Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2012
Publication Date: August 4, 2012
Citation: Funnell-Harris, D.L., Sattler, S.E., Prom, L.K., Dowd, P.F., Pedersen, J.F. 2012. Response of sorghum modified for bioenergy to grain and stalk fungal pathogens. American Phytopathological Society. Available: http://www.apsnet.org/meetings/Documents/2012_Meeting_Abstracts/aps12abS76.htm. Technical Abstract: Sorghum is a versatile feedstock crop for cellulosic biofuels production. Reducing lignin content results in increased ethanol conversion efficiency. Two mutations in lignin biosynthesis were used to decrease lignin content and alter its composition. Near isogenic lines were developed with brown midrib (bmr)-6 and bmr12, which are deficient in cinnamyl alcohol dehydrogenase and caffeic acid 0-methyltransferase, respectively. Assessing Fusarium spp. infection of field-grown grain showed a significant reduction in Gibberella fujikuroi isolates in bmr grain, as compared with wild-type (WT); in particular, Fusarium proliferatum colonization was limited in bmr12 grain. Fusarium sp. cf. bullatum colonization was absent in bmr12, while this genotype was common in bmr6 and WT grain. Peduncles inoculated with Fusarium thapsinum, Fusarium verticillioides or Alternaria alternata had significantly smaller mean lesion lengths on bmr6 or bmr12 plants, relative to WT. Basal stalk inoculations with Fusarium stalk rot pathogens showed that bmr lines were as resistant as wild-type lines. Responses of bmr plants to foliar pests, including Colletotrichum sublineolum and chewing insects, provided further evidence that reduced lignin lines were not more susceptible, and in some cases were more resistant, to common sorghum pathogens and other pests as compared to WT lines.