Cross-amplification and characterization of microsatellite loci for three species of <Emphasis Type="Italic">Theobroma</Emphasis> (Sterculiaceae) from the Brazilian Amazon

This study reports on the cross-species amplification of 23 microsatellite markers previously developed for Theobroma cacao L. (Sterculiaceae), source of chocolate in three economically important Amazonian species of Theobroma (T. grandiflorum, T. subincanum, T. sylvestre). Thirteen of the 23 microsatellite loci tested were polymorphic across the three species at 2–13 alleles per locus. The observed heterozygosity per locus varied from 0.18 to 0.84 and expected heterozygosity ranged from 0.28 to 0.87. The high level of transferability and genetic information content of these microsatellite loci indicate their usefulness for population genetic, mating system and breeding studies of these economically important Amazonian fruit trees.     

普通菜豆基因组SSR标记开发及在豇豆和小豆中的通用性分析

分子标记具种属间通用性可提高其利用效率,并降低标记开发成本。本研究基于Roche 454超高通量测序技术获得普通菜豆基因组测序结果,共开发了560个普通菜豆基因组SSR标记。利用2份普通菜豆品种对标记进行初步筛选,有421个标记能够有效扩增。用新开发的标记分析16份豇豆和16份小豆的通用性。结果显示,185个普通菜豆基因组SSR标记在豇豆中能有效扩增,通用性比率为43.9%;161个SSR标记在小豆中能有效扩增,通用性比率为38.2%;在豇豆和小豆中都能获得有效扩增条带的标记共138个;并且普通菜豆基因序列SSR标记在豇豆和小豆中的通用性比率高于基因间序列SSR标记。通用性标记的多态性分析表明,豇豆和小豆的多态性比率分别为34.0%和24.8%;且豇豆和小豆中基因间标记的多态性都比基因内标记的多态性高。上述通用性标记为豇豆属作物的多样性评价、连锁图谱的构建及基因定位等方面的研究提供了便利。     

鹅掌楸EST-SSR引物开发及通用性分析

通过对6520条鹅掌楸EST序列进行检索,在364条ESTs中发现394个SSRs,鹅掌楸EST-SSRs平均密度为每8.5kb含有1个SSR;在检索出的SSRs中,二核苷酸重复单元的SSRs类型最多,占总数的61.9%。利用SSR-ESTs序列共设计176对EST-SSR引物,其中132对在鹅掌楸上有扩增产物,66对扩增出多态,多态性引物占所设计引物的36.9%。这批EST-SSR引物在物种之间具有较高的通用性。研究表明在鹅掌楸中表现多态的66对EST-SSR引物,85%在中国马褂木中有扩增,54%在白玉兰中有扩增。     

度日模型与简化型能量平衡模型的时空推广性分析——以乌鲁木齐河源1号冰川为例

以乌鲁木齐河源1号冰川为试验对象,对目前在区域尺度广为应用的2种物质平衡模型度日模型(DDM)与简化型能量平衡模型(s EBM)在时间与空间上的推广性进行分析。结果表明,在试验设定的条件下,s EBM唯有时间推广性较好,而DDM的时空推广性皆较差。通过理论分析得到相同的结论,且发现冰川表面气温直减率与降水垂直梯度取值的准确性,对提升2种模型的空间推广性具有重要意义。     

Interplay between physical and predator landscapes affects transferability of shorebird distribution models

Coastal landscapes with extensive intertidal mudflats provide non-breeding habitat for Arctic shorebirds. Few attempts have been made to develop and test landscape-level models predicting the intertidal distribution of these birds. We modelled the distribution of a Holarctic species, Dunlin (Calidris alpina), at a hemispherically important non-breeding site, the Fraser River Delta, British Columbia, Canada, in seasons with different predator landscapes. We trained the models during a season when nocturnal predators were common and tested temporal transferability of the models on independent datasets when nocturnal predators were absent. Snowy Owls (Nyctea scandiaca) influenced Dunlin distribution and thus model transferability. After accounting for their presence, models displayed good to excellent discrimination, i.e. prediction of the instantaneous and cumulative (over low tide period) probability of mudflat use by Dunlin, in fore- and backcasting applications. Model calibration was good or else, where over-prediction was observed, the reason for the bias was identified. The distribution models may predict mudflat use by Dunlin and possibly related species given relevant data describing the intertidal landscape. The models are amenable to GIS application, describe the amount of use per hectare of the intertidal zone and can be used to determine and visualise relative and absolute suitability of intertidal areas. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Development of novel chloroplast microsatellite markers for Dendrobium officinale, and cross-amplification in other Dendrobium species (Orchidaceae)

