关中地区古耕作土壤和现代耕作土壤微形态特征及意义

【目的】通过对土壤微形态研究试图阐明陕西关中地区现代土壤的发育过程和微形态标志。【方法】用偏光显微镜对LGT剖面不同发生层的薄片进行了观察和影像定量分析。【结果】不同发生层的矿物组合十分相似,石英（Q）和长石（Pl）占绝对优势,但C/F15?m值、不同矿物间的比例、颗粒形态等有明显差异。土壤形成物主要是粘土矿物、方解石和无定形Fe,Ap层中有大量针状方解石微晶、次生粘土和蚯蚓粪粒,BC层方解石数量多且形态最复杂,Bt1和Bt2层方解石很少,但有大量粘土亚胶膜。【结论】所谓的"堆垫土"实际上由两部分组成,下部BC主要是全新世晚期堆积的风积物,表层Ap是2000年以来人类不断施加土粪、风尘堆积和农耕活动的综合产物。     

岩原鲤的研究概况和进展

岩原鲤[Procypris rabtmdi(Tehang)]是一种长江中上游水系特有的珍稀保护动物,其分布区域狭窄,种群数量少,再加上环境巨变和滥捕,使岩原鲤野生资源日益枯竭,濒临灭绝,已被列入<中国濒危动物红皮书>.结合大量的文献和自己的研究结果,从分类地位、种群生态、形态学、生理生化、遗传学和人工养殖等方面较为全面地总结了岩原鲤的研究概况和进展,指出了岩原鲤种群研究中存在的一些问题以及今后的研究方向.     

植物群体遗传进化研究方法探析

[目的]评估植物群体遗传进化研究涉及的相关算法软件,为该研究领域提供方法选择参考.[方法]利用重测序数据,就群体遗传进化研究的各种算法做比较,对相关算法分析效果做对比评估.[结果]评估结果表明,进化树耗时和数据大小、模型选择均有较大关系,两者共同决定运算时间,另外运算效果还和多序列的比对效果有很大关系.群体结构分析fastStructure、Admixture软件运算速率、准确度较Structure软件有明显提高.主成分分析耗时相对较少,可用Cluster和R软件实现,两款软件的计算结果可相互验证;连锁不平衡分析推荐Plink2软件.[结论]算法及软件的选择对植物群体遗传进化研究的效率、结果影响较大.     

三系两系杂交水稻比较研究

三系两系杂交水稻是提高水稻产量最有效的技术。比较三系两系不育系遗传、选育,恢复系选育以及杂交水稻组合选育,对于正确认识三系两系杂种优势具有重要意义。本文综述了三系两系不育系遗传和选育、三系两系恢复系选育、三系两系杂交水稻组合的选育理论与实践等方面进展,并比较了中国水稻数据中心三系两系杂交水稻新组合产量差异。笔者认为三系两系杂交水稻育种技术不同,但两系三系杂交水稻不存在优劣之分。讨论了存在的问题,包括杂交水稻杂种优势机理、三系两系杂交水稻材料创新与育种技术等问题。针对以上问题,建议进一步研究杂交水稻杂种优势机理;加强三系两系亲本改良,聚合更多的优良基因,有更强的配合力;采用常规育种技术结合分子育种,提高三系两系亲本育种效率。     

Insertion site of FLAG on foot-and-mouth disease virus VP1 G-H loop affects immunogenicity of FLAG

