光强对盾叶薯蓣生长发育及皂素含量的影响

摘要

以生长1年的‘安姜3号'盾叶薯蓣(Dioscorea zingiberensis)为研究材料,用盆栽方法对其进行不同遮阴处理,研究其生长发育、根茎产量和皂素含量等的变化特征.结果显示:(1)全光照下薯蓣植株生长较弱,20%自然光下生长茂盛;随着光照强度的减弱,株高、茎粗、叶片厚度和鲜叶质量都呈先升后降的趋势;自由水含量总体上呈上升趋势,自由水与束缚水的比值呈先升后降趋势;中等遮阴条件下茎分支数最多,叶面积较小,叶宽与叶长的比值也较小;(2)中度遮阴下总叶绿素和叶绿素a含量最大,而叶绿素b随着光强的减弱大致呈先降后升的趋势.(3)随着光照强度的减弱,根鲜重大致呈增加的趋势,根部芽头数量呈先升后降趋势,根部含水量呈先降后升趋势,皂素含量则与之相反.研究发现,不同光照条件下薯蓣根茎鲜重无显著差异,但光照条件对其地上部分和地下部分生物量的分配却有显著影响;‘安姜3号'盾叶薯蓣在40%自然光强下生长发育最好且皂素含量最高.%Using one-year old ' Anjiang 3 variety of Dioscorea zingiberensis ', we took the method of bonsai to research the growth,the root production and saponin production of them which living in different light conditions.The results showed: (1)The plants which were living in natural light were thinnest and smallest.While,the plants which were living in 20％ of natural light are flourishing;With the light intensity attenuated, stem length, stalk circumference, leaf thickness and fresh leaf mass were all presented openings downward parabolic trend;Free water content was overall an upward trend, the rate of free water/bound water was presented openings downward parabolic trend;The plants which living in medium light intensity had the most branch number of seedling form root, the smaller leaf area and the smaller rate of the leaf width/length.(2)The plants which living medium light intensity had the most chlorophyll and chlorophyll a contents,while the chlorophyll b was presented openings upward parabolic trend with the light intensity attenuated.(3)With the light intensity attenuated, there was an roughly increase tendency of the fresh root mass and an openings downward parabolic trend of the rate of shoots, however, the diosgenin content had an opposite trend.The result indicated that there were appreciable impact to biomass allocation of the ground part and the underground parts of the D.zingiberensis.Variance Analysis showed that there was significant difference between fresh root mass of the D.zingiberensis which living in different light intensity.In 40％ of natural light 'Anjiang 3 variety of D.zingiberensis' got the best growth as well as the largest saponin accumulation.