Developing nematode-resistant plants—method selection Which approach(es) can be used within breeding and biotechnology pipelines to develop plant lines resistant to nematodes?
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AEmbryo rescue (to capture interspecific resistance from wide crosses)
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BMutation breeding (to create novel resistance alleles)
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CNon-recombinant DNA approaches (e.g., selection, somaclonal variation)
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DAll of these
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ENone of these
Answer
Correct Answer: All of these
Explanation
Introduction / Context:Nematodes severely impact crop yields. Resistance can be introduced by several non-transgenic strategies: wide hybridization aided by embryo rescue, induced mutation breeding, and conventional selection including somaclonal variants from tissue culture.
Given Data / Assumptions:
- Goal is resistance without necessarily using recombinant DNA.
- Multiple pipeline tools can contribute complementary advantages.
- Final selection is based on bioassays and agronomic performance.
Concept / Approach:Embryo rescue salvages hybrids from wide crosses that might otherwise abort, transferring resistance from wild relatives. Mutation breeding creates new alleles that may confer resistance. Non-recombinant DNA methods include recurrent selection, marker-assisted backcrossing if markers are available, and exploiting somaclonal variation.
Step-by-Step Solution:
Use embryo rescue to introgress resistance from wild species.Apply mutagens (physical/chemical) to generate diversity; screen progeny for resistance.Leverage non-transgenic selection pipelines to fix and stack favorable alleles.Verification / Alternative check:Greenhouse and field nematode inoculation tests validate resistance; molecular markers can track introgressed segments.
Why Other Options Are Wrong:
- Each single approach may work, but the question asks which can be used—collectively “All of these” is most complete.
Common Pitfalls:Failing to pyramid resistance sources; relying on a single mechanism can lead to breakdown under field pressure.
Final Answer:All of these