中国柑橘大实蝇遗传多样性分析

利用4对微卫星引物对采自中国7省市的18个柑橘大实蝇地理种群进行标记,并进行遗传多样性分析。结果表明,从供试柑橘大实蝇地理种群检测到的等位基因数为19~30个,平均为23.06个,且4个微卫星位点(Bp125、BcuF 1.6、Bcac 5.10、Bcac 6.10)的等位基因数分别为7、14、9、8个。对18个柑橘大实蝇种群的哈迪—温伯格平衡测试结果显示,其卡方值的变化范围为5.582~∞,各种群间差异显著(变化范围为0.000~0.694)。表明中国柑橘大实蝇种群的遗传多样性较高,且不同种群间存在较大的遗传分化。     

基于线粒体COI基因全长的无锡地区橘小实蝇种群来源分析

本研究以1 535 bp的COI基因全长作为分子标记,通过测序得到橘小实蝇[Bactrocera dorsalis(Hendel)]的海南、广东、广西、湖南、湖北、云南、四川、江西、福建、浙江、上海及江苏的12个种群共240头橘小实蝇个体的COI基因,对其进行种群遗传结构研究,分析江苏无锡地区橘小实蝇的入侵来源。结果表明,研究所涉及的橘小实蝇种群间呈现较显著的遗传结构,但并未出现距离隔离现象,且随着采样点经度和纬度的增加单倍型多样性呈减弱趋势。12个橘小实蝇地理种群分为3个组群进行AMOVA分析显示,组群间变异占总体变异的1.46%,组群内种群间变异占总体变异的4.07%,组群内个体间变异占总体变异的94.47%。表明本研究所涉及范围内的橘小实蝇有由南向北扩散的趋势,无锡地区的橘小实蝇种群很可能来源于广东、江西及浙江地区。     

苹果小吉丁虫微卫星开发及其种群遗传结构分析

为研究苹果小吉丁虫Agrilus mali Matsumura的种群遗传结构,采用磁珠富集法以生物素标记探针(AC)_(12)和(AG)_(12)构建苹果小吉丁虫微卫星文库,根据阳性克隆测序获得的微卫星侧翼序列设计引物,筛选和开发苹果小吉丁虫多态性微卫星标记,并利用开发的微卫星标记对其不同地理种群的遗传结构进行分析。结果显示,从微卫星文库中的300个阳性克隆中筛选得到248个含有微卫星片段的克隆子,阳性克隆率为82.7%,其中完美型微卫星131个,占52.8%;不完美型90个,占36.3%;混合型27个,占10.9%,表明磁珠富集法开发新微卫星标记的效率较高。从获得的248个苹果小吉丁虫微卫星中筛选获得7个多态性微卫星位点,这7个位点在苹果小吉丁虫8个地理种群样本中的等位基因数为10~23个,有效等位基因数为1.674~12.218个,多态信息含量为0.304~0.796。8个苹果小吉丁虫种群的观测杂合度为0.095~0.676,期望杂合度为0.469~0.755,Shannon指数为0.791~1.621,遗传距离为0.071~0.788。采自新疆维吾尔自治区的7个苹果小吉丁虫种群之间遗传相似度较高,但其与辽宁省种群的遗传相似度较低。     

基于分子遗传标记技术的实蝇种群遗传关系研究进展

分子遗传标记技术已用于分析实蝇的种群遗传关系,本文介绍了分子遗传标记技术在实蝇的起源、入侵、定殖、扩散及其他方面的研究进展,首次分析了我国实蝇种群遗传研究的现存问题并针对检疫性实蝇种群遗传关系研究提出了建议.     

老挝中北部地区果实蝇属(Bactuocera)害虫种类初步调查

2008年4月至2009年3月,在老挝境内应用性引诱剂对琅南塔、乌多姆赛、琅勃拉邦和万象4省进行了实蝇诱捕.放置了24个诱捕器,诱捕到果实蝇属(Bactrocera)实蝇1233头,15种.其中,琅勃拉邦省实蝇种类最多;橘小实蝇种群数量最大;瓜实蝇、南瓜实蝇、颜带实蝇、橘小实蝇、锈实蝇分布最广.     

