水分胁迫下细子龙的生长及光合特征研究

对细子龙(Amesiodendron chinense)在不同水分梯度胁迫下的生长及光合生理特征进行研究。结果表明:细子龙的地径、苗高相对生长率、叶片相对含水量随着土壤水分减少而减少,差异达到显著水平; 20%水分处理的叶绿素含量最低,与其他处理差异显著; 光合速率P_n、蒸腾速率T_r、气孔导度Gs、水分利用率WUE随着土壤水分的减少而降低,细胞间CO₂浓度随着土壤水分的减少而增加; 水分胁迫引起细子龙光合速率下降是非气孔限制因素的影响。     

重庆野生百合花蕾诱导再生植株技术研究

为了重庆野生百合资源的有效保护和开发利用,以重庆地区野生百合花蕾为试验材料,采用植物组织诱导培养的方法对其再生植株技术进行了研究。结果表明：以即将开放的百合花蕾为外植体材料,消毒容易,无污染;通过对花蕾各器官（花冠、花托、花丝、花药、花柱、柱头、花梗）的诱导培养,表明试验所选的1号培养基MS+ 6-BA 1.0 mg/L+ NAA 0.5 mg/L能诱导花冠、花托、花丝出芽,2号培养基MS+ 6- BA 0.5 mg/L+ NAA 0.5 mg/L仅能诱导花冠出芽;幼芽增殖以MS+ 6-BA 1.0 mg/L+ NAA 0.5 mg/L的增殖系数最高,为3.2,增殖幼苗生长健壮;生根培养以14号培养基(MS+ NAA 0.4 mg/L)诱导百合生根最佳,生根率为100%;移栽结果以18号培养基(MS+ IBA 0.5 mg/L)的生根培养苗成活率较高,达到了85%。     

集约化种植条件下土壤硝态氮动态变化及累积特征研究

选取江阴市沿江平原地区的3种典型农业种植区,即大棚葡萄集约化种植基地、蔬菜集约化种植基地和常规种植农田为研究对象,通过田间现场采样分析的方法研究了不同种植方式下土壤剖面硝态氮含量的动态变化和累积特征.结果表明,葡萄种植基地0-100 cm各土层硝态氮含量随时间的变化波动较大,而蔬菜种植基地和常规种植农田的表层土壤硝态氮含量变化幅度大于深层土壤;3种典型种植区的土壤硝态氮含量均呈现随着土层深度的增加而逐渐减小的趋势,其中土壤硝态氮含量最大值出现在葡萄种植基地的20-40 cm土层中;葡萄种植基地各土层硝态氮平均累积量均高于蔬菜种植基地和常规种植农田,大棚葡萄集约化种植基地0-00 cm土层硝态氮平均累积总量高达400.96 kg/hm2,显著高于蔬菜集约化种植基地和常规种植农田的累积总量,这进一步表明不合理过量追肥导致土壤中硝态氮大量累积,增大了氮素淋失和地下水环境污染的风险.     

尼日利亚热带雨林地区的内陆山谷中土壤发育和肥力特征: 矿物成分和粒度分布

The particle-size distribution and mineralogical composition of the clay (< 2 μm) and fine-sand (0.25--0.10 mm) fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades (S/I), hydroxyl-Al interlayered 2:1 type clays (HICs), vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-Al and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles. The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the harmattan. The findings might describe a site-specific deposition pattern of harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.     

基于土地利用详查数据的陕西省耕地变化动态分析

本文基于土地利用详细调查数据 ,应用单一土地利用类型动态度、土地利用类型相对变化率、土地利用类型转移速率、土地利用类型新增速率和土地利用类型变化速率全面刻画了陕西省 1 991— 2 0 0 1年耕地的动态变化。结论是 :在 1 991— 2 0 0 1年间 ,陕西省全省耕地在减少 ,各地减少的程度不同 ,延安减少最多 ,渭南减少最少 ;耕地变化存在明显地区性差异 ,耕地变化比陕西省耕地变化大的地区有延安、铜川、咸阳和商洛 ,其它地区耕地变化比全省耕地变化小。耕地转移的方向各地明显不同 ,增加耕地的来源也各不相同     

O/W型牛肉肌内脂肪的配制工艺

对模拟脂肪的配制工艺参数进行优化,并对显著影响模拟脂肪乳化稳定性的乳化剂、蛋白质和盐等因素进行进一步研究,确定最优配比.实验结果表明,油水比70:30(w1/w2)的条件下,主要影响成分的最优配比为单甘酯1.6%(w/w1 w2)、蔗糖酯0.4%(w/w1 w2)、大豆分离蛋白0.5%(w/w2)、乳清浓缩蛋白0.1%(w/w2)、氯化钠0.1%(w/w2).65℃条件下预热25 min并在19 000 r转速下乳化3×30 s,可获得稳定性更好的模拟脂肪.最终确定的模拟脂肪工艺为:预热→乳化→脱气→冷却.     

