In selfincompatible plants how will offspring Sgenotype freq

In self-incompatible plants, how will offspring S-genotype frequencies differ from H-W expectations? What aspect of S-allele frequencies would you expect to be most predictable in natural populations?

Solution

The HW principal makes 2 postulates :

number one: after a single episode of random mating genotype frequencies can be expressed as simple function of allele frequencies which means that genetic characteristics of populations can be described in terms of frequencies of a relatively few alleles rather than the much larger possible zenotypes.

number 2 in the absence of external forces like selection mutation genotype frequencies remain constant over time.

The Sloci are extremely polymorphic that means there are number of multiple alleles in the population.

in compatibility is controlled by a single allele in the haploid pollen grain. If we observe the mechanism in the Petunia all pollen grains are incompatible as well compatible the growth of incompatible pollen tube stops in the style with this block is created by An s- locus enoded ribonuclease which is synthesized within the style destroys its RNA molecules yhus stopping the Pollen tube growth.

Hi number of s alleles are usually a feature of natural self incompatible populations since sll are subject to strong negative frequency dependent selection.

A dominant s- alleleem was identified for each plant using dihybrifross analysis of phenotypes.