基于DNA条形码技术的湖南省柑橘主产区实蝇幼虫分子鉴定

为明确湖南省柑橘主产区的实蝇入侵为害现状,从该省7个市(自治州)22个地点收集柑橘蛆果中的幼虫,利用DNA条形码技术对其进行分子鉴定,并以DNA条形码序列作为分子标记探究橘大实蝇Bactrocera minax的20个中国地理种群(湖南省6个组群共16个种群、其它3省市4个种群)以及1个印度地理种群间的亲缘地理关系,分析橘大实蝇在我国的遗传进化关系。结果表明,仅采集自邵阳市城步苗族自治县柑橘蛆果中的5头幼虫被鉴定为蜜柑大实蝇B. tsuneonis,其余21个地点采集的595头幼虫均被鉴定为橘大实蝇。21个橘大实蝇地理种群的平均单倍型多样性为0.75,核苷酸多样性为0.0032,核苷酸差异数为2.13,中国所有地理种群均具有较高的遗传多样性;单倍型网络进化图显示湖南、重庆、贵州种群共享的单倍型H3为原始单倍型,表明其为比较原始的种群;AMOVA分析结果显示种群内个体间遗传变异占总体变异的59.04%,是遗传变异的主要来源;遗传分化结果表明湖南省6个组群间均出现了中度至高度的遗传分化,FST在0.0521～0.7795之间。表明DNA条形码技术可用于蜜柑大实蝇和橘大实蝇幼虫的分子鉴定及其种群遗传进化分析。     

橘小实蝇分子系统发育研究进展

橘小实蝇[Bactrocera(Bactrocera)dorsalis(Hendel)]是一种世界危险性检疫害虫,寄主范围广,能为害250多种瓜果蔬菜,给果蔬业带来严重的经济损失。本文综述了同工酶电泳、RFLP、核酸序列分析、微卫星分析及基因芯片技术等分子生物学技术在橘小实蝇分子系统发育方面的研究进展,并探讨了橘小实蝇分子系统发育研究中存在的问题和发展方向。     

贵州省实蝇种类监测情况研讨

通过在贵州省36个县(市、区)的772个监测点的监测发现:贵州省主要实蝇种群为南瓜实蝇、瓜实蝇和橘小实蝇,未发现地中海实蝇,其中南瓜实蝇为优势群体,占54.8%。实蝇活动高峰在8月上旬至9月中旬,主要发生于果园、蔬菜基地、水果批发市场等地。     

实蝇科昆虫线粒体基因组研究进展

实蝇科昆虫种类繁多、世界广泛分布、具有重要经济意义,其种类鉴定、种群遗传、系统发育等方面的研究倍受植物检疫学和入侵生物学等领域的关注。线粒体基因组已被广泛应用于多个昆虫类群的进化与系统发育等研究。本文对实蝇科昆虫线粒体基因组的测序现状、基因组的结构和基因排列、碱基组成、进化速率及其在实蝇中的应用等方面的研究进展进行介绍、讨论与展望,并提示其对实蝇科害虫的入侵防控具有重要的理论和实践指导意义。     

中国疫区内苹果蠹蛾微卫星位点的扩增稳定性及遗传多样性

为揭示欧洲苹果蠹蛾微卫星位点在中国苹果蠹蛾群体遗传学研究中的有效性,以12对微卫星引物对采自中国主要疫区新疆、甘肃、黑龙江的8个苹果蠹蛾地理种群的120头个体在各位点的遗传多样性及扩增稳定性进行研究。所选取的12个微卫星位点中,有8个能够稳定扩增,各位点在大多数种群中均显示偏离哈迪-温伯格平衡,各位点上的平均等位基因数量为3.750～12.500,平均观察杂合度Ho为0.025～0.783,平均期望杂合度He为0.284～0.892。位点Cp2.P和Cp4.56分别具有较低的观察杂合度(0.109、0.025)和较高的近交系数Fis(0.806、0.954),说明这2个位点上的杂合子非常缺乏,其余6个位点均具有较高的杂合度水平和等位基因数量,适用于中国疫区内苹果蠹蛾微卫星分子标记研究。     

The comparative genetics of Phytophthora1

Mechanisms generating variation in Phytophthora are assessed. Patterns of inheritance are typically those of a diploid organism. The increasing availability of single gene markers is allowing the breeding system in heterothallic species to be defined. The genetics of virulence and fungicide resistance is summarized; somatic recombination and variation in chromosome number is discussed. Rapid advances in basic genetics, population genetics and evolution are expected through the application of the new techniques for manipulating DNA in vitro. The complexity of the problem is not underestimated.     

