Removal of the main inflorescence to induce reflowering of loquat

Abstract

Loquat (Eriobotrya japonica Lindl.) is an evergreen fruit tree species of the Rosaceae, and its unique flowering time greatly hinders its production. To explore the artificial regulation of loquat flowering time, we removed the main inflorescence (by cutting it) to induce reflowering. For different loquat tree cultivars with different stages, the inflorescence was removed by cutting the main floral axis at two alternative positions: the upper or the lower position beneath the inflorescence, and it was found that the proportion of reflowering resulting from removing the upper position of the main floral axis of yellow-flesh loquat cultivars during the full-bloom stage was the highest. In addition, compared with those of the normal-growing panicles, the number of flower buds and branch axes of the reflowering panicles decreased significantly after cutting. Importantly, these newly produced inflorescences flowered 2–4 months later than normal-growing inflorescences did, effectively prolonging both the flowering and fruiting time. In addition, qRT-PCR results showed that EjFT1, EjFT2, EjAP1–1 and EjAP1–2 were highly expressed in the floral axis. These findings highlighted a new method for extending the production cycle of loquat and provided a reference for the flowering regulation of loquat and other economically important fruit tree species.