Influence of nursery soil amendments on water relations,root architectural development,and field performance of Douglas-fir transplants

This experiment evaluated the influence of manure, peat, and vermiculite incorporated at low and high rates (0.0118 and 0.0236 m³/m²) and under two soil moisture regimes on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedling (1+0 for 1+1) xylem water potential (_xylem), whole-plant growth, root architectural development, and subsequent field performance under fertilized and non-fertilized conditions. Trends in soil moisture retention were observed (high manure > high peat > control) but there were no differences in _xylem. Root length in the wetter soil moisture experiment was initially (three months) greatest for seedlings in high vermiculite and least in high manure but there were no differences among treatments at lifting (eight months). Mean height was greatest for seedlings grown in vermiculite and peat (wetter nursery experiment) after two field seasons. Field fertilization (35 g/seedling) with controlled-release fertilizer in the planting hole stimulated height growth initially, but decreased height and diameter growth during the second growing season. Dramatic improvements associated with the use of nursery soil amendments were not realized, but the failure to identify negative effects, a potential reduction in disease incidence, and improvement of nursery soil physical and chemical properties may justify their use.     

不同栽培基质的水分散失规律比较研究

对比研究了进口基质与东北草炭,东北草炭与蛭石、珍珠岩配成的混合基质以及东北草炭与保水剂混合后在40℃恒温下的水分运动特性。结果表明:进口基质的保水性明显优于东北草炭;在东北草炭中加入20%的蛭石时,东北草炭的保水性能达到了与进口基质相类似的水平;而且在东北草炭中加入5 g.kg-1保水剂也能达到与进口基质相类似的水分散失曲线,从而为穴盘育苗基质的国产化和标准化生产奠定了基础。     

水稻根茎发生机制初探

用蛭石培养 ,研究水稻种子不同播种深度与幼苗根茎发生的关系 ,并对水稻的根茎现象进行了初步的探讨。结果表明 :蛭石培养过程中根茎的发生与水稻种子植入深度有密切的关系 ,根茎的伸长长度随着播种深度的增加而增加 ;水稻根茎长度品种间有差异 ,不同的水稻品种在相同的播种深度下根茎的表现不一样     

栒子试管苗蛭石支撑生根培养及炼苗移栽研究

[目的]探讨蛭石作培养基支撑物对栒子试管苗生根培养及炼苗移栽的影响。[方法]将栒子微茎置于蛭石支撑的培养基进行生根培养。将培养成的栒子试管苗经开瓶炼苗2周后带坨移入营养钵中,观察移栽后的成活率,并观察开瓶炼苗期间栒子试管苗叶片气孔在黑暗条件下的开闭状况。[结果]栒子微茎在蛭石支撑的培养基中可形成正常的试管苗,其生根率达到88．3％,显著高于琼脂培养基（66．7％）。对栒子试管苗移栽前进行2周的开瓶炼苗,可使其叶片气孔的关闭功能得到明显恢复。栒子试管苗经炼苗带坨移栽后,在不喷雾、不覆膜及午后空气相对湿度低至60％的条件下成活率达到86．7％,显著高于常规移栽（31．7％）。[结论]该研究为完善栒子组织培养快繁技术提供依据。     

不同基质配比对黄瓜穴盘育苗的影响

研究了不同蛭石基质对黄瓜穴盘育苗的影响,试验以蛭石为主,加以黄沙、炉渣和菇渣,复配出六种不同配比的育苗基质,以商品营养土作对照,以黄瓜为供试材料进行育苗试验,研究以蛭石为主不同基质对黄瓜穴盘育苗的影响,旨在选出适宜黄瓜幼苗生长的较优基质配比。试验结果表明：处理T2（蛭石∶黄沙∶炉渣∶菇渣=2∶1∶2∶2）、T3（蛭石∶黄沙∶炉渣∶菇渣=2∶0∶1∶1）和T4（蛭石∶黄沙∶炉渣∶菇渣=4∶1∶2∶1）符合黄瓜穴盘育苗基质的要求,处理T2、T3、T4株高与对照(CK)无显著差异;处理T2、T4茎粗、叶面积和壮苗指数均显著高于对照(CK);T2根系活力和叶绿素含量显著高于对照(CK);T3、T4叶绿素含量与对照(CK)无显著差异;T3壮苗指数高于对照(CK),综合来看T2、T3、T4适宜作为黄瓜穴盘育苗基质。     

Evaluation of a technique to obtain development-stage-synchronised earthworms (Eisenia fetida )

