Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 2011
Publication Date: January 4, 2012
Citation: Liu, J., Bell, A.A., Stipanovic, R.D., Puckhaber, L.S. 2012. Phylogenetic analysis based on the PKS gene involved in fusaric acid biosynthesis production reveals close relationship between US race 1 lineage isolates & Australian biotype isolates of Fusarium Oxysporum f. sp. Vasinfectum (Abstract). Proceedings of the Beltwide Cotton Conferences, January 3-6, 2012, Orlando, Florida. p. 12659. Technical Abstract: Isolates of Fusarium oxysporum f. sp. vasinfectum, the causal agent of fusarium wilt of cotton, vary significantly in their virulence. Isolates have been further subcategorized into pathogenic races based on their differential interaction with host genotypes. Phylogenetic analysis based on three nuclear genes revealed several lineages consisting of race 1 (includes race 2 and 6), race 3 (includes race 5), race 4 (includes race 7), race 8, and Australian biotype lineages. The Australian lineage is the most distantly related amoung the lineages. Because the pathogenicity of a pathogen depends primarly on its virulence factors, using virulence factor related genes for the phylogenetic analysis may reveal better relationships of various pathotypes in terms of host specificity and disease mechanism. We have previously identified and cloned a PKS gene involved in fusaric acid biosynthesis and confirmed that fusaric acid, a potent phytotoxin of cotton, plays an important role in the pathogenicity of the Australian biotype isolate. The objective of this reserach is to test whether the phylogenetic analysis based on partial sequences of this PKS gene can provide disease mechanism based relationships amoung existing races and biotypes. Our results with PKS gene genealogy revealed cose relationship between US and race 1 lineage isolates and Australian biotype lineage isolates, and correlates with their similar host ranges.