Phytophthora Science and Management, Centre for Climate Impacted Terrestrial Ecosystems, Harry Butler Institute, Murdoch University, Perth, WA, 6150, Australia; Plant Pathology Division, Bangladesh Agricultural Research Institute, Gazipur, 1701, Bangladesh.
Phytophthora Science and Management, Centre for Climate Impacted Terrestrial Ecosystems, Harry Butler Institute, Murdoch University, Perth, WA, 6150, Australia.
Fungal Biol. 2021 Jun;125(6):477-484. doi: 10.1016/j.funbio.2021.01.009. Epub 2021 Jan 31.
Analysis of soil samples using High Throughput Sequencing (HTS) frequently detects more Phytophthora species compared with traditional soil baiting methods. This study investigated whether differences between species in the timing and abundance of sporangial production and zoospore release could be a reason for the lower number of species isolated by baiting. Stems of Eucalyptus marginata were inoculated with ten Phytophthora species (P. nicotianae, P. multivora, P. pseudocryptogea, P. cinnamomi, P. thermophila, P. arenaria, P. heveae, P. constricta, P. gondwanensis and P. versiformis), and lesioned sections for each species were baited separately in water. There were significant differences between species in timing of sporangia production and zoospore release. P. nicotianae, P. pseudocryptogea, P. multivora and P. thermophila released zoospores within 8-12 h and could be isolated from lesioned baits within 1-2 days. In contrast, P. constricta did not produce zoospores for over 48 h and was only isolated 5-7 days after baiting. P. heveae and P. versiformis did not produce zoospores and were not recovered from the baits. When species were paired in the same baiting tub, those that produced zoospores in the shortest time were isolated most frequently, while species slow to produce zoospores, or which produced them in lower numbers, were isolated from few baits or not at all. Thus, species differences in the timing of sporangia production and zoospore release may contribute to the ease of isolation of some Phytophthora species when they are present together with other Phytophthora species in an environmental sample.
利用高通量测序（HTS）分析土壤样本通常比传统的土壤诱饵法检测到更多的疫霉菌种。本研究调查了物种在孢子囊产生和游动孢子释放的时间和丰度上的差异是否是诱饵法分离到的物种数量较少的原因。用十种疫霉菌（P. nicotianae、P. multivora、P. pseudocryptogea、P. cinnamomi、P. thermophila、P. arenaria、P. heveae、P. constricta、P. gondwanensis 和 P. versiformis）接种尾叶桉的茎，然后将每种疫霉菌的损伤部位分别单独诱饵在水中。在孢子囊产生和游动孢子释放的时间上，不同物种之间存在显著差异。P. nicotianae、P. pseudocryptogea、P. multivora 和 P. thermophila 在 8-12 小时内释放游动孢子，可以在 1-2 天内从受伤的诱饵中分离出来。相比之下，P. constricta 超过 48 小时都不产生游动孢子，并且仅在诱饵后 5-7 天才能分离出来。P. heveae 和 P. versiformis 不产生游动孢子，也不能从诱饵中回收。当将物种配对放在同一个诱饵罐中时，那些在最短时间内产生游动孢子的物种最常被分离出来，而那些游动孢子产生时间较长、产生数量较少的物种则很少或根本无法从诱饵中分离出来。因此，孢子囊产生和游动孢子释放的时间上的物种差异可能导致某些疫霉菌种在与其他疫霉菌种共同存在于环境样本中时，更容易被分离出来。
