Systematic Study On The Characters Of Seed And Cultivating Technology Of The Bambusa Distegia

Bambusa distegia is one of the main economic bamboo species in Southwest China, distributing in Sichuan, Guizhou and Yunnan province, which has larger volume and extensive utilization both in industry and agriculture. B. distegia is characteristic with thin culm-wall, long fiber and so on and a superior material used of braiding summer sleeping mat and papermaking. Recently, in order to relieve contradiction between supply and demand and following the advancement of the integrative wood(bamboo)-pulp-paper, the development and exploitation and utilization of the bamboo-pulp-paper forest has been paid more attention increasingly .Based on looking up the related literature, the study on the characteristic,growth law and cultivating seedling technique is less in recent years. The seed sowing quality, growth law of one-year-old seedling, biomass, fertilization of orthogonal method was studied in detail, and the evaluation of quality and the grade of seedling were also discussed. The results are as follows.1. Fruit is cystocarp , latex yellow, spindle type .The surface of seedling with coat is smooth and without feather, thin and flat in the belly, and there is a obvious vertical groove. the seed length and diameter with coat were approximately9.4mm, 3.3mm and without it 7.5mm, 3.1mm, seed purity rate and water content respectively were 79.95%and 36.81%, the seeds easily become mildewed and not of viability during storage ,which have high safe moisture content,1000-seed weight with skin and without it were 46.09g and 36.86g respectively,germination rate, average germination potential and growing field germination percentage are 72%,27% and40%;mean germination speed 8days.2. The time continues 30～40 day from seed germination to the formation of the seedling,which is called original seedling, the mean height is 10.20cm, the highest 14.70cm, mean basal diameter0.4mm, the max0.44mm. The basal part of original seedling appeared lateral buds which grow the first tillering seedling, a clump evenly has 5～6 times tillering.Taking the height net growth increment as sample by periodical observation, the height growth process of the B. distegia seedling is divided into 4 stages by the sequential sample cluster analysis :emergence stage (May 8～May 25) ,early growth stage (May 26～Jul 12),rapid growth stage(Jul13～Aug 27)and late growth stage(Aug 28～Dec 27),according to the growth characteristic of the different stages ,the key countermeasures of the cultivating seedling is put forward in order to improve the quality and productivity.Tillering seedling is thicker and stronger than the original seedling, the growth of the basal diameter quickens in Jul～Aug, the increase of the first and second generation tillering seedling are obvious, the basal diameter growth decreases after Aug.The roots system changs with the growth of the seedling, namely the length and quantity of the first-order lateral roots and the second-order lateral roots increase, by fitting model and related analysis between the roots and aboveground(height, ground diameter and leaf area), the results show that the both are interdependent.3.The change of the moisture content of the leaf , stem and root in different stages are evident . The order of moisture content of the modular is rootï¹¥stemï¹¥leaf.The order of biomass of the modular of the bamboo seedling is stemï¹¥leafï¹¥root after 60 days, the ratio of the biomass of the stem, leaf, root accounting for the whole is 48.74%,34.03%,17.23%; the order of biomass of the modular of the bamboo seedling is leafï¹¥stemï¹¥root after 90 days, the ratio of the biomass of the leaf, stem, root accounting for the whole is 41.98%,40.99%,17.03%; the order of biomass of the modular of the bamboo seedling was stemï¹¥leafï¹¥root after 190 days, the ratio of the biomass of the leaf, stem, root accounting for the whole is 61.89%,30.93%,7.18%; the order of biomass of the modular of the bamboo seedling is stemï¹¥leafï¹¥root after 280 days, the ratio of the biomass of the leaf,stem, root accounting for the whole is 70.85%,23.84%,5.31%.The distribution rhizome and the ratio of the biomass of the modular show that the increase in the stem and leaf are quicker in the early growth stage, rapid growth stage and late growth stage. By means of the allometry equations between the root biomass and stem biomass, the allometry constant k was less 1, which shows that the seedling growth trend to multi-branchs in the early growth stage,rapid growth stage and late growth stage.4. The best integration of the different integration of urea,dispotassium hydrogen phosphate,compound fertilizer are A₁B₃C₃D₃, A₂B₁C₂D₃ and A₃B₂C₁D₃ respectively. The primary-secondary order of the different integration which have effect on the growth of height and diameter were D>A>C>B, A>C>D>B.5. The different density has remarkable impact on ramets angle. The ramets angle of the clump gradually increase, with the density decreasing. The change trend of the angle between the lateral branch and stem are that the order of the angle of the four level (from down to up)are X₁>X₂>X₃>X₄ with the same density; the angle between the lateral branch and stem at the same height increased with the decreasing in the density; the different density has obvious influence on the height and root length, haven't on basal diameter. Through establishing the mathematical model between height , diameter and root length, knowing that density and height , basal diameter appeares oppositive relationship.6. The morphological factors of the bamboo seedling is analysed by factors analysis, which shows that height, basal diameter , quality of the lateral , leaves quality and ramets quality are main evaluation index. Based on the quality evaluation index,the seedling is divided intoâ… ,â…¡,â…¢grade, choosing theâ… ,â…¡grade to afforest to improve survival ratio in the in production.