Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2009
Publication Date: August 1, 2009
Citation: Noll, L.W., Prakash, S., Tilley, M., Bean, S.R., and Little, C.R. 2009. Viability, quality, and protein content associated with sorghum caryopses infected with grain mold fungi. Phytopathology 99: S94. Technical Abstract: Grain mold (GM) of sorghum is a yield-limiting disease that impacts caryopsis viability and quality. Several fungi, including Fusarium thapsinum (FT) and Curvularia lunata (CL), colonize the caryopsis during development. The viability of caryopses (including Sureno, Tx2911, SC170, BTx623, BTx631, and Tx430) harvested after FT and CL inoculation treatments at anthesis was measured using a tetrazolium violet assay. Germination, emergence and vigor were also measured and re-isolation ratios (RIS) were calculated from harvested grain for FT and CL. Using the single kernel characterization system (SKCS), caryopses were measured for hardness, weight, moisture, and diameter. Total protein and kafirins (gamma and non-gamma) were also measured. GM resistant (GMR) genotypes produced caryopses that showed improved viability staining, germination, emergence, vigor and decreased RIS as compared to GM susceptible (GMS) types. SKCS data indicated that inoculations with FT and CL reduced weight and diameter of harvested caryopses. Inoculations had a significant effect upon total protein accumulation in grains (P < 0.05); the response varied by genotype and treatment. Levels of gamma-kafirin also varied by genotype and treatment, whereas non-gamma varied by genotype only. Gamma-kafirin content and hardness increased in FT- and CL-inoculated 'Sureno' (GMR). Further studies are needed to elucidate the underlying structural characteristics associated with high quality grain and resistance to GM fungi.