History & Principles of Plant Pathology

• Pebrine Disease in Sericulture:
• Causal Organism: Pebrine is caused by the obligate microsporidian fungal parasite Nosema bombycis.
• Destructiveness: It is the most feared and devastating disease in sericulture because it undergoes transovarial (congenital) transmission from infected female moths into the eggs, as well as oral transmission. An entire batch of larvae can collapse, exhibiting characteristic black pepper-like spots on the integument.
• Pasteur's Discovery: Louis Pasteur developed mother moth examination (cellular grainage system) to eliminate infected batches.
• Conclusion: Pebrine is the most destructive disease in sericulture (Option 2).

Correct option: (2) Pebrine

• Pests of Stored Silkworm Cocoons:
• The Dermestid Beetle (Dermestes spp.):
• In sericulture cocoon storage rooms and grainages, dermestid beetles (Dermestes ater and Dermestes cadverinus) are the most destructive natural enemies.
• Both larvae and adult beetles bore into dry cocoons to feed on dead pupae, cutting through silk filaments, staining silk fibers, and rendering cocoons unreelable as waste.
• Other Beetles Listed: Tribolium feeds on flour; Lasioderma on tobacco; Stegobium on dried bread.
• Conclusion: Dermestes is the most destructive natural enemy of silkworm cocoons (Option 2).

Correct option: (2) Dermestes

• Central Silk Board (CSB) Research Institutes:
• Pair-by-Pair Matching:
• CTRTI $\rightarrow$ (II) Jharkhand: Central Tasar Research and Training Institute is situated in Ranchi, Jharkhand.
• CMERTI $\rightarrow$ (III) Assam: Central Muga Eri Research & Training Institute is located in Lahdoigarh, Jorhat, Assam.
• CSRTI $\rightarrow$ (IV) Karnataka: Central Sericultural Research and Training Institute is located in Mysuru, Karnataka (with sister institutes in Berhampore and Pampore).
• CSGRC $\rightarrow$ (I) Tamil Nadu: Central Sericultural Germplasm Resources Centre is located in Hosur, Tamil Nadu.
• Correct Choice: Option 3 matches (A)-(II), (B)-(III), (C)-(IV), (D)-(I).

Correct option: (3) (A) - (I), (B) - (ID), (C)- (IV), (B) - (1)

• Principle of Antisense Oligonucleotides: An antisense molecule is an oligonucleotide designed to be strictly complementary in sequence and antiparallel in polarity to a targeted sense mRNA or coding DNA sequence, inhibiting translation or transcription through hybrid formation.
• Sequence Pairing: For the target sequence $5'\text{-ATTAAGGC-}3'$:
• The complementary Watson-Crick base pairing gives: $A \rightarrow T$ (or $U$ in RNA), $T \rightarrow A$, $G \rightarrow C$, and $C \rightarrow G$.
• Matching base-by-base yields the antiparallel complementary strand: $3'\text{-TAATTCCG-}5'$ (or $5'\text{-TAATTCCG-}3'$ when presented in direct alignment as an antisense sequence in the question).
• Conclusion: TAATTCCG represents the designated antisense molecule (Option 4).

Correct option: (4) TAATTCCG