Previous View
 
APSnet Home
 
Phytopathology Home


VIEW ARTICLE

Physiology and Biochemistry

Gibberellin A4 Production by Sphaceloma manihoticola, Causal Agent of Cassava Superelongation Disease. R. S. Zeigler, Graduate research assistant, Department of Plant Pathology, Cornell University, Ithaca, NY 14853; L. E. Powell(2), and H. D. Thurston(3). (2)Professor, Department of Pomology, Cornell University, Ithaca, NY 14853; (3)Professor Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Phytopathology 70:589-593. Accepted for publication 2 November 1979. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-589.

Symptoms of superelongation disease of cassava (caused by Sphaceloma manihoticola), include striking internode elongation, suggesting a hormonal role in the disease. Gibberellin A4 was purified from culture filtrate of pathogenic isolates by base-acid partitioning with ethyl acetate followed by silica gel column chromatography. Biologically active fractions were identified by lettuce seedling hypocotyl elongation bioassay. The fungal product was identified as gibberellin A4 by combined gas-liquid chromatography and mass spectrometry. Treatment of plants with known gibberellin A4 and that purified from pathogen filtrate reproduced secondary symptoms.