First report of damping-off caused by Pythium aphanidermatum in the seedlings of wax gourd grown in the seedling period

Abstract

In February 2023, seedlings of wax gourd (Benincasa hispida (Thunb.) Cogn.) developed water-soaked rot on hypocotyls in the seedling period in Japan. The diseased seedlings eventually displayed damping-off. A Pythium sp. was isolated from the hypocotyls and was identified as Pythium aphanidermatum based on the morphological characteristics and internal transcribed spacers region of DNA sequences. The same symptoms were observed when seedlings were inoculated with the isolated fungus. Moreover, the same fungus was reisolated from the damping-off seedlings. This is the first report of damping-off in wax gourd seedlings caused by P. aphanidermatum during the seedling period in Japan.