First report of Meloidogyne graminicola infecting banana in China.
Bananas (Musa spp.) are one of world's most popular fruits, and China is the third largest banana-producing country in the world. Root-knot nematodes, Meloidogyne spp., are common pests of banana worldwide, but damage to this crop caused by M. graminicola has not been reported up to now. During a survey of root-knot nematode species infecting banana in Fujian Province, China, swollen, galled primary and secondary root samples of Musa nana cv. Tianbao (AAA) were collected from two commercial fields in Nanjing County in May 2013. The affected plants did not exhibit obvious above-ground symptoms. Seriously infected roots were malformed and dehiscent, with the tissue discolored and rotting. Examination of symptomatic roots revealed one to several females of Meloidogyne sp. within each gall, with egg masses that were often completely embedded within the gall without protruding through the root surface, and with second-stage juveniles (J2) hatched inside the galls. Population densities of this nematode ranged from 452 to 2056 eggs and J2 per 5 g of fresh roots. Males were rarely observed. Based on morphological characteristics, sequence analysis of the rDNA internal transcribed spacer region and pathogenicity tests, the causal agent was confirmed as M. graminicola. This is thought to be the first report of a natural infection of banana with M. graminicola.