Author
LIMA, FLAVIA - Federal University Of Goias | |
HARAGUCHI, MITSUE - Biological Institute, Brazil | |
Pfister, James | |
GUIMARAES, VICTOR - Federal University Of Goias | |
ANDRADE, DIOGO - Federal University Of Goias | |
RIBEIRO, CAROLINA - Federal University Of Goias | |
COSTA, GUSTAVO - Biological Institute, Brazil | |
ARAUJO, ANA - Biological Institute, Brazil | |
FIORAVANTI, MARIA - Federal University Of Goias |
Submitted to: International Journal of Poisonous Plant Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/10/2013 Publication Date: 4/1/2013 Publication URL: https://handle.nal.usda.gov/10113/5454538 Citation: Lima, F.G., Haraguchi, M., Pfister, J.A., Guimaraes, V.Y., Andrade, D.D., Ribeiro, C.S., Costa, G.L., Araujo, A.L., Fioravanti, M.C. 2013. Weather and plant age affect the levels of steroidal saponin and Pithomyces chartarum spores in Brachiaria grass. International Journal of Poisonous Plant Research. 2:45-53. Interpretive Summary: Brachiaria species are cultivated worldwide in tropical and subtropical climates as the main forage source for ruminants. Numerous tropical and warm-season grasses cause photosensitization via liver toxicity, among them several species of Brachiaria. Steroidal saponins present in these plants may be responsible for liver damage. However, sporidesmin and other mycotoxins (types of fungus growing on plants) are likely to produce synergistic effects, which could explain the sporadic incidence of poisoning. The objective of this study was to evaluate the relation between steroidal saponins, fungal spores present in Brachiaria, and the possible influence of weather factors on saponin and spore levels. The saponin detected in B. brizantha and B. decumbens was protodioscin. The saponin concentration was higher in immature plants during early growth; further, B. decumbens had a higher amount of saponin than found in B. brizantha. The level of saponin concentration was moderately influenced by weather variables; the two main variables were the maximum sunshine duration and total cumulative precipitation. P. chartarum spore count was higher in older plants and did not differ between B. brizantha and B. decumbens. Spore counts were mainly influenced by maximum precipitation and average evaporation Technical Abstract: Brachiaria species are cultivated worldwide in tropical and subtropical climates as the main forage source for ruminants. Numerous tropical and warm-season grasses cause hepatogenous photosensitization, among them several species of Brachiaria. Steroidal saponins present in these plants may be responsible for liver damage. However, sporidesmin and other hepatotoxic mycotoxins are likely to produce synergistic effects, which could explain the sporadic incidence of poisoning. The objective of this study was to evaluate the relation between steroidal saponin, Pithomyces chartarum spores present in Brachiaria, and the possible influence of meteorological factors on saponin and spore levels. The saponin detected in B. brizantha and B. decumbens was protodioscin. The saponin concentration was higher in immature plants during early growth; further, B. decumbens had a higher amount of saponin than found in B. brizantha. The level of saponin concentration was moderately influenced by weather variables; the two main variables were the maximum sunshine duration and total cumulative precipitation. P. chartarum spore count was higher in older plants and did not differ between B. brizantha and B. decumbens. Spore counts were influenced by maximum precipitation and average evaporation. |