防治荒漠化的“三圈”生态-生产范式机理及其功能

防治荒漠化的“三圈”生态-生产范式,是干旱生态系统优化与重建的新结构。根据在鄂尔多斯和新疆等地的研究和实践,从干旱生态系统结构、过程和功能来讨论荒漠化防治的“三圈”范式。地理圈层结构（地理地带性）是“三圈”范式的自然地理背景。从宏观尺度和功能方面划分,“三圈”范式在空间尺度上有大“三圈”和小“三圈”之分,大“三圈”控制洲际范围的荒漠化扩展及沙尘暴蔓延,小“三圈”则以控制区域性风沙活动、沙尘暴和就地起沙的危害。防治荒漠化工程是复杂的多元组合和多功能的系统,我国西北地区受荒漠化影响严重,宏观的大“三圈”与多区域的小“三圈”有机结合,形成圈圈相护、层层设防的严密防护与生产系统,有效地控制大范围风沙危害、改善地方气候与小气候,并对发展经济,提高人民生活发挥重要作用。因此,“三圈”范式的概念与结构既是以自然地理地带性为基础,又是人类对自然、环境与生态系统格局的规律认识,更是科学的人类恢复、重建干旱区生态环境与可持续发展的生态设计范式。     

盐渍化胁迫下油葵对土壤原油污染的适应性及其改良措施

为了探究植物在盐渍化胁迫下对原油污染的适应性及改良措施,本研究以油葵作为研究对象,进行了原油-氯化钠-脱硫石膏盆栽正交试验和煤渣-沸石-脱硫石膏-锯沫盆栽正交试验.结果表明: 在盐渍化条件下,随着原油浓度的增大,油葵幼苗株高相对生长率(RGR)、地上生物量RGR、根氮磷比均显著减小,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性呈先增加后显著降低的趋势;随着锯沫体积分数的加大,油葵株高RGR和地上生物量RGR均显著增加,SOD活性逐渐降低,说明锯沫在改良盐渍化原油污染土壤方面比煤渣、沸石和脱硫石膏效果显著.在盐渍化条件下,原油污染能够降低油葵幼苗的生长率,锯沫对改良原油污染有较好的效果.     

花生苗期耐盐性评价及耐盐指标筛选

评价鉴选耐盐品种对于盐碱地花生生产具有重要意义。采用盆栽试验,设置不同盐胁迫浓度,对200个花生品种(系)萌发至幼苗期通过出苗速度、植株形态和生物量等指标进行耐盐性系统评价。结果表明,随盐胁迫浓度的增加,出苗时间延长,植株形态建成抑制加重,物质积累减少。鉴选花生品种耐盐性强弱的适宜盐胁迫浓度为0.30%—0.45%,超过此浓度不能出苗。地上部形态和生物量可作为耐盐评价的首选指标,主根长和出苗速度可作为辅助指标用以判断花生品种的综合耐盐能力。200个品种(系)在不同盐胁迫浓度下均可分成高度耐盐型、耐盐型、盐敏感型和高度盐敏感型4组。耐盐品种数量随盐胁迫强度加大而下降,盐敏感品种数量则上升。0.15%浓度下200个品种全部出苗,4个类型品种数分别占供试材料的29.0%、39.0%、27.5%和4.5%;0.30%浓度下185个品种出苗,4个类型品种数分别占供试材料的5.5%、34.5%、23.5%和29.0%;0.45%浓度下107个品种出苗,4个类型品种数分别占供试材料的5.5%、5.5%、20.0%和22.5%。14个品种在各盐浓度胁迫下均表现耐性,10个品种在各盐浓度胁迫下均表现敏感,为花生耐盐机理研究及生产应用提供了不同类型材料。     

50年来山东塔山植被与物种多样性的变化

为分析塔山植被与物种多样性50a自然演替和动态变化,2009-2010年,采用系统勘踏法和典型取样法进行了调查。当前塔山主要植被类型为"黑松林-赤松林-栓皮栎林"。50a间,该区针叶林从黑松(Pinus thunbergii)林演替为黑松林、赤松(P. densiflora)林和油松林(P. tabulaeformis)为主的混合针叶林,但针叶林的整体优势度下降,以栓皮栎(Quercus variabilis)和麻栎(Q. acutissima)为建群种的阔叶林面积明显增大,由针叶林向阔叶林的演替趋势明朗。物种丰富度为草本层>灌木层>乔木层,Shannon-wiener指数和Simpson指数为灌木层>草本层>乔木层,物种多样性较低,处于森林演替初期。     

小鼠BTB/锌指结构新基因Bsg6的克隆及表达谱分析

Bsg6 (brain specific gene 6) 是用消减差异筛选的方法克隆的小鼠头部特异表达 新基因. Bsg6基因cDNA长3 871 bp,编码一个670个氨基酸残基的蛋白,GenBank 登录号AY635051,位于小鼠第4号染色体,由2个外显子构成. Bsg6蛋白含有一个N端BTB（Broad complex, Tramtrack, and Bric a brac）结构域和两个C端C２Ｈ２型锌指结构域. 小鼠Bsg6蛋白与其在人类和鸡中同源蛋白的同源性分别为86.2%和79.1%. Bsg6在小鼠胚胎中的表达具有一定动态性,在E8.5的小鼠胚胎中,Bsg6主要在前脑和神经管表达. 在E9.5的小鼠胚胎中,Bsg6的表达明显增强并主要集中在前脑的端脑部. Bsg6在E10.5小鼠胚胎端脑的表达出现了下降,但是在中脑和后脑的表达增加,此外,Bsg6 mRNA的表达还出现在肢芽和尾部. 在HH10期的鸡胚中,Bsg6主要在头部和神经管前端表达. Northern杂交结果显示,Bsg6在很多小鼠成体组织中没有表达,但是在破骨细胞瘤中高表达. Bsg6的表达谱提示,Bsg6可能是在器官形成期对脑的发育起到重要作用的转录因子,而且其表达受到严格的调控,此外Bsg6还能与肿瘤的发生有关.     

