FUNGI ISOLATED FROM AGARICUS BISPORUS IN TEHRAN PROVINCE WITH SPECIAL REFERENCE TO VERTICILLIUM FUNGICOLA

Abstract

During 2003-04 major mushroom production units of Tehran province were sampled and 103 fungicolous isolates were obtained (Table 1). <em>Verticillium</em> <em>fungicola</em> (with 50 isolates), <em>Trichoderma</em> <em>harzianum</em> (with 24 isolates), <em>Cladobotryum</em> <em>dendroides</em> (with 16 isolates) and <em>Acremonium</em> <em>crotocinigenum</em> (with 11 isolates) were the most frequent fungi associated with the cultivated mushroom, <em>Agaricus</em> <em>bisporus</em>. The report of <em>A</em>. <em>crotocinigenum</em> and two varieties of <em>V</em>. <em>fungicola</em> (<em>fungicola</em> and <em>flavidum</em>) is new to the mycoflora of Iran. The validity of temperature tests for distinction between <em>T. harzianum</em> and <em>T. aggressivum</em> is under question as the Iranian isolates of <em>T. harzianum</em> have the same growth rate as those of <em>T</em>. <em>aggressivum</em>, but based on molecular data (AFLP) they are different from both species. They could however represent a new taxon. <em>Verticillium fungicola</em> causes dry bubble disease and also distortion and mummification of the fruit-bodies of <em>Agaricus</em> <em>bisporus</em> (Fig. 1). The two varieties are indistinguishable from each other on morphological grounds (Fig. 3), but they are distinct at ITS level (Fig. 2).