA sequence comparison with known Fusarium races clearly suggested that Uzbekistan Fusarium genotypes can be classified in three groups: group 1) as race 1, 2, & 6; group 2) as race 3; and group 3) as race 4 or 7. Our research provided for the first time a comprehensive study on the identification of Fusarium races collected from different regions of Uzbekistan. In addition, this study will help breeders to develop resistance management strategies to combat the Fusarium wilt disease by breeding resistant cotton cultivars in Uzbekistan.
Technical Abstract: A collection of isolates of Fusarium oxysporum f.sp. vasinfectum (FOV) from cotton in Uzbekistan was characterized based on a candidate gene sequencing approach. As a first step, cotton seedlings were artificially infected with eight randomly selected unknown FOV isolates from the collection, FOV strains were re-isolated, and monospore cultures were obtained for genomic DNA preparation. Candidate genes such as elongation factor (EF-1a), beta tubulin (BT), and ribosomal DNA (rDNA) were sequenced from these unknown Uzbekistan FOV isolates and a set of eight known races of FOV (races 1, 2, 3, 4, 6, 7, 8, and Australian VCG1112) were collected from world research centers. A parsimony based phylogenetic analysis of known races of FOV together with unknown FOV isolates from the Uzbekistan collection clearly suggested that Uzbekistan FOV genotypes can be classified in three groups: group 1) as race 1, 2, & 6; group 2) as race 3; and group 3) as race 4 or 7. Based on EF-1a pair-wise genetic distances, no difference was observed between races 4 and 7 of FOV. Results from our research provided for the first time a comprehensive study on the identification of FOV races collected from different regions of Uzbekistan. In addition, this study will help breeders to develop resistance management strategies to combat the Fusarium wilt disease by breeding resistant cotton cultivars in Uzbekistan.