A porcine circovirus type 2 (PCV2) mutant with 234 amino acids in capsid protein showed more virulence in vivo, compared with classical PCV2a/b strain

Background

Porcine circovirus type 2 (PCV2) is considered to be the primary causative agent of postweaning multisystemic wasting syndrome (PMWS), which has become a serious economic problem for the swine industry worldwide. The major genotypes, PCV2a and PCV2b, are highly prevalent in the pig population and are present worldwide. However, another newly emerging PCV2b genotype mutant, which has a mutation in its ORF2-encoded capsid protein, has been sporadically present in China, as well as in other countries. It is therefore important to determine the relative virulence of the newly emerging PCV2b genotype mutant, compared with the existing PCV2a and PCV2b genotypes, and to investigate whether the newly emerging mutant virus induces more severe illness.

Methodology/Principal Findings

Twenty healthy, 30-day-old, commercial piglets served as controls or were challenged with PCV2a, PCV2b and the newly emerging mutant virus. A series of indexes representing different parameters were adopted to evaluate virulence, including clinical signs, serological detection, viral load and distribution, changes in immune cell subsets in the peripheral blood, and evaluation of pathological lesions. The newly emerging PCV2 mutant demonstrated more severe signs compatible with PMWS, characterized by wasting, coughing, dyspnea, diarrhea, rough hair-coat and depression. Moreover, the pathological lesions and viremia, as well as the viral loads in lymph nodes, tonsils and spleen, were significantly more severe (P<0.05) for piglets challenged with the newly emerging mutant compared with those in the groups challenged with PCV2a and PCV2b. In addition, a significantly lower average daily weight gain (P<0.05) was recorded in the group challenged with the newly emerging PCV2 mutant than in the groups challenged with the prevailing PCV2a and PCV2b.

Conclusions

This is believed to be the first report to confirm the enhanced virulence of the newly emerging PCV2 mutant in vivo.     

人类新基因WDR70的克隆及初步研究

运用基于基因组数据库的特定基因同源新基因的克隆策略得到一个人类新基因WDR70 ,该基因编码一个包含 12个WD4 0结构域的蛋白。WDR70的cDNA序列长 2 2 6 6bp ,预测编码蛋白含 6 30个氨基酸 ,理论分子量为 70× 10 3 u ,染色体定位为 17p13.1。以小鼠胚胎为模型进行整体原位杂交 ,结果显示WDR70基因在 8.5d小鼠胚胎中没有表达 ,而在 9.5d和 10 .5d的小鼠胚胎的脑部有特异表达。由此推断该基因对胚胎期脑部的发育有重要的影响。     

小麦叶片β-1,3-葡聚糖酶的诱导、纯化与抗菌活性

三个小麦品种331、抗倒680和鲁麦23经氯化汞、水杨酸或核黄素处理后,叶片中的β-1,3-葡聚糖酶活性均有不同程度的升高.氯化汞处理24h对品种331该酶活性的诱导作用最强.因此取用氯化汞处理24 h的331小麦叶片研磨得到粗酶液.将粗酶液经硫酸铵分级沉淀、Phenyl-Sepharose Fast Flow疏水层析、DEAE-Sepharose Fast Flow阴离子交换层析和Sephacryl S-100分子筛层析,得到了SDS-PAGE凝胶电泳谱带单一的β-1,3-葡聚糖酶样品.经SDS-PAGE(12%)和凝胶过滤层析,测得其分子量约为52.0～53.6 kD.抗菌试验测定显示,纯化的β-1,3-葡聚糖酶对供试的4种病原真菌的生长、孢子萌发或芽管伸长都有一定程度的抑制作用.     

A new species of Viola L. (Violaceae) from South Anatolia

A new species of Viola L., Viola yildirimlii M. Dinç & Y. Bağcı sp. nov. from South Anatolia is described and illustrated. It is found on the rocky slopes of Aladağ National Park, in the county of Adana, south Turkey, at an elevation of 1800 m. It belongs to Viola , subsect. Viola , and is similar to the Turkish endemics Viola isaurica Contandr. & Quézel and V. kizildaghensis M. Dinç & Ş. Yıldırımlı. Diagnostic morphologic characters for a detailed discrimination from two similar taxa and other Turkish Eflagellatae species are discussed.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 477–482.     

Characterization and mapping of a novel mutant sms1 (senescence and male sterility 1) in rice

Plant senescence plays diverse important roles in development and environmental responses.However,the molecular basis of plant senescence is remained largely unknown.A rice spontaneous mutant with the character of early senescence and male sterility (sms) was found in the breeding line NT10-748.In order to identify the gene SMS1 and the underlying mechanism,we preliminarily analyzed physiological and biochemical phenotypes of the mutant.The mutant contained lower chlorophyll content compared with the wild t...