XVI International Botanical Congess
Lisianthus (Eustoma grandiflorum, Gentianaceae), is an ornamental flower which requires an extended period of 5-7 months from sowing to first flower initiation. Lisianthus is generally considered as a facultative long day (LD) plant. We studied the effect of day length on flower initiation and development, and found that the transition from vegetative to reproductive stage occurred earlier in plants grown under LD than under short day (SD) conditions. Plants grown under LD conditions were also taller and bore less flowers per inflorescence than those grown in SD. Aiming to investigate molecular factors involved in flower development, we searched for the lisianthus homologue of the flower-meristem-identity gene LEAFY (LFY). We isolated a 140 bp fragment of the lisianthus LFY homologue, sharing 65% similarity with LFY in Arabidopsis. By RT-PCR we found that the lisianthus LFY homologue was expressed in apical meristems before and after flower induction, and in the leaves before flower induction. The relationship between lisianthus LFY homologue expression and flower development under different conditions is currently being studied.