钩梢整枝对麻竹笋产量影响的激素和单糖调控机制

Effects of Pruning Hormonal and Single-Sugar Regulation by Hooking Shooting on the Yield of Dendracalamus latiforus

【目的】通过麻竹钩梢整枝保留不同竹枝盘数,改变竹子地上、地下器官激素和营养物质分配,研究影响麻竹笋产量激素和单糖调控机制,创新笋用竹林培育方式,以实现麻竹高效、丰产、矮化和园艺化栽培方式.【方法】采用酶联免疫法(ELISA)和高效液相色谱法(HPLC)等方法,测定大田和盆栽种植麻竹不同钩梢整枝处理后竹笋内源激素、单糖含量以及调查其发笋数量、时间和累积笋产量。【结果】麻竹笋用林培育方式可采用钩梢保留1~2盘枝,保留1~2盘留枝处理的麻竹单笋质量、出笋个数、平均产量和累积产量显著大于其他钩梢修枝处理;麻竹笋产量与笋体内源激素种类、含量水平呈密切相关:在整个出笋期间,GA1+3含量与单笋质量呈极显著正相关,IAA和ABA含量与单笋质量呈显著正相关,而GA4+7和ZR含量与单笋质量无明显相关,麻竹笋个体增大主要是由IAA、GA和ABA 3类内源激素协同调控:2盘留枝处理笋体IAA和ABA含量显著高于其他不同留枝处理,其中出笋盛期间,2盘留枝处理IAA含量最高,达109.53 ug·g-1FW;其IAA变化趋势呈先低后高,符合顶端优势IAA学说中IAA变化规律;不同处理笋体中葡萄糖含量和果糖含量呈极显著相关,相关系数高达0.90(P<0.01)。【结论】IAA促进细胞伸长生长,形成和维持竹蔸或竹杆与笋体间的"营养库壑",促进碳水化合物的运输、分配、代谢,保障竹笋快速生长对糖分的供应需要,ABA主要是促进糖类物质的运输和代谢,GA1+3主要是促进细胞伸长生长,而GA4+7对笋体生长中作用较小,笋体生长发育的碳水化合物源主要是蔗糖,而非淀粉;竹笋生长强大的顶端优势是由其顶端高浓度的IAA所致。

【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 accumulatedshoot 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 !g·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＊＊. 【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.