POSITIVE PHOTOTROPISM AND HYDROMORPHOGENESIS IN GERMINATION STRUCTURES OF CONIDIOBOLUS SPECIES

ABSTRACT The mode of germination of conidia of the tested fungi was dependent upon water. The short, wide conidiophores which formed on conidia normally produced secondary conidia spontaneously; however, if they contacted moisture before initiation of secondary conidia could occur, they turned into germ-tubes instead. Since these conidiophores are known to sprout towards light, illumination through agar media, for instance, led to their contacting the wet substrate, resulting in germ-tube formation. Germ-tubes followed the direction of eight narrow wave-bands of light from near ultra-violet through red, by tip-displacement mechanism, and they could be considered homologous to conidial conidiophores. Hyphae of C. obscurus on water agar grew towards light. In darkness, media composition determined direction of sprouting from conidia, and hence their mode of germination.