Determination of reaction of root-knot nematode (Meloidogyne spp.) populations in some pepper gene resources resistant to nematode

Virulence reaction of root-knot nematode populations is one of the major limited factors to use of nematode resistant variety in the nematode management and virulent populations eliminate the effectiveness of genes that providing resistance. In the present study, virulence / avirulence reaction of root-knot nematode populations collected from West Mediterranean Region of Turkey was investigated in resistant pepper accessions that include nematode resistance genes; N, Me5, Me7-Mech1, Me1-Mech2. Fifty one root-knot nematode populations were pure cultured from single egg mass in the susceptible Tueza F1 tomato cv. under controlled conditions. Afterwards, the populations were identified by morphologically according to perineal patterns and molecularly with species specific scar primers. The populations of twenty-six Meloidogyne incognita, twenty-one M. javanica, three M. hapla and one population M. arenaria were confirmed by taxonomic studies. None of all root-knot nematode populations observed virulent reaction to Carolina Wonder carriying N gene. While M. incognita, M. arenaria and M. javanica were showed avirulent reaction, M. hapla reproduced on CM334 pepper accession including Me7-Mech1 nematode resistant genes. Four M. incognita populations, D4, F6, K4 ve KA2 showed virulent reaction and break down nematode resistance in PM217 pepper line including Me1-Mech2 genes. The ratio of virulence (Ch constant) M. incognita populations D4, F6, K4 and KA2 were detected 0.86, 0.65, 0.96 and 0.95, respectively. Meloidogyne arenaria K18 population broken down Me5 nematode resistance gene in Yolo Wonder pepper accession. Additionally, four M. javanica populations, K16, F7, F4 and A1, reproduced in Yolo Wonder line including Me5 gene and reproduction potential (RP) of these M. javanica populations were detected between 1.15 and 3.25 in this pepper line. Three M. hapla populations showed virulent reaction in the PM217 and Yolo Wonder pepper lines including Me1-Mech2 and Me5 RN genes. As a result of the study, it was observed that Carolina Wonder and CM334 pepper accession having N and Me7-Mech1 genes provided more stable nematode resistance in pepper to control root-knot nematode populations.