What structures can be found in the fungal disease shown in the photo?

Question

BlackTom AI · Accepted Answer

Powdery mildew fungi (order Erysiphales) form superficial white, powdery colonies made of chains of asexual conidia and produce round, dark sexual bodies called chasmothecia (formerly cleistothecia).

1) Relevant concepts
- Powdery mildew appearance: white, powdery patches on leaf surfaces composed of hyphae and conidia.  
- Asexual reproduction: conidia are often produced in chains on specialized conidiophores and are readily rubbed off.  
- Sexual reproduction: chasmothecia are closed, spherical fruiting bodies that contain asci/ascospores; in powdery mildews these overwinter and release spores later.

2) Step‑by‑step reasoning from the photo
- The image shows a leaf with many discrete, white powdery spots across the upper surface, typical of powdery mildew rather than rusts or downy mildews.  
- Powdery mildews are ascomycetes in the Erysiphaceae; their diagnostic microscopic structures are chains of conidia (asexual) visible as the powder and chasmothecia (sexual) appearing later as dark specks.  
- Therefore the structures you would expect on this disease are conidial chains and chasmothecia.

3) Calculations
- No numerical calculations are needed; identification is morphological.

4) Why the correct answer is correct
- Chains of conidia explain the powdery, easily dislodged white surface mycelium; chasmothecia explain later-forming small, dark overwintering bodies characteristic of powdery mildew species.

5) Why other options are incorrect
- Sporangiospores/sporangia (Zygomycetes/oomycetes) produce a different wet-looking sporulation and are not responsible for powdery mildew.  
- Pycnidiospores in pycnidia are coelomycete (some ascomycetes) fruiting bodies that look like tiny black dots in lesions, not the powdery colony here.  
- Basidiospores from basidia are produced by basidiomycetes (rusts, smuts, mushrooms); rusts produce pustules, not powdery colonies.  
- Aeciospores/aeicia are rust stage structures, also inconsistent with this powdery appearance.

6) Conclusion
- The observed disease is powdery mildew; the correct structures are chains of conidia and chasmothecia, which matches the provided answer.

What structures can be found in the fungal disease shown in the photo?单项选择题

类似问题

Citrus greening disease was first introduced to which state?

Which of the following statements correctly describe post-harvest disease infection?

Which method listed below is correct about non-visual symptoms caused by plant pathogens?

What does it tell you when a non-wounded inoculated fruit did not produce any symptoms whereas, wounded inoculated fruit became infected?

You notice one of the plants in your glasshouse trial shows severe necrosis, dieback and chlorosis on the leaves as shown in the photo below. You suspect a bacterial infection of the leaves. What will be your next step to confirm your diagnosis?

Which of the following statement are CORRECT about root and wood rot fungi that infect plants?

What organism causes the deadly “sudden oak death disease”?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单