Characteristics Of Indocalamus Forest Structure And Active Ingredients In Bamboo Leaves

There are 34 species in the genus of Indocalamus, which mainly distributes in southern watershed of Yangtzi River. The resources of Indoclamus species have not been well utilized yet. To promote comprehensive utilization of Indocalamus species, we studied the growth and development, the relationship between process, stand density control, stand structure and biomass ofⅠ. herklotsii andⅠ. decorus. The main leaf bio-active ingredients and influencing factors were investigated. The main results could be described as follows:In experiment sites, the number of 2-year- old culms is the largest, following by the number of one-year-old culms. The 4-year-old culms are the least. The shooting period ofⅠ. herklotsii was from the first ten-day of February to the last ten-day of May. The dynamic change of shoot quantity followed as slow-fast-slow pattern. The rate of the degraded shoots was highest in the last shooting phase. The later the shoots emerge from soil, the shorter the degraded shoots were. The height growth of young culms could be modeled by Logstic curve, and the growth time of culms shorted with their shooting time. The branches did not grow until culms stopped growing. The current culms only had first class branches.The above-ground part of bamboo plant could be divided into 3 modular organisms, namely, culm, branch and leaf sheath and leaf blade. The moisture contents of modular organisms ofⅠ. herklotsii andⅠ. decorus were ordered asfollows:branch and leaf sheath the biggest, and then the culm, and leaf blade was the least. The moisture content of each modular organism became lower with the increase of bamboo age, with branch and leaf sheath had the biggest decline ranges. Biomass of individual culm and the ratio of various modular organism biomass differed among species and age-classes. Biomass of individual culm ofⅠ. herklotsii was much bigger than that ofⅠ. decorus. The ratio of culm biomass to total above-ground biomass was the biggest, and that of leaf was the least. The individual culm of 3-year-old had the biggest biomass. As forⅠ. decorus, the ratio of leaf biomass to total above-ground biomass was the largest, and the biomass of individual culm of 2-year-old had bigger biomass than that of 1-year- old.There were significant differences in the growth characteristics of new culms betweenⅠ. herklotsii andⅠ. decorus, and as well as the biomass per unit area in different treatment after bamboo stand structure was adjusted. Biomass and ratio of each modular organism ofⅠ. decorus differed among different treatments. When the number of culms and shoots were left more than 120 and 60 respectively, the aboveground biomass and leaf biomass per square meter both reached their maximum values.The optimum experimental conditions to extract flavonoids fromⅠ. longiauritus leaves using water bath can be achieved using:ethanol concentration 85%(v/v), liquid/solid ratio 20:1 (mL: g), water temperature 85℃, extraction time 50min. Under the optimum experimental conditions, the yield of total flavonoids of bamboo leaves could be up to 2.23%.A microwave-assisted extraction method was used for the extraction of tea polyphenols(TP) fromⅠ. longiauritus leaves. The optimum experimental conditions included:extracting temperature 70℃, ethanol concentration 70%(v/v), liquid/solid ratio 20:1(mL:g), microwave-assisted extraction time 20min. Under the optimum experimental conditions, the yield of TP of bamboo leaves was came up to 6.24%.The bio-active ingredient contents in leaves of three bamboo species varied with bamboo species and leaves harvesting time. The range of total flavonoids content was 1.7%～2.69%, tea polyphenols content was 5.52%～7.55%, and soluble sugar content was 1.02%-8.50%. There were significant differences among different species and different seasons. Leaves ofⅠ. latifolius had the highest contents of bio-active ingredients. The bio-active ingredient content for each species increased with leaf age. The period from Dec. to Mar. was the best time to collect leaves. Leaves ofⅠ. latifolius had the highest contents of the three active ingredients suggestingⅠ. latifolius had more potential value than the other two species.