COMPARATIVE HOST TISSUE-REACTIONS OF MUSA-ACUMINATA (AAA-GROUP) CVS POYO AND GROS MICHEL ROOTS TO 3 BANANA-PARASITIC NEMATODES

In a comparative histopathological investigation, Poyo and Gros Michel cultivars of Musa acuminata (AAA triploid) were inoculated with Radop holus similis, Helicotylenchus multicinctus or Hoplolaimus paraobustus and were grown in a greenhouse under tropical conditions. R. similis infected all the cortical parenchyma layers of the roots, reaching the vascular cylinder, but it stayed more superficial in Gros Michel root s. Red-brown cytoplasmic globules appeared in the cortical parenchyma cells of Gros Michel only. H. multicinctus infected much of the outer cortical parenchyma in roots of both cultivars with a few phenolic cel ls occurring around the superficial lesions. H. pararobustus penetrate d only the immediate sub-epidermal tissues in both cultivars. The diff erences observed between nematodes and cultivars reflect specific host -nematode interactions on bananas.