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

Self-incompatibility

• Evolution seems to favour (and be favoured by) genetic variability. Genetic variability is promoted by out breeding (sexual reproduction between genetically dissimilar parents)
• Sexual reproduction is so popular throughout the world of living things is still a hotly-debated question, but the fact remains. Plants, being anchored in position, have a special problem in this regard
• Many employ the services of animals (e.g., insects, birds, bats) to transfer pollen from plant to plant.
• But if the flowers have both sex organs: anthers producing pollen (the source of the male gametes) and the pistil producing the egg (the female gamete).

Dioecy

• The imperfect flowers are present on separate plants
• Dioecy is the equivalent of the separate sexes of most animals. But it is rather rare
• Some examples
• Poplars
• Hollies

Monoecy

• The imperfect flowers are present on the same plant
• But if they mature at different times, self-fertilization is avoided
• Cucurbits are common example