Rhizopus stolonifer (Ehrenb.) Vuill.
Rhizopus stolonifer is one of the important members in Mucoromycota and they are commonly known as ‘bread molds’. This fungus is widely distributed but commonly found in tropical and subtropical regions.
R. stolonifer can colonize on various substrates and some of them are bread, fruits (strawberries and other berries), vegetables, soil, and air. During the infection of fruits, the fruit surface first becomes soften followed by leaking from the fruit surface. Finally, the fruit is covered with wispy, fuzzy black and white mycelia of the pathogen (Figure 1). The colonies are white in PDA and V8 media and the colonies have black heads at the end due to sporulation.
The common feature of identification of Rhizopus group is rhizoids. Unlike other members of Rhizopus group, R. stolonifer has complex, well developed rhizoids (Figure 2). The sporangiophores are 1-3 mm long and 20-25 µm in diameter. Columella and sporangiospores are attached to the sporangiophore. Spoangiospores are 150- 250 x 275-300 µ and they are angular- subglobose to ellipsoidal in shape (Figure 3). Generally, the columella is half of the sporangial height. The sexual reproduction of R. stolonifer occurs by fusing the two gametangia and it results zygospores (Figure 4). The sexual reproduction of R. stolonifer takes place during unfavorable conditions.
- Schipper, M. A. 1984. A revision of the genus Rhizopus The Rhizopus stolonifera group and Rhizopus oryzae. Studies Mycol. 25:1-19.