Status and Population Diversity of Plant-Parasitic Nematodes in Medicinal Plants of Uttarakhand

Plant-parasitic nematodes (PPN) are the most important group of soil-borne pathogens prevailing around the root of medicinal plants causing a reduction in plant growth and yield. Because Uttarakhand is known as India's herbal state, this work aimed to assess the diversity of PPN communities with medicinal plants in the soils of Uttarakhand. Herein, nematode communities were characterized in soil samples collected from four districts with an altitude range of 180–3000 meters above mean sea level. Eleven PPN genera belonging to 10 families were identified among which two genera Meloidogyne spp. and Heliocotylenchus spp. were most dominant. At elevations below 500 meters above mean sea level, the most common nematodes were Pratylenchus spp. and Meloidogyne spp., and among plants Safed Musli (Chlorophytum borivilianum) and Sarpagandha (Rauvolfia serpentia) recorded the highest population density of nematodes. At 900–1900 meters above mean sea level range all associated nematodes exhibited 100% frequency except for Tylechorhynchus spp., Trichodorus spp., and Rotylenchulus spp. and Tulsi (Ocimum tenuiflorum) plant showed the highest population of these associated nematodes. At range above 2000 meters above mean sea level, Chopcheeni (Samilax china) had the largest population of PPNs, with Meloidogyne spp. being the most frequent nematode. Rich diversity of plant parasitic nematodes have been discovered in association with medicinal plants, which might pose a severe danger to their production.