Breeding of Vegetable, Spice and Tuber crops (2+1)

Terminology

Autopolyploidy

• Autopolyploids are polyploids with multiple chromosome sets derived from a single species.
• Autopolyploids can arise from a spontaneous, naturally occurring genome doubling, like the potato.
• Others might form following fusion of 2n gametes (unreduced gametes). Bananas and apples can be found as autotriploids.
• Autopolyploid plants typically display polysomic inheritance, and are therefore often infertile and propagated clonally perfect.

Allopolyploidy

• Allopolyploids are polyploids with chromosomes derived from different species. Precisely it is the result of doubling of chromosome number in an F1 hybrid.
• Amphidiploid is another word for an allopolyploid. Some of the best examples of allopolyploids come from the Brassicas, and the
• Triangle of U describes the relationships among the three common diploid Brassicas (B. oleracea, B. rapa, andB. nigra) and three allotetraploids (B. napus, B. juncea, and B. carinata) derived from hybridization among the diploids.
• Current day cultivated Okra is an example of an allopolyploid.