Incidence and Characterization of Rice Root Nematodes, Hirschmanniella mucronata, from Rice Fields in Pathum Thani Province, Thailand

Abstract

The rice root nematodes, Hirschmanniella oryzae and H. mucronata, are serious and widespread threats to global rice production, especially in tropical and subtropical zones. Reliable and efficient identification of these nematodes is vital to nematode control and management. In this current study, 36 soil or rice root samples were collected from rice fields located in Pathum Thani province and used for nematode extraction. The results demonstrated that Hirschmanniella sp. was found in all paddy fields, especially in Muang District, where RD47 rice cultivars were grown at soil pH of 5.9. Molecular identification based on the analysis of 28S rRNA and 18S-ITS1-1.58S genes revealed 98 – 99 % similarity to H. mucronata, and its phylogenetic trees were grouped with H. mucronata from Cambodia and Philippines. Likewise, the morphometric characterization revealed remarkable features of H. mucronata with long body (1,639 - 2,329 µm), long stylet (24 - 27 µm) and an obvious mucron at the end of terminus. Therefore, the main rice root nematode species found in Pathum Thani’s rice fields were H. mucronata.
 HIGHLIGHTS
 
 The rice root nematodes, Hirschmanniella, are presented the predominant plant-parasitic nematodes in rice cultivated areas of Pathum Thani province, Thailand
 Population densities of Hirschmanniella are encountered in rice roots than in soil, especially in RD47 rice cultivars grown in Muang District
 Both of morphological and molecular characterization illustrating the species of rice root nematodes were mucronate
 This is a first description on the molecular characterization of mucronata from rice fields in Thailand
 
 GRAPHICAL ABSTRACT

Molecular phylogeny and morphological studies reveal a 30‐year‐old rain tree (Samanea saman) maintains populations of Meloidogyne enterolobii, a new host plant in Thailand

“…DNA extraction : 18 Meloidogyne females from the following: 12 females from the rain tree, M. enterolobii ; four females from the chilli field, M. enterolobii ; and two females from tomato, M. incognita , were used for DNA extraction, modified from Holterman et al (2006) and Beesa et al (2021). In brief, one female Meloidogyne was placed in a 0.5‐mL polymerase chain reaction (PCR) tube filled with 25 μL of sterilized distilled water.…”