Susceptibility of Seven Caladium (Caladium 3 hortulanum) Cultivars to Meloidogyne arenaria, M. enterolobii, M. ?oridensis, M. incognita, and M. javanica

摘要

Thereisnoknownroot-knotnematode(Meloidogynespp.)resistanceincaladium(Caladium3hortulanum),anornamental foliage crop grown from tubers, but cultivars have been reported to differ in their level of susceptibility.Research was conducted to assessthe relativesusceptibility of seven widelygrown caladiumcultivarsto thespeciesof Meloidogyne whichoccur in thesoutheastern United States, where caladium cultivars are commonly planted in commercial and residential landscapes.Root-knot nematode species tested were Meloidogyne arenaria, Meloidogyne enterolobii (=M.mayaguensis), Meloidogyne ?oridensis, Meloidogyne incognita, and Meloidogyne javanica.All of the caladium cultivars tested were susceptible to galling by all species of Meloidogyne tested; however M.javanica caused the least severe galling.Meloidogyne enterolobii produced high numbers of eggs per gram of fresh root on all cultivars tested, with cv.Freida Hemple having the highest number (14,799 eggs/g fresh root).Meloidogyne javanica also reproduced at a high level on most cultivars tested.Overall, the number of eggs of M.arenaria, M.?oridensis, and M.incognita was low on all caladium cultivars tested.Meloidogyne javanica was isolated from caladium roots in high numbers regardless of the cultivar.Meloidogyne incognita had low numbers of second stage root-knot nematode juveniles (J2) isolated from soil of all cultivars.The high level of reproduction of M.enterolobii and the high rate of isolation of M.javanica from roots, as well as the low rate of isolation of M.incognita from soil, are not re?ected in gall ratings where M.javanica ratings were low but high numbers of eggs and J2 were present in roots.An increased understanding of cultivar susceptibility levels and the reproductive capacity of common root-knot nematode on caladium under various environmental conditions is needed to better manage nematode-infested planting sites and improve caladium growth.