Reaction of different pomegranate (Punica granatum) cultivars to root-knot nematode (Meloidogyne incognita race 2)

Root-knot nematodes (Meloidogyne spp.) are considered among the most important pathogens leading to great damage to agricultural products. So far, different practices such as crop rotation, resistant cultivars, and chemical compounds have been used for controlling these nematodes. High cost of chemical compounds and their environmental problems has attracted the researchers’ attention for using non-chemical methods for nematode management. The exploitation of resistant varieties is one of the most important approaches to managing plant-parasitic nematodes. The present study aims to evaluate the reaction of 15 different varieties of pomegranate to RKN, M. incognita race 2.

The morphological characters of isolated nematodes were evaluated after sampling, along with identifying the nematode species. The experiment was conducted in greenhouse conditions with a temperature ranging from 22-26°C based on the completely randomized design with factorial arrangement. First, pomegranate cuttings were rooted and inoculated with 2000 eggs and second-stage juveniles of the nematode per kg of soil. Then, host plant growth traits such as length, fresh and dry weight of stems, and roots, as well as developmental stages of the nematodes including the number of galls, egg mass, and reproduction factor were evaluated in different cultivars of pomegranate 90 days after inoculation. The final rating was conducted based on the Canto-Saenz system (1985). Finally, the data were analyzed by using SPSS 24 software, and Duncan test and t-test were used for comparing the means.

Based on the results, Malas-e Torsh cultivar was tolerant (GI≤2, RF>1), Malas-e Shirin and Tabestani were hypersusceptible (GI>2, RF≤1), and Agha Mohammad Ali, Alak-e Torsh, Bahabadi, Berit-e Poust Ghermez, Golnar, Naderi, Bihasteh-e Ravar, Pous Sefeed-e Shirin, Bihasteh-e Shomal, Poust siah, Souski-e Taft and Shahsavavar-e Yazdi were evaluated as susceptible (GI>2, RF>1).

Based on the results,tolerance of only one cultivar against root-knot nematodes should be considered by experts and farmers.