Department of Plant Pathology and Department of Soil Science , University of Wisconsin-Madison, Madison, Wisconsin 53706.
Appl Environ Microbiol. 1987 Sep;53(9):2106-10. doi: 10.1128/aem.53.9.2106-2110.1987.
The effect of spore inoculum density, medium concentration, and temperature on slime-spot formation, spore yield, and mycelium production by Colletotrichum gloeosporioides on agar media were studied with a simple microplate assay. A steady-state spore yield (spore-carrying capacity) independent of inoculum density was reached only on media that supported good fungal growth and sporulation. The spore-carrying capacity was reached earlier, the denser the inoculum. On standard mycological media a high inoculum density (2.5 x 10 spores per ml) resulted in a slimy mass of conidia forming a slime spot, a phenomenon associated with greatly reduced mycelium formation and indicative of microcycle conidiation. In contrast, for a similar inoculum density, enhanced mycelial growth preceded sporulation and overrode slime-spot formation on highly concentrated media; a very low medium concentration resulted in much less mycelium, but spore production was also decreased. Exposure to suboptimal growth temperatures of 36 to 48 degrees C for up to 8 days did not induce microcycle conidiation from inocula that did not form a slime spot at 28 degrees C.
采用简单的微量板测定法，研究了孢子接种密度、培养基浓度和温度对胶孢炭疽菌在琼脂培养基上形成粘液斑、孢子产量和菌丝体生长的影响。只有在支持良好真菌生长和孢子形成的培养基上，才能达到与接种密度无关的稳定孢子产量（孢子承载能力）。接种密度越高，达到孢子承载能力的时间越早。在标准的真菌学培养基上，高接种密度（每毫升 2.5 x 10 个孢子）导致形成粘液斑的大量分生孢子，这是微环式分生的现象，与菌丝体形成大大减少有关，表明微环式分生。相比之下，对于类似的接种密度，增强的菌丝体生长先于孢子形成，并在高浓度培养基上克服了粘液斑的形成；培养基浓度非常低会导致菌丝体减少，但孢子产量也会减少。在 36 至 48 摄氏度的亚最佳生长温度下暴露长达 8 天，不会诱导在 28 摄氏度时不形成粘液斑的接种物进行微环式分生。
