What is the Difference Between Ascospores and Conidia

The key difference between ascospores and conidia is that ascospores are sexual spores produced inside the ascii by ascomycetes during sexual reproduction, while conidia are asexual spores produced inside conidiophores by conidial fungi during asexual reproduction.

A spore is a unit of sexual or asexual reproduction in biology. It is adapted for dispersal and survival for extended periods of time in unfavourable conditions. Normally, spores form part of the life cycle of many fungi, algae, and protozoa. Fungi can produce both sexual spores and asexual spores in their life cycle. For example, a sac fungus reproduces sexually by means of sexual spores called ascospores. On the other hand, a conidial fungus reproduces asexually by means of asexual spores called conidia. Ascospores and conidia are two types of spores found in the life cycle of fungi.

CONTENTS

1. Overview and Key Difference
2. What are Ascospores 
3. What are Conidia
4. Similarities – Ascospores and Conidia
5. Ascospores vs Conidia in Tabular Form
6. Summary – Ascospores vs Conidia

What are Ascospores?

Ascospores are sexual spores produced inside structures called ascii during sexual reproduction. This kind of spore is very specific to fungi classified as ascomycetes. Ascus produces ascospores under optimal conditions. Generally, a single ascus contains eight ascospores. These eight spores are produced through meiosis division followed by a mitotic division. Then the single ascus releases its ascospores. Blumeria graminis forms ascospores under humid conditions. These spores show variable developmental patterns, unlike conidia, after landing on a suitable surface or substrate.

Saccharomyces fungus produces ascospores when it is grown in V-8, acetate ascospore agar, Gorodkowa media. These ascospores are globose. Each ascus of Saccharomyces fungus contains one to four ascospores. The asci usually do not rupture at maturity. The ascospores of saccharomyces can be stained with kinyoun and ascospore stains. Furthermore, when stained with Gram stain, ascospores of Saccharomyces appear gram-negative and vegetative cells appear gram-positive.

What are Conidia?

Conidia are asexual spores produced inside structures called conidiophores in conidial fungi during asexual reproduction. Conidium is sometimes termed as asexual chlamydospore. It is an asexual non-motile spore of fungus. Conidia are also called mitopores. This is due to the fact that the conidia are generally produced through a cellular process called mitosis. Conidia can develop into new organisms if conditions are favourable. The asexual reproduction in ascomycetes involves the making of conidia through a specialized stalk known as conidiophore.

The morphology of conidiophore is often distinctive between species. Furthermore, there are two types of conidia made by fungi: macroconidia and macroconidia. Macroconidia are relatively large and complex conidia, while microconidia are small and simple in nature.

What are the Similarities Between Ascospores and Conidia?

• Ascospores and conidia are two types of spores found in the life cycle of a fungus.
• Both types of spores are produced by specialized structures.
• They can germinate.
• Both types of spores can form fungal hyphae.

What is the Difference Between Ascospores and Conidia?

Ascospores are sexual spores produced during sexual reproduction, while conidia are asexual spores produced during asexual reproduction. So, this is the key difference between ascospores and conidia. Ascospores are produced inside ascii, while conidia are produced inside the conidiophores. Furthermore, ascospores generate from meiosis division, whereas conidia generate from mitotic division. Thus, this is another significant difference between ascospores and conidia.

The following infographic lists the differences between ascospores and conidia in tabular form for side by side comparison.

Summary – Ascospores vs Conidia

Ascospores and conidia are two types of spores found in the life cycle of a fungus. Ascospores are sexual spores produced by sexual reproduction in structures called ascii in ascomycetes fungi, while conidia are asexual spores produced by asexual reproduction in structures called conidiophores in conidial fungi. Thus, this summarizes the difference between ascospores and conidia.

Reference:

1.“Ascospore.” An Overview | ScienceDirect Topics.
2. “Conidium.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Asci with ascospores” By George Shepherd (CC BY-NC-SA 2.0) via Flickr
2. “Conidia Formation Image” By Zeeshan 93 – Own work (CC BY-SA 4.0) via Commons Wikimedia