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1.
广东大中型水库底泥重金属含量特征及潜在生态风险评价   总被引:17,自引:1,他引:17  
广东省45宗大中型水库底泥重金属含量分析评价结果表明:除Cr外,广东省大中型水库底泥中Cu、Zn、Pb和Cd含量均高于广东省土壤重金属含量背景值.广东省四大地理区域中,粤北地区大中型水库底泥Cu、Zn、Pb和Cd平均含量均为最高,分别为89.71、321.21、154.95mg/kg和1.46mg/kg;其次是粤东和粤中地区;粤西大中型水库底泥Cu、Zn、Pb和Cd平均含量均为最低,但Cr平均含量居四大区域之首,为130.81mg/kg.粤东和粤北大中型水库底泥重金属富集系数以Cd最高;粤中和粤西大中型水库底泥重金属富集系数则以Cu最大.总体而言,粤北大中型水库底泥重金属具有很强的潜在生态风险,粤东和粤中大中型水库底泥重金属潜在生态风险程度为中等;粤西大中型水库底泥重金属属于轻微生态风险程度.结果说明,广东省大部分地区大中型水库底泥的重金属潜在生态风险主要是由于底泥中Cd的潜在生态风险系数过高所造成.人为生产活动,特别是矿产开采造成的污染是广东省大中型水库底泥重金属潜在生态风险等级提高的主要原因.  相似文献   

2.
为研究油茶(Camellia oleifera A)嫁接时穗条和砧木创伤后内源激素动态变化规律,解析影响砧穗嫁接面愈合的生理机制,为油茶砧穗愈合生长机理提供理论支持。以树龄6年的长林18号和53号的穗条和实生砧木为材料,按照芽苗砧嫁接方法切割穗条S0(0 min)、S10(10 min)、S40(40 min)和砧木茎段Z0(0 min)、Z10(10 min)后,利用液质联用法(HPLC-MS)测定吲哚乙酸(IAA)、脱落酸(ABA)、反式玉米素(TZR)、玉米素(Zeatin)、水杨酸(SA)和茉莉酸(JA)含量,分析不同时间段内源激素变化及品种间差异的关系。结果显示:创伤后18号的TZR、Zeatin和SA含量总体高于53号;18号IAA、SA和JA逐渐下降;TZR和Zeatin分别在S10和S0达最高值后下降;ABA在S10达最高值。53号IAA和JA爱S10达最高值后下降;TZR、Zeatin和SA在S10达低值后逐渐上升;ABA在S0达高值后逐渐下降。砧木茎段创伤前后激素含量除JA外18号高于53号;两品种Z0时激素含量下降,Z10后上升,仅53号ABA和SA含量在Z0达高值后下降。砧木茎段和根部激素含量在品种间除JA外18号高于53号,茎段的IAA、ABA高于根部,其他激素为根部高于茎段。激素比值在品种间和部位间差异明显;IAA/ABA、IAA/TZR、IAA/Zeatin和IAA/JA、ABA/TZR、ABA/Zeatin和ABA/JA比值为53号高于18号;穗条内SA/IAA为18号高于53号,SA/JA和SA/ABA为53号高于18号;砧木茎段均为18号高于53号;TZR/SA、TZR/JA比值在穗条和砧木茎段为18号高于53号。两品种创伤后IAA与JA极显著正相关,而IAA与SA,SA与JA在18号极显著正相关,53号极显著或显著负相关;53号TZR、Zeatin、SA间极显著或显著正相关,JA与TZR、Zeatin和SA极显著负相关。砧木茎段创伤后18号激素间为极显著或显著正相关;53号TZR和Zeatin与IAA、JA极显著正相关,与SA存在显著负相关,SA与JA有显著负相关。砧木茎段和根部间品种间仅在SA与各激素间相关性存在差异,其他激素间存在极显著正相关或负相关。综上所述,砧穗创伤后激素水平上18号在创伤面易于愈伤组织发育,而53号抗逆激素水平较高且与细胞分裂增殖类激素负相关,可能影响53号嫁接后愈合生长;嫁接应在创伤后10 min内较为适宜;砧穗间激素含量及比值的差异可能会影响后期嫁接部位形态重建以及穗条生长。  相似文献   

