IPOMEAMARONE CONTENT IN DISEASED AND NON-DISEASED TISSUES OF SWEET POTATOES INFECTED WITH DIFFERENT PATHOGENS

Nonmarketable fleshy sweet potato roots infected naturally or by inoculation with individual pathogens were analyzed to quantitatively assess ipomeamarone in infected and noninfected tissues of the same potato. Ipomeamarone was not detected in tissues infected by Meloidogyne incognita or Streptomyces ipomoea. No more than 300 .mu.g ipomeamarone/g was detected in tissues infected by Monilochaetes infuscans, Rhizopus stolonifer and internal cork virus. Higher concentrations of ipomeamarone were detected in tissues infected by Fusarium oxysporum, Sclerotium rolfsii, Diplodia tubericola, Ceratocystis fimbriata, Macrophomina phaseoli and Plenodomus destruens. Little or no detectable ipomeamarone was found on analysis of surrounding noninfected tissue.