Defining autopolyploidy: Cytology, genetics, and taxonomy

Area of Science:

• Genetics
• Evolutionary Biology
• Cytogenetics

Background:

• Autopolyploidy involves multiple genome copies originating within a single species.
• Cytological autopolyploidy is characterized by polysomic inheritance (random chromosome pairing and segregation).
• Distinguishing taxonomic and cytological definitions is crucial for understanding polyploid evolution.

Purpose of the Study:

• To review methods for categorizing taxonomic and cytological autopolyploids.
• To investigate the frequency of documented polysomic inheritance in autopolyploids.
• To assess the impact of inheritance patterns on polyploid species classification.

Main Methods:

• Overview of cytological, marker-segregation, and genomics methods.
• Systematic literature review of inheritance data in autopolyploid species.
• Analysis of polysomic vs. disomic inheritance patterns.

Main Results:

• Polysomic inheritance is prevalent (91%) in documented autopolyploid species and synthetic polyploids.
• No clear cases of disomic inheritance were found in autopolyploids.
• Seven species with polysomic inheritance may be misclassified allopolyploids, and five others show mixed inheritance.

Conclusions:

• Polysomic inheritance is common in autopolyploids, supporting their cytological definition.
• Inheritance patterns can challenge taxonomic classifications, potentially re-labeling allopolyploids as autopolyploids.
• Further cytogenetic and genomic research is essential for accurate polyploid origin and inheritance type determination.