Materials for Pythium flora of Japan. X. Occurrence, identification and seasonality of Pythium spp. in three pond waters and mud soils in Osaka

Host plant development, water level and water parameters shape Phragmites australis-associated oomycete communities and determine reed pathogen dynamics in a large lake

“…Overall species richness in the present study is consistent with previous traditional isolation studies on oomycete diversity of aquatic environments, where similar species numbers could be found (e.g. van der Plaats‐Niterink, 1975; Hallett & Dick, 1981; Abdelzaher et al , 1995). A qualitative isolation study on similar sites at Lake Constance using reed baits revealed eight oomycete species (Nechwatal et al , 2008a), five of which could also be detected within our study (≥99% ITS sequence identity).…”

“…Gessner et al , 1993; Schadt et al , 2003; Fryar et al , 2004; Nikolcheva & Bärlocher, 2005). In Pythium species, dominance and community composition have been observed to be fluctuating both relatively quick as well as on a more long‐term basis (van der Plaats‐Niterink, 1975; Ali‐Shtayeh et al , 1986; Hardman & Dick, 1987; Abdelzaher et al , 1995). However, the identification of single factors responsible for such changes in natural ecosystems is difficult, because the seasonality recorded is rather the net result of several complex interactions in the ecosystem than being based on distinct correlations with single environmental factors (Hallett & Dick, 1981).…”

“…Temperature and external ion and oxygen concentration changes are known to interact with oomycete growth and sporulation (van der Plaats‐Niterink, 1981; Walker & van West, 2007), and a decline in oomycete isolation frequencies with rising water temperatures and decreasing oxygen contents during summer has repeatedly been reported (e.g. Hallett & Dick, 1981; Misra, 1982; Ali‐Shtayeh et al , 1986; Abdelzaher et al , 1995; Marano et al , 2008). In our study, too, significantly higher water temperatures accompanied by changing ion and oxygen concentrations and decreasing species diversities during the August samplings were recorded.…”

“…Several of these studies have suggested possible environmental factors that influence the structure of such communities and might explain the emergence of a particular pathogen (Balcì & Halmschlager, 2003; Jung et al , 2005; Jung, 2009; Moralejo et al , 2008). In the genus Pythium and other oomycetes, culture‐based studies have delivered detailed data on possible correlations between community fluctuations in water and soils and environmental factors to explain the changes observed (van der Plaats‐Niterink, 1975; Misra, 1982; Ali‐Shtayeh et al , 1986; Hardman & Dick, 1987; Abdelzaher et al , 1995; Marano et al , 2008). However, so far, no particular attention has been given to the competition between saprophytic and plant pathogenic species and the potential impact of environmental influences on Pythium ‐mediated plant diseases in natural ecosystems.…”

Systematics and molecular pathogenesis of oomycetes with emphasis on flagellar genes

“…(Uzuhashi, et al, 2010). A nother interesting observation in (Hallett & Dick, 1981, Abdelzaher, et al, 1995, whereas terrestrial habitats are dominated by Pythium species with globose sporangia (Ali-Shtayeh, et al, 1986). Apparently the transition o f globose Clerk, 1970, Donaldson & Deacon, 1993, Rand & Munden, 1993, Tyler, et a l, 1996, Leano, et a l, 1998.…”