共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Studies of mycoheterotrophs, defined as plants that obtain carbon resources from associated mycorrhizal fungi, have fundamentally contributed to our understanding of the importance and complexity of symbiotic ecological interactions. However, to date, the reproductive ecology of these organisms remains empirically understudied, with existing literature presenting hypotheses about traits including a generalist pollination syndrome and autogamous self-pollination. To address this gap in our knowledge of the reproductive ecology of mycoheterotrophic plants, we comparatively analyzed three species of two monotropoid genera, Monotropa and Monotropsis. During three consecutive years of field observations and manipulations of four populations of Monotropa uniflora, seven of M. hypopitys (both red and yellow color forms), and two of Monotropsis odorata, we investigated flowering phenology, pollination ecology, breeding system, floral herbivory, and reproductive effort and output. Contrary to previous predictions, our results revealed that taxa are largely outcross-pollinated and specialized toward Bombus pollinators. Additionally, species differ in breeding system, timing and duration of reproductive development, fluctuations in reproductive effort and output, and fitness impacts of herbivory. This study is the first thorough investigation of the reproductive ecology of mycoheterotrophic species and provides insight into possible limitations in reproductive traits imposed by a mycoheterotrophic life history. 相似文献
3.
4.
The northern part of Serbia, known as Pannonian Serbia, is a lowland region. The autochthonous (indigenous) flora is classified
as either steppe, forest-steppe, sand dune or salt flat. Most of the area has been developed agriculturally, thereby reducing
the amount of land containing preserved habitats. The flora of this region was collected over a period of several years, supplying
new data on the distribution of numerous plant species. The first data on the distribution of flora in Pannonian Serbia for
Humulus scandens and Ophris scolopax subsp. Cornuta is presented in this study. The local regions cited were the first time precisely recorded regions were made after a period
of over 100 years, for Cardamine impatiens, Monotropa hypopitys subsp. hypopitys, Ononis pusilla, Globularia punctata, Gymnadenia odoratissima and Carex brevicollis. The groups, Peucedanum carvifola and Galium tenuissimum, quite rare in the northern part of Serbia, were found at new localities. In order to present the data, the authors used
the method of indirect mapping on UTM grid, with 10 × 10 km as the basic unit. This method is compatible with the edition
Atlas Florae Europaeae. 相似文献
5.
Aims: The aim of this study was to develop a sensitive real-time polymerase chain reaction (PCR) assay for the rapid detection of Cladosporium fulvum in tomato leaves. Methods and Results: Three PCR primer pairs were designed based on the nucleotide sequences of: (i) the internal transcribed spacer regions of ribosomal RNA; (ii) a microsatellite region amplified by the microsatellite primer M13; and (iii) the β-tubulin gene of C. fulvum. Each primer pair amplified the expected target DNA fragment from geographically diverse isolates of C. fulvum. No PCR products were amplified with these primer pairs from DNA of other fungal species. Among the three pairs of primers, the primer pair CfF1/CfR1 developed based on the microsatellite region was the most sensitive. Using this sensitive primer pair, a real-time PCR assay was developed to detect early infection of C. fulvum in tomato leaves. Significance and Impact of the Study: DNA regions amplified by the microsatellite primer M13 have a high potential for developing highly sensitive species-specific PCR primers for the detection of phytopathogenic fungi. The real-time PCR assay developed in this study is useful in monitoring early infection of C. fulvum, and can help growers make timely decisions on fungicide application. 相似文献
6.
By using enriched genomic libraries, microsatellite-containing sequences were isolated from lettuce (Lactuca sativa) with high efficiency. With this approach, a sizeable fraction (up to 55%) of the clones contained a microsatellite. In about half of these clones, primers could be designed for PCR amplification of the microsatellite. This yielded 28 primer sets amplifying unambiguously scorable products, of which 26 showed polymorphisms in a test set of six lettuce varieties. Practically all microsatellite-amplifying primer sets yielded products in lettuce's nearest relative, L. serriola, but only half of the primer sets yielded products in the more distant species L. saligna and L. virosa. An average polymorphism information content (PIC) value of 0.55 and an average number of 3.5 alleles per locus were in the normal range for a self-fertilizing species like lettuce. In addition, the incidental cloning of a microsatellite-containing repeat family, apparently specific for Lactuca, is reported and the implications for the efficient retrieval of single-locus microsatellite sequences are discussed. The microsatellite loci isolated will be useful for distinguishing lettuce cultivars and for screening diversity of genetic resources. 相似文献
7.
