Crop cytogenetics — understanding triticale as a cereal hybrid Triticale, recognized as the first widely publicized man-made cereal, is an example of which chromosomal category created by interspecific hybridization and chromosome doubling?

Introduction / Context:
Triticale is a hybrid of wheat (Triticum) and rye (Secale) developed to combine yield and quality traits of wheat with stress tolerance of rye. Its cytogenetic classification illuminates how plant breeders use chromosome manipulation to stabilize interspecific crosses.

Given Data / Assumptions:

• Triticale arises from crossing two different genera/species: Triticum × Secale.
• Chromosome doubling is needed to restore fertility.
• We are to classify the resulting chromosome constitution.

Concept / Approach:

Allopolyploidy refers to polyploidy involving chromosomes from different species. After hybridization, chromosome doubling (e.g., via colchicine) creates pairing partners for each chromosome set, enabling meiotic stability and fertility. Autopolyploidy, by contrast, involves duplication of a single species’ genome rather than combining different genomes.

Step-by-Step Solution:

Verification / Alternative check:

Plant breeding literature and cytogenetics texts explicitly describe triticale as an allopolyploid derived from wheat × rye.

Why Other Options Are Wrong:

Autopolyploidy duplicates one genome; triticale contains distinct genomes. “Man-made crossing” without polyploidy ignores the essential chromosome doubling. “Artificial evolution” is vague. “Haplodiploidy” describes certain animal sex-determination systems, not crops.

Common Pitfalls:

Confusing general hybridization with the specific chromosomal status (polyploidy across species).

Final Answer:

Artificial allopolyploidy