Study On The Karyotype Of Aspergillus Oryzae Conidia And Preliminary Analysis Of The Germination Components

In this study, we preliminary analyzed the differences between the germination components of haploconidia and multiconnidia of Aspergillus oryzae FS1125, and lay the foundation for the next step to explore the genetic regulatory background of A. oryzae karyotype variation. The main contents and results are as follows:(1)To determine the spore producing time and the culture method for spore germination of A. oryzae FS1125. The mature spores of A. oryzae FS1125 were formed and collected after 9-10 days culture on solid Czapek-Dox Medium (CD-M). The spore germination rate reach 84.8% after 6.5h culture on solid CD-M plate, and 88.9% in 4.5h culture on liquid CD-M, respectively. And 4.5h culture in liquid CD-M was determined as the time for collection the spore germination in early stage.(2)The karyotype and nuclear particle size of A. oryzae FS1125 were analysized. DAPI nuclear staining and fluorescence microscopy were used to analyze the karyotype and nuclear particle size of A. oryzae FS1125. The results showed that the karyotype of two or more than two nuclei were mainly accounted for the proportion of nuclei, of which the haploconidia accounted for about 9.1%, diploconidia about 36.4%, and multinucleate conidia of 54.5%. The nuclear particle size distributed in the range of 3 to 9 ?m, and 91% concentrated in 4 to 7um; There are at least 50% of the haploconidia's size at 3 ?m, and only the haploconidia was found in 3 ?m particle size. Thus, the membrane filtration method for the separation of haploconidia and multinucleate conidia was set up.(3)Preliminary analysis of the differences between the germination components of the haploconidia and multinucleate conidia. The spore germinations of haploconidia and multinucleate conidia were collected, respectively. The germination extracts of the two karyotype were scanned in full wavelength and detected by UPLC UV absorption, and the haploconidia and multinuclear germination extracts had no obvious difference in their maximum absorption peak. However, when the two kind of germination extracts were analyzed by thin-layer chromatography (TLC), different spots were observed by visualization with sulfuric acid ethanol or iodine.