What rust is crucifers in caused by

Answer – Albugo Campesters

Species of mucor do not have –

Answer – Stoten

Plasmogramy is mucor by –

Answer – Somatogamy

Sexual Reproduction take place is –

Answer – Ascomycetes & Basidiomycetes

Fungi are alway –

Answer – Hetrotrophic

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SHORT TYPE QUESTIONS

Answer any two only

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2. Septate Mycelium

• Definition:
  Septate mycelium refers to fungal hyphae divided into distinct compartments or cells by cross-walls called septa. Each septum contains a small pore, which allows the movement of nutrients, organelles, and cytoplasm between the cells, ensuring cellular communication and efficient nutrient distribution.
• Characteristics:
• Septa act like partial partitions, preventing the entire mycelium from being affected if one section is damaged.
• Pores in septa facilitate cytoplasmic flow while compartmentalizing the fungal structure.
• Examples:
• Found in Ascomycetes (e.g., Penicillium and Aspergillus) and Basidiomycetes (e.g., Agaricus or mushrooms).
• Importance:
• The septate structure provides strength to the fungus and enables differentiation of specific regions in the fungal hyphae.
• It helps the organism survive injury or stress, as individual sections can remain functional even if part of the mycelium is damaged.

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3. Asexual Reproduction in Alternaria

• Introduction:
  Alternaria is a genus of ascomycete fungi that reproduces primarily through asexual reproduction. It causes leaf spot diseases in crops such as tomatoes, potatoes, and brassicas.
• Process of Asexual Reproduction:

1. Conidiophore Formation:
   • The fungus produces specialized stalk-like structures called conidiophores on the surface of the host plant.
2. Conidia Development:
   • Conidia are produced at the tips of conidiophores. These conidia are multicellular, dark-colored, and often have transverse and longitudinal septa.
   • Conidia are resistant to environmental stress and facilitate the spread of the fungus.
3. Dispersal:
   • Conidia are dispersed by wind, rainwater, or mechanical contact and reach new plants or plant parts.
4. Germination:
   • When the conidia land on a suitable surface under favorable conditions, they germinate and form new fungal colonies, initiating infection.

• Significance:
• Asexual reproduction allows Alternaria to spread quickly over large areas, leading to rapid outbreaks of crop diseases.

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4. Life Cycle of Albugo (White Rust)

The life cycle of Albugo candida (the causal agent of white rust) consists of both asexual and sexual phases.

1. Asexual Reproduction:

• Infection Initiation:
• The fungus produces sporangia on the surface of infected plant tissues, particularly leaves and stems. These sporangia form white pustules, which give the disease its name.
• Sporangia Dispersal:
• Sporangia are dispersed by wind or water splashes.
• Zoospore Release:
• Under moist conditions, sporangia release zoospores (motile spores) that swim to the plant surface.
• Infection and Colonization:
• Zoospores penetrate the plant tissue through stomata or wounds, infecting the host and developing new fungal colonies.

2. Sexual Reproduction:

• Formation of Gametangia:
• During unfavorable conditions, the fungus forms oogonia (female structures) and antheridia (male structures) inside the plant tissue.
• Fertilization:
• The antheridium fertilizes the oogonium, leading to the formation of a thick-walled oospore (a dormant spore).
• Germination:
• Once conditions improve, the oospore germinates and produces new sporangia, restarting the asexual phase of the life cycle.

Significance:

• The dual reproductive strategy allows the fungus to spread quickly and survive unfavorable conditions, making it a persistent problem in cruciferous crops.

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5. Red Root of Sugarcane

• Introduction:
  Red Root disease is a fungal disease of sugarcane caused by various fungi, including Pythium species and Fusarium. It primarily affects the roots, leading to poor plant development and reduced yields.

Symptoms:

1. Red Discoloration:

• The infected roots show reddish or brown discoloration, especially on the inner tissues.

1. Stunted Growth:

• Infected plants exhibit poor growth due to impaired nutrient and water absorption.

1. Root Rot:

• Severely infected roots begin to rot, further reducing the plant’s ability to anchor and take up nutrients.

Causal Agents:

• The disease is caused by soil-borne fungi such as Pythium arrhenomanes or Fusarium species that thrive in waterlogged or poorly drained soils.

Control Measures:

1. Crop Rotation:

• Avoiding continuous sugarcane cultivation helps reduce the fungal population in the soil.

1. Proper Drainage:

• Ensuring good field drainage reduces fungal growth.

1. Use of Fungicides:

• In severe cases, applying appropriate fungicides to the soil can control the disease.

1. Healthy Seedlings:

• Using disease-free planting material ensures healthy crop establishment.

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