C. Latouche‐Hall A. Ramboer E. Bandou H. Caron S. Decroocq 《Molecular ecology resources》2002,2(3):228-230
Dicorynia guianensis is a canopy tree endemic to French Guyana and the first to be exploited as timber wood. To investigate levels of diversity and dynamics of gene flow in a 40‐ha study plot, highly polymorphic microsatellite markers were developed. An enriched microsatellite library was constructed and seven microsatellite primer pairs were developed. Total genomic DNA was extracted and amplified from cambium tissue from 172 adult individuals. The level of genetic diversity was found to be low. A large heterozygote deficiency was found at one locus. This was resolved by redesigning the primer set. 相似文献
8.
A novel method for genotyping microsatellite alleles using primer extensions and mass spectrometry analysis has been developed.
Following PCR amplification of the target region, a genotyping primer, with its 3′ end directly flanking the microsatellite
repeats, was extended by a mixture of dNTPs complementary to the nucleotides composing the microsatellite. The length and
molecular weight of extended primers vary with the number of repeats present in the allele(s) under examination. The weights
of extension products were determined using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF
MS) and used to identify genotypes on the basis of differential primer extension. This is a platform that is not gel based
and is amenable to multiplexing and automation. The technique enables identification of heterozygous progeny in which alleles
differ by a single trinucleotide repeat. The method is illustrated by genotyping a polymorphic microsatellite identified in
an intron of the barleyMlo gene. 相似文献
9.
The European mink Mustela lutreola is regarded as one of the most endangered mammals in the world. We chose to characterize microsatellite loci in order to investigate the pattern of decline of this species. We used primer pairs developed for a related species Mustela vison to genotype individual of Mustela lutreola. Out of 19 primer pairs used 8 were useful for our purpose. The conservation of primer sequence point out the problem of neutrality of some microsatellite loci as this conservation could be related to strong selection pressure on those loci. Finally we present the first data allowing an estimation of heterozygosity of French population of European mink. 相似文献
10.
Marion S. Röder Jens Plaschke Susanne U. König Andreas Börner Mark E. Sorrells Steven D. Tanksley Martin W. Ganal 《Molecular & general genetics : MGG》1995,246(3):327-333
The potential of microsatellite sequences as genetic markers in hexaploid wheat (Triticum aestivum) was investigated with respect to their abundance, variability, chromosomal location and usefulness in related species. By screening a lambda phage library, the total number of (GA)n blocks was estimated to be 3.6 x 104 and the number of (GT)n blocks to be 2.3 x 104 per haploid wheat genome. This results in an average distance of approximately 270 kb between these two microsatellite types combined. Based on sequence analysis data from 70 isolated microsatellites, it was found that wheat microsatellites are relatively long containing up to 40 dinucleotide repeats. Of the tested primer pairs, 36% resulted in fragments with a size corresponding to the expected length of the sequenced microsatellite clone. The variability of 15 microsatellite markers was investigated on 18 wheat accessions. Significantly, more variation was detected with the microsatellite markers than with RFLP markers with, on average, 4.6 different alleles per microsatellite. The 15 PCR-amplified microsatellites were further localized on chromosome arms using cytogenetic stocks of Chinese Spring. Finally, the primers for the 15 wheat microsatellites were used for PCR amplification with rye (Secale cereale) and barley accessions (Hordeum vulgare, H. spontaneum). Amplified fragments were observed for ten primer pairs with barley DNA and for nine primer pairs with rye DNA as template. A microsatellite was found by dot blot analysis in the PCR products of barley and rye DNA for only one primer pair. 相似文献
11.
We present a new set of 15 polymorphic microsatellite primer sequences developed from Ficus carica L. The variability of specific microsatellite regions was assessed in wild population of figs from the northern Adriatic coast and all 15 primer pairs showed single‐locus amplification with a total of 65 alleles and an observed heterozygosity ranging from 0.285 to 0.863. The 15 new microsatellite loci represent a significant tool for population genetic structure studies and will be further used to investigate the origin and maintenance of genetic variation within and between populations of figs along the Adriatic coastal region. 相似文献
12.
New softwares for automated microsatellite marker development 总被引:9,自引:0,他引:9
Martins W de Sousa D Proite K Guimarães P Moretzsohn M Bertioli D 《Nucleic acids research》2006,34(4):e31
Microsatellites are repeated small sequence motifs that are highly polymorphic and abundant in the genomes of eukaryotes. Often they are the molecular markers of choice. To aid the development of microsatellite markers we have developed a module that integrates a program for the detection of microsatellites (TROLL), with the sequence assembly and analysis software, the Staden Package. The module has easily adjustable parameters for microsatellite lengths and base pair quality control. Starting with large datasets of unassembled sequence data in the form of chromatograms and/or text data, it enables the creation of a compact database consisting of the processed and assembled microsatellite containing sequences. For the final phase of primer design, we developed a program that accepts the multi-sequence ‘experiment file’ format as input and produces a list of primer pairs for amplification of microsatellite markers. The program can take into account the quality values of consensus bases, improving success rate of primer pairs in PCR. The software is freely available and simple to install in both Windows and Unix-based operating systems. Here we demonstrate the software by developing primer pairs for 427 new candidate markers for peanut. 相似文献
13.
