Progressive inhibition of fruit development by carpic dominance in cucumber. The eldest fruit (left) inhibits the growth of fruit 2, causes arrest of growth on fruit 3 and causes immediate senescence of fruit 4

It is relatively well-known that branches can inhibit the growth of other branches – so-called ‘apical dominance’. It is less well-known that fruit also exert dominance, and can inhibit the growth of both inflorescences (exchangeable dominance) and other fruit (carpic dominance). We are interested in understanding all these phenomena, and whether they represent aspects of the same basic mechanism.

Carpic dominance can result in a whole spectrum of effects, ranging from mild growth inhibition to the complete abscission of the ‘dominated’ fruit. Carpic dominance prevents plants from over-investing in fruit, which is a sound evolutionary strategy in wild plants. However, this phenomenon causes yield losses – both potential and actual – in crop species. We aim to understand the molecular mechanisms behind carpic dominance, using a range of approaches. Arabidopsis displays very  weak carpic dominance, so one of our main tasks is to identify a good model species for this process!