Flower primary purpose of a flower is reproduction. Since the flowers are the reproductive organs of plant, they mediate the joining of the sperm, contained within pollen, to the ovules — contained in the ovary. Pollination is the movement of pollen from the anthers to the stigma. The joining of the sperm to the ovules is called fertilization. Normally pollen is moved from one plant to another, but many plants are able to self pollinate. The fertilized ovules produce seeds that are the next generation. Sexual reproduction produces genetically unique offspring, allowing for adaptation. Flowers have specific designs which encourages the
Self-incompatibility some extent. The loci responsible for SI in heterostylous flowers, are strongly linked to the loci responsible for flower polymorphism, and these traits are inherited together. Distyly is determined by a single locus, which has two alleles; tristyly is determined by two loci, each with two alleles. Heteromorphic SI is sporophytic, i.e. both alleles in the male plant, determine the SI response in the pollen. SI loci always contain only two alleles in the population, one of which is dominant over the other, in both pollen and pistil. Variance in SI alleles parallels the variance in flower morphs, thus pollen