INFLUENCE OF FUSARIUM-SOLANI ON CHEMOTAXIS OF ZOOSPORES OF PHYTOPHTHORA-PARASITICA AND PHYTOPHTHORA-CITROPHTHORA AND ON DISTRIBUTION OF C-14 IN CITRUS TISSUES AND ROOT EXUDATE

Chemotaxis of zoospores of Phytophthora parasitica and P. citrophthora was reduced when sweet orange or Troyer citrange roots were colonized by Fusarium solani as compared to non-colonized roots. The proportions of C-14 in the leaves and stems of plants inoculated with P. citrophthora were greater than either the controls or plants inoculated with F. solani. Whereas, the proportions of C-14 in roots and root exudates of plants infected with P. citrophthora were less than those of the controls or plants inoculated with F. solani alone. When plants were inoculated with P. parasitica either alone or with F. solani, the proportion of C-14 in the root exudate fraction was less than the controls. There was no difference in partitioning of C-14 among leaf, stem or roots of infected plants as compared to the controls.