31. One common characteristic of opisthokonts is that flagellate cells, such as the Zoospore morphological types ). 32. Zoospores need water to swim through the soil, therefore infection is most likely in moist soils.33. During rainy periods, chlamydospores in soil may germinate in water to produce sporangia and release zoospores . 34. As an oomycete, " P . halstedii " releases motile zoospores as secondary inoculum. 35. "Saprolegnia " filaments ( hyphae ) are long with rounded ends, containing the zoospores . 36. Additionally, the capillaries formed by soil particles act as a natural filter and effectively trap many zoospores . 37. In many zoospores , the nucleus lies partially within the aggregation of ribosomes and was invariably situated laterally. 38. In contrast, most other oomycetes do not have a vesicle and the zoospores form in the sporangia. 39. Once the plant dies, more sporangium can form, release zoospores , and repeat the infection cycle. 40. After primary infection, zoospores serve as a main source of inoculum throughout the rest of the season.
