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为保护野生资源,满足人工栽培的需要,以东风菜叶柄为材料,进行了愈伤组织诱导、分化培养,不定芽生根培养,试管苗生根继代增殖培养、移栽、定植的研究,建立起变异植株的无性系。结果表明:MS+2,4-D2.5mg/L是叶柄愈伤组织培养的理想培养基;MS+GA30.5mg/L+AgNO31.5mg/L+NAA 0.1mg/L是愈伤组织分化培养的理想培养基;用NAA20mg/L的无菌溶液对不定芽切口进行处理后,接种到White+IAA0.1mg/L培养基上培养,是不定芽生根培养和试管苗生根继代培养的理想方法;定植的试管苗保持了野生东风菜的所有植物学性状。 相似文献
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In microcosm experiments Porcellio scaber increased litter disappearance of oak and alder litter. Alder litter disappeared at more than twice the rate of oak litter.
Soil texture did not influence the disappearance of oak litter; however, disappearance of alder litter was enhanced on silt
rather than on sand. P. scaber enhanced microbial communities (i.e. microbial respiration and microbial biomass) on both silt and sand when feeding on either
alder or oak. Overall, microbial respiration increased 10-fold when isopods fed on oak litter on sand and 20-fold when isopods
fed on alder litter on sand. On silt, the initially high microbial respiration remained constant when isopods fed on oak and
doubled when they fed on alder litter. In all treatments without P. scaber there was a decrease in microbial respiration over the 12-week experimental period. The availability of macronutrients (Corg, Ntot, P, K, Mg, Ca) in the topsoil was increased when P. scaber fed on alder litter but less pronounced when P. scaber fed on oak litter. Using sand as a substrate, there was an apparent increase only for Corg, Mg and Ca; on silt, increases in Corg, Ntot and P were measured. Under field conditions the contribution of P. scaber to nutrient fluxes will be higher on sand than on silt.
Received: 1 July 1999 相似文献
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Saltmarshes, functionally important habitats in the marine–terrestrial ecotone that are regularly affected by tidal inundation, are mainly detritus-based in terms of fluxes of nutrients and energy. With respect to the mediating influence of saltmarsh detritivores on microbial colonisation of detritus and on decomposition processes, we tested whether the “intermediate disturbance hypothesis” (IDH) is also applicable to the effects of stress in this stressful environment. Decomposition experiments with litter of the cordgrass, Spartina anglica, and with terrestrial [Porcellio scaber (Isopoda)] and marine/semi-terrestrial [Orchestia gammarellus (Amphipoda)] detritivores as well as animal-free controls were carried out in an artificial saltmarsh system. Different daily flooding regimes served as experimental levels of stress. Both litter mass loss and microbial respiration were mostly higher under aquatic than under terrestrial conditions, no matter whether detritivores were present or not. Considering the intertidal zone, low to intermediate daily inundation rates resulted in increased microbial respiration and an increased influence of detritivores on litter mass loss in early stages of cordgrass decomposition with high rates of detritus mass loss, and intermediate tidal stress led to higher microbial cell counts throughout the entire experiment. Summarised over 3 months, regression analyses suggested that microbial activity and detritus mass loss show a trend towards highest values at low inundation rates and under permanent