Chara之卵孢子萌發

Oospore germination in two species of Chara

Germination of the oospores of Chara contraria Kützing and C. zeylanica Willd. was investigated with respect to the effect of a variety of environmental factors, among them, photoperiod, presence or absence of oxygen, culture medium, and temperature. The results indicated that the oospores of the species investigated require a period of dormancy before germination. This period may be shortened by treatment at low temperature (5° to 7°C), but if this is omitted, germination follows ultimately, but is delayed. Germination occurs under both aerobic and anaerobic conditions, contrary to reports in the literature. The ontogeny of the protonema and of the primary axis in early germination has been described for Chara contraria and is essentially similar to the general pattern described by earlier investigators for other species of the genus. Studies of the organism in culture indicated clearly the important role of the rhizoids in generating secondary protonemata and, thus, in the colonization of a given substrate.