禾谷丝核菌基因组SSR标记的开发及评价

群体遗传学研究对于了解病原菌的流行、变异及进化规律具有重要意义。但是到目前为止,对小麦纹枯病菌禾谷丝核菌群体遗传结构的了解并不深入,缺乏有效的SSR标记是主要原因。本研究根据禾谷丝核菌全基因组序列进行了微卫星位点搜索并设计SSR引物,通过电泳筛选和测序验证,最终筛选出12个多态性较好且稳定可靠的SSR标记。利用这些标记对收集自我国安徽、江苏、河南三省的23个禾谷丝核菌菌株进行了多态性分析,结果发现禾谷丝核菌基因组中长片段微卫星位点较少。12对引物扩增出的等位基因数平均为6.1个,期望杂合度平均为0.651,观测杂合度平均为0.508,表明这些标记具有较高的多态性,能够满足禾谷丝核菌群体遗传学研究需要。本研究为进一步进行禾谷丝核菌的多样性、群体遗传结构分析及进化学研究提供了有效工具。     

DNA分子标记在植物真菌病害研究中的应用

小麦纹枯病是一种重要的土传病害,在世界各地均有发生,我国主要发生在黄淮海流域的冬小麦产区,造成巨大的产量损失。国内外均有报道小麦品种之间存在抗病性差异,但关于抗性筛选的研究较少。作者于1993～1995年通过室内接菌试验、田间接菌试验和自然病地调查,对102个常见的小麦品种(系)和育种材料进行了鉴定,结果如下。 1 材料与方法     

14C-三唑酮在小麦幼苗上的吸收分布和影响因素

综述了近年来ＤＮＡ分子标记技术在植物真菌病害研究中的应用现状和潜力,内容涉及病原菌的种类鉴定,群体遗传,毒性变异,毒性基因迁移,菌源传播及植物抗病基因定位,克隆和标记辅助选择等植物病理学的诸多方面,列举了代表性应用实例,展望了ＤＮＡ分子技术在植物病理学研究中的广阔前景,提出了我国今后进一步开展有关研究的基本途径。     

Population genetic diversity and structure of the pecan scab pathogen,Venturia effusa,on cv. Desirable and native seedlings,and the impact of marker number

Scab (Venturia effusa) is the major cause of economic loss in pecan in the south-eastern USA. We explored population genetic diversity and structure among orchards of cv. Desirable and native seedlings, and within-orchard variability among trees of all cultivars sampled. We compared the ability of 30, 15 and 7 previously developed microsatellites to characterize the population genetic diversity and structure of V. effusa. Analyses of molecular variance (AMOVA) provided little evidence of structure dependent on cultivar, but there was some evidence of structure between orchards of a cultivar based on distance. Individual orchard AMOVA showed that three of 11 orchards had between-tree population structure. Among six populations from cv. Desirable, a Mantel test showed that geographic distance was related to the pairwise genetic divergence (R² = 0.84). Among 11 orchards of various cultivars there was little difference in diversity using 30, 15 or 7 markers, or population structure based on AMOVA. Some minor differences in population structure were seen based on discriminant analysis of principal components, or dendrograms. Thus, depending on the objectives, future studies may use as few as 15 or 7 markers without losing ability to discern population genetic diversity or structure. More populations exhibited linkage disequilibrium when using 15 or 30 markers compared to when using seven markers. Knowledge of population genetics of V. effusa in relation to host genotype is needed to understand pathogen population interactions and gene flow, knowledge that will help underpin future breeding efforts to develop durable resistance in this long-lived orchard tree.     

Monitoring changing virulence patterns of <Emphasis Type="Italic">Uromyces appendiculatus</Emphasis> in the resistant pinto bean cultivar Olathe by rep-PCR

Corresponding molecular markers associated with avirulence or virulence genes in the bean rust pathogen are currently unknown, although host resistance genes have been linked to molecular markers in bean. The changing virulence patterns in pathotypes of Uromyces appendiculatus collected over a 14-year period after the release of the Ur-6 resistance gene on the USA high plains were therefore analyzed using rep-PCR molecular markers. Isolates from two neighbouring pathotype groups from Colorado and Nebraska were screened using the rep-PCR primer Box-AIR. The PCR fragment Box ₄₇₅ was cloned and sequenced and a specific primer set ATA-2 was designed. This primer yielded 10 polymorphic products which allowed separation of these isolates into two distinct groups and will be useful for future analysis of the population genetics of this organism.     

