Phenotypic variation observed among individual mango trees of the same variety within an orchard often stems from rootstocks derived from seeds due to_______________?
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Answer: A. Polyembroyonic
Explanation
Polyembryony causes a single fertilized seed to produce multiple distinct plant embryos simultaneously. This biological phenomenon generates nucellar seedlings that inherit diverse genetic traits from maternal tissues. Using these variable seedling rootstocks inevitably creates noticeable phenotypic variation among grafted orchard trees. Mango seeds frequently exhibit polyembryony where both zygotic and nucellar embryos develop inside one seed. Phenotypic variation refers to observable physical differences in tree size, leaf shape, and fruit characteristics. Uniform rootstock production remains challenging when growers rely on polyembryonic seeds for nursery propagation.
Commercial fruit growers prefer uniform rootstocks to ensure consistent tree performance and predictable orchard yields. Plant breeders study polyembryony carefully to develop true-to-type rootstocks for modern high-density fruit plantations. Understanding rootstock genetics helps farmers minimize unwanted tree-to-tree variability within established mango orchards. Variable root stock size is a secondary outcome rather than the root genetic cause of polyembryony. Mono-embryonic seeds produce only a single embryo and would not generate the multi-seed variation described. All the above is incorrect because mono-embryonic seeds contradict the specific mechanism of polyembryony.
- Subject
- Agriculture
- Category
- Agriculture
- Topic
- —
- Difficulty
- medium
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