شناسایی و تعیین پراکنش گونه‌های مختلف نماتد ریشه‌گرهی در باغات پسته استان‌های کرمان و خراسان رضوی

Pistachio is one of the most economically important horticultural plants in Iran and the world. The largest areas of pistachio cultivation and production are in Kerman and Khorasan Razavi provinces, respectively. Despite the increase in pistachio cultivated areas in Iran, the amount of its production has decreased. Recently, Iran, which has always been the top pistachio producer in the world, has been reduced to the second place, after the United States. Pistachio yield is reduced by different factors, including root-knot nematodes. Therefore, in this study, several soil and root samples were collected from pistachio orchards in Kerman and Khorasan Razavi provinces. All root-knot nematode populations were reared and purred on tomato (Solanum lycopersicum L. cv. Early Urbana) in a greenhouse. Species identification was done based on the morphological and morphometric characters of females, males and second-stage juveniles. To confirm the species identification, molecular methods were used based on the amplification and sequencing of the ribosomal and mitochondrial regions of females. Based on the present study, the infection of pistachio orchards with root-knot nematode in these two provinces was 73.8% (Kerman province, 82.22% and Khorasan Razavi province, 64.1%). Four species of root-knot nematodes, including Meloidogyne arenaria, M. cruciani, M. incognita and M. javanica, which belong to the tropical root-knot nematodes group, were identified in Kerman province. In Khorasan Razavi province, all the mentioned species were present except M. incognita. According to this study, M. javanica was the dominant species of root-knot nematodes in pistachio orchards of both provinces. M. arenaria and M. cruciani, were reported for the first time from pistachio orchards in Khorasan Razavi province. Based on the results of this study, root-knot nematode species are spreading in pistachio orchards, therefore, further monitoring measures are needed to prevent their dominance.