3.
Skakun VN  Aseev MV  Shawi A  Baranov VS 《Genetika》1999,35(9):1280-1288
The allele polymorphism of the AGC short tandem repeat (STR) of exon 1 of the androgen receptor (AR) gene located in Xq11-12, ATCT STR of intron 40 of the von Willebrand factor (vWF) gene located in chromosome 12p12, and AGAT STR of an anonymous DNA sequence (STRX1) from the short arm of the X chromosome was analyzed in the Georgian, Uzbek, and Russian populations. Polymerase chain reaction (PCR) with DNA of unrelated persons revealed 14 AR, 7 vWF, and 7 STRX1 alleles in Georgians; 14, 8, and 6 alleles, respectively, in Uzbeks; and 16, 8, and 9 alleles, respectively, in Russians. The heterozygosity at these STR was 0.61, 0.78, and 0.46 in Georgians; 0.60, 0.83, and 0.44 in Uzbeks; and 0.80, 0.70, and 0.58 in Russians. The correspondence of genotype frequencies to the Hardy-Weinberg equilibrium was observed with AR STR in Russians and Uzbeks, STRX1 STR in Georgians, and vWF in all three populations. A significant deviation from the equilibrium was found for STRX1 in Russians and Uzbeks and AR in Georgians. The potential of individualization was 0.05 for AR, 0.13 for vWF, and 0.18 for STRX1 in Georgians; 0.04, 0.09, and 0.13, respectively in Uzbeks; and 0.05, 0.14, and 0.07, respectively, in Russians. The allele and genotype frequency distributions of each STR were analyzed in all three populations. Allele frequencies in the populations were compared by the Kolmogorov-Smirnov test. The Russian population significantly differed in allele frequencies of the three STR from Uzbeks and in those of STRX1 and AR from Georgians. Georgians and Uzbeks significantly differed in vWF and STRX1 frequencies. The possibility of using the three STR in molecular diagnosis of the corresponding monogenic diseases, population genetic studies, and personal identification is discussed.  相似文献   

4.
猪激素敏感脂酶和甘油三酯水解酶基因组织表达特性研究   总被引:1,自引:0,他引:1  
以八眉猪为研究对象,采用RT-PCR和Western blot方法对猪激素敏感酯酶(HSL)和甘油三酯水解酶(TGH)基因组织表达特点进行了研究。RT-PCR半定量检测显示,HSL基因的mRNA在检测的7种组织中都有表达,其中在脂肪组织表达量较高,中等程度表达于心脏、肝脏、肺、脾和肾脏。TGH基因在7种组织也均有表达,其中肝脏和脂肪组织表达量较高,心脏和肾脏次之,脾脏和肺脏表达量较低。Western blot检测显示,HSL基因在大网膜脂肪和皮下脂肪表达量最高,而在肾脏中没有检测到表达,其他组织中中度表达;TGH基因在大网膜脂肪、皮下脂肪、肝脏、肺脏和脾脏组织中表达,其中在脂肪组织和肝脏组织中表达量最高,而在心脏和肾脏中没有检测到表达。以上结果表明:HSL和TGH基因存在转录后调控,这可能与其在不同组织中的功能差异有关。  相似文献   

5.
目的:探讨高原鼢鼠对洞道低氧高二氧化碳环境的代谢适应机制。方法:用酶活力分析法,分析春季、夏季和秋季高原鼢鼠血清乳酸脱氢酶(LDH)活力、乳酸含量和组织LDH活力,用聚丙烯酰胺凝胶电泳法分析血清和组织LDH同工酶谱。结果:高原鼢鼠血清LDH活力在春夏秋三季具有明显的差异,春季高于夏季,夏季高于秋季,血清乳酸含量表现出同样的变化趋势;春季血清中五种同工酶条带都清晰可见,夏季血清中LDH5和LDH4清晰可见,秋季血清中只能看见LDH5带。骨骼肌、心肌和脑组织LDH活力较高,而且从春季到秋季显著降低;肝、肾和肺组织LDH活力较低,肝组织LDH活力春季显著高于夏季和秋季,夏秋两季之间没有明显差异;肾和肺组织LDH活力在春季与夏季之间没有明显差异,但秋季明显降低。心、肝、肺、肾、脑和肌肉组织LDH同工酶谱,在春夏秋三季都显示出五条带,并表现出明显的组织差异;各组织同工酶含量也有不同程度的季节差异。结论:高原鼢鼠体内糖酵解过程具有明显的季节性变化,从春季到秋季依次降低,这与它们的季节性活动特点和洞道中氧气和二氧化碳的季节性波动有关。  相似文献   

