小熊猫日粮营养成分分析

对成年小熊猫日粮的采食量以及日粮中的主要营养成分含量进行了测定。试验结果表明,平均每只小熊猫每天摄入蛋糕77.61g、馒头96.28g、苹果456.83g和竹叶90.97g;平均每只小熊猫每天摄入粗蛋白48.28g、粗脂肪13.56g、粗纤维65.30g、灰分23.39g;总日粮的干物质中,粗蛋白含量为26.82%、粗脂肪含量为7.53%、粗纤维含量为36.28%、灰分含量为12.99%、水分含量16.37%。     

取材时期和母树来源对水曲柳体细胞胚诱导的影响

以水曲柳(Fraxinus mandshurica Rupr.)不同母树、不同发育阶段的未成熟合子胚切离子叶为外植体,研究了外植体发育时期和母树来源对该树种体细胞胚诱导的影响。结果表明:外植体的取材时期、母树来源及二者的交互作用对水曲柳体胚诱导均具有极显著影响(p0.01),影响大小依次为取材时期采种母树交互作用;7月下旬到8月上旬是水曲柳体胚诱导的最佳采种时期,此时种子的胚乳已固化,合子胚形态分化完成,胚大小达到胚腔的2/3左右,47株母树的平均诱导率分别达到15.86%和16.77%,最高的4株母树的诱导率达到53.33%~66.67%。     

Evaluation of functional diversity in rhizobacterial taxa of a wild grass (Saccharum ravennae) colonizing abandoned fly ash dumps in Delhi urban ecosystem

Metal rich fly ash dumps may serve as repository of ecologically useful multi-functional rhizobacteria having potential use in the development of vegetation at the dumps. Therefore, in the present study bacteria from the rhizosphere of a wild perennial grass colonizing Indraprastha and Badarpur fly ash dumps of Delhi region were purified, identified and functionally characterized. The fly ash had low levels of nutrients, moisture and organic matter coupled with toxic levels of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn). Both the dumps were mostly barren except for a few patches of Saccharum ravennae and some weedy species. Sixty five dominant, morphologically distinct rhizobacteria were purified, which belonged to 18 genera and 38 species. Gram-positive bacteria were dominating in the fly ash environment. Bacillus spp. and Paenibacillus spp. were common at both the dumps. Multi-metal tolerance was shown by diverse bacterial taxa. The minimum inhibitory concentration (MIC) was highest for As (12.5-20.0 mM) and Pb (7.5-10.0 mM), although many rhizobacteria also possessed significant tolerance to Cr, Zn, Ni, Cu, Co and Cd. The tolerance profiles of rhizobacteria to different metals may be ranked in the decreasing order as As > Pb > Cr > Zn > Ni > Cu > Co > Cd > Hg. Majority of rhizobacteria showed good siderophore activity. Multiple-metal tolerance was also coupled with high siderophore production in some of the isolates (Microbacterium barkeri IPSr74, Serratia marcescens IPSr90 and IPSr82, Enterococcus casseliflavus BPSr32, Bacillus sp. IPSr80, Pseudomonas aeruginosa BPSr43 and Brochothrix campestris BPSr3). Most of the bacteria could grow on nitrogen-deficient medium. However, the dominant nitrogen-fixers reported from the rhizosphere of other Saccharum species were not detected. S. marcescens IPSr90 was the only rhizobacterium, which showed ACC-deaminase (ACCD) activity. Proportion of phosphate-solubilizing bacteria was high. Considerable improvement in the seedling establishment, plant weight and shoot length in rhizobacterial inoculated plants of S. ravennae in fly ash environment indicated the significance of rhizobacteria in its colonization and spread to the dumps. Representative rhizobacteria, with high MIC (for most of the metals) and good plant growth promoting (PGP) traits comparable to commercially useful bacterial inoculants were identified as S. marcescens IPSr82 and IPSr90, P. aeruginosa BPSr43, Paenibacillus larvae BPSr106, Arthrobacter ureafaciens BPSr55, Paenibacillus azotofixans BPSr107 and E. casseliflavus BPSr32. S. ravennae and some of these rhizobacteria may be potentially useful for the development of inoculation technologies for conversion of barren fly ash dumps into ecologically and economically productive habitats.     

3种改良剂对油菜生物量及其吸收重金属的影响

通过连续三季盆栽试验研究粉煤灰、膨润土、腐殖酸提高油菜生物量,降低油菜Cd、Pb、Cu、Zn浓度的效果。结果表明,膨润土、腐殖酸、粉煤灰的施入提高油菜生物量的效果第二季好于第一、三季。仅考虑对生物量的影响,改良剂效果为膨润土>腐殖酸>粉煤灰。第二季膨润土降低油菜Cd浓度效果较好;第二季粉煤灰、第二季膨润土及第二、三季腐殖酸降低油菜Pb浓度效果较好,3种改良剂均有降低油菜中Pb浓度的效果;3种改良剂均未显著影响油菜中Cu浓度;第二季膨润土降低油菜Zn浓度效果较好。3种改良剂抑制土壤重金属进入油菜的效果不同,应用时可根据改良剂特点适时施入土壤,充分发挥改良剂吸附、固定重金属的作用。     

