Molecular Genetic Features of Polyploidization and Aneuploidization Reveal Unique Patterns for Genome Duplication in Diploid Malus
Figure 1
Schematic Summary of the Features of Gametic Combinations for Apple Polyploidization in Diploid Malus.
Ova have two cytotypes, n and 2n ova; spermatozoa have a range but classified-into three cytotypes, n, 2n, and aneuploid spermatozoa for apple polyploidization. ‘n−1’ and ‘n+1’ refers to two aneuploid spermatozoa for aneuploidization. Diploid Malus exhibited a unique gametic combinational pattern, ova preserving euploidy exclusively, while spermatozoa presenting both euploidy and aneuploidy, for polyploidization. Molecular features showed that non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for apple polyploidization. Figure depicts only three basic chromosomes with different colours in the legend to elucidate the basic chromosome number in the apples is odd.