Time-dependent sporulation, conidial size and germ tube formation in Alternaria tenuissima (Kunze ex Pers.) Wiltshire on different media

Time-dependent sporulation, conidial size and germ tube formation in Altern aria tenuissima (Kunze ex Pers.) Wiltshire on different media were studied. The results indicate that maximum number of first spore was formed on pota to dextrose agar (PDA) and new leaf extract of pigeon pea followed by old l eaf extract of pigeon pea and distilled water (DW). The sporulation was rel atively poor on other media. The maximum number of spores in a det. chain w ere produced on PDA and albumen +0.9% sodium citrate. Only one spore was se en in DW. According to time-dependent sporulation, the media were divided i nto three categories: on some media the first spore was formed in 18 h, in another group it took 30-36 h and in the third group the first conidium was formed after 40 h. Four germ tubes were commonly formed on most of the med ia. The largest conidia were observed on potato dextrose and the smallest o nes were seen on DW.