Nine pairs of polymorphic chloroplast microsatellite primers were developed for Dendrobium officinale Kimura et Migo, an endangered herb. Levels of polymorphism were tested across a total of 55 individuals from four natural populations (12–15 individuals per population). Allele numbers varied from two to four per locus, while the number of haplotypes ranged from four to six per population. Transferability of the nine polymorphic chloroplast microsatellite primers was checked on an additional set of 51 Dendrobium individuals (belonging to 17 different species). Three markers could be transferable to all the species tested, while the remaining six markers successfully cross-amplified in most species tested. Moreover, polymorphism of the nine chloroplast microsatellite primers was tested across Dendrobium moniliforme (L.) Sw. and Dendrobium loddigesii Rolfe. All of them were polymorphic in D. moniliforme, while seven of which were polymorphic in D. loddigesii. These polymorphic chloroplast microsatellite primers developed for D. officinale will be a useful tool for the study of genetic diversity, population genetic structure, evolution of D. officinale and establishment of effective conservation strategies.     

Novel genomic and EST-derived SSR markers in Japanese chestnuts

A total of 366 novel simple sequence repeat (SSR) markers were developed in Japanese chestnut (Castanea crenata), comprising 220 genomic SSRs derived from enriched genomic libraries and 146 expressed sequence tag (EST)–SSRs obtained from large-scale EST sequencing analysis. Thirty accessions, comprising Japanese, Chinese (C. mollissima), European (Castanea sativa), and American chestnuts (Castanea dentata), were used for evaluation of SSR polymorphism and transferability across species. The EST–SSRs showed less polymorphism than the genomic SSRs and were more transferable. The mean observed heterozygosity (H_O) and the mean expected heterozygosity (H_E) of genomic SSRs in the Japanese chestnuts were 0.63 and 0.68, respectively; those of EST-SSRs were each 0.47. Although about 80% of the genomic SSRs were amplified in all 4 species, more than 95% of the EST–SSRs were transferable across all 4 species. The many novel SSRs developed in this study will be applicable for the construction of genetic linkage maps, QTL analysis of phenotypic traits, high-throughput genotyping of marker-assisted selection, and association genetics.     

杨树基因组SSR标记在康定柳中的通用性分析

SSR分子标记因具有共显性遗传、高度多态性、重复性和稳定性好、易于实现自动化等优点,在遗传育种等方面有着广泛的应用前景。本研究在杨树基因组中随机选取622对SSR引物对来自5个不同群体的康定柳雌雄各20个个体,共计200个进行了通用性分析。结果表明：杨树基因组SSR标记在康定柳中的通用性达到7.88%。     

马铃薯SSR标记在茄子上的通用性分析

目前有多种发展微卫星标记（SSR）的方法,对基因组未测序的物种利用近缘物种引物进行跨物种扩增是一种简便方法。本研究利用马铃薯的640对SSR引物对茄子进行扩增,并利用获得的多态引物进行了12份茄子材料的聚类分析。结果表明：192对引物能够在茄子基因组DNA上扩增出清晰、稳定条带,引物通用率为30．05％;10对引物在随机选择的4份材料上有多态性,聚类分析结果表明类群与材料的来源、果实形态、颜色及青枯病抗性间没有相关趋势。     

基于RNA-seq牡丹SSR标记开发及通用性分析

从牡丹花色候选基因中开发一套SSR标记,为牡丹花色分子遗传学研究和分子标记辅助育种提供帮助.本研究基于高通量转录组测序技术(RNA-seq)获得了278条涉及调控牡丹花色形成的Unigenes序列,利用SSRIT在128条Unigenes中检测到215个SSR位点,出现频率为46.04％.其中优势重复基序为二核苷酸、三...