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运用扫描电镜对玉兰亚属44种(8个种，36个品种)植物的花粉形态特征进行了观察研究。44种植物的花粉粒均为单粒，具单沟，为N1P3C3类型花粉，呈长球形或超长球，中等大小(41.49～69.46)μm×(18.50～27.64)μm，左右对称。花粉极面观近球形，赤道面观为椭圆形或长椭圆形，侧面观为舟形。花粉壁表面纹饰较为原始，可以分为6类：孔状纹饰、疣状凸起纹饰、横纹状纹饰、脑沟状凹陷纹饰、短棒状孔穴纹饰和瘤状凸起纹饰。研究结果表明：玉兰亚属不同植物花粉形状、萌发孔沟等特征近似，外壁纹饰差异较大，因此花粉形态可以用于区分不同种类；但不能准确区分玉兰品种，仅可作为品种分类的辅助参考指标。 相似文献
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以32个栽培牡丹品种为试材,采用扫描电镜的方法,对栽培牡丹品种的花粉进行形态学比较,以期为栽培牡丹品种在花粉形态的分类上提供参考依据.结果 表明:32个栽培牡丹品种的花粉既有相似性又有差异性,花粉均呈单粒存在,均具有三拟孔沟,在赤道轴、极轴长、萌发沟长、网脊宽、网孔直径、极面观、赤道面观以及外壁纹饰上均有很大不同,通过对花粉形态的量化指标进行聚类分析,将供试的32个栽培牡丹品种进行品种群分类.通过对花粉形态进行的主成分分析,发现花粉外壁纹饰、花粉粒大小以及花粉萌发结构能够作为品种群分类的重要依据. 相似文献
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对浙江不同分布地杨梅雄株观察表明,雄株在花序形态及花粉数量、发育度上有明显差异。电镜扫描观察 发现,杨梅花粉赤道面观近椭圆形,极面观为钝三角形,花粉具3个萌发孔,萌发孔呈不规则圆形,3孔间成三角状; 不同样品间花粉粒及萌发孔的大小有差异,花粉粒大小在27.1μm×26.1μm-22.3μm×18.3 μm,萌发孔大小在3.48 μm×3.31μm-1.65μm×1.12μm;不同产区采集的花粉外壁纹饰不同,呈鱼鳞状或颗粒状突起,可分成光滑型、粗糙型 和中间型。观察可为杨梅授粉机理研究及杨梅雄株鉴定分类、育种亲本选择提供科学依据。 相似文献
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鸢尾属12种（变种）植物花粉形态及其系统学意义 总被引：1，自引：0，他引：1
对鸢尾属12份材料的花粉形态进行了扫描电子显微镜观察。结果显示：（1）白花马蔺和马蔺花粉大小相似,形状、萌发孔、外壁纹饰和网脊形态相同,网脊宽度不同;（2）四川鸢尾、薄叶鸢尾和锐果鸢尾的花粉形状、外壁纹饰和网脊形态相同,均无明显萌发孔,锐果鸢尾花粉较小,表明这3个物种的亲缘关系较近;（3）蝴蝶花和扁竹兰花粉大小基本相同,前者形状为扁球形,后者为近球形;萌发器官、表面纹饰和网脊形态相同,网眼内无颗粒,表明这两物种亲缘关系较近;（4）扇形鸢尾与蝴蝶花和扁竹兰二者相比,在花粉粒大小,表面纹饰均上均有较大差异,表明扇形鸢尾与蝴蝶花和扁竹兰的亲缘关系较远。讨论了鸢尾属5个亚属的花粉形态特征及演化趋势。 相似文献
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中国野生葡萄花粉形态学研究 总被引：12，自引：2，他引：10
对原产中国 2 3种或变种 ,共计 71个类型的野生葡萄及 9个其它栽培种或品种的花粉形态进行了系统观察研究。根据花粉大小 ,可将葡萄花粉分为五类 ,并给出了分类标准 ;花粉粒赤道宽与极轴长之比 (E/P) ,既可用于正常花粉的形态分类 ,又可作为不同种类花粉育性的形态鉴定指标 ;除巨峰为四沟孔类型外 ,其它正常花粉种类的花粉粒均为三沟孔型 ,雌能花种类的花粉无萌发沟孔存在 ;另外还对花粉壁表面孔穴大小、密度进行了测定和描述分类 相似文献
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AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β-particles emission from 188Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by 188Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [3H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G0/G1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation. 相似文献
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AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration. 相似文献
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AIM: To examine the autoantibody against α1-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α1-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α1-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α1-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension. 相似文献
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《International Journal of Fruit Science》2013,13(3):101-120
Abstract Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared. 相似文献
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The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species. 相似文献
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《International Journal of Fruit Science》2013,13(1):139-156
Abstract This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality. 相似文献
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多效唑对猕猴桃离体试管苗生长及内源激素的影响 总被引：18，自引：0，他引：18
多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。 相似文献
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HU Zhi-cheng ZHU Jia-yuan ZHU Bin GUO Dong CHEN Bin ZHANG Kai HU Kun-hua LI Ming-tao TANG Bing 《园艺学报》2011,27(9):1802-1806
AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars. 相似文献
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AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [3-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10-6-10-4 mmol/L) stimulated [3-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [3-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10-6-10-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl2 for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation. 相似文献
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Fulé Peter Z. Crouse Joseph E. Heinlein Thomas A. Moore Margaret M. Covington W. Wallace Verkamp Greg 《Landscape Ecology》2003,18(5):465-486
Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献