Crop case study: which tropical fruit crop was successfully engineered to resist a lethal viral disease, enabling recovery of production in affected regions?
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APassion fruit
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BPapaya (resistant to papaya ringspot virus)
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CMango
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DLychee
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EBanana
Answer
Correct Answer: Papaya (resistant to papaya ringspot virus)
Explanation
Introduction / Context:Papaya production in Hawaii was devastated by papaya ringspot virus (PRSV). Transgenic papaya expressing viral coat protein provided effective resistance and restored the industry, serving as a landmark in plant biotechnology.
Given Data / Assumptions:
- PRSV causes severe yield loss and fruit deformities.
- Conventional control was ineffective once the virus became widespread.
- Coat-protein–mediated resistance can prevent successful infection.
Concept / Approach:By inserting a PRSV coat protein gene into papaya, the plant interferes with the virus life cycle, conferring high levels of field resistance. The varieties (e.g., Rainbow, SunUp) demonstrated durable protection and became a success story for biotech crops beyond the major cereals.
Step-by-Step Solution:
Identify the fruit: papaya.Identify the pathogen: papaya ringspot virus.Select the option that names papaya and the correct virus.Verification / Alternative check:Public records and peer-reviewed studies document the dramatic rebound of Hawaiian papaya after adoption of PRSV-resistant transgenic lines.
Why Other Options Are Wrong:
- A/C/D/E: While viruses affect many fruits, the celebrated, well-documented transgenic rescue case is papaya vs PRSV.
Common Pitfalls:Confusing this with citrus greening (bacteria) or banana bunchy top (different pathosystem); those require other strategies.
Final Answer:Papaya (resistant to papaya ringspot virus)