A very large literature exists on this topic. And a lot of it is on plants. Some key concepts applied to soapberry bugs are in various Scott Carroll papers. Look for phenotypic plasticity first and the underlying genetics that permit plasticity under some circumstances. Some oldies but goodies:

Carroll SP, Corneli PS. 1999.The Evolution of Behavioral Norms of Reaction as a Problem in Ecological Genetics: Theory, Methods, and Data. Pages 52-68 in Geographic Variation in Behavior: Perspectives on Evolutionary Mechanisms (S.A. Foster and J.A. Endler, Eds.) Oxford University Press.

Carroll SP, Corneli PS. 1995. Divergence in Male Mating Tactics between Two Populations of the Soapberry Bug: II. Genetic Change and the Evolution of a Plastic Reaction Norm in a Variable Social Environment. The Journal of Behavioral Ecology 6:46-56.

Lots of newer literature too. Do a Google Scholar or PubMed search to find newer stuff.

Plasticity describes the ability of an organism to change its phenotype in response

to changes in the environment through physiological, biochemical, anatomical or behavioural modifications, if it's only implemented during the lifetime of the organism under certain conditions and is reversible, is called acclimation, if the modification has been evolved through generations is called adaptation.

Plants are tolerant toward genomic alterations: in addition to indels and transposons; tandem duplication, segmental duplication and whole genome duplication are frequent, producing redundant copies or variants of genes.

After this events, gene expression is not simply the sum of that in the ancestral diploids. Some genes are immediately either upregulated or downregulated.

Often, one parental genome appears to dominate the other, in that the gene copies from one parent are preferentially upregulated.

If a mutation disables one gene copy, natural selection will not eliminate the plant

with the mutation because the other, non-mutated copy is still functioning.

The mutated copy often becomes a pseudogene, a sequence that cannot be transcribed or translated properly and might gather more and more mutations becoming a random sequence. Thus, the number of genes will gradually drop back to the approximate number that was in the diploid parents; genes that

were duplicated will return to being single copy.

However some gene copies evolve accumulating mutations and responding to selection.

Certain broad classes of genes are often retained in duplicate, whereas other classes are generally returned to single copy. In general, transcription factors, protein kinases, and ribosomal genes are often retained in duplicate, whereas many genes of metabolism are single copy, suggesting that their duplicates were eliminated or lost soon after duplication.

The new copy of the gene can partake of the function of the ancestral gene subfunctionalization or acquire a new function through mutation neofunctionalization. (i.e. new expression domain or different binding targets). The history of the genus Clarkia is a good example.

These processes accelerate the breeding as well as natural evolution.

The history of Triticum, Gossypium, Tragopogon and Brassica are a wonderful examples.