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991.
印度血桐与中平树是大戟科血桐属植物,该属植物具有多种药用价值,被广泛应用于民间医学中许多疾病的治疗,这两种植物种子中含有的神经酸也引起了研究者的高度关注。为确定适合印度血桐与中平树的全基因组测序研究策略,该研究采用二代高通量测序技术,结合生物信息学的方法首次测定了印度血桐与中平树的基因组大小、杂合率、重复率等基因组信息并初步分析了两种材料的SSR序列特征。结果表明:(1)印度血桐与中平树的基因组大小分别为986.84和946.23 M。(2)印度血桐与中平树的杂合率分别为0.75%和0.65%,重复序列比例分别为73.02%和71.5%。(3)通过对2种材料基因组序列的SSR特征分析,在印度血桐中共鉴定了4 499 185个SSR,在中平树中共鉴定了4 969 098个SSR。该研究结果为印度血桐与中平树SSR分子标记的筛选、开发以及全基因组深度测序提供了理论指导。 相似文献
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《植物生态学报》2016,40(4):364
Aims
Accurate estimation of carbon density and storage is among the key challenges in evaluating ecosystem carbon sink potentials for reducing atmospheric CO2 concentration. It is also important for developing future conservation strategies and sustainable practices. Our objectives were to estimate the ecosystem carbon density and storage of Picea schrenkiana forests in Tianshan region of Xinjiang, and to analyze the spatial distribution and influencing factors.
Methods
Based on field measurements, the forest resource inventories, and laboratory analyses, we studied the carbon storage, its spatial distribution, and the potential influencing factors in Picea schrenkiana forest of Tianshan. Field surveys of 70 sites, with 800 m2 (28.3 m × 28.3 m) for plot size, was conducted in 2011 for quantifying arbor biomass (leaf, branch, trunk and root), grass and litterfall biomass, soil bulk density, and other laboratory analyses of vegetation carbon content, soil organic carbon content, etc.
Important findings
The carbon content of the leaf, branch, trunk and root of Picea schrenkiana is varied from 46.56% to 52.22%. The vegetation carbon content of arbor and the herbatious/litterfall layer was 49% and 42%, respectively. The forest biomass of Picea schrenkiana was 187.98 Mg·hm-2, with 98.93% found in the arbor layer. The biomass in all layers was in the order of trunk (109.81 Mg·hm-2) > root (39.79 Mg·hm-2) > branch (23.62 Mg·hm-2) > leaf (12.76 Mg·hm-2). From the age-group point of view, the highest and the lowest biomass was found at the mature forest (228.74 Mg·hm-2) and young forest (146.77 Mg·hm-2), respectively. The carbon density and storage were 544.57 Mg·hm-2 and 290.84 Tg C, with vegetation portion of 92.57 Mg·hm-2 and 53.14 Tg C, and soil portion of 452.00 Mg·hm-2 and 237.70 Tg C, respectively. The spatial distribution of carbon density and storage appeared higher in the western areas than those in the eastern regions. In the western Tianshan Mountains (e.g., Ili district), carbon density was the highest, whereas the central Tianshan Mountains (e.g., Manas County, Fukang City, Qitai County) also had high carbon density. In the eastern Tianshan Mountains (e.g., Hami City), it was low. This distribution seemed consistent with the changes in environmental conditions. The primary causes of carbon density difference might be a combined effects of multiple environmental factors such as terrain, precipitation, temperature, and soil. 相似文献
Accurate estimation of carbon density and storage is among the key challenges in evaluating ecosystem carbon sink potentials for reducing atmospheric CO2 concentration. It is also important for developing future conservation strategies and sustainable practices. Our objectives were to estimate the ecosystem carbon density and storage of Picea schrenkiana forests in Tianshan region of Xinjiang, and to analyze the spatial distribution and influencing factors.
Methods
Based on field measurements, the forest resource inventories, and laboratory analyses, we studied the carbon storage, its spatial distribution, and the potential influencing factors in Picea schrenkiana forest of Tianshan. Field surveys of 70 sites, with 800 m2 (28.3 m × 28.3 m) for plot size, was conducted in 2011 for quantifying arbor biomass (leaf, branch, trunk and root), grass and litterfall biomass, soil bulk density, and other laboratory analyses of vegetation carbon content, soil organic carbon content, etc.
