Species track record: the production of high-quality, uniform somatic embryos has historically been most successful in which crops?

Introduction / Context:
Somatic embryogenesis success varies widely by species. Some model systems consistently yield uniform, vigorous embryos suitable for synthetic seed research and commercialization pilots.

Given Data / Assumptions:

• Carrot and alfalfa have long-standing protocols with reliable embryogenesis.
• Uniformity and conversion rates are key for synthetic seed viability.
• Woody perennials and certain tropical species remain challenging.

Concept / Approach:
Species choice influences embryo morphology, synchronization, and germination. Carrot and alfalfa protocols deliver repeatable results, making them benchmark systems for encapsulation studies.

Step-by-Step Solution:

Verification / Alternative check:
Numerous reports demonstrate high conversion rates from encapsulated embryos in these two species compared to more recalcitrant crops.

Why Other Options Are Wrong:

• D/E: While research exists, uniformity and large-scale reliability are less established than in the model systems.

Common Pitfalls:
Assuming success in one species translates directly to another; medium composition and growth regulators must be optimized per crop.

Final Answer:
Both (a) and (b)