ARS | Publication request: Fusarium spp. Associated with Field-Grown Grain of Near-Isogenic Low Lignin and Wild-Type Sorghum

Submitted to: Fungal Genetics Reports
Publication Type: Abstract Only
Publication Acceptance Date: December 4, 2008
Publication Date: March 17, 2009
Citation: Funnell-Harris, D.L., Pedersen, J.F. 2009. Fusarium spp. Associated with Field-Grown Grain of Near-Isogenic Low Lignin and Wild-Type Sorghum. Fungal Genetics Reports. 56 (Supp):238.

Technical Abstract: Fusarium spp. associated with field-grown grain of near-isogenic low lignin and wild-type sorghum. Deanna Funnell-Harris and Jeff Pedersen, USDA-ARS, Lincoln, NE Previous studies indicated that low lignin brown midrib (bmr) sorghum may be more resistant to Fusarium spp. than wild-type and that phenolic profiles of near-isogenic plants varied depending on bmr genotype. bmr-6 and bmr-12 were backcrossed into wild-type backgrounds, resulting in reduced lignin near-isogenic genotypes. When grain from wild-type and low lignin plants were analyzed for Fusarium spp., bmr-6 and bmr-12 had significantly reduced colonization by Fusarium moniliforme sensu lato. Fusarium isolates were genotyped using sequence analysis of the translation elongation factor gene. F. thapsinum was the most frequently isolated species with F. bullatum, F. proliferatum and F. pallidoroseum also commonly recovered. Colonization of bmr-12 grain appeared to be less diverse than that of bmr-6 and wild-type grain. While 65% of isolates from bmr-12 plants were F. thapsinum, 44% and 40% of isolates from bmr-6 and wild-type grain, respectively, were this species. F. bullatum isolates were readily recovered from wild-type and bmr-6 grain, but no such isolates were detected in bmr-12 grain. When inoculated with F. thapsinum, lesions produced on bmr-12 plants were significantly smaller than those on wild-type plants, while inoculation with F. armeniacum or F. verticillioides produced smaller lesions on bmr-6 plants as compared with wild-type. These data suggest that differences in accumulation of phenolic precursors in bmr plants may affect colonization by Fusarium genotypes.