Genetic variation within a clone

Genetic variation within a clone may arise due to :

1. Mutation:

• The frequency is generally very low (10-5 to 10-7).
• Ordinarily dominant mutations would be expressed in the somatic tissue. A mutant allele would be homozygous only when.

i) both the alleles in a cell mutate at the same time producing the same mutant allele or

ii) The mutant allele is already in heterozygous condition in the original clone. Though rare, both these events are possible. Bud mutations may often produce chimeras i.e. an individual containing cells of two or more genotypes.

2. Mechanical mixture:

• Mechanical mixtures produce genetic variation within a clone much in the same way as in the case of purelines.

3. Sexual Reproduction:

• Occasional sexual reproduction would lead to segregation and recombination.
• The seedlings obtained from sexual reproduction would be genotypically different from the asexual progeny.
• It is evident that only clones would tend to became variable atleast in annuals and biennials. Eg. Potato