Nematode resistance in bananas: screening results on some new Mycosphaerella resistant banana hybrids

Banana hybrids with resistance to Yellow Sigatoka and Black Leaf Streak disease were evaluated for resistance to the burrowing nematode Radopholus similis and to the lesion nematode Pratylenchus coffeae in a growth chamber at 24–28°. Plants produced by tissue culture were acclimatised for 6 weeks prior to inoculation. Forty-five days after inoculation with nematodes, the root systems were processed and nematode numbers assessed. Two cultivars of Grande Naine (Musa AAA, Cavendish subgroup, ITC1256 and cv902) and one cultivar of Yangambi Km5 (Musa AAA, Ibota subgroup, ITC1123) were used respectively as susceptible and resistant controls. Results based on multiplication rates and root infestations showed that three of these hybrids (FB918, FB919 and FB924) were not significantly different from the resistant control Yangambi Km5 with a lower multiplication of R. similis. Similarly four of these hybrids (FB918, FB919, FB920, FB924) showed a lower multiplication of P. coffeae, not significantly different from the same resistant control. This is the first study that shows a partial resistance to both nematode species, R. similis and P. coffeae within synthetic hybrids of M. acuminata, adding an important extra value to these dessert banana hybrids formerly bred to resist to Mycosphaerella leaf spot diseases.