不同放牧方式对中蒙荒漠草原植被和土壤特性的影响

本文对不同放牧方式下荒漠草原植被群落特征与表层土壤理化特性进行比较研究,结果表明：不同放牧方式下建群种和多年生杂草类植被群落高度、盖度、重要值比较结果为：游牧区>定居放牧区。一年生杂草类植物高度、盖度比较结果为：定居放牧区>游牧区;游牧区表层土壤砂土含量、pH值显著低于定居放牧区（P<0.05）,中壤土含量显著高于定居放牧区（P<0.05）;游牧区的土壤全氮、速效钾均有极显著高于定居放牧区（P<0.01）,游牧区全氮含量高于定居区近3倍。表层土壤全钾比较结果为：定居放牧区>游牧区。     

东莨菪内酯对家蚕生长发育及经济性状的影响

为明确植物源物质东莨菪内酯对家蚕的生长发育和经济性状的影响。采用食下毒叶法测定东莨菪内酯不同浓度药液对家蚕生长发育和经济性状的影响。结果表明：用东莨菪内酯4000、2000、1000 mg/L药液分别处理家蚕,其出现摆头、吐液等轻微中毒症状。用东莨菪内酯125~4000 mg/L药液分别处理家蚕,至5龄的累计死亡率为24%~80%,延迟了家蚕各龄期的发育。东莨菪内酯各浓度药液处理家蚕后对其经济性状具有显著性影响,其全茧量、茧层量、化蛹率和蛹体重均显著低于对照处理,但对家蚕的茧层率不存在显著性影响。东莨菪内酯对家蚕具有慢性累积毒性,对其生长发育及经济性状造成显著性影响。     

播种期对黄花蒿生长、产量及青蒿素含量的影响

目的:探索黄花蒿适宜的播种期.方法:在黄花蒿花蕾前期,测定不同播种期黄花蒿生物量;采用柱前衍生-RP-HPLC法测定青蒿素含量.结果:播种越早,黄花蒿株高和地径越大,叶青蒿素含量和总干重越高.结论:在广西桂北地区,以1～2月播种最为适宜.     

Allelopathic Effect of Eucalyptus globulus Labill. on Cyperus rotundus L. and Cynodon dactylon L. Pers.

The allelopathic potential of Eucalyptus globulus Labill. (gum tree) fresh and dried leaf leachates was studied using two perennial weeds, viz. purple nutsedge (Cyperus rotundus L.) and bermuda grass (Cynodon dactylon L. Pers) as test weeds. Aqueous leachate of fresh leaves of eucalyptus significantly suppressed the establishment of vegetative propagules and early seedling growth of the weeds. Leachate of fresh leaf cuttings had growth inhibitory effect on bermuda grass but showed growth promotion effect on purple nutsedge. Similarly the leachate of dried leaves of eucalyptus had differential influence on the growth of the two weeds. There is a possibility to harness the allelochemicals of eucalyptus leaves as herbicides for the management of these perennial weeds.     

Fertility,plant morphology,and transmission rates of the extra chromosome in single and double trisomics of Solanum tuberosum L. Group Tuberosum

Summary Initial single and double trisomics of S. tuberosum Group Tuberosum cv. Gineke were successfully crossed with and backcrossed to clones obtained through inbreeding of self-compatible dihaploids of the same variety. Some trisomics showed reduced flowering or flower abnormalities and contributed therefore only to a small extent. Berry-set and seed-set varied considerably. There was no relation between these phenomena, nor was there any relation between either berry-or seed-set and the identity of the extra chromosome in the female parent. Seed-set seemed to be influenced by the male parent. When a more inbred male parent was used in the crosses with trisomics this often resulted in less seed per cross. There was no clear relation between seed-set and stainability of the pollen grains, but both the strong selection for good pollen and the high level of self-compatibility, have apparently contributed to the success of the crosses. The double trisomic plants yielded less seed than most single trisomics. Only three of the single trisomics produced stainable pollen and two of them yielded progeny when used as male parent in crosses or selfings.In the progenies several of the trisomic types could be distinguished on the basis of plant morphology in the young seedling stage. For ten different trisomics the morphotype is being described. The average rate of female transmission of the extra chromosome was about twenty per cent, but there was a wide variation, both between and within the various trisomic types. The results indicated that for chromosomes 3 and 8 the rate of transmission was higher than the average value. In one out of two trisomic types male transmission of the extra chromosome occurred, with a rate of 4.7%. The possible causes for the observed differences in female transmission of the extra chromosome are being discussed.     

