Mashua: Tetraploid Variability

Twelve sets of three tubers each of seedlings out of Blanca mashua. Each is a little bit different, with mostly white or light yellow skin and various shades of red or purple eyes.

The domesticated varieties of mashua (Tropaeolum tuberosum) are tetraploid, meaning that they have four copies of each chromosome.  This allows the plant to carry twice the genetic diversity of a diploid organism (like most animals and many plants).  Balanced against that, mashua is most likely an autoploid, meaning that it became tetraploid by doubling its […]

Potato Ploidy and Endosperm Balance Number

A micrograph showing two potato guard cells comprising a stomatum. The chloroplasts in each guard cell are marked. Six are present in one and seven in the other.

Introduction How Seeds are Formed Domesticated and Wild Potatoes Ploidy Monoploid and Haploid Numbers Haploids Interactions of Ploidy in Crosses Unreduced (2n) Gametes Endosperm Ratio Endosperm Balance Number The Potato Gene Pool Triploid Domesticated Potatoes The Genetics of EBN Manipulating Ploidy A Final Note on Probability Determining Ploidy Morphological Evalutation Guard Cell Counts Chromosome Counts […]