Abstract
It has been reported that the viability of Erysiphe graminis immersed in water after inoculation to barley coleoptile was not noticeably different from that kept in air, and the fungus eventually formed conidia 120hr after the onset of incubation. In the present study, it is reported that the viability of E. pisi is also unaffected by immersing in water after inoculation to barley coleoptile. However, immersed E. pisi formed abnormally elongated germ tubes at higher frequency than that of unimmersed ones. When germ tubes emerged from upper sites of conidium equater, the frequency of elongated germ tubes was much higher than that of conidia which emerged germ tubes from sites lower than the equater in both the air and water conditions. Moreover, the emerging sites of germ tubes were affected by environment conditions to which conidia had been exposed; if the conidia were incubated in air, more than 60% of germ tubes emerged from lower sites of conidium equater, while the emerging sites of germ tubes were at random when the conidia had been incubated in water.