6.
洪湖野菰及其化学成分分析   总被引:3,自引:0,他引:3  
野菰(Zizania latifolia)是湖北省洪湖中优势水生维管束植物,其群落占全湖355平方公里面积的127平方公里。茎和叶的年生物量为4379克鲜重/平方米,全湖总年产量121700吨干重,目前未被利用。野菰各器官的蛋白质和氨基酸含量分别以百分干重表示:根,7.0和4.76;根状茎,11.3和8.85;茎,9.5和7.15;嫩茎梢,22.4和16.53;叶,16.8和14.61。500克干叶的必需氨基酸含量接近100克干重草鱼幼鱼背肌的必需氨基酸含量。脂肪:叶中3.4~4.2,茎中2.2;粗纤维:叶中26.8~28,茎中24.2;灰分:叶中10.0,茎中5.8。菰茎含可溶性糖类30%以上,其中葡萄糖,果糖、蔗糖和麦芽糖是主要成分。结果表明野菰是一种优质饲料。  相似文献   

7.
The severe lethal chondrodystrophies in man result in a common clinical syndrome including shortening of the face, mandible, and limbs. Studies of three lethal chondrodystrophic mutants in mice, viz., chondrodysplasia (cho), cartilage matrix deficiency (cmd), and disproportionate micromelia (Dmm), which share this syndrome, were performed with the aim of identifying histochemical, immunofluorescence, or ultrastructural differences which might exist among these hereditary cartilage disorders. We examined limb cartilage epiphyses from day 18 normal and mutant fetuses and observed repeatable, mostly qualitative differences. All observations were made relative to the normal control. Histochemical staining of matrix proteoglycan was moderately decreased in cho and Dmm cartilage and markedly decreased in cmd when compared to the normal control. Staining of matrix collagen was irregular in distribution in cho, increased in cmd, and decreased in Dmm. Immunofluorescence of proteoglycan was increased in the matrix of cho and Dmm and decreased in cmd. Immunofluorescence of type II collagen was heterogeneous and moderately decreased in the matrix of cho, increased in cmd, and markedly decreased in Dmm. Immunofluorescence of link protein in cho was localized in the cellular-pericellular region as in the normal and appeared increased in the matrix of cmd and Dmm. Immunofluorescence of chondronectin was localized in the cellular-pericellular region and appeared normal in all three mutants. Major differences in cellular and matrix ultrastructure were observed among the mutants, including a decreased frequency of small-diameter collagen fibrils in cho and Dmm, increased density of collagen fibrils in cmd, and dilated RER in Dmm. These observations demonstrate that distinct structural and possibly molecular differences exist among the chondrodystrophies. In the case of cmd, the differences correlated with a previously reported molecular defect, viz., absence of core protein of cartilage specific proteoglycan in the cartilage of this mutant. It is anticipated that the methods used in the present study can be applied to humans in case classification and in identifying potential mouse-human correlates.  相似文献   

8.
陈淳 《人类学学报》1983,2(4):331-408
通过中国十个重要细石器遗址中细石核的观察,对中国细石核的类型和工艺技术作一初步的区分和综合的比较,以探讨中国细石器传统在时间和空间上的分布特点。同时与发现于东北亚、西北美的细石核进行对比,从它们之间的异同来看这一地区在文化上的传承关系。  相似文献   