Indicative properties of fly‐ash affected forest soils in Northeastern Germany

Many forest ecosystems in Germany are strongly influenced by emissions of pollutants like SO₂ and alkaline dusts. To quantify and evaluate the consequences of long‐term fly ash deposition on forest soils, a study was conducted in pine stands (Pinus sylvestris) in the Dübener Heide in Northeastern Germany. This forest area has been influenced mainly by emissions from coal‐fired power plants and the chemical industry of the industrial region Bitterfeld‐Wolfen‐Zschornewitz since the early 1900. The study sites are located along a fly ash deposition gradient of 8, 16, 14, 18, and 25 km away from the main emission source in Bitterfeld (sites 1, 2, 3, 4, and 5, respectively). Samples of the organic horizons (Oi, Oe, and Oa) and mineral topsoil (0—10 cm) were taken in fall 1998 and analyzed for their ferromagnetic susceptibility and total ash content. Scanning electron microscopy (SEM) and energy dispersive X‐ray microanalysis (EDX) were performed on selected samples to differentiate between the pedogenic and atmospheric origin of the mineral components in the organic horizons. As a result of the long‐term deposition, ferromagnetic fly ash components are mainly accumulated in the Oe and Oa horizons of the forest soils studied. Ferromagnetic susceptibility was significantly higher (p ≤ 0.05) in the Oe horizon of sites 1 and 2 compared to sites 3, 4, and 5. Unusually high total ash contents for organic horizons of > 74 % were determined in the Oa at all sites. SEM revealed 3 distinct features of persistent fly ash deposits from coal‐fired power plants within the organic horizons that can be defined as ”︁stable glasses” with magnetic properties, aluminum‐silicate‐minerals, and slag fragments. SEM and EDX indicated that a great portion of the mineral particles found in the organic horizons of forests soils influenced by fly ash are from atmospheric sources. For detection of atmospheric lignite‐derived deposition into forest soils, the Oe and Oa horizons have to be considered as specific diagnostic horizons because they show indicative properties for such soils.     

Dry farming with soils under natural tephra cover in Lanzarote, Spain

Abstract. The volcanic island of Lanzarote (Canary Islands, Spain) is one of the most arid parts of the European Union. During the eruptions of 1730–36, a third of the island was covered with lava and pyroclastic material. In areas under basaltic tephra, an agrosystem has been developed that allows a form of dry farming that has become a key component of the local economy. This article illustrates the effectiveness of the layer of natural tephra mulch in conserving soil and water.     

锯木灰渣改良退化菜园紫色土壤的效果研究

以重庆市九龙坡区白市驿镇蔬菜基地为试验平台,通过大田试验,研究了锯木灰渣不同施用量还田1年后对酸性紫色土改良效果,并进一步分析了锯木灰渣对土壤微生物群落及微生物碳、氮的影响,以期为紫色菜园退化土壤养分和酸化的修复提供合理措施,同时实现循环农业的可持续发展。结果表明:(1)锯木灰渣施用能显著提高蔬菜产量,且随着施用量的增加呈增加趋势,其中锯木灰渣施用量为18 000 kg hm~(-2)时,产量较未施用锯木灰渣(A0)处理显著提高了76.1%~121.9%;(2)经锯木灰渣处理的退化紫色土表层和亚表层的有机质含量和pH提高,尤其是锯木灰渣施用量为18 000 kg hm~(-2)的改良效果较佳,但是过高的锯木灰渣施用量处理对土壤交换性H~+、Al~(3+)效果反而下降,而施用量为12 000~15 000 kg hm~(-2)处理的效果较佳,其中表层土壤交换性H~+、Al~(3+)分别为0.19~0.20,0.63~0.67 cmol kg~(-1);(3)12 000~15 000 kg hm~(-2)的锯木灰渣施用量对土壤碱解氮和速效钾的提升效果较佳,18 000 kg hm~(-2)处理的有效磷含量最大,较A0处理增加了55.3 mg kg~(-1);(4)无论在表层土壤还是亚表层土壤中,细菌的种群数量分布最多,其次为真菌和放线菌,分别在12 000,9 000,6 000 kg hm~(-2)锯木灰渣施用量下的种群数量达到最大值;9 000~12 000 kg hm~(-2)处理对提高表层土壤微生物量碳含量较为明显,较A0显著提高了70.4%~78.7%,18 000 kg hm~(-2)处理的土壤微生物生物量氮(SMBN)含量最大(40.54 mg kg~(-1)),其次为9 000 kg hm~(-2)处理(34.32 mg kg~(-1))。综上,锯木灰渣施用量为12 000~15 000 kg hm~(-2)时对退化紫色土的改良效果较好。     

绒毛白蜡插条不定根的发生及其影响因素

分别以绒毛白蜡1年生苗干和3年生苗干作材料，研究了插条不定根的解剖学特征和形态特征，以及影响不定根发生的因素。结果表明：绒毛白蜡插条不定根起源于形成层周围，内与木质部连接，向外穿过皮层而延伸。不定根在插条上呈散生状态，插条下切口处，形成的不定根较多，但无典型的愈伤组织生根现象，光照、插壤和不同的激素处理都影响不定根的发生。     

粉煤灰改良砂姜黑土对小麦生长发育的影响

采用大田与盆栽的方法 ,研究了粉煤灰改良砂姜黑土对小麦生长发育的影响 .结果表明 ,粉煤灰改良砂姜黑土能促进小麦根系的生长、幼穗分化和分蘖的消长 ,提高了分蘖质量、小穗可孕率和产量 .粉煤灰搀和量以 2 4× 10 4 kg·hm-2 的效果为好 .     

高铝粉煤灰蒸压制品强度的研究

利用X射线衍射、扫描电镜、红外光谱对高铝粉煤灰进行了分析,在不同蒸压制度下通过未反应CH量的测定、结合水量的测定、冷热盐酸中溶出量的变化以及XRD、SEM等方法对该粉煤灰的蒸压性能进行了研究。结果表明,该粉煤灰的主要矿物组成为刚玉、莫来石、赤铁矿和少量玻璃相,不含二氧化硅。在不同蒸压制度下,该粉煤灰石灰蒸压试样中水化产物主要为C-S-H(I)和水石榴石,水石榴石的量较多,蒸压试样的强度很低,其原因与粉煤灰中可参与反应的硅的量少有关。