Studies on the Sclerotia of Sonic Species in The Genus Aspergillus

THIS study is part of a large study concerning with the sclerotia of some species of genus Aspergillus. In the present study, the sclerotia of different aspergilli (Aspergillus sclerotioniger, A. sclerotiorum, A. candidus, A. flavus, A. piperis, A. ochraceus, A. robustus, A. sepultus, A. petrakii, A. melleus, A. parasiticus and A. sclerotiicarbonarius) were examined concerning their morphological and anatomical characters. The mature sclerotia in the cultures of the used aspergilli appeared with different shapes (globose, sub-globose and oval). Transverse sections of mature sclerotia revealed two regions; the outer region, considered as rind, while the inner region proposed as medulla. These aspergilli were tested also by polymerase chain reaction (PCR) technique for the presence of sclerotium regulator (Sc1R) gene. The results indicated that eight of them contain this gene; these were A. petrakii, A. sepultus, A. robustus, A. sclerotiicarbonarius, A. melleus, A. sclerotioniger, A. parasiticus and A. sclerotiorum. These species exhibited bands with different molecular weights when tested for presence of Sc1R gene. Each Aspergillus species showed one band with specific molecular weight, these bands ranged in size; the highest was 436 bp (A. parasiticus) while the lowest was 134 bp (A. sclerotiicarbonarius).