Botany - B.Ye. Yakubenko 2017

Part Two. The System of the Organic World
Chapter V. The System of the Organic World
Laboratory Class Topic 10.26. Phylum Zygomycota. Class Zygomycetes

Object. Order Mucorales, representative — pin mold or black bread mold (Mucor mucedo (L.) Fres.)

Tasks:

1. Examine and study the general appearance of Mucor.

2. Carefully study the sporangiophore and sporangium of Mucor.

3. Study individual Stages of the development cycle using charts and models, and draw the complete Life Cycle of Mucor in your laboratory notebook.

Equipment and Materials: MBR-1 or Biolam microscopes, magnifying glasses, forceps, germinated Mucor mycelium, models, and other accessories.

Procedure for preparing the Mucor slide. Line Petri dishes with filter paper. Moisten the paper and place a piece of white bread on it. It is advisable to sow Mucor spores in advance. Cover the dish with a lid and place it in an incubator or near a heating radiator. Over time, the spores germinate, forming a mycelium with sporangiophores. In the Petri dish, locate sporangiophores with sporangia on the germinated mycelium. Take a small piece of the mycelium and place it in a drop of Water on a clean Glass slide. Cover the mycelium with a coverslip. Secure the prepared slide on the Microscope stage using stage clips.

Microscopic examination of the Mucor slide. Using low and high magnification of the microscope, carefully observe and study Mucor (Fig. 75), grown from a single spore. It resembles a young seedling: its lower part branches in the form of a "ROOT system" and produces numerous fine ramifications — hyphae. Together, they form the mycelium, or fungal thallus, appearing as a highly branched giant Cell without transverse septa, meaning the mycelium is aseptate. Long, unbranched sporangiophores rise upward from the mycelium, terminating in sporangia.

Inside the sporangium lies the columella, which is an extension of the sporangiophore. Numerous small, spherical black spores are formed around it.

Conclusion. The Mucor mycelium is well-developed, aseptate (coenocytic), and multinucleate. Asexual reproduction occurs via sporangiospores. The sexual process is zygogamy.

Self-Check Questions

1. What type of mycelium does Mucor have, and what is its mode of Nutrition?

2. On what substrates does Mucor colonize?

3. What Methods of reproduction can be distinguished in Mucor?

4. What Two Types of spores are formed in Mucor?

5. Name the Structural components of the sporangium.