Reaction of banana germplasm to inoculation with Xanthomonas campestris pv musacearum

Abstract

Pot trial to evaluate the reaction of Uganda's local banana germ plasm to artiticial inoculation with Xanthomonas campestris pv musacearum (Xcm) was established in 2004 and 2005 in Mukono district, Uganda. X. campestris pv musacearumcauses infection causes premature fruit ripening and leaf wilting, killing every affected plant hence leading to total yield loss. The disease is managed through cultural practices but it was thought that use of resistant varieties would provide a better management option. Potted plants in a farmer's field were therefore inoculated with a bacterial suspension containing I xI OK bacterial cells/ mL of Xcm. I mL of bacterial suspension was injected into the petiole of the youngest open leaf using a hypodermic needle. Twenty fiv~ plants of each of the 42 banana genotypes were involved in the study. Wilt disease developed in the three months old banana plantlets of all local germ plasm tested except for Musa halbsiana. Ke\' Words: Genotypes, Musa sp., Uganda RESUME Les essais de pot ont evalues les reactions des germplasmes des varietes locales (Ougandaise) de Ia banane a I' inoculation artificielle avec Xanthomonas compestris p. v musacearum etaient etablies en 2004 et 2005 dans le district de Mukono en Ouganda. Les infections aux Xanthomonas compestris p. v musacearum causent un murussement premature des fruits ct le declenchement des feuilles, tuant chaque plante affectee et ainsi contribuant a une perte to tale du rendement. La maladie est controle a travers des pratiques culturales mais il etait pense que I 'utilisation des varietes resistantes incitera des bonnes options de gestion. Les pi antes dans les pots sur les fermes des paysans etaient alors inoculees avec une bacterie en suspension contenant I x JOK cellules des bacteries/mL de Xcm. Un mL de bacterie en suspension etait injecte dans un petiole de Ia plus jeune feuille en uti I is ant une aiguille. Vingt cinq pi antes de chacun de 42 genotypes de banane etaient considereesdans cette etude. La maladie de alanguissement developpee sur une plantule de Ia banane de trois mois des germplasmes locaux testes a !'exception de Musa balhsiana.