History & Principles of Plant Pathology

• Morphology of Cercospora cucurbiticola:
• Statement (I) is false: Cercospora mycelium is largely internal, and descriptions vary; however, statement II is unequivocally false because Cercospora species produce conidiophores grouped in fascicles on an internal stroma without sterile setae.
• Statement (II) is false: Needle-like sterile setae are characteristic of the genus Colletotrichum (acervulus), NOT Cercospora.
• Conclusion: Both Statement (I) and Statement (II) are false (Option 2).

Correct option: (2) Both Statement (I) and Statement (II) are false.

• Conidial Morphology in Powdery Mildew Genera (Erysiphaceae):
• Phyllactinia corylea (Phyllactinia guttata): An endophytic/ectophytic powdery mildew of deciduous trees (mulberry, hazelnut, oak). It produces unique, massive, solitary clavate (club-shaped or rhomboid) conidia on conidiophores that arise from internal hyphae through stomata with a bulbous basal swelling.
• Other Genera:
• Leveillula taurica: Produces dimorphic conidia (first-formed lanceolate, subsequent cylindrical).
• Uncinula necator & Podosphaera: Produce doliiform or cylindrical conidia in chains.
• Conclusion: Phyllactinia corylea has clavate type conidia (Option 2).

Correct option: (2) Phyllactinia corylea

• Nematode Resistance in Banana Cultivars:
• Cultivar 'Yangambi Km5' (AAA, Ibota subgroup): A landmark diploid/triploid banana cultivar widely renowned for high genetic resistance against the destructive burrowing nematode Radopholus similis through rapid suberin and lignin deposition in cortical root cells.
• Susceptibility to Pratylenchus: While 'Yangambi Km5' resists Radopholus similis, it is susceptible and does not confer resistance to the lesion nematode Pratylenchus goodeyi.
• Conclusion: Statement (I) is incorrect but Statement (II) is correct (Option 4).

• Feeding Habits of the Cigarette Beetle (Lasioderma serricorne):
• Pest Biology: The cigarette beetle (family Ptinidae/Anobiidae) is an omnivorous pest of stored commodities.
• Hosts: It feeds vigorously on cured tobacco and dried pyrethrum flowers (resistant to nicotine and pyrethrins due to symbiotic yeast Symbiotaphrina), as well as high-protein animal meals such as meat meal and dried fish meal.
• Conclusion: Feeds normally on (A) Pyrethrum and tobacco and (B) Meat and fish meal (Option 1).

Correct option: (1) (A) and (B) only.