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排序方式: 共有109条查询结果,搜索用时 46 毫秒
1.
采用扫描电镜对三角梅42个品种的花粉形态作观察,参考已发表的三角梅花粉育性的数据,探究花粉形态和花粉育性的联系。采集42个三角梅品种的花粉,人工干燥后进行电镜形态观察,采集3000倍下的近极面观、远极面观、赤道面观、侧面观以及10000倍下的外壁网脊等图片,确定三角梅不同品种花粉的整体外观形态。测定花粉的大小、萌发沟数量,对比不同品种和不同花粉部位的芽突数量。三角梅花粉呈现单侧凹陷、单侧突出的凸饼状结构,三角梅不同品种的花粉粒直径在21.64~31.14 μm之间。少数品种的萌发沟有3个,萌发沟少于3个的品种主要集中于花粉育性低的品种中。花粉表面网脊状褶皱,褶皱上芽突数量不等,不同品种有所差别。芽突数量与植株花粉育性关系密切,花粉育性高的品种花粉表面芽突数量多于花粉育性低的品种。花粉粒表面芽突数量减少,降低三角梅花粉的附着能力,这有可能是导致该品种花粉育性极低的原因之一。 相似文献
2.
随着景观改造的多样性,药用植物园也成为城市园林营造景观的一种方式。厦门市忠仑公园集科普、教育、观赏功能为一体,药用植物园区景观改造以人为本,以科普教育为宗旨,在保证药用植物景观的基本功能的前提下,塑造优美的景观,既能弘扬中华民族药用文化知识,又能为周边居民提供一个互动学习科普知识、修养身心的场所。 相似文献
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黄金宝树栽培技术及其在园林景观中的应用 总被引:1,自引:0,他引:1
论述了黄金宝树的特征特性,总结了其栽培技术,并提出该树种在园林景观中的置景应用模式,以期促进黄金宝树资源的保护、利用和开发。 相似文献
5.
[目的]对烤烟不育系催芽包衣丸化种的农艺、经济性状进行研究。[方法]以MSK326裸种(T1)、催芽MSK326包衣种(T2)、MS云烟85裸种(T3)、催芽MS云烟85包衣种(T4)、MS云烟87裸种(T5)和催芽MS云烟87包衣种6个材料进行试验,田间设计采用完全随机区组设计,3次重复,种植密度16 500株/hm2,小区面积24 m2,小区株数5×9株。[结果]在丽江市玉龙县的自然和土壤条件下,采取相同的栽培和调制技术,催芽包衣丸化种比其裸种出苗、成苗均早2~3 d,苗期烟株的生长势和生长整齐度均优于未催芽裸种,但在生物学特性、农艺性状、抗逆性、原烟外观质量等方面无明显差异,在经济性状上差异显著但无统一规律。[结论]为我国大面积推广烤烟不育系催芽包衣丸化种提供理论了依据。 相似文献
6.
Wenxin Wang Jianxin Wang Ruihua Yan Runying Zeng Yaqiang Zuo Dingquan Wang Wu Qu 《Marine drugs》2021,19(8)
The neoagaro-oligosaccharides, degraded from agarose by agarases, are important natural substances with many bioactivities. In this study, a novel agarase gene, agaW1540, from the genome of a deep-sea bacterium Shewanella sp. WPAGA9, was expressed, and the recombinant AgaW1540 (rAgaW1540) displayed the maximum activity under the optimal pH and temperature of 7.0 and 35 °C, respectively. rAgaW1540 retained 85.4% of its maximum activity at 0 °C and retained more than 92% of its maximum activity at the temperature range of 20–40 °C and the pH range of 4.0–9.0, respectively, indicating its extensive working temperature and pH values. The activity of rAgaW1540 was dramatically suppressed by Cu2+ and Zn2+, whereas Fe2+ displayed an intensification of enzymatic activity. The Km and Vmax of rAgaW1540 for agarose degradation were 15.7 mg/mL and 23.4 U/mg, respectively. rAgaW1540 retained 94.7%, 97.9%, and 42.4% of its maximum activity after incubation at 20 °C, 25 °C, and 30 °C for 60 min, respectively. Thin-layer chromatography and ion chromatography analyses verified that rAgaW1540 is an endo-acting β-agarase that degrades agarose into neoagarotetraose and neoagarohexaose as the main products. The wide variety of working conditions and stable activity at room temperatures make rAgaW1540an appropriate bio-tool for further industrial production of neoagaro-oligosaccharides. 相似文献
7.
根据铜藻转录组测序数据来进行微卫星标记的发掘,共获得2 800个微卫星位点。二碱基重复出现的次数最多,占32.82%,其次是三碱基重复,占25.21%;在所有重复单元类型中,AC/GT出现频率最高,占9.18%;重复序列的长度则主要集中在12~20 bp,占72.79%;重复次数主要集中在5~10次,占74.14%。随机选取74对引物进行验证,最终获得18个具有多态性的微卫星标记。对31株铜藻个体进行检测和评价,共扩增得到43个等位基因,每个位点平均等位基因数为2.39,平均有效等位基因数为1.91,平均观测杂合度(H_o)为0.318,平均期望杂合度(H_e)为0.449,平均多态信息含量(PIC)为0.365,在18个位点中有11个显著偏离Hardy-Weinberg平衡(P0.05)。开发的微卫星标记为后续铜藻多样性、起源和迁移等遗传学问题研究提供了有力支撑。 相似文献
8.
随着国家对新能源汽车的大力支持以及各地政府对环境保护的高度重视,国内新能源客车产量需求剧增,很多公司已对传统生产线进行改造或新建生产线。本文结合目前行业现状,阐述了客车底盘产线布置的关键点及常用的布置方案,对各种布置方案的优缺点进行对比分析,对我国客车底盘装配效率的提升有重大意义。 相似文献
9.
Late gestation is an important period for rapid development of the sow's mammary gland and fetus. It is becoming more and more important to provide a suitable nutrient level in late gestation period for improve the reproductive efficiency of sow. Demand of energy, protein and amino acids for mammary gland and fetus in sows at late gestation are different. To provide reasonable nutrition for fetus, at the same time for the needs of mammary gland are still seldom reported. In this paper, the effects of dietary energy, protein and amino acids levels on the development of mammary gland and the growth of fetus were reviewed,the authors propose the requirement of energy, protein amino acid and reasonable proportion in sows at late gestation, in order to give some guidance for pig farmers. 相似文献
10.
Yinnan Mu Xiang Wan Kebing Lin Jingqun Ao Xinhua Chen 《Fish physiology and biochemistry》2013,39(5):1267-1276
In the present study, we examined the liver protein profiles of the large yellow croaker (Pseudosciaena crocea) exposed to polyriboinosinic:polyribocytidylic acid [poly(I:C)], a viral mimic, using the differential proteomic approach. Sixteen altered protein spots were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry or matrix-assisted laser desorption ionization time of flight/time of flight mass spectrometry, including eight upregulated proteins and eight downregulated proteins. These altered host proteins were classified into six categories based on their biological function: cellular process, metabolic process, biological regulation, binding, and catabolic process, highlighting the fact that response to poly(I:C) induction in fish seems to be complex and diverse. Moreover, four corresponding genes of the differentially expressed proteins were validated by relative quantitative real-time PCR. Western blot analysis further demonstrated the changes in protein abundance of natural killer enhancing factor and peroxiredoxin 6. These results will be helpful in furthering our understanding of the changes of physiological processes in liver of fish during virus infection. 相似文献