Physiology of Flower Bulbs

Almost all bulbous plant species are monocots, including the economically important ornamentals tulip and lily. Cultivation occurs in temperate climate regions with the Netherlands being world-wide the leading producer of tulips. Unfortunately, development of a new cultivar in this species takes more than 20 years due to its low propagation rate and long juvenile phase. Tulip seeds require up-to seven annual growth cycles to produce a flowering bulb, which subsequently produces only two to three daughter bulbs a year.

We aim to decipher the propagation and flowering time controlling processes in tulip at the physiological and molecular levels. The tulip genome is approximately 200 times larger than the genome of the plant model species Arabidopsis thaliana, which make molecular studies of biological processes challenging. Nevertheless, a combined physiological and molecular approach is followed to obtain insight in flowering and propagation behaviour. We apply e.g. state-of-the-art Next Generation Sequencing (NGS) technologies to identify key genes and markers for the processes under study. Furthermore, lily is explored to shed light on propagation, because this species can be easily propagated by in vitro methods in contrast to tulip.