Perithecial formation in Gelasinospora reticulispora

Abstract

When hyphae in the basal region of 72-hold, dark-grown mycelium of G. reticulispora (Greis et Greis-Dengler) C. et M. Moreau (Sordariaceae) were exposed to a microbeam of monochromatic blue light, perithecial initials were induced only in hyphae located within or in the vicinity of the light spot. The average distance from the periphery of the microbeam spot to perithecial initials produced outside the spots was 100-200 μm, regardless of the beam diameter or the incident light energy. The maximum distance of a perithecium formed outside a microbeam spot was ca. 700 μm. The inductive effect of blue light became detectable at 100 J m(-2) and reached a maximum at 1000 J m(-2), regardless of beam diameter. A microphotographic examination showed that the microbeam irradiation was effective only in hyphae rich in protoplasm.

Photocontrol of Fungal Development

“…Using a large spectrograph at the National Institute for Basic Biology at Okazaki, Japan (Watanabe et al, 1982), two action spectra were reexamined. Perithecial formation in Gelasinospora reticulispora has been known to be induced by blue light with a cryptochromatic action spectrum applied after an inductive dark period (Inoue and Furuya, 1975). Inoue and Watanabe (1984) observed that two kinds of photoreactions were involved in the UV-region because the fluence response curve showed that the perithecial number first increased, saturated at a lower level than that caused by blue light, and decreased when the fluence of 280 nm-light was increased, which was not the case when the inducement was by blue light.…”

“…Perithecial formation in Gelasinospora reticulispora has been known to be induced by blue light with a cryptochromatic action spectrum applied after an inductive dark period (Inoue and Furuya, 1975). Inoue and Watanabe (1984) observed that two kinds of photoreactions were involved in the UV-region because the fluence response curve showed that the perithecial number first increased, saturated at a lower level than that caused by blue light, and decreased when the fluence of 280 nm-light was increased, which was not the case when the inducement was by blue light. An action spectrum for inducing perithecial formation exhibited a peak at 280 nm, whereas that for inhibitory action showed a peak around 260-270 nm, which had harmful effects on the organisms.…”

Blue Light Photoreception

“…Inoue and Furuya [24] used a 200 pm diameter beam with Gelasinospora a fungus in which perithecia are induced via cryptochrome. They found that only 'protoplasm rich' hyphal areas could be induced.…”