The dependence of the penetrance of mutant genes on environment and genotypic background

✍ Scribed by W. Gottschalk

• Publisher: Springer Netherlands
• Year: 1978
• Tongue: English
• Weight: 770 KB
• Volume: 49
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00187810

✦ Synopsis

Two polymeric genes of the Pisum genome, bif-1 and bif-2, alter the monopodial shoot structure of the pea plant into dichotomy. They show an unstable penetrance being influenced by environmental factors as well as by specific genes of the genome. Under moderate climatic conditions, the penctrance ranges between 40 and 80% while it goes down to 0% under hot and dry conditions. A high pcnetrance results in a seed production superior to that of the initial line while low penetrance influences the seed production negatively.

The gene efr for early flowering and ripening reduces the penetrance of bifl. A further reduction occurs by incorporating gent ion for an increased number of ovules per carpel into the genome. Gene ion, however, influences the penetrance of bif-1 only in the presence of efr. Gene sg-I responsible for the reduction of the grain size stabilizes the penetrancc of bif-2. This stabilizing effect is also maintained under those environmental conditions which reduce the penetrance of bif-I down to 0%. The stabilization leads to an increase of the seed production per plant.