Important findings
The carbon content of the leaf, branch, trunk and root of Picea schrenkiana is varied from 46.56% to 52.22%. The vegetation carbon content of arbor and the herbatious/litterfall layer was 49% and 42%, respectively. The forest biomass of Picea schrenkiana was 187.98 Mg·hm-2, with 98.93% found in the arbor layer. The biomass in all layers was in the order of trunk (109.81 Mg·hm-2) > root (39.79 Mg·hm-2) > branch (23.62 Mg·hm-2) > leaf (12.76 Mg·hm-2). From the age-group point of view, the highest and the lowest biomass was found at the mature forest (228.74 Mg·hm-2) and young forest (146.77 Mg·hm-2), respectively. The carbon density and storage were 544.57 Mg·hm-2 and 290.84 Tg C, with vegetation portion of 92.57 Mg·hm-2 and 53.14 Tg C, and soil portion of 452.00 Mg·hm-2 and 237.70 Tg C, respectively. The spatial distribution of carbon density and storage appeared higher in the western areas than those in the eastern regions. In the western Tianshan Mountains (e.g., Ili district), carbon density was the highest, whereas the central Tianshan Mountains (e.g., Manas County, Fukang City, Qitai County) also had high carbon density. In the eastern Tianshan Mountains (e.g., Hami City), it was low. This distribution seemed consistent with the changes in environmental conditions. The primary causes of carbon density difference might be a combined effects of multiple environmental factors such as terrain, precipitation, temperature, and soil. 相似文献
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目的了解大学生齿龈内阿米巴感染状况,探讨其与口腔疾病的关系。方法在新疆乌鲁木齐市5所大学随机抽取516名大学生,用一次性口腔探针从龈缘处取垢物,生理盐水涂片,吉姆萨染色后光学显微镜下观察。结果齿龈内阿米巴的感染率为37.02%。男、女生感染率分别为36.49%和37.66%,经比较差异无统计学意义(P0.05);汉族、维吾尔族感染率分别为33.83%和42.86%,经比较差异有统计学意义(P0.05);不经常刷牙者感染率高于经常刷牙者(44.81%vs 33.70%,P0.05);使用普通牙膏者感染率高于使用药物牙膏(44.12%vs 33.65%,P0.05);有口腔疾病患者感染率高于健康者(9.03%vs 47.85%,P0.05)。结论齿龈内阿米巴在大学生这个人群中感染率较高,口腔疾病的发生发展可能与齿龈内阿米巴的感染存在相关性。 相似文献
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【背景】辣木瑙螟是在我国辣木上新发现的一种小蛾类害虫,主要以幼虫取食叶片为害,严重时可将叶片全部取食。目前该虫在我国云南省已有分布,对辣木产业威胁极大。【方法】通过室内试验、田间调查和收集整理辣木瑙螟相关资料,研究并总结了辣木瑙螟的寄主植物、地理分布、形态特征、部分生物学特性、危害和发生情况。【结果】人工饲养与初步观察显示,辣木瑙螟幼虫期约16.17 d,蛹期约10.25 d,从初孵幼虫到成虫共需约26.42 d。在云南省元江县的调查结果显示,辣木被害株率达94%以上,单株虫量最高达302头·株-1,经常采收的地块枝被害率达80.80%、被害指数达0.54,受害程度显著高于未采收地块。【结论】关于辣木瑙螟的年生活史、世代数、危害损失、防治方法等方面尚待进一步研究。随着辣木种植面积的扩大,其他与辣木种植环境相似的地区也可能有辣木瑙螟的分布。因此,需采取系统调查和大田普查的方法加强监测,防止该虫蔓延。 相似文献
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石漠化治理过程中农民参与意识与响应——以广西壮族自治区河池地区为例 总被引:4,自引:0,他引:4
基层农民在石漠化治理中有着不容忽视的作用,但对其态度及参与意愿的了解相对较少。基于参与性调查方法,按不同石漠化程度,对广西河池地区环江县、都安县、大化县33个屯154户居民石漠化治理过程中参与意识与响应进行了调查。结果表明,了解石漠化的农民所占比例较小,且随石漠化程度的增加反而减少。影响农民石漠化治理参与意识的主要因素是农民的文化程度和年龄,但生态示范区内农民参与意识要远好于非示范区。生态农业模式能被多数农民所接受,但因存在成本、农产品销路、技术等问题而实施难度大。政府支持的经济发展模式往往具有经济生态双重效益,但实施过程复杂;农民自发形成的发展模式通常具有收益高及操作简单等特点,但规模往往较小,且受市场影响较大。因此,石漠化治理过程中,一方面需要加强对重度石漠化地区农民的宣传教育,同时充分发挥生态示范区的作用,增加示范区的辐射范围;另一方面,在支持已有发展模式的同时,应重点支持种桑养蚕、手工品加工等农民自发形成的发展模式,并开拓农产品市场。总之,在石漠化治理过程中,政府加大支持力度,科研单位提供技术指导,农民群众积极配合,形成政府-科研单位-基层农民共同参与的石漠化治理模式。 相似文献
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