Occurrence of spontaneous tetraploid nucellar mango plants

Abstract

A putative polyploid seedling tree appeared among the polyembryonic mango (Mangifera indica L.) ‘Gomera-1’, widely used as a rootstock in the Canary Islands. Initially detected because of its wider and more coriaceous leaves, further studies showed that fruit from this seedling are considerably larger than normal, although all other fruit characteristics (including polyembryony) were similar to those of standard ‘Gomera-1’ (G-1) fruit. The progeny of this plant has, to date, proved to be morphologically identical to the mother plant. Studies of seedlings from normal G-1 trees growing in the same orchard showed that 10% of the plants had morphological characteristics similar to those of the putative polyploid seedling. Flow cytometry and chromosome count analyses confirmed that G-1 is diploid, whereas the putative polyploid is a stable tetraploid. The study also showed that the morphologically abnormal seedlings from diploid parent trees were spontaneous tetraploids.