 The aim of this experiment was to investigate whether Eisenia fetida hatchlings of different ages, kept initially without food, could be used to obtain worms of a comparable development stage (measured as growth) with similar maturation properties (measured as clitellum development). Seven groups of hatchlings, each differing in age by 7 days (range: 0–42 days) were collected as follows. Cocoons were kept in water in multicell containers and individuals that hatched during a 24-h period were placed on moist vermiculite with no food, at weekly intervals. The longest period that hatchlings were fasted was 42 days, after which food was added and growth monitored for 50 days. No differences in weight gain between the different batches were observed. Analysis of the growth curves and attainment of sexual maturity (clitellum development) indicated no effect of age or stage of development at the onset of feeding. It was concluded that this technique allows the production of cohorts of E. fetida, synchronised with respect to development stage, for use in toxicological and biological investigations that require control of factors such as development stage, age and size, and in particular for use in toxicological experiments complying with OECD regulatory procedures. Received: 16 June 1997     

蛭石引发对结缕草种子发芽率和发芽速度的影响

试验采用最终发芽率分别为90%(当年收获)、83%(贮藏1年)、74%(贮藏2年)、15%(贮藏3年)的结缕草(Zoysia japonica)种子为材料,以蛭石作为固体引发基质,研究水势和时间对种子最终发芽率、50%发芽时间和平均发芽时间的影响。结果表明,蛭石引发处理对当年收获和贮藏1年的结缕草种子的最终发芽率没有影响,但显著提高了贮藏2年和3年种子的最终发芽率,分别比对照提高了9%和12%;随着引发处理水势的增加和处理时间的延长,4份不同贮藏年限的种子50%发芽时间和平均发芽时间均有不同程度的缩短,分别比对照缩短1.8~3.0 d和2.1~8.2 d。与PEG溶液引发相比,蛭石固体引发最佳处理的水势更高,为-0.4~-0.1MPa;处理时间更长,为3~4 d。     

沙漠乔桑离体快繁与试管苗生根基质的研究

用常规组织培养方法对沙漠乔桑待萌发冬芽、萌发侧芽进行外植体消毒,以MS(Murashige和Skoog,1962)作基本培养基,添加不同质量浓度的BA(6-苄基腺嘌呤)、NAA(萘乙酸),配制不同激素组合的培养基,筛选出最适宜的诱导、增殖和生根培养基配方.然后,以蛭石代替琼脂设计生根培养基质、加糖与不加糖、灭菌与不灭菌等不同的培养方案,进行试管苗扦插生根的试验研究.研究结果表明:最适宜的桑芽诱导萌发的培养基为MS 1.0 mg/LBA 0.1mg/L NAA;快速繁殖的培养基为MS 0.5mg/LBA 0.05mg/LNAA;试管苗的生根培养基可以用蛭石代替琼脂,不加糖、不灭菌,添加0.2 mg/L的NAA,试管苗的生根与琼脂培养基没有差别,且能提高移栽成活率、降低成本.研究结果可为沙漠乔桑的工厂化生产提供借鉴.     

不同大豆品种萌发期抗旱性鉴定方法研究

为筛选出大豆萌发期抗旱性鉴定的适宜试验条件,以大豆品种陇中黄601、恳鉴豆15、九农29、长农16为供试材料,采用蛭石法和滤纸法进行发芽试验,运用内源转录间隔区(Internally Transcribed Spacer,ITS)序列分析法进行发芽床筛选,测定各供试大豆品种的发芽率、硬实豆数、发霉豆数,并进行了蛭石湿度和PEG-6000浓度筛选。结果表明,蛭石法发芽试验能明显减少大豆发芽试验中产生霉菌的种类与数量,适宜在大豆萌发期抗旱性鉴定中应用。且在蛭石湿度为170%、PEG-6000浓度为22%的条件下,不同大豆品种间的发芽率差异比较明显,硬实豆数和发霉豆数少,试验数据可靠,可作为大豆萌发期抗旱性鉴定试验的适宜条件。且在此条件下,4个供试大豆品种的抗旱性表现由强到弱依次为陇中黄601、九农29、长农16、恳鉴豆15。     

马铃薯试管薯形成的影响因素研究

以马铃薯品种大西洋脱毒试管苗为材料,研究了切段苗龄、温度、激素、光照对马铃薯试管薯诱导的影响,在此基础上,进一步研究了蛭石覆盖茎节代替黑暗条件的不同培养方式对马铃薯试管薯诱导的影响。结果表明,结薯与切段的苗龄有关,用培养100 d左右的苗即老的切段、白天25℃,夜间18℃的室温变温、培养基中添加激素6-BA浓度为2.5~5.0 mg/L时,试管薯诱导率高;在上述条件下,将蛭石灭菌后按每瓶30mL直接倒入原来的培养瓶覆盖试管苗下部茎节2~4节,简称"固体 蛭石"培养方式,能够使覆盖茎节处快速生出匍匐茎,最终形成块茎,平均单株结薯1.9个。