Distribution and molecular identification of Meloidogyne spp. parasitising flue-cured tobacco in Yunnan, China

Abstract

Twenty-one populations of root-knot nematodes (RKNs) were recovered from diseased roots collected from flue-cured tobacco in 21 locations in Yunnan (China) during 2014-2015. Molecular diagnosis on species was performed based on characteristics of sequences of D2-D3 expansion domains of the 28S rDNA and sequence characterised amplified regions (SCAR). SCAR results identified 13 populations as Meloidogyne arenaria, six as M. javanica and two as M. incognita. Meloidogyne arenaria is the predominant species with a detection rate of 61.9%, followed by M. javanica (28.5%) and M. incognita (9.5%). The tobacco RKNs were mainly distributed in western, central, and southwestern Yunnan, particularly in the western areas. Meloidogyne arenaria and M. javanica mainly occurred in Lincang (southwestern Yunnan) and Yuxi (central Yunnan), and M. incognita only in Zhaotong (northeastern Yunnan). Phylogenetic analysis based on inferences using LSU D2-D3 sequence data revealed that all 21 populations of Meloidogyne in this study are in a monophyletic clade in relation to other RKNs.

Keywords

• tobacco
• 28s lsu rdna
• scar
• root-knot nematode