Seasonal Variation Of Starch Content In Dendrocalamus Giganteus And Phyllostachys Edulis And Its Relationship To Insect Damages

As a renewable biomass materials, banboo,on the one hand it has high value and broad application prospects, on the other hand, it has the high starch bamboo high sugar content, resulting in vulnerability to the erosion of trunk borers that depend on starch as a food which effect the industrial use of bamboo and Applications. This paper was mainly to find an accurate method of measuring the starch content of bamboo; fully understand the seasonal changes of starch content of bamboo and the relationship that with the Dinoderus minutus Fabriciu and Lyctus brunneus Stephens; define the best natural harvesting season of bamboo to gain the Low starch content; establish experimental methods of bamboo insect damages and search for rapid identification method of percentage content on bamboo starch. This research studied on the Dendrocalamus giganteus from Simao region of Yunnan and Phyllostachys edulis from Zhuzhou region of Hunan with the help of spectrophotometer to measure the starch content, of production of microscopic sections to observe the distribution of starch, of colorimeter to measure the colour. It had mainly studied on the starch content, seasonal changes of starch content, starch morphology, the distribution of starch, pest's experimental methods and the method of bamboo percentage content of starch.The conclusions as follows:(1) It is scientific and precise method on testing starch of bamboo with spectrophotometer, ant it is suitable to the corporation and individual as a reference method which need to test bamboo starch content.(2) The starch content present of Dendrocalamus giganteus has two wave ridges in one year. Two peak values respectively are 2.5%, 3.5%; the starch content present of Phyllostachys edulis only has one wave ridges in oneyear, the peak valuesis 5.82%.(3) The starch mainly distributes in the parenchyma cell cavity of bamboo, in lateral section of Dendrocalamus giganteus and Phyllostachys edulis, Starch distributes in bamboo inner culm, and the whole bamboo link has starch distribution in middle and topmost parts. There are very few starch in Dendrocalamus giganteus and Phyllostachys edulis during they are pregnant. Starch-grains in Dendrocalamus giganteus and Phyllostachys edulis are hexahedron, circle and indefinite.(4) The damage degree of bamboo node is more serious than other parts. The silverfish eats bamboo mainly through bamboo node and bamboo inner clum, the bamboo insect damages could be divided into four ranks: mild, little serious, serious, and very serious. Weightlessness rate respectively is: below 2%,2%～5%,5%～10%,above 10%. The Dendrocalamus giganteus with low starch content can be fell in February, June and July. The Phyllostachys edulis with low starch content can be fell from May to December.(5) The establishment method of fast recognition graph on bamboo starch content has been applied for the patent, the patented claim has accepted(6)"The rank appraisal on silverfish damages degree in bamboo"has been applied for the Yunnan Province provincial standard, this standard has been authorized.