菜用大豆与普通大豆未成熟子粒硬度与结构研究

测定了7个菜用大豆与7个普通大豆品种未成熟鲜子粒经不同热烫时段后的硬度,并通过冷冻切片、显微技术比较了其结构上的差异性.结果表明:菜用大豆与普通大豆在种皮栅栏细胞层厚度上的差异不大,但菜用大豆栅栏细胞层密度(33.13个/mm2)显著高于普通大豆(29.50个/mm2);菜用大豆滴漏细胞层厚度(99.64μm)极显著大于普通大豆(57.94μm);而普通大豆子叶细胞层密度高于菜用大豆,且二者在内层细胞排列密度上的差异性达到了极显著水平.菜用大豆硬度(平均549.3gf)明显小于普通大豆(平均608.4gf),且热烫时两种类型大豆硬度降低的规律不同,菜用大豆在热烫3～6min时,硬度降低速率(48.99gf/min)最大,此前此后较小;而普通大豆在3-6min时,硬度降低速率(11.67gf/min)最小,此前此后却较大,这可能与它们在子粒结构上的差异性有关.此研究将未成熟大豆硬度和子粒宏观结构联系起来,对菜用大豆食味品质的基础性研究与菜用大豆速冻加工前的热烫工艺研究上都有一定意义.     

Lesions in the Larynx of Wistar RccHan: WIST Rats

Specific regions in the rat larynx exhibit cellular changes in response to inhaled xenobiotics. These regions include the base of the epiglottis, ventral pouch, and medial surfaces of the vocal processes of the arytenoid cartilages. 1 , 2 In order to collect information on the usefulness of trimming techniques, the influence of different vehicles, the impact of different application routes in toxicity studies, and differences between induced vs. spontaneous lesions, the data obtained from a large number of inhalation and non-inhalation studies performed in Wistar RCCHan(TM): Wist rats at Harlan Laboratories Ltd Switzerland, all evaluated or reviewed by the same pathologist, were compiled for a detailed review. The value of different trimming techniques was deemed to be greatest for transverse and sagittolongitudinal section techniques, as compared to horizontolongitudinally section techniques. The comparison of lesions encountered in control rats of inhalation studies treated with different vehicles did not reveal differences in the type, distribution pattern, incidence and/or severity of spontaneous lesions. The types of lesions were also independent of different application routes in non-inhalation studies compared to inhalation studies. The pattern of spontaneous lesions in the rodent larynx was determined by degenerative and inflammatory lesions starting most often in the submucosal glands by desiccated secretion followed by mineralization and local inflammation or were induced by impacted foreign bodies. Squamous metaplasia was recorded in the respiratory epithelium overlaying the ventral gland as a spontaneous lesion in male Wistar rats from inhalation studies with a maxim of 20.0% in an inhalation oncogenicity study. Induced metaplastic changes recorded in the larynx were reversible. Other induced lesions in inhalation studies consisted of submucosal edema, necrosis, inflammation and/or granuloma. Induced lesions in non-inhalation studies were found to be exclusively related to reflux laryngitis or food impaction. It is concluded, that in rodents induced lesions of the larynx differ in type, distribution pattern, severity and incidence from spontaneous lesions.     

Pathological and phylogenetic features of prevalent canine distemper viruses in wild masked palm civets in Japan

Ten wild masked palm civets infected with canine distemper virus (CDV), captured in Japan from 2005 to 2007, were histopathologically and phylogenetically analyzed. Phylogenetic analysis based on the amino acid sequences of the H protein of two CDV isolates from masked palm civets revealed that the two isolates were classified into the clade of recent isolates in Japan. Histopathologically marked lesions of virus encephalitis were present in the brain, whereas gastrointestinal lesions were absent or at a mild degree. The distribution of the lesions resembles that of recent CDV cases in dogs. Therefore, recent CDV infections in masked palm civets could be caused by recently prevalent CDV in dogs. The possibility of the masked palm civet as a spreader of CDV among wildlife is also discussed.