The G-H loop of the foot-and-mouth disease virus(FMDV) virion contains certain dominant immunogenic epitopes, as well as an arginine-glycine-aspartic acid(RGD) motif that is recognized by cell surface integrin receptors. Previous experiments indicate that it is critical to maintain virus structural integrity when inserting an exogenous epitope into the surface of an FMDV structural protein. However, it remains to be determined how factors such as different insertion positions affect interactions among the virus, cells and host immune system. In this study, one infectious c DNA clone of the swine FMDV Cathay topotype strain O/CHA/90 was constructed. Then, a FLAG marker(DYKDDDDK) was inserted upstream(–4) or downstream(+10) of the RGD motif to generate tagged viruses vFLAG-O/CHA/90 or vO/CHA/90-FLAG, investigating the possibility of expressing foreign antigen and effect on its immunogenicity. Compared to the parental virus, both tagged viruses exhibited similar plaque phenotypes, suckling mouse pathogenicity and antigenicity. Additionally, the FLAGtag insertion position did not change the use of integrin-mediated cell entry by the tagged viruses. Interestingly, both tagged vaccines protected pigs against challenge with the parental virus O/CHA/90 and induced immune responses against FMDV in BALB/c mice and pigs, but only vaccination with vFLAG-O/CHA/90 generated anti-FLAG antibodies. Our findings demonstrated that two sites(RGD–4 and RGD+10) tolerated the insertion of an exogenous gene in the swine FMDV O/CHA/90 strain. However, only RGD–4 was a novel and appropriate inserting site which could tolerate exogenous FLAG. The resultant tagged virus is a promising candidate for FMD vaccine which can be differentiating infected from vaccinated animals(DIVA).     

Invasion genetics of alien insect pests in China: Research progress and future prospects

An unwelcome side effect of the globalization of the world's economy and dramatic increase in human mobility and trade has been a marked increase in species invasions that have posed severe threats to the ecological, economic, and/or social stability of the introduced regions. In this review, we analyzed the application of molecular markers in invasion genetics of invasive alien insect pests (IAIPs) in China based on a bibliometric survey. Our report discusses the considerable progress that has been made during the past two decades in understanding the invasion genetics of IAIPs in China. We reviewed the major findings in the main topics including the effects of origin and routes of invasion on genetic structure, spatial and temporal genetic changes, factors contributing to the genetic changes of IAIPs, and genetic mechanisms involved in IAIPs' invasions. On the other hand, some of these research areas remain relatively unexplored in China, especially those pertaining to spatial and temporal genetic changes of IAIPs and genetic mechanisms of IAIPs' invasions. Finally, the future research prospects of IAIPs in China are discussed. We hope this review will stimulate an interest in and provide an increased understanding of the field of invasion genetics of IAIPs in China, and provide a basis for future research in this area.     

玉米茎腐病研究进展

系统综述了玉米茎腐病的发病症状、分级标准、致病菌、致病机理、抗性遗传规律、抗性基因定位和抗病机理的研究进展,并提出了抵御玉米茎腐病的综合防治措施。     

反向遗传技术在传染性法氏囊病病毒研究中的应用

传染性法氏囊病是鸡的最严重疾病之一,其病原是鸡传染性法氏囊病病毒(IBDV),IBDV基因组为两片段双链RNA,变异株和超强毒株的出现,给传统的疫苗免疫带来了新的挑战,因此,加强对IBDV的基础研究是控制该病的关键.RNA的结构不稳定成为阻碍RNA病毒研究的主要障碍,近年来兴起的反向遗传技术将RNA病毒的基因组转化为cDNA,从而使RNA病毒的基因操作成为可能,也使RNA病毒的研究获得了快速的发展.文章就传染性法氏囊病病毒反向遗传操作研究的意义、方法、概况及相关分子生物学进行了全面综述.     

Comparative Genomics for Gene Isolation in Legumes

The similarity in gene order between closely related taxa suggests that genomic information from model systems should facilitate gene isolation and characterization in target crops. If this is the case, a great deal of effort and investment can be saved by focusing attention on a few model systems that have appropriate applicability. Pea （Pisura sativum） provides a good test case： its genome is large and the insertion sites for repetitive elements, which comprise the bulk of its genome, are highly polymorphic （Jing et al., 2005; Vershinin et al., 2003）, so we expect a great deal of structural polymorphism between the genomes of Pisum lines. Yet the genetic map of Pisum is essentially coUinear with Medicago （Choi et al., 2004; Kalo et al., 2004）.     

TILLING技术及其在农作物中的应用现状

TILLING技术是一种全新的反向遗传学研究方法。文章简要介绍了TILLING技术的原理、操作流程、技术要点及其特点,并总结了TILLING技术在麦类、玉米及水稻研究中的应用现状。