FLORAL INDUCTION IN GROWING BUDS OF LYCHEE (LITCHI-CHINENSIS) AND MANGO (MANGIFERA-INDICA)

Buds of potted plants of the terminal flowering tree species lychee (L itchi chinensis) and mango (Mangifera indica) forced to begin growth a t high temperatures (florally non-inductive) and then transferred to l ow temperatures produced inflorescences, so the whole process of flora l induction can occur in growing buds. Floral initials were visible in lychee within 39 days of transfer to low temperature and 30 days in m ango, indicating that floral induction occurs relatively quickly in bo th species. In most cases where plants were transferred to winter ambi ent temperatures for floral induction, pre-activated (growing) buds fl owered more consistently than buds that were dormant at the time of tr ansfer. If the buds were small when plants were transferred from high temperature to low temperature, leafless inflorescences formed. If bud s were a little larger, leafy inflorescences formed, with leaves basal ly and flowers terminally. Lf the buds were larger again, the shoots w ere purely vegetative. All these observations are consistent with flor al induction occurring while the bud is growing and provide for much i mproved experimental systems for studying the physiology of floral ind uction in species such as lychee and mango.