Prevalence and Characterization of Plant-Parasitic Nematodes Existing in RD41 Rice Fields in Pathum Thani Province, Thailand, with Emphasis on Hirschmanniella mucronata and Meloidogyne graminicola

Plant parasitic nematodes (PPNs) are one of the most destructive pests affecting rice growth worldwide. In this study, populations of PPNs associated with RD41 rice fields in Pathum Thani Province, Thailand, were surveyed and the dominant PPNs found in the fields were identified using a combination of morphological and molecular traits. A total of 105 soil or root samples were taken from 21 paddy fields in 7 districts of Pathum Thani, and nematode extraction was processed in a laboratory. In all sampled rice fields, 6 nematode genera, namely Hirschmanniella sp., Meloidogyne sp., Pratylenchus sp., Tylenchorhynchus sp., Helicotylenchus sp., and Tylenchus sp., were extracted. Of these 6 nematode genera, Hirschmanniella sp. was the most prevalent in both soil and root samples (66.7 - 100 % occurrence observed), followed by Meloidogyne sp., which was found in only 4 districts of the province (0.2 to 8.7 % occurrence observed). The species of these predominant PPNs were morphologically and molecularly characterized. The identification results remained consistent across morphological features and molecular techniques, confirming the presence of Hirschmanniella mucronata and Meloidogyne graminicola in the studied rice fields. The results of this study provide useful baseline data of the occurrence of PPNs in Thailand's rice fields. The incidence of some PPNs found in this study is likely to become a significant factor limiting rice production yields if they are not better managed. HIGHLIGHTS Plant-parasitic nematode (PPN) populations in RD41 rice fields located in Pathum Thani province, Thailand were examined Six PPN genera were extracted from soil and root samples The predominant PPNs were characterized using morphological and molecular traits The main PPNs were identified as mucronata and M. graminicola This study provides useful baseline data of PPNs found in Thailand's rice fields GRAPHICAL ABSTRACT