Reaction of Musa hybrids to Pratylenchus coffeae and its differential biochemical response to nematode infection

Abstract

Twenty-five hybrids, obtained by crossing six resistant diploids with commercial triploid bananas, were screened for their reaction to the root lesion nematode Pratylenchus coffeae in pots under glass-house conditions. Based on lesion indices of roots and rhizomes, the hybrids H-02-34, H-02-07, H-02-08, H-02-21, H-02-25, H-02-31 and NPH-02-01 were rated tolerant to the nematode. Among the tolerant hybrids H-02-34 and NPH-02-01 (AAB) appeared the most promising. The changes in root content of peroxidase (PO), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) and lignin were also investigated. Relatively higher enzyme activity was observed in tolerant hybrids than in susceptible ones. An isozyme analysis of PPO revealed the induction of specific isoforms in the leaves of tolerant hybrids inoculated with the nematode.