Reproduction potential and Host range of Meloidogyne enterolobii and Meloidogyne incognita.

Meloidogyne enterolobii, is one of the economically important root-knot species as its ability to develop and reproduce on host plants carrying resistance to other major root-knot nematodes. Recent reports around the world on wide range of plants species including major crops depicts its wide spread. Due to polyphagous nature of M enterolobii and limited control measures, it is important to understand host range to reduce further spread and develop control measures. Meloidogyne incognita and other tropical RKN species are controlled using resistant cultivars carrying Mi gene, but recent reports have shown that virulent isolates of M. incognita are capable to overcome resistance. To determine the host range of 8 M. enterolobii populations and 2 virulent isolates of M. incognita, a study was conducted within the framework of ANR (FR)/DFG (DE) project AEGONE (431627824). 20 crops species previously classified as non-, minor- or major-hosts to M. enterolobii were challenged under greenhouse conditions with 8 M. enterolobii populations (collected from different geographic areas and hosts) and 2 virulent isolates of M. incognita reared as single egg mass lines. Based on the determined reproduction factor (RF), crops were categorized as good-host (RF is ≥1), poor-host (RF between 0 and 1) or non-host (RF=0). Among 20 plant species, 10 showed RF values ≥ 1 for all 8 M. enterolobii populations and 12 showed RF values ≥ 1 for both virulent isolates of M. incognita. Although several reports suggested roses as minor-host to M. enterolobii, no reproduction was observed in all M. enterolobii populations and as well in M. incognita isolates tested. Contrary to recent reports, phacelia and fodder radish were good hosts for 5 and 7 populations of M. enterolobii, respectively. Based on the results it was demonstrated that several populations of M. enterolobii and virulent isolates of M. incognita are capable of reproducing on crops previously reported as non-hosts. Therefore, further studies are underway to investigate the potential to adapt to initially poor hosts, the related costs of fitness and to determine variations on the genome level with differences in host compatibilities. [ABSTRACT FROM AUTHOR]