The hyphae of rhizopus species are typically non-septate, fast-growers and white in colour. The main identifying feature of the Rhizopus species is the presence of rhizoids at the base. In this context, we will discuss the features, structure and the different reproduction methods in Rhizopus. Rhizopus consists of two kinds of hyphae, namely vegetative and reproductive hyphae. Vegetative hyphae differentiate into two types, namely s tolon and rhizoids and the reproductive hyphae turn into sporangiophores.
Reproductive Hypha : It consists of sporangiophores that grow vertically from the stolon. Sporangiophores are unbranched, elongated, columellate, and they give rise to the reproductive structures called sporangiospores.
Its cell wall is composed of chitin chitosan, lipids, proteins etc. Its protoplasm consists of many nuclei, mitochondria, endoplasmic reticulum and other cytoplasmic inclusions like the ribosome, oil droplets, vacuoles etc. Columella : It arises from the sporangiophore and appears dome or umbrella-shaped. The surface of columella can be smooth or rough. The columella is hygroscopic in nature, and its primary function is water absorption. Sporangium : It attaches with the columella and a long sporangiophore.
The shape of the sporangium is spherical or globose. It carries the reproductive structures called sporangiospores. The size of the sporangium is 0.
Sporangiospores : These are the asexual spores that are globose to ovoid and unicellular. The colour of sporangiospores is hyaline to brown. It reproduces by vegetative , asexual and sexual methods. Sometimes the thallus of the Rhizopus breaks accidentally or due to some other factors into the few fragments, after which each fragment give rise to a new thallus on favourable conditions.
When conditions are good the sporangia, containing numerous haploid spores of which are produced through mitosis, release the spores into the surrounding atmosphere. These spores then may land on a moist surface and the life cycle repeats. Side note: Rhizopus stolonifer spores are usually dispersed in hot dry weather and they contain allergic proteins, which can cause respiratory and nasal symptoms in humans, such as coughing, chest discomfort and allergic reactions.
Note: Rhizopus nigricans is a synonym for Rhizopus stolonifer. To learn about another fungus that has a similar life cycle as Rhizopus stolonifer , please go to Aspergillus fumigatus. Proceed on to learn about the interactions Rhizopus stolonifer has with other things. Black Bread Mold Rhizopus stolonifer.
Reproduction: Rhizopus stolonifer style Rhizopus stolonifer exhibits both sexual and asexual reproduction. Asexual Reproduction In asexual reproduction, special non-motile hyphae called sporangiophores produce sporangia that form in an upright fashion.
Sexual Reproduction In sexual reproduction, resistant spherical spores are formed, called zygospores. Zygospores are thick-walled, which make them highly resistant to environmental hardships.
The word zygospore comes from the Greek word zygos, which means joining. The zygospores are the only diploid phase of Rhizopus stolonifer reproduction.
They are composed of two suspensor cells, which are the former gametangia or hyphae. There is a suspensor cell on either side of a large, rough, dark brown spore. The suspensor cells are present to provide support. The zygospore forms from two special haploid hyphae of opposite mating types that touch due to hormones and being in close proximity of each other.
0コメント