9.
1962—2010年甘肃省黄土高原区干旱时空动态格局   总被引:2,自引:0,他引:2  
借助ArcGIS 9.3和SPSS软件平台,根据甘肃省黄土高原区33个气象站1962—2010年气象资料,利用综合气象干旱指数(CI)从干旱率、干旱强度和干旱频率三方面对甘肃省黄土高原区近50年的干旱时空变化特征进行了分析。结果表明:春、秋季干旱率呈现显著增加趋势,夏、冬季干旱率呈略微增加趋势;夏季干旱频率最大,春季、秋季次之,冬季最少;春、秋季干旱以2000年来最为严重,夏季干旱以2000年以来、20世纪70年代和90年代均较严重,冬季干旱以20世纪80年代最为严重;甘肃省黄土高原区逐年干旱持续日数和干旱强度存在明显的年际波动,线性变化趋势明显;从空间分布来看,春、夏和秋季干旱多发区主要集中在甘肃省黄土高原区西北部,而106°E以西"临洮-通渭-天水"一线和庆阳东南部是干旱多发区变幅最大的地方,冬季干旱多发区主要集中在甘肃省黄土高原区南部。  相似文献   

10.
P Ernfors  C Wetmore  L Olson  H Persson 《Neuron》1990,5(4):511-526
Cells expressing mRNA for hippocampus-derived neurotrophic factor (HDNF/NT-3) or brain-derived neurotrophic factor (BDNF) were identified by in situ hybridization. In the rat brain, HDNF mRNA was predominantly found in pyramidal neurons in CA1 and CA2 of the hippocampus. Lower levels of HDNF mRNA were found in granular neurons of the dentate gyrus and in neurons of the taenia tecta and induseum griseum. BDNF mRNA-expressing cells were more widely distributed in the rat brain, with high levels in neurons of CA2, CA3, and the hilar region of the dentate gyrus, in the external and internal pyramidal layers of the cerebral cortex, in the claustrum, and in one brainstem structure. Lower levels were seen in CA1 and in the granular layer of the hippocampus, in the taenia tecta, and in the mammillary complex. In peripheral tissues, HDNF mRNA was found in glomerular cells in the kidney, secretory cells in the male rat submandibular gland, and epithelial cells in secondary and tertiary follicles in the ovary. Cells expressing BDNF mRNA were found in the dorsal root ganglia, where neurons of various sizes were labeled.  相似文献   

11.
Observations on granulocyte peroxidase of 123 teleosts are reported and correlated with previous studies to put occurrence of fish granulocyte peroxidase in a phylogenetic perspective. Eosinophil peroxidase occurs in archaic groups such as lungfish and sturgeons, but is usually weak and infrequently observed in chondrichthyans, and in teleosts occurs in some elopomorphs, is consistently observed in stomiiforms, is rarely observed and usually weak in acanthopterygians and absent from salmoniforms, scopelomorphs and paracanthopterygians. Peroxidase is absent from lungfish and sturgeon neutrophils, is present in neutrophils of some elopomorphs and clupeimorphs. both of which are basal teleost groups, but in salmoniforms and higher teleosts is consistently observed in neutrophils. although often weak in pleuronectiforms.
Loss of eosinophil peroxidase and development of neutrophil peroxidase in teleosts may be due to inefficient phagocytosis and loss of peroxidase with degranulation in eosinophils, being superseded by concentration of peroxidase in phagosomes in neutrophils.  相似文献   

12.
为探讨火烧干扰以及微地貌差异对高原湿草甸植被的影响,以高原湿草甸优势种华扁穗草( Blysmus sinocompressus Tang et F. T. Wang)为研究对象,分别在经历火烧干扰和未烧的湿地中选择平地和地垄作为样地,研究了不同生长期以及不同年份华扁穗草地上部的灰分含量和热值(包括干质量热值和去灰分热值)变化。结果表明:在火烧平地、火烧地垄、未烧平地和未烧地垄4类样地中,不同生长期以及不同年份间华扁穗草地上部的灰分含量和热值均有一定差异。在火烧平地、火烧地垄和未烧平地3类样地中,与生长初期相比,生长旺盛期华扁穗草地上部的灰分含量均降低,其干质量热值和去灰分热值均升高;而在未烧地垄样地中,与生长初期相比,生长旺盛期华扁穗草地上部的灰分含量显著升高,其干质量热值和去灰分热值则均略降低。从样地类型看,在生长旺盛期,平地样地中华扁穗草地上部的灰分含量均低于地垄样地,其干质量热值和去灰分热值均高于地垄样地,其中,其灰分含量在火烧平地样地中最低、在未烧地垄样地中最高;其干质量热值和去灰分热值在火烧地垄样地中均最低、在未烧平地样地中均最高,但总体无显著差异。随时间推移,火烧样地特别是火烧平地样地中华扁穗草地上部的灰分含量增加,而其干质量热值和去灰分热值则有所降低但总体上与未烧样地间无显著差异。总体上看,在火烧样地中,华扁穗草地上部的干质量热值和去灰分热值低于未烧样地;而在平地样地中,其干质量热值和去灰分热值高于地垄样地。研究结果显示:火烧干扰和微地貌差异对华扁穗草地上部的灰分含量和热值均有一定的影响,据此,建议将植物地上部的灰分含量和热值作为高原湿草甸植被优势种响应环境扰动的参考指标。  相似文献   