Community structure and biomass distribution of seagrasses and macrofauna in the flores sea,Indonesia

In several locations in the Flores Sea region the community structure and the biomass distribution of seagrasses were studied along transects perpendicular to the shoreline. The share of each species within a sample plot was estimated, divided in above- and below-ground biomass. Statistics regarding substrate coverage, shoot density and leaf-area index were sampled. A standard relation was calculated between seagrass dry weight, ash-free dry weight and organic carbon content.The biotic data were related to environmental factors: DOC and nutrients in the water, salinity, tidal amplitude, sediment composition. A relation was estimated between bottom coverage of seagrasses and standing stock. Further calculations of biomass-production ratios allow a quick and rough estimate of seagrass productivity. Maximum above-ground biomass values (500–700 g AFDW·m⁻²) together with qualitative data indicate resource (= space) partitioning among the component seagrasses within a community, and suggest a carrying capacity of the reefflat habitat for seagrass density and biomass.A tentative model was constructed, starting from a constant, non-distributed multispecies vegetation in the lower intertidal and subtidal zone on sand and coral rubble, and moving into several suboptimal situations. The upper shore carries an impoverished, constrained vegetation (irregular tides, desiccation, harvesting). Sediment reworking by animals and physical displacement of sand disturbs the vegetation and favours pioneer species. Muddy habitats bordering mangroves carry monospecific stands showing extremely high biomass (e.g. below-ground Enhalus acoroides 3500 g AFDW·m⁻²). Thalassia hemprichii and Enhalus acoroides are the most constant species in all habitats mentioned.Macrofauna biomass within the seagrass beds fluctuated widely (maximum values 50–70 g AFDW·m⁻² in mixed seagrass vegetations) and only a weak relation between benthic macrofauna biomass and seagrass community structure and biomass was found.     

成熟度和贮藏温度对黄菇娘品质的影响

为探究黄菇娘适宜的采收时间和贮藏温度,对不同成熟度果实及其在不同温度贮藏后的生理指标和感官风味进行测定。结果表明：成熟过程中,黄菇娘开花后7~21 d果实不具备食用价值,28 d开始转黄,35 d发育成熟。贮藏前,萼片深黄时采收的果实风味最佳。萼片浅黄时采收并于3 ℃贮藏45 d后仍可以保持较好的品质和相对较低的褐变指数及腐烂指数,贮藏60 d后,褐变指数和腐烂指数迅速升高。因此,3 ℃贮藏可作为黄菇娘采后维持果实品质、延长保鲜期的有效措施。另外,贮藏期间果实变化特点表明试验品种‘粒粒甜’黄菇娘具较好的贮藏价值。     

朝鲜蓟降血糖作用研究现状和展望

朝鲜蓟作为药食兼用的天然植物,具有良好的保健功能。研究表明,朝鲜蓟提取物具有抗氧化、抑菌、抗癌、降血脂、降血糖等生物活性。由于近年来糖尿病及其并发症的患病率逐年增高,就朝鲜蓟在降血糖作用方面的研究进行了综述,以促进朝鲜蓟产品开发及相关研究的开展。     

反义PPO基因对马铃薯块茎褐化的影响

对刚收获和贮藏5个月后的12个转基因马铃薯品系及对照块茎进行褐化指标的生理检测,发现2个检测时期的各褐化指标在供试品系间差异均达到显著或极显著水平。综合2个检测时期并与对照相比,PPO活性降幅为26.01%~48.65%;酚物质含量降低22.83%~54.81%;褐化强度除GD-9-qc-1低于对照40.45%~46.78%外,其余品系高于对照或与对照无差别。切割块茎发现,大部分转基因品系较对照褐化出现晚,褐化程度低,褐化指数低于对照88.0%~98.86%。PPO的化学定位显示,低褐化转基因品系的多酚氧化酶集中于维管束环,含量明显少于对照,其中GD-9-qc-1仅有少量多酚氧化酶显现出来,推测是由于反义PPO基因抑制块茎POT32基因表达的结果。进一步的方差、相关分析表明,除对多酚氧化酶含量抑制外,反义PPO基因还降低酚物质含量以减轻块茎损伤褐化。     

