Sporulation of Hirsutella minnesotensis growing from second-stage juveniles of Heterodera glycines

• Author(s): Chen, S.; Liu, S.;
• Abstract: Hirsutella minnesotensis is a new parasite of the second-stage juveniles (J2) of Heterodera glycines. The objective of this study was to determine when it sporulates and how many spores it produces for each colonized J2. Three isolates (FA2-1, WA23-1 and MA13-1) of the fungus were examined. J2 were exposed to fungal cultures on corn grits for 2 days before they were transferred onto a circular area of a petri dish where a 1-cm-diam water agar disk had been removed and 0.1 ml of water had been added. The dishes were sealed with parafilm and maintained at 25degreeC. The number of spores produced by the fungus growing from each J2 was recorded at intervals of 1-4 days for 38 days after inoculation (DAI). Results showed FA2-1 and WA23-1 began sporulation at 7 DAI, and MA13-1 at 10 DAI. The highest numbers of spores on the mycelium per colonized J2 were 23 for FA2-1 at 12DAI, 35 for WA23-1 at 14 DAI, and 16 for MA13-1 also at 14 DAI. At 17 DAI, most spores germinated, but after 18 DAI the number of spores on the mycelium decreased quickly. At 38 DAI, no or only a few spores were observed on the mycelium.
• Publication Date: Jun 2001
• Journal: Phytopathology