Suitable characters for selective breeding in Eisenia fetida (Oligochaeta)

Selective breeding of invertebrates has been suggested by many but studied by few. The possibilities of improving characters like biomass, maturation time, coccoon production rate, and hatching success of cocoons for the earthworm Eisenia fetida were examined in the present study. The results showed that biomass, maturation time, and number of hatchlings could be successfully improved by selective breeding, although a concomitant tendency to a lower reproductive rate, as found in vertebrates, was observed. Other characters like cocoon production rate, hatching success, and number of hatchlings per cocoon also showed promising results.     

赤子爱胜蚓全长cDNA文库的构建及初步鉴定

以赤子爱胜蚓(Eisenia foetida)为材料,λTriplex2TM为载体,利用SMART技术构建全长cDNA文库,从而筛选全长目的基因并研究其结构和功能。经测定原始文库滴度为1.3×106pfu/mL,扩增总文库滴度为1.0×108pfu/mL,重组率达到99%以上,插入片段长度在1.1 kb左右。该文库的建立为功能性新基因的发现奠定了坚实的基础。     

蚯蚓堆制处理对牛粪性状的影响

在最适的湿度和接种密度条件下，室内接种赤子爱胜蚓处理未腐熟牛粪，同时以不接种蚯蚓的未腐熟牛粪和自然堆制的腐熟牛粪为对照，研究了蚯蚓堆制处理对牛粪性状的影响。结果表明，赤子爱胜蚓处理显著增加了未腐熟牛粪国矿质氮和速效磷的含量，提高了碱性磷酸酶的活性，降低了微生物量碳、氮的含量和脲酶的活性，对蔗糖酶活性无显著影响赤子爱胜蚓处理的牛粪中细菌在短期内(15d内)数量显著增加，真菌和放线菌的数量变化不明显，蚯蚯处理产物与自然堆制的腐熟牛粪对照相比较，矿质氮和速效钾要高于腐熟牛粪，但速效磷无显著差异；微生物量碳氮和酶活性均显著高于自然腐熟牛粪；细菌、真菌和放线菌的数量也高于自然腐熟牛粪，但波动较大。     

蚯蚓在工业固体废物和杂草vermiprocessing过程中的营养循环研究

Vermicomposting is a biotechnological process that enables the recycling of organic waste materials into manure through the combined action of earthworms and mesophilic microorganisms.In this study,a 13-week experiment was carried to vermiprocess food industry sludge mixed with diferent bedding materials including two weeds,water hyacinth and parthenium,as well as cow dung,in diferent combinations employing earthworms of the species Eisenia fetida.Eight vermibins containing one kilogram of the waste mixtures (dry weight basis) were established for vermicomposting.Vermiprocessing significantly increased nitrogen,phosphorous,and potassium contents of the mixtures.However,a decrease in pH,organic carbon,and C:N ratio was observed after vermiprocessing.The heavy metal contents in the vermicomposts were higher than the initial values but within permissible limits.These results indicated that the studied wastes can be converted into good quality manure by vermiprocessing,which indicated their agricultural values as a soil conditioner if mixed with weeds in appropriate ratios.     

VERMICOMPOSTING AS A NITROGEN SOURCE IN GERMINATING KIDNEY BEAN IN TRAYS

This study assessed the effectiveness of vermicompost as a germination media and nitrogen source for kidney bean Phaseolus vulgaris L. Five treatments were tested, based on the addition of increasing quantities of barren soil to vermicompost, and irrigated with four treatments of increasing urea-water solution. Chemical analysis of the different mixtures of vermicompost and barren soil were made. Percentage germination, plant growth, and foliar nitrogen assimilation were measured. Bean seeds in vermicompost germinated earlier than those planted in barren soil, but germination was less than 60% in trays with 85% and 100% vermicompost. Plants in vermicompost were taller and appeared to be healthier-looking. Plants with 0%, 50% and 85% vermicompost concentrations assimilated about 4 mg·L^?1 more nitrogen than other treatments (25% and 100%). Plants in the 85% vermicompost mixture had the best response to nitrogen assimilation.     

铜、镉单一及复合污染对蚯蚓的急性毒性效应

以赤子爱胜蚓(Eisenia foetida)为对象,采用滤纸急性毒性试验法研究了铜、镉单一及复合污染对蚯蚓的急性毒性效应。单一试验结果表明,铜和镉对蚯蚓作用24 h的LC50分别为147.3,244.3 mg.L-1,作用48h的LC50分别为72.1,192.1 mg.L-1。复合试验结果表明,铜、镉复合污染24 h对蚯蚓的急性毒性具有明显的协同作用,复合污染48 h时,低浓度的Cu与Cd具有协同作用,高浓度的Cu与Cd具有拮抗作用。     

PFOA对赤子爱胜蚓的急性毒性效应

采用滤纸接触试验和人工土壤试验方法,分别以24h、48h和7d、14d为试验周期,研究持久性有机污染物全氟辛酸(perfluorooctanoic acid,PFOA)对赤子爱胜蚓(Eisenia foetida)的急性毒性效应。滤纸接触法测得的24h和48h的半数致死剂量(LD50)分别为25.715×10-3 mg/cm2和19.298×10-3 mg/cm2。人工土壤法测得的7d和14d的LD50分别为964.85 mg/kg和932.79mg/kg。随PFOA浓度升高赤子爱胜蚓的死亡率增加,呈现出明显的剂量-效应关系。研究结果表明,赤子爱胜蚓的死亡率可以作为对土壤中持久性有机污染物PFOA进行定量表征的一种生物标志物。     

赤子爱胜蚓处理土壤重金属Pb、bu复合污染效果研究

近年来，土壤重金属污染日益严重，且大多数以复合污染的形式出现，因此寻求一种有效处理重金属复合污染的方法迫在眉睫。本文模拟在重金属污染的土壤中接种赤子爱胜蚓，研究赤子爱胜蚓对Pb、Cu两种重金属的单一耐受力，设置Pb实验浓度分别为1000mg/kg、1500mg/kg、2000mg/kg、2500mg/kg；Cu实验浓度分别为120mg/kg、160mg/kg、200mg/kg、240mg/kg。结果表明，赤子爱胜蚓对Pb的耐受力明显高于Cu的耐受力。在此基础上研究了Pb、Cu复合污染下，赤子爱胜蚓对重金属污染土壤的重金属富集及耐受力变化情况。在Pb胁迫下，蚯蚓对Cu的富集降低，在Cu的胁迫下，蚯蚓对Pb的富集明显降低。赤子爱胜蚓对重金属Pb的富集量随着土壤中重金属的浓度增加而增加。蚯蚓体内重金属Pb、Cu的浓度升高对蚯蚓的活动会造成一定程度的抑制作用，导致蚯蚓对土壤中的重金属Pb、Cu的富集效果降低。