马齿苋多糖对小鼠的抗衰老作用

用D-半乳糖制备衰老小鼠模型,同时经灌胃100、200、400 mg/马齿苋多糖,观察其对血清中超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性、丙二醛(MDA)含量和对动物缺氧存活时间及游泳时间的影响。结果表明,马齿苋多糖能不同程度增加血清中SOD及GSH-Px活力,极显著降低MDA含量。此外,马齿苋多糖还能极显著延长小鼠在缺氧条件下的存活时间和常温游泳时间。说明马齿苋多糖具有明显的抗衰老作用。     

三氮苯类除草剂对水稻染色体结构、蛋白质含量及组分的影响

比较研究了不同浓度三氮苯类除草剂对水稻幼苗生长、叶绿素及可溶性蛋白质含量、根尖分生组织染色体结构、分生组织和叶绿体蛋白质组分的影响。结果表明,在0.1 mg /L Atrazine处理水稻后培养1周。幼苗高度由(10.8±1.7) cm（对照）降至 (8.2±0.7) cm,叶绿素含量由(1.07±0.013) mg/g FW（对照）降至(0.97±0.013) mg/g FW,     

Cr、Co、Pb 单一胁迫对浮萍SOD、POD、MDA的影响

为了探讨重金属Cr、Co、Pb对浮萍超氧化物歧化酶(SOD)、过氧化物酶(POD)、丙二醛(MDA)的影响,帮助建立以浮萍为主的重金属污水处理模型。通过模拟重金属污染环境,以水生104有氮培养液培养浮萍,分光光度法测 SOD、POD、MDA 变化。结果表明：在重金属单一胁迫下浮萍 SOD、POD、MDA呈现规律性变化,重金属离子浓度在较低水平下,浮萍通过活性氧清除系统能有效抵御重金属伤害;当Cr6+、Co2+、Pb2+离子浓度分别超过1.5、0.8、0.5 mmol/L 时,浮萍活性氧清除系统被破坏,受到金属离子伤害不可修复。因此得出在浮萍为主重金属污染处理模型中,通过设计污染水体流速保证 Cr6+、Co2+、Pb2+离子浓度分别在1.5、0.8、0.5 mmol/L 及以下,从而获取最佳处理模型。     

生物有机肥对养心菜品质和产量的影响

利用研制的包含多种功能菌(白黄链霉菌TD-1、固氮菌JZ1、无机磷分解菌JWP1、有机磷分解菌JP12、解钾菌JK1)的菌剂对不同原料配比制成的农业有机废弃物堆肥进行二次发酵,制得具有促生功能的生物有机肥,并用于扦插养心菜种植中,探究生物有机肥对养心菜产量和品质的影响。结果表明:相较于不施肥组和未二次发酵处理的有机肥组,不同原料配比的二次发酵生物有机肥对养心菜的产量和品质有明显提高。在种植70 d后,N3M生物有机肥组的养心菜生长指标较佳,须根分支数、单株产量最高,分别为15.00根和11.89 g,株高增量达到456.10%,显著高于不施肥组。在品质指标中,N3M处理组养心菜的单宁含量为2.19 mg·kg^-1,较不施肥组降低了40.5%,养心菜涩味明显降低,同时该组养心菜的VC和总黄酮含量较不施肥组和未二次发酵组也有所提高。综上所述,施用适宜配方的生物有机肥能促进养心菜生长,同时提高其品质和产量。因此,生物有机肥可作为一种绿色环保肥料用于农业生产。     

EMS诱变对缘毛雀麦和直立型扁蓿豆种子萌发的影响

采用0.9％EMS(甲基磺酸乙酯)对缘毛雀麦和直立型扁蓿豆进行不同时间(15,18,45,48 h)浸种处理,测定其发芽起始时间、发芽率、幼苗鲜重等,以探讨EMS对2种牧草种子萌发的影响.结果表明:用0.9％EMS浸种处理15h对缘毛雀麦种子萌发无显著影响,但延长处理3h后则有较显著(p＜0.01)的抑制作用;直立型扁蓿豆种子在处理45 h时相对发芽率显著下降.以相对发芽率达半致死剂量为标准,缘毛雀麦和直立型扁蓿豆种子用0.9％EMS处理的适宜时间分别为18h和48 h.     