13.
社鼠组织器官同工酶的研究   总被引:5,自引:0,他引:5  
傅必谦  袁虹 《兽类学报》1997,17(2):141-145
用聚丙烯酰胺凝胶等电聚焦电泳方法,分析了社鼠的肝、肾、心肌、骨骼肌、肺、脾和脑等多种组织器官的LDH、ADH、EST、和SOD4种同工酶,对各组织器官的酶带数目和分布,以及酶活性进行了比较研究。结果表明,社鼠的LDH同工酶、ADH同工酶和EST同工酶具有比较明显的组织特异性,而SOD同工酶的组织特异性较低。肺和脾除EST同工酶活性较高外,脑除LDH同工酶活性较高外,其它3种同工酶的活性均较低;而肝和肾中4种同工酶的活性普遍很高。心肌和骨骼肌因氧张力不同而使LDH同工酶酶谱存在明显差异,但其它3种同工酶酶谱却非常相似。同工酶的组织特异性与各组织器官所执行的生理功能是相一致的  相似文献   

14.
S. Xie  Y. Cui    T. Zhang  Z. Li 《Journal of fish biology》2000,57(4):867-880
Feeding ecology of three small fish species, Hypseleotris swinhonis, Ctenogobius giurinus and Pseudorasbora parva was studied seasonally in the Biandantang Lake, a small, shallow lake in central China. Gut length, adjusted for total body length, was significantly higher in spring than in other seasons for all the three species. Seasonal changes in gut length were not associated with changes in food quality. Weight of fore-gut contents, adjusted for body weight, was significantly higher in winter and spring than in summer and autumn in H. swinhonis and C. giurinus , and significantly higher in autumn than in spring and summer for P. parva. Percentage of empty fore-guts was highest in summer and lowest in spring for H. swinhonis and C. giurinus , and highest in winter and lowest in autumn for P. parva. Diet of the three small fishes showed apparent seasonal changes, and these changes reflected partly the seasonal fluctuations of food resources in environment. Diet breadth was high in winter and low in autumn for H. swinhonis , high in winter and low in spring and summer for C. giurinus , and high in autumn and low in spring for P. parva. Diet overlaps between pairs of species were biologically significant in most cases, except between H. swinhonis and P. parva in summer and autumn and between C. giurinus and P. parva in autumn.  相似文献   

15.
Lipid content in mammalian oocytes or embryos differs among species, with bovine and porcine oocytes and embryos showing large cytoplasmic droplets. These droplets are considered to play important roles in energy metabolism during oocyte maturation, fertilisation and early embryonic development, and also in the freezing ability of oocytes or embryos; however, their detailed distribution or function is not well understood. In the present study, changes in the distribution and morphology of porcine lipid droplets during in vivo and in vitro fertilisation, in contrast to parthenogenetic oocyte activation, as well as during their development to blastocyst stage, were evaluated by transmission electron microscopy (TEM). The analysis of semi-thin and ultra-thin sections by TEM showed conspicuous, large, electron-dense lipid droplets, sometimes associated with mitochondrial aggregates in the oocytes, irrespective of whether the oocytes had been matured in vivo or in vitro. Immediately after sperm penetration, the electron density of the lipid droplets was lost in both the in vivo and in vitro oocytes, the reduction being most evident in the oocytes developed in vitro. Density was restored in the pronculear oocytes, fully in the in vivo specimens but only partially in the in vitro ones. The number and size of the droplets seemed, however, to have decreased. At 2- to 4-cell and blastocyst stages, the features of the lipid droplets were almost the same as those of pronuclear oocytes, showing a homogeneous or saturated density in the in vivo embryos but a marbled or partially saturated appearance in the in vitro embryos. In vitro matured oocytes undergoing parthenogenesis had lipid droplets that resembled those of fertilised oocytes until the pronuclear stage. Overall, results indicate variations in both the morphology and amount of cytoplasmic lipid droplets during porcine oocyte maturation, fertilisation and early embryo development as well as differences between in vivo and in vitro development, suggesting both different energy status during preimplantation development in pigs and substantial differences between in vitro and in vivo development.  相似文献   