inundation, although microbial density was higher under longer daily inundation. Access to detritus by detritivores enhanced both litter mass loss and microbial respiration, especially in later decomposition stages, whereas microbial density was reduced by detritivores. In conclusion, we predict that overall the decomposition of cordgrass detritus in saltmarshes is promoted in the intermediate to high area of the intertidal zone with daily inundation of ca. 4–10 hours where both marine and terrestrial detritivores have access to promote decomposition processes through feeding and mediating microbial activity. 相似文献
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研究地胆头提取液中总多酚和类黄酮含量及其生理活性。测定了不同地胆头提取液的总多酚含量、类黄酮含量及其清除DPPH自由基的能力,并比较了不同料液比的地胆头提取液对血管紧张素转化酶(ACE)的抑制率。结果表明:不同提取剂提取的地胆头总多酚和类黄酮含量不同,其中,丙酮提取液中总多酚和类黄酮含量分别为12.27 mg/g、7.50 mg/g,均高于乙醇、甲醇、水提取液中的总多酚和类黄酮含量;地胆头丙酮、甲醇、乙醇提取液对DPPH自由基的清除率分别为94.60%、93.41%、90.87%,均高于人工合成氧化剂BHT(89.15%)和地胆头水提取液(62.75%);地胆头提取液对ACE的抑制效果随着料液比的增加而越明显,其中,1∶10的料液比下,乙醇地胆头提取液对ACE抑制率达到96.67%。通过本研究得出,在地胆头乙醇、甲醇、水、丙酮4种提取液中,丙酮提取液的总多酚和类黄酮含量最高,且其抗氧化性效果最佳,乙醇地胆头提取液的抗高血压能力最强。地胆头提取液具有明显的抗氧化性和抗高血压等生理活性,在功能食品及中草药领域里具有良好的开发应用前景。 相似文献
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Population parameters (mortality of females, reproductive success, longevity of juveniles) of the common woodlouse, Porcellio scaber (Isopoda, Oniscidea), were examined with respect to the influence of varying leaf litter attributes: pH level, microbial
cellulase activity, microbial dehydrogenase activity, protein content, nitrogen content, water content, tannin content, total
phenol content and toughness of the leaves. These attributes were combined by using Principal Component Analysis. We obtained
three Principal Components (PC) that were defined as “acidification,”“microorganisms” and “tree species.” The PCs explained
85% of the variance of leaf litter attributes. The PC “acidification” mainly influenced the mortality of females (P<0.001), while the longevity of juveniles showed significant correlation to the PC “microorganisms” (P<0.05). The PC “tree species” showed no influence on the observed population parameters, indicating that the leaf litter species
itself had no direct influence on the population parameters of P. scaber. The reproductive success of females could not be explained by either of the PCs, but was influenced by cellulolytically
active microorganisms (P<0.01). From these results, we conclude that acidification and reduced microbial activity in the field will cause a decrease
in population density of P. scaber.
Received: 30 July 1996 相似文献
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2015年3月—2016年6月,每个月定期对杨叶肖槿(Thespesia populnea)虫害进行调查。结果表明,杨叶肖槿栽培过程中害虫种类主要有7种,隶属5目7科。其中棉卷叶野螟(Sylepta derogate)、瘤缘蝽(Acanthocoris scaber)和八点广翅蜡蝉(Ricania speculum)最常发生且为害最严重。在栽培过程中,可采取如下防治措施:(1)棉卷叶野螟可利用黑光灯诱杀成虫,在产卵盛期至卵孵化盛期喷菊酯类杀虫剂;(2)瘤缘蝽的防治应及时清除枯枝落叶及林边杂草,摘除有卵的叶片,在若虫孵化盛期选择高效、低毒、低残留农药施药;(3)八点广翅蜡蝉可采用化学药剂进行防治,也可悬挂诱虫灯诱杀成虫。 相似文献
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地胆头提取物的急性和亚急性毒性研究 总被引:1,自引:0,他引:1
采用650mL/L乙醇热回流浸提结合冰冻干燥法,制备了地胆头提取物。分别给昆明种雄性小鼠腹腔注射不同剂量的地胆头提取物,研究该提取物对小鼠的急性毒性和亚急性毒性试验。结果表明,地胆头提取物对供试小鼠腹腔注射的LD50为2123.24mg/kg,959/6可信限为1742.86mg/kg~2503.62mg/kg,地胆头提取物对供试小鼠属于低毒。亚急性毒性试验结果表明,地胆头提取物未引起供试小鼠临床表现和体重异常,未引起心、肺和肾等脏器的病理变化,但高剂量的地胆头提取物能够导致肝脏中央静脉轻度充血。 相似文献