Effect of genotype,environment and carbohydrate on anther culture response in head cabbage (Brassica oleracea L. convar. capitata (L.) Alef.)

Summary The effect of genotype, growing conditions for donor plants and type and concentration of carbohydrate in the culture medium was investigated for anther culture of head cabbage (white cabbage, savoy cabbage, pointed-headed cabbage). Strong genotypic effects on embryo formation from the cultured anthers were shown as well as superior embryo formation from anthers of field grown donor plants compared to plants grown in the greenhouse. When comparing 7, 10 and 13% sucrose in the medium, embryo response increased with increasing sucrose concentration. With maltose, which was generally inferior to sucrose as carbohydrate source for anther culture, the embryo response did not increase with maltose concentration above 10 per cent.     

不同供氮水平对春小麦产量、氮肥利用率及氮平衡的影响

【目的】研究施氮量对春小麦产量、氮肥利用率、土壤中硝态氮累积及氮平衡的影响,旨在了解在宁夏引黄灌区减少施氮量的可行性。【方法】通过田间小区试验,设置0、120、240、360 kg/hm24个施氮量,探讨不同施氮水平对作物和环境的影响。【结果】施用氮肥可显著提高春小麦的籽粒产量、籽粒蛋白质含量及成熟期地上部总吸氮量,但过量施用氮肥对籽粒增产和蛋白质含量提高不显著。氮肥利用率随着施氮量的增加呈现降低趋势,根据差值法计算结果,当施氮量分别为120、240、360 kg/hm2时春小麦的氮肥利用率分别为27.2%、24.3%、18.2%,表明多达81.8%～72.8%的氮肥没有被作物吸收利用。氮平衡计算的结果进一步表明,未被当季小麦利用的肥料主要以无机氮的形式存在于0～150cm土层内,施氮量分别为120、240、360 kg/hm2时氮肥的土壤残留率依次为41.6%、33.1%和29.7%,而相应的表观损失率为31.2%、42.6%、52.1%。【结论】综合考虑春小麦产量、品质和环境安全,本试验条件下,春小麦的合理施氮量应控制在120～240 kg/hm2之间。     

不同植物生长调节剂对卷丹百合鳞片扦插繁殖的影响研究

通过对比6-BA、IAA、NAA、5-IBA、2,4-D 5种植物生长调节剂对卷丹百合埋片繁殖的影响研究,结果表明:2,4-D对卷丹百合鳞片繁殖和生根的效果优于其它各种激素,鳞茎增殖率分别高达5.8,平均生根为1.86条;5种植物生长调节剂不利于卷丹百合鳞片扦插小鳞茎的生长.     

不同贮藏条件对贵州小桐子花粉活力的影响

为了实现贵州小桐子花粉的长期贮藏,实现小桐子的高产、稳产,采用TTC法测定花粉活力、培养液培养测定花粉萌发率,研究了室温(20℃)、室温干燥(20℃)、低温(4℃)、低温冷冻(-20℃)及超低温真空冷冻(-80℃)5种贮藏条件对小桐子花粉活力及萌发率的影响.结果表明,20℃室温贮藏和20℃室温干燥贮藏条件下保存的花粉活力及花粉萌发率仅能维持20d和30d,4℃低温可以贮藏60d,-20℃低温冷冻可以贮藏180d,-80℃超低温真空冷冻条件下贮藏360d后,花粉活力可以保持48.62％,花粉萌发率还可以保持45.33％,完全可用于花粉贮藏和种子小年时的人工辅助授粉.     

化杀灵改良剂(wpG)对甘蓝型油菜杀雄效果的研究

应用新型杀雄剂化杀灵改良剂(wpG)对油菜的杀雄效果进行研究,结果表明:以0.65μg/ml和0.8μg/ml浓度的化杀灵改良剂(wpG)在现蕾期处理,全不育株达90%以上。杀雄后的油菜花瓣皱缩、色淡、花丝缩短,花药干瘪开裂无花粉或有败育花粉,自交不结实,异交结实正常。喷药次数与杀雄效果无明显关系。