16.
Circadian rhythms in noradrenergic (NE) and dopaminergic (DA) metabolites and in cyclic nucleotide production were measured in discrete regions of rat brain. A circadian rhythm was found in the concentration of the NE metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), in the hippocampus. No MHPG rhythm was found in frontal, cingulate, parietal, piriform, insular or temporal cortex, or in hypothalamus. Circadian rhythms in the concentration of the NE metabolite, 3,4-dihydroxyphenylglycol (DHPG), occurred in occipital and parietal cortex and hypothalamus, with no rhythm observable in temporal or insular cortex, hippocampus, pons-medulla or cerebellum. The 24-hr mean concentration of MHPG varied 3.5-fold, highest in cingulate and lowest in parietal, temporal and occipital cortex. The 24-hr mean concentration of DHPG varied 6-fold, highest in hypothalamus and lowest in parietal cortex. Circadian rhythms in the concentration of the DA metabolite, homovanillic acid (HVA), were found in olfactory tubercle, amygdala and caudate-putamen, but not in nucleus accumbens. A circadian rhythm in the concentration of the DA metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), occurred in nucleus accumbens, but not in olfactory tubercle or caudate-putamen. The mean 24-hr concentration of HVA was highest in caudate-putamen, intermediate in nucleus accumbens, and lowest in olfactory tubercle and amygdala. The mean 24-hr concentration of DOPAC was highest in nucleus accumbens and lower in olfactory tubercle and caudate-putamen. Circadian rhythms were found in the concentration of cyclic GMP (cGMP) in all regions measured except parietal cortex. The mean 24-hr concentration varied 128-fold, highest in nucleus accumbens, frontal poles, and hypothalamus and lowest in cingulate cortex. Circadian rhythms in cyclic AMP (cAMP) concentration were found in piriform, temporal, occipital, cingulate, and parietal cortex, amygdala and nucleus accumbens. No rhythms were found in frontal or insular cortex, hypothalamus, hippocampus, caudate-putamen or olfactory tubercle. The 24-hr mean cAMP concentration varied 4-fold, highest in parietal cortex and lowest in caudate-putamen and amygdala. Norepinephrine metabolites and dopamine metabolites were rhythmic in few regions. It is, therefore, unlikely that the rhythmicity measured in adrenergic receptors is, in general, a response to rhythmic changes in adrenergic transmitter release. The putative second messenger response systems, especially cGMP, were more often rhythmic. The rhythms in cGMP are parallel in form and region to those in the alpha 1-adrenergic receptor and may act as 2nd messenger for that receptor.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

