Characterization of Pythium nunn newly recorded in Japan and its antagonistic activity against P. ultimum var. ultimum

Abstract

Two isolates of Pythium nunn, newly recorded in Japan, were obtained from soils in Nagano and Fukuoka prefectures, characterized, and tested for antagonistic activity against P. ultimum var. ultimum. The morphology of both isolates corresponded with those of the original description of P. nunn. The rDNA-ITS sequences of the two isolates were identical to each other and had a high similarity with the sequences of the type strain of P. nunn. The two P. nunn isolates were mycoparasitic toward P. ultimum var. ultimum and suppressed damping off of cucumber seedlings caused by the pathogen at an early stage of plant growth.

Suppressive effects of <i>Pythium oligandrum</i> on soybean damping off caused by <i>P. aphanidermatum</i> and <i>P. myriotylum</i>

“…Biocontrol efficacy of P. oligandrum strain D11 was performed against soybean damping off caused by P. aphanidermatum strain D1 and P. myriotylum strain OPU894 by the method of Kobayashi et al (2010) with several modifications (Fig. 1).…”

An ecological network approach for detecting and validating influential organisms for rice growth

“…The reasons why we focused on these two species in 2019 are multifold. First, they can be relatively easily manipulated; G. nunn had already been isolated and cultivated ( Kobayashi et al, 2010 ; Tojo et al, 1993 ) and C. kiiensis is an insect species and relatively large (several mm to cm). Second, the two species had not been reported to be pathogens; using pathogen species under field conditions is not recommended in the experimental field because they might have adverse effects on nearby agricultural systems.…”

“…Second, the two species had not been reported to be pathogens; using pathogen species under field conditions is not recommended in the experimental field because they might have adverse effects on nearby agricultural systems. G. nunn is a potential biocontrol agent and is reported to be beneficial for vegetables ( Kobayashi et al, 2010 ). C. kiiensis is a common midge species around the study region (including in rice paddy fields).…”

“…In 2019, we focused on two species, G. nunn and C. kiiensis ( Figure 3—figure supplement 1 ). At the time of that analysis, these choices were reasonable: G. nunn was previously reported to have some antagonistic activity against pathogens to vegetables such as Pythium ultimum ( Kobayashi et al, 2010 ) and did not have any clear detrimental effects on rice (which was necessary in order not to spread potential pathogens to nearby farms), and C. kiiensis (midge) is a common freshwater insect species in the study region. C. kiiensis may have effects on water quality (e.g.…”

Caracterización de especies de la familia Pythiaceae asociadas al cultivo de soja en la provincia de Buenos Aires

“…P. nunn ha sido eficiente antagonista de P. ultimum, P. aphanidermatum y Phy. vexans, entre otros microorganismos (Lifshitz et al, 1984;Fang y Tsao, 1994;Sakura Kobayashi et al, 2010). Por su parte P. periplocum, está citado como hiperparásito de Botrytis cinerea (Paul, 1999).…”