TY - JOUR AU - Talubnak, Chulalak AU - Schoonbeek, Henk-jan AU - Parinthawong, Nonglak AU - Jaenaksorn, Tanimnun PY - 2022/03/28 Y2 - 2024/03/29 TI - Morphological and Molecular Identification of Pythium spp. from Hydroponically-Grown Lettuce JF - Science & Technology Asia JA - Sci Tech Asia VL - 27 IS - 1 SE - DO - UR - https://ph02.tci-thaijo.org/index.php/SciTechAsia/article/view/242341 SP - 143-154 AB - <p>Herein, hydroponic <em>Pythium communities</em> in Thailand were investigated. The 38 <em>Pythium</em> isolates from asymptomatic and symptomatic lettuce roots were identified using morphological and molecular features. The data indicated that <em>P. aphanidermatum</em> and <em>P. myriotylum</em> were the predominant species. Regarding the rDNA-ITS study, all isolates were identified as <em>P. aphanidermatum</em>, <em>P. myriotylum</em>, <em>P. deliense</em>, or an unidentified <em>Pythium </em>species. The reconfirmation of the three unidentified <em>Pythium</em> isolates using the cytochrome oxidase subunit I (COI) gene in comparison to the representative isolates was achieved using <em>P. aphanidermatum</em> and <em>P. myriotylum</em>. The COI phylogenetic trees were similar to that of the ITS tree. Addi-tionally, pathogenicity of the <em>Pythium</em> representative isolates to plant seeds was evaluated in a laboratory assay. The seedlings suffered serious symptoms from <em>P. myriotylum</em> SR31 infection, with 90-100% disease severity. The other isolates presented disease severity of less than 20% when compared with uninoculated control. This study provides a comprehensive identification of <em>Pythium</em> root rot in lettuce grown on hydroponics in Thailand and provides information on beneficial microorganisms and a resistance inducer in lettuce root rot.</p> ER -