17.
对位于福建省和浙江省8个地区39个村庄的乡村人居林4种林型(庭院林、道路林、水岸林和游憩林)的树木结构特征进行了调查和分析.结果表明:两省的乡村人居林共有乔木61科130属201种,共有灌木34科52属76种;福建省乡村人居林中乔木种类较为丰富;浙江省乡村人居林中灌木种类较为丰富.4种林型中,庭院林树种数最多,道路林树种数最少;组成庭院林的乔木树种和单株数均最多,而组成道路林的乔木树种及单株数均最少;组成庭院林和游憩林的灌木树种和单株(丛)数均较多,组成水岸林的灌木树种及单株(丛)数最少.在福建省和浙江省乡村人居林中,常绿树种、乡土树种和2003年以前种植的树种株数较多,分别占两省乡村人居林树木总株数的71.05%、85.57%、61.20%和65.95%、76.02%、61.43%;栽植截干和管护截干株数均较少,但浙江省乡村人居林中栽植截干和管护截干的株数均多于福建省.福建省乡村人居林中乔木的胸径、树高、冠幅和枝下高的均值均明显大于浙江省,而两省灌木的地径、树高、冠幅和枝下高的均值差异较小.福建省的游憩林及浙江省的水岸林中乔木的胸径最大,而福建省的水岸林及浙江省的庭院林中灌木的地径最大;福建省乡村人居林中胸径10.0 cm以上的乔木所占比例高于浙江省,其中福建省的4种林型中胸径在30.0 cm以上的乔木树种的平均胸径、种类数及株数均高于浙江省.两省乡村人居林中频度最高的10个树种明显不同,仅香樟[ Cinnamomum camphora (L.)Presl]共存于两省所有林型中.  相似文献   

18.
啮齿动物作用下退耕地山杏种子扩散与贮藏的季节变化   总被引:2,自引:0,他引:2  
啮齿动物对植物种子的取食和扩散影响种子的时空分布,继而影响种子的萌发和幼苗建成,因而在森林更新中起着重要作用.在国有济源市愚公林场,选择退耕地生境,于春季、夏季、秋季分别释放人工标记的山杏种子,观察啮齿动物扩散与埋藏山杏种子的季节性差异.结果表明:1)退耕地中的啮齿动物主要包括大林姬鼠、社鼠、黑线姬鼠;2)山杏种子扩散速率在春季显著慢于夏季,夏季显著慢于秋季;3)种子搬运量受季节和种子状态交互作用影响,春季显著少于夏季,夏季显著少于秋季;4)不同季节种子平均搬运距离不同,秋季不同状态种子的搬运距离均大于春季和夏季;5)啮齿动物对山杏种子的贮藏点大小多为1粒种子,少量为2、3粒种子,且贮藏点大小与季节间存在显著的交互作用,春季单粒种子的贮藏点数量显著少于夏季和秋季,而夏季与秋季的贮藏点则倾向于多粒种子;6)在夏季和秋季各有5枚(共释放1800枚)被啮齿动物分散贮藏的山杏种子建成幼苗.  相似文献   

19.
The distribution of vasotocin and mesotocin in the pituitary and central nervous system in male chickens was determined using radioimmunoassays. Neither peptide was detected in the pineal. Mesotocin, but not vasotocin, was detected in the cerebellum. Both peptides were found in the septal area, archistriatum, paleostriatum, optic lobe, anterior, medial and posterior hypothalamus, midbrain, pons, medulla oblongata, and the anterior and posterior pituitary. Equal amounts of the 2 peptides were present in the septal area, archistriatum and anterior hypothalamus whereas vasotocin was more abundant (2- to 10-fold) in the paleostriatum, optic lobe, midbrain, and pituitary. The amount of mesotocin was about twice that of vasotocin in the medulla oblongata and the medial and posterior hypothalamus. The wide distribution of vasotocin and mesotocin in extrahypothalamic sites in the central nervous system suggests that the peptides may, as in mammals, have a role in a variety of autonomic and endocrine regulatory processes in chickens.  相似文献   

20.
We have localized p55, a thyroid hormone-binding protein found in the endoplasmic reticulum in cultured cells, in samples of normal human and monkey tissues, using a monoclonal antibody with cryostat sections and immunoperoxidase histochemistry. Large amounts of p55 were found in many tissues, generally corresponding to the amount of endoplasmic reticulum contained in each cell type. Intense localization of p55 was found in cells of the anterior and intermediate pituitary lobes, in epithelial cells of thyroid follicles, in the glandular epithelium of mammary gland, in hepatocytes, in Paneth cells and Brunner's glands in duodenum, in acinar cells of pancreas, in adrenal cortical cells, and in scattered interstitial fibroblastic cells in many tissues. These results suggest a potential role for thyroid hormone and p55 in regulating protein synthesis or secretion in multiple organs.  相似文献   

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