The Effects Of The Soil Water Contents In Process Of Formation Of Floral Buds In Longan

The effects of different contents of water in soil on the formation of longan's floral buds was probed. The anatomical structure was observed at different stages of the formation of longan's floral buds , and the dynamic changes of the contents of inclusion in the leaves of the bearing mother canes at the same term were determined .The results were follows.1. Among four treatments, the contents of water in the soil by the treatment A ranged from 14.11% to 21.46%, averaging 17.15%, and its heading percentage reached to 91.67%; However, the contents of water in the soil by treatment B ranged from 25.35% to 39.32%, averaging 31.22%, and its heading percentage was 45.83%.Therefore, the contents of water in the soil from 14.11% to 21.46% was beneficial to the formation of longan's floral buds2. The results of anatomical observation showed that the whole process of longan's floral buds was divided into five stages, which were respectively the inducing stage of floral buds ( from 27^th December to 25^th January), the forming stage of the primordial in the inflorescence principal axis (from 25^th January to 28^th February), the differentiation stage of the inflorescence ( from 28^th February to 21^th March), the rapidly forming stage of the multiply lateral inflorescences (from 21th March to 4th April when the whole inflorescence had formed),the stage of the formation of the organs in the flower (from 21^th March to 19^th April ). The five formation stages were a successive developmental process with overlapping and alternativeness. The division of the formation of floral buds above is based on the relative peak of each stage of morphological differentiation in the whole process.3. The contents of the soluble sugar in the leaves of the bearing mother canes by treatment a maintained at a higher level during the inducing stage of floral buds. Therefore, the high contents of soluble sugars were beneficial to inducement of longan's floral buds. At the stage of the inducing stage of floral buds, the changing trend in the contents of soluble sugar was similar to that of ABA.4. In treatment A, the contents of Putrescine of the leaves in the bearing mothercanes maintained at a high level during the inducing stage of floral buds, which was three to four times to that in treatment B, it was suggested that the higher contents of Putrescine was beneficial to inducing of longan's floral buds. In addition, in treatment A, the contents of Putrescine reached maximum on 28th March, when most of the multiply lateral inflorescences primordial had started to differentiate, it was suggested that Putrescine may help to the activation of generating tissue. While in treatment B , the contents of Putrescine reached maximum on 21th March , when most of the primordial had started to differentiate floral organs ,it was suggested that the higher contents of Putrescine was not beneficial to formation of floral organs. In treatment A, the contents of Sperdine trended to decrease at the stage of inducing of floral buds and morphological differentiation, but to increase sharply at the end of morphological differentiation, it was suggested that Sperdine is probably beneficial to initiation and promotion of inducing of the flowersIn the four treatments ,the rank for the contents of Spermine was B>OD>A, it was suggested that the higher Spermine was not beneficial to inducing of the floral buds. On Contrary, compared with Putrescine and Sperdine , The range of the contents of Spermine was widely in different treatments, almost occupied by 50% of total PAs, Therefore, it was deduced that the effects of the contents of water in soil on the formation of Longan floral buds was performed by changing the percentage of Spermine in total PAs.5. In treatment A, the ratio of Put/Spd was bigger than 1 during the whole inducing stage of floral buds, it was suggested that the critical value of the formation of Longan floral buds was probably equal to 1 during the inducing stage of floral buds.6. In treatment A, the contents of ABA in the leaves of the bearing mother maintained at a higher level during the inducing stage of floral buds. After the morphological differentiation, the contents of ABA flucated, but in generally, trended to descend gradually, it was suggested that the higher content of ABA was beneficial to inducing of the floral buds; decreas in the contents of ABA probably resulted from its antagonism with other endogenous hormones.In treatment A, the contents of GA3 maintained at a higher level during the inducing stage of floral buds, it was suggested that the lower GA3 was beneficial to inducing of the...