Specialization is measured against the company and the market, not against a textbook. Knowledge of proprietary marker panels, validated selection thresholds and an internal trait database can qualify. Deep general skill in plant breeding, however distinguished, describes an industry rather than an organization and will not support the petition.
Ask what a competitor could not hire off the street
The useful question is not how good she is but what would have to be rebuilt if she left. A rival seed company could recruit an accomplished breeder next month. It could not recruit somebody who knows which markers this firm validated against its own germplasm, why three of them were discarded after four seasons of contradictory data, or how the scoring logic in the database handles missing observations.
That is the substance the petition should be built from. Two drafting habits weaken otherwise strong cases. The first opens with academic credentials, which are relevant to whether she is a professional and irrelevant to whether her knowledge is special.
The second uses the word unique without ever saying what is unique. Naming the systems, saying when the company developed them, and explaining what depends on them turns an adjective into a fact an officer can weigh.