Effects of Shading Treatments on Growth of Asimina triloba(L.) Dunal Seedlings

[Objective]The study was conducted to investigate the effects of shading treatments on growth of Asimina triloba （L） Dunal seedlings and provided the theoretical basis for seedling production. [Method]70 day-old A. triloba seedlings had similar stem diameter and plant height and good growth vigour were taken as tested materials in 2005. 4 light gradient treatments which were the natural light with 100% light intensity, one-layer, two-layer and three-layer black shading network with the light transmittance rate of 50%, 25% and 12.5% were set up to study the effects of different shading treatments on growth of A. triloba. [ Result] With the shading treatments of one-layer and two-layer net, the plants of A. triloba seedlings grew rapidly. As the intensity of illumination decreased, the cetents of chlorophyll a （ Chl. a）, chlorophyll b （ Chl. b） and total chlorophyll increased at first and then reduced. At the same time the chlorophyll a/b value became smaller. Under natural light, the plants tended to consume more water and the soil temperature at 15：00 p. m was higher. There was a smaller difference among various treatments. [ Conclusion]The suitable shading treatment to the growth of A. triloba seedlings was under the light transmittance rate of 50% and height and stem diameter of trees increased fast. Chlorophyll a （ Chl. a）, chlorophyll b （ Chl. b） content in leaves of A. triloba seedlings were highest comparing with those in other conditions.

遮荫处理对泡泡树幼苗生长的影响

[目的]为了研究遮荫对泡泡树幼苗生长的影响,为其苗木生产提供理论依据。[方法]于2005年选择干茎粗、株高基本一致且长势良好的70 d苗龄的泡泡树为材料,设全光照(100%光强)1、层、2层和3层黑色遮光网(透光率分别为为50%、25%和12.5%)4个光照梯度处理,研究了不同遮荫处理对其生长的影响。[结果]1层网和2层网遮荫处理的泡泡树幼苗植株生长较快;随着光照强度的减弱,泡泡树叶片中叶绿素a、叶绿素b以及叶绿素总量先增加后逐渐降低,叶绿素a/b的值随之变小;全光照处理下,幼苗消耗较多水分,在下午15:00时土壤温度显著较高;遮荫处理组间差异较小。[结论]50%透光率的遮荫有助于泡泡树幼苗生长,株高及干径增长快。在透光率为50%的遮荫条件下,泡泡树叶片的叶绿素a含量及叶绿素总量最高,幼苗生长较为适宜。

美国泡泡树的商业价值及繁殖栽培技术

泡泡树原产于美国,它有着优良的观赏价值、营养价值及药用价值,具有巨大的市场潜力。为了丰富我国经济林栽培树种,对美国泡泡树的性状、营养成分、药用机理、品种、繁殖栽培及加工技术等方面进行了论述,为泡泡树在我国的繁殖、栽培和推广奠定了一定的理论基础。

泡泡树繁殖技术研究

介绍了泡泡树的生物学特性,种子繁殖技术,嫁接繁殖技术等。

泡泡果的染色体核型分析

观察了泡泡果(Asim ina triloba(L.)Dunal)的染色体并进行了核型分析,结果表明:其核型公式为:2 n=2 x=16=14 sm(2 SAT)+2 st,第8对染色体上有1对明显大于短臂的大随体。按Stebb ins的核型分类标准,它属“3 B”型,较不对称,为较进化的类型。

北美泡泡树ISSR标记开发及遗传多样性分析

以泡泡树[Asirnina triloba（L．）Dunal]品种‘Mango’为实验材料，从100个ISSR（Inter-simple sequence repeat）引物中筛选出6个多态性高、重复性好的引物。利用这6条引物，对13个泡泡树品种及其半同胞家系和6个种源的48个样品进行遗传多样性分析。通过DNA检测，扩增出2337条谱带，其中多态性条带为1930，多态性比率为82．6％。聚类分析结果表明，供试材料相似系数介于0．59～0．99之间。供试材料在相似系数0．91处的DNA水平上的类群划分和形态特征一致。该研究为泡泡树新品种培育的亲本选择及杂种鉴定提供理论依据。