REACTION OF BANANA CULTIVARS TO THE Meloidogyne javanica X Fusarium oxysporum f. sp. cubense COMPLEX

ABSTRACT The interaction Fusarium oxysporum f. sp. cubense (Foc) x nematode and the genetic variability of Foc are the main problems with potential to affect the use of resistant varieties in the management of the Panama disease. The objective of this work was to evaluate the interaction between Foc and Meloidogyne javanica on the banana of the Prata Anã, Grande Naine and BRS Princesa cultivars. The experiment was conducted in a randomized block design, with six treatments and ten replications, which differed in the inoculation time of each pathogen. Simultaneous inoculation with Foc and M. javanica, inoculation with Foc one week before inoculation with M. javanica, and inoculation with M. javanica one week before inoculation with Foc. In addition to the controls, Foc isolated, M. javanica isolated, and cultivars without the pathogens. The seedlings were transplanted in 3-liter pots with sterile soil infested with 40 grams of Foc inoculum at the concentration of 1x106CFU/gram and 1000 eggs and J2 of M. javanica. At the end of 56 days, the treatments with 'Grande Naine' presented the highest reproduction factors of M. javanica. In the 'Prata Anã' no interaction was observed between Foc x M. javanica. The treatments with simultaneous inoculation of the two pathogens, and with Foc a week before, in the 'BRS Princesa', presented the highest external disease indices (DI), which promoted the highest AUDPC. The highest internal DI were observed in the treatments Foc+Mj+Grande Naine, Foc+Mj+BRS Princesa, Mj+Grande Naine+Foc and Foc+BRS Princesa+Mj. The simultaneous presence of M. javanica and Foc increases the severity of the Panama disease in Grande Naine and BRS Princesa cultivars.

摘要 尖孢镰刀菌古巴专化型（Fusarium oxysporum f. sp. cubense, Foc）与线虫的互作，以及Foc的遗传变异，是制约抗病品种在巴拿马病防控中应用潜力的核心问题。本研究旨在探究Foc与爪哇根结线虫（Meloidogyne javanica）在Prata Anã、Grande Naine及BRS Princesa三个香蕉品种上的互作效应。本实验采用随机区组设计，设置6个处理组与10次生物学重复，各组间的差异在于两种病原菌的接种时序：Foc与爪哇根结线虫同步接种、Foc提前1周接种爪哇根结线虫、爪哇根结线虫提前1周接种Foc；此外设置3组对照：单独接种Foc菌株、单独接种爪哇根结线虫菌株，以及不接种任何病原菌的空白对照组。供试香蕉幼苗移栽至容积为3升的花盆中，盆土为灭菌土壤，分别按1×10^6 CFU/克的浓度接入40克Foc菌剂，并接种1000粒爪哇根结线虫卵及二龄幼虫（J2）。接种56天后，‘Grande Naine’组的爪哇根结线虫繁殖系数最高；在‘Prata Anã’组中未观测到Foc与爪哇根结线虫的互作效应。在‘BRS Princesa’组中，两种病原菌同步接种及Foc提前接种的处理，其外部病害指数（Disease Index, DI）最高，对应的病害病程曲线下面积（Area Under the Disease Progress Curve, AUDPC）也最大。内部病害指数最高的处理包括：Foc+Mj+Grande Naine、Foc+Mj+BRS Princesa、Mj+Grande Naine+Foc及Foc+BRS Princesa+Mj。研究结果表明，爪哇根结线虫与Foc同时存在时，会加重‘Grande Naine’与‘BRS Princesa’香蕉品种的巴拿马病发病严重程度。