Resistant Pepper Carrying N, Me1, and Me3 have Different Effects on Penetration and Reproduction of Four Major Meloidogyne species

Root-knot nematode (Meloidogyne spp.) exhibits a substantial problem in pepper production, causing reduction in yield throughout the world. Continued assessment for root-knot resistance is important for developing new resistance cultivars. In this study, the effect of Me and N genes on the penetration and reproduction of M. incognita race 3, M. arenaria race 1, M. javanica, and M. haplanaria was examined under controlled greenhouse conditions using susceptible and resistant pepper lines/cultivars (Mellow Star, Yolo Wonder B, Charleston Belle, HDA-149, HDA-330, PM-217, and PM-687) differing in the presence or absence of resistant genes. The penetration and resistance responses of these pepper lines differed depending on the nematode species. More second-stage juveniles penetrated roots of susceptible control cultivar Mellow Star than roots of resistant cultivars/lines. Although, there was no significant difference in the nematode penetration among resistant lines 1 and 3 days after inoculation (DAI), variability in the penetration of M. incognita, M. javanica, and M. haplanaria was observed 5 DAI. This demonstrates the variability among different nematode resistance genes to invasion by Meloidogyne spp. Based on nematode gall index (GI) and reproduction factor (RF), Charleston Belle, HDA-149, PM-217 and PM-687 showed very high resistance (GI < 1 and RF < 0.1) to M. incognita, M. arenaria, and M. javanica. Although, all the Meloidogyne-resistant pepper lines evaluated were resistant to M. javanica and M. haplanaria, the susceptible cultivar Mellow Star was a good host for all nematode species having an RF ranging from 8.1 to 34.7. The N, Me1, and Me3 genes controlled resistance to reproduction of all species of Meloidogyne examined.