Particular Structure of Plasmopara viticola Populations Evolved Under Greek Island Conditions

ABSTRACT Plasmopara viticola populations collected from three islands in the Ionian Sea-an arm of the Mediterranean Sea to the west of Greece-were analyzed with microsatellite molecular markers in order to investigate the pathogen population structure. Downy mildew populations from mainland regions previously studied were found to have high genotypic diversity and limited clonality; however, populations under Mediterranean island conditions mostly showed limited variation and the epidemics basically were driven by the multiple clonal infections of one or a few genotypes. Populations from different islands were differentiated from each other, whereas genetic divergence also was found among subpopulations of the same plot. Polyploid individuals and individuals that overwintered in asexual form were observed in some cases. The findings obtained by this population genetics study improve our understanding of the biology of the pathogen and lead to potential alternative control measures for the disease.     

分子标记在水稻稻瘟病病害系统研究中的应用

 现行水稻品种稻瘟病抗性寿命短已成为水稻生产的主要障碍之一,造成水稻品种稻瘟病抗性容易丧失的主要原因是现时尚未有客观、可靠的技术方法获知育种地区真实的病原菌群体结构及其演化规律,另外,对水稻品种稻瘟病抗性的遗传基础不十分清楚也是其原因之一。本文概述了近几年来分子标记在稻瘟病病原菌群体结构分析和抗病品种抗病遗传分析中的应用,以及抗性基因标记技术的发展,并探讨应用分子标记辅助获得稻瘟病稳定控制的策略及实际应用中的若干问题。     

Molecular markers for genotyping anastomosis groups and understanding the population biology of Rhizoctonia species

Soil-borne Rhizoctonia fungi cause serious diseases in several plant species. For the classification of these fungi, the number of nuclei in a hyphal cell and the anastomosis reaction are important criteria. Although Rhizoctonia spp. has a wide host range, the causal agents have been reported to be selective for host plant families or species and lead to severe disease. Reports of new diseases, particularly in new host plants, and severe damage in agricultural fields incurred by subdivided or newly found groups of Ceratobasidium and Waitea circinata (a varied teleomorph of Rhizoctonia) have been increasing in recent years. The food production environment is altering because of climate change, introduction of potential new host plants, and heavy use of chemicals that reduce microbial diversity. These changes favor the occurrence of new diseases incurred by undefined anastomosis groups (AGs) or subgroups of Rhizoctonia spp. On the basis of the phylogenetic relationships of AGs and subgroups in Rhizoctonia spp., molecular markers for discriminating the groups of the Rhizoctonia species complex have been developed. The application of genetic markers, in the form of microsatellites or simple sequence repeats (SSR), has become increasingly important in fungal genetics. The analyses of population genetics for Rhizoctonia spp. using SSR markers elucidated the modes of sexual and asexual reproduction, phylogeographical distributions, and global migrations associated with adaptation to agroecosystems.     

Identification,characterisation and discriminatory power of microsatellite markers in the parasitic weed Orobanche cumana

Orobanche cumana is an obligate root parasite of sunflower. It represents a major agricultural problem in many countries of southern and eastern Europe. Information on O. cumana population genetics, structure and dynamics is scarce, particularly due to the lack of suitable molecular markers for such studies. The objective of this study was to identify and characterise simple sequence repeat (SSR) markers for O. cumana. Four thousand two hundred SSR‐containing candidate sequences were obtained from O. cumana using next‐generation sequencing, from which 298 SSR primer pairs were designed and 217 of them used for validation. Seventy nine SSR primers produced reproducible, high quality amplicons of the expected size that were polymorphic among 18 O. cumana populations from different geographical locations and hosts (sunflower, wild hosts from the Compositae family). The number of alleles per locus ranged from 2 to 10, with an average polymorphism information content value of 0.37. The O. cumana SSR markers were highly transferable to the closely related species Orobanche cernua. SSR markers showed high resolving power; UPGMA cluster analysis allowed proper classification of Orobanche spp. samples into species (O. cumana and O. cernua), geographical origin and host. The functional SSR markers reported in this study constitute a valuable tool for genetic analyses in O. cumana and related species and will contribute insights into the biology and genetics of this parasitic weed.