Mitochondrial Haplotype-based Identification of Root-knot Nematodes (<i>Meloidogyne</i> spp.) on Cut Foliage Crops in Florida

Abstract

Florida accounts for more than 75% of the national cut foliage production. Unfortunately, root-knot nematodes (RKN) (<i>Meloidogyne</i> spp.) are a serious problem on these crops, rendering many farms unproductive. Currently, information on the <i>Meloidogyne</i> spp. occurring on most commonly cultivated cut foliage crops in Florida, and tools for their rapid identification are lacking. The objectives of this study were to (i) identify specific RKN infecting common ornamental cut foliage crops in Florida and (ii) evaluate the feasibility of using the mtDNA haplotype as a molecular diagnostic tool for rapid identification of large samples of RKN. A total of 200 <i>Meloidogyne</i> females were collected from cut foliage plant roots. <i>Meloidogyne</i> spp. were identified by PCR and RFLP of mitochondrial DNA. PCR and RFLP of mitochondrial DNA were effective in discriminating the <i>Meloidogyne</i> spp. present. <i>Meloidogyne incognita</i> is the most dominant RKN on cut foliage crops in Florida and must be a high target for making management decisions. Other <i>Meloidogyne</i> spp. identified include <i>M. javanica</i>, <i>M. hapla</i>, <i>Meloidogyne</i> sp. 1, and <i>Meloidogyne</i> sp. 2. The results for this study demonstrate the usefulness of the mtDNA haplotype-based designation as a valuable molecular tool for identification of <i>Meloidogyne</i> spp.