Plant Pathology Science

Vahabi S, Charehgani H, Abdollahi M, Rezaei R (2021) Response of eight melon cultivars to Meloidogyne javanica. Plant Pathology Science 10(2):65-73.       Doi: 10.2982/PPS.10.2.65.

 Introduction: The Root-knot nematodes (Meloidogyne spp.) are one of the most damaging plant pathogens with a wide host range and cause major losses to agricultural crops. The use of resistant cultivars is considered a safe, economical, and effective method to control these nematodes. Materials and Methods: In the present study, eight melon cultivars namely Ahlam, 105, Tracey, Ronak, Deltagrin, Mac, Holar, and Veno were evaluated for their response to M. javanica. The seeds were planted in 2 kg pots and maintained under natural conditions in Khormuj city, Bushehr province. Seedlings at the four-leaf stage were inoculated with 5000 eggs and second-stage juveniles. The factorial experiment was conducted in a completely randomized design with five replicates. Sixty days after nematode inoculation, the plants were harvested and the plant growth and nematode population indices were evaluated. Results: The results showed that the nematode reproduction factor was significantly lower in Ronak, Deltagrin, and Veno than in the other cultivars. No significant difference was observed in shoot fresh weight of nematode inoculated and non-inoculated plants of Ronak cultivar. Conclusion: Ronak, Delta-green and Veno cultivars are less susceptible to M. javanica.

 Introduction: This research was conducted with the aim of determining the reaction of 32 tomato genotypes from the plant gene bank of Iran to the root-knot nematode Meloidogyne javanica, to identify resistant genotypes during two years under greenhouse conditions. Materials and Methods: After purifying the nematode population and planting the seeds of 32 tomato genotypes and reaching the stage of 3-4 leaves, each treatment was inoculated with 6000 eggs and larvae of M. javanica in five replicates, and 60 days after inoculation, vegetative traits and traits related to nematode population were determined in each treatment, and based on gall index (GI) and nematode reproductive factor (Rf), the reaction of genotypes to nematode was determined. Results: Eighteen  genotypes with Rf>1 and GI>2, 23 genotypes with Rf<1 and GI>2, and three genotypes TN-72-938, TN-72-1041 and TN-72-1012 with Rf≤1 and GI≤2, were identified as susceptible, moderately resistant, and resistant to this destructive nematode respectively. Conclusion: These three resistant genotypes can be used in the M. javanica management program.