Monthly variations of Oomycetes (zoosporic fungi) and aquatic Hypomycetes at Sohag (Upper Egypt)

Abstract

Fifty-eight fungal species related to twenty-six genera of <i>Perenosporales</i> and <i>Saprolegniales</i> (32 species, 7 genera, 671 colonies) and aquatic <i>Hyphomycetes</i> (26 species; 19 genera; 1038 colonies) were recovered from the surface water (zoosporic fungi) and submerged decaying leaves (aquatic <i>Hyphomycetes</i>) samples collected monthly (10 samples each month) during the period of experiment (18 months). The richest samples in either zoosporic fungi or aquatic <i>Hyphomycetes</i> were those of comparatively low or moderate temperature, high contents of organic matter and dissolved oxygen. The pH volue and the total soluble salts did not show any regular monthly variations and did not exhibit any considerable influence on fungal population. <i>Achlya racemosa</i>, <i>Dictyuchus sterile</i> (<i>Saprolegniales</i>) and <i>Alatospora acuminata</i>, <i>Trisclophorus monosporus</i> (aquatic <i>Hyphomycetes</i>) were the most prevalent species. Some fungal species showed their highest population in winter months whereas others in summer months. Moreover, some species were recovered throughout the year. One species of <i>Saprolegniales</i> (<i>Isoachlya toruloides</i>) and three species of aquatic <i>Hyphomycetes</i> (<i>Exophiala jeanselmei</i>, <i>Flabellospora</i> Sp. and <i>Varicosporium delicatum</i>) are new records to Egypt.