Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2001
Publication Date: 12/20/2001
Citation: GALE, L.R., CHEN, L., KISTLER, H.C. POPULATION GENETICS OF FUSARIUM GRAMINEARUM FROM CHINA. NATIONAL FUSARIUM HEAD BLIGHT FORUM PROCEEDINGS. 2001. Abstract.
Technical Abstract: In order to address questions of genetic diversity, gene flow and recombination among populations of the Fusarium head blight pathogen in China, a collection of strains was made from the important grain-producing region of the lower Yangtze River Valley. Diseased wheat heads were collected at 5 meter intervals along a transect in four production wheat fields in Zhejiang Province. The four fields ranged in distance from each other from 50 km to 200 km. DNA was extracted from 204 strains, transferred to solid support, and probed with 6 DNA clones that hybridize to DNA fragments characteristic for particular lineages within the F. graminearum complex. All 204 strains from China gave a pattern of hybridization identical to that of DNA from known strains of F. graminearum lineage 6. The DNAs were further hybridized to 9 clones capable of detecting polymorphic loci within lineage 6 and a telomere-containing probe ethat further resolved genotypes. High levels of gene flow were detected among the four China populations (mean Nm = 11. 1; range 6.6 to 65) and the populations were extremely similar (Nei's unbiased genetic identity, I = 0.96 to 0.99). As a result, the strains from the four fields were considered part of a single large population. Gene diversity for the 9 single copy loci within the population was high (h = 0.35; range = 0.17 to 0.58) and the average number of alleles per locus was 3.3. Multilocus haplotypes were constructed from the allelic information of the nine polymorphic loci. Clones having the same multilocus haplotype originated primarily from isolates obtained from the same wheat head. Whether high genotypic diversity is caused by frequent sexual recombination is currently being explored.