Abstract: [Objective] The yield and quality of bamboo shoot depend upon species, site, climate, environment and cultivation techniques. High-yield cultivation techniques of sympodial bamboo shoot were mainly restricted in such traditional measures as adjustment of bamboo stand density and age structure, fertilization, shoot harvesting as well as disease and pest control in recent 5 decades. In this study, the different layers of branches on culm were controlled by pruning, and the distribution of endogenous hormone and nutrients in the above-ground organs and under-ground organs were investigated to study the regulatory mechanism of bamboo shoot yield by hormone and single sugar, which innovates shoot-oriented bamboo cultivation techniques and realizes the high-yield and effective bamboo cultivation model in a dwarf and horticulture way.[Method] Enzyme-linked immunosorbent assay(ELISA) and high performance liquid chromatography(HPLC) were adopted to determine the endogenous hormones and soluble sugar content of Dendrocalamus latiflorus shoot in field and potted cultivation subjected to different pruning. Meanwhile shooting situation and accumulated shoot yield were also investigated.[Result] With a high-yield cultivation model of D. latiflorus, one or two layers of bamboo branches were retained on a culm. The result showed that the single bamboo shoot weight, shoot number, average yield and cumulative yield of the 1-2 layers of bamboo branches left on a culm were significantly greater than those of other pruning treatments. The bamboo shoot yield of D. latiflorus was closely related to the kind and content of endogenous hormone in shoot body. During the whole shooting period, GA₁₊₃ content was significantly proportional to the single bamboo shoot weight, and IAA and ABA contents were positively correlated with the single bamboo shoot weight, while GA₄₊₇ content and ZR content were not significantly related to the single bamboo shoot. The IAA content of bamboo shoot treated by 2 layers of branches left on a culm was significantly higher than that with other treatments, and its IAA content reached the highest, with 109.53 μg·g^-1 FW at its shooting peak period. The bamboo shoot growth was mainly regulated by 3 kinds of hormones of IAA, GA and ABA. The change trend of IAA content was initially low and then high, which accords with the change pattern of IAA in the apical dominance theory. The glucose content was significantly correlated with fructose content, and their correlation coefficient was 0.90^[DK]**.[Conclusion] It is concluded that bamboo shoot growth of D latiflorus is mainly regulated by 3 kinds of endogenous hormones of IAA, GA and ABA, and carbohydrate. IAA would mainly promote cell elongation, and maintain a nutrient supply sink between bamboo stump or culm and bamboo shoot for carbohydrate transportation, distribution and metabolism to meet nutrient demand by fast-growing shoot. ABA could promote carbohydrate transportation and metabolism, and GA₁₊₃ promote cell elongation as IAA does. However, GA₄₊₇ seems to be a little function in bamboo shoot growing process. The main carbohydrate for bamboo shoot growth is sucrose, rather than starch; powerful bamboo's apical dominance is attributed by the high IAA concentration on the top.

Key words: Dendrocalamus latiflorus, pruning, hormone, soluble sugar, shoot, mechanism, yield