A sequencing strategy is described for the rapid recovery of DNA sequences flanking repeat sequences of microsatellites in plant nuclear genomes. Primers that represent a perfect microsatellite repeat and end in a 3′ degenerate base have been used to sequence directly from microsatellite repeats in one direction. The procedure allows the design of one flanking primer that is then used to sequence back through the repeat to define the microsatellite site precisely and also provides for the design of the second flanking primer. The strategy is versatile with various repeat sizes and different categories of microsatellites; perfect, imperfect, and compound were found to be suitable templates for analysis. 相似文献
14.
J. P. Varghese B. Rudolph M. I. Uzunova W. Ecke 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):115-119
Microsatellite markers have assumed great significance in biological research. The isolation and characterisation of microsatellites
involves DNA library construction and screening, DNA sequencing, primer design and PCR optimisation. When a microsatellite
is situated close to the beginning or end of a cloned fragment, specific primers cannot be designed for one of the flanking
sequences, thus hindering the utilisation of such microsatellites as markers. The present approach was to use one 5′-anchored
primer complementary to the microsatellite sequence in combination with one specific Cy5- labelled primer with a view to retrieving
useful microsatellites, which would otherwise be lost. Six pairs of a 5′ anchored primer and a specific primer were used across
a set of 31 Brassica napus winter cultivars and one accession each of five additional Brassica species. Using laser fluorometry a single labelled product was observed after amplification with each of four primer pairs,
and one primer pair gave two labelled products. Three products corresponded in size with the products expected if 5′ anchoring
was effective, indicating the amplification of locus-specific full-length products including all of the microsatellite repeats.
All six primer pairs showed polymorphisms across the Brassica species examined, but only one primer pair showed polymorphisms within B. napus, making it useful for genetic analysis in rapeseed cultivars. The other primer pairs could be useful in studying gene introgression
into B. napus or for investigating interspecific crosses involving different Brassica species.
Received: 5 August 1999 / Accepted: 1 November 1999 相似文献
15.
Microsatellite markers were developed for studies of the genetic diversity and population substructure of Lindera benzoin, Lauraceae (spicebush). Nuclear microsatellite sequences were obtained from DNA libraries that were enriched for (CA), (GA), (AAG) and (ATG) repeat motifs. From 69 microsatellite sequences, 20 primer sets were developed. Of these, 11 primer pairs resulted in amplified polymorphic loci. In 29 samples of eastern Pennsylvania spicebush plants, the number of microsatellite alleles ranged from two to 16 per locus with observed heterozygosity values ranging from 0.10 to 0.82. 相似文献
16.
Mutations in the sequence flanking the microsatellite at the KAP8 locus prevent the amplification of some alleles 总被引:3,自引:0,他引:3
The microsatellite described for the glycine- and tyrosine-rich keratin locus ( KAP8 ) in sheep was used to type nine large three-generation families comprising the AgResearch International Mapping Flock. The apparent non-Mendelian inheritance in these families suggested that some of the microsatellite alleles were not being amplified. Sequence analysis showed that a deletion within one of the published primer sites was the likely cause of the 'null' alleles. By redesigning the primer all alleles could be amplified. 相似文献
17.
S. Yu. Kordicheva G. A. Rubtsova M. A. Shitova G. O. Shaikhaev K. I. Afanasiev L. A. Zhivotovsky 《Russian Journal of Genetics》2010,46(8):1019-1022
Population studies with the use of microsatellite markers face a problem of null alleles, i.e., the absence of a PCR product,
caused by the mutations in the microsatellite flanking regions, which serve as the sites of primer hybridization. In this
case, the microsatellite primer associated with such mutation is not amplified, leading to false homozygosity in heterozygous
individuals. This, in turn, results in biased population genetic estimates, including the excess of homozygotes at microsatellite
loci. Analysis of the population structure of a Pacific salmon species, chum salmon (Oncorhynchus keta Walbaum), revealed the presence of null alleles at the Oke3 microsatellite locus in the population samples, in which an excess of homozygotes was observed. The analysis was performed
using different combinations of modified primers chosen to match the Oke3 locus. The use of these primers enabled identification of true heterozygotes among those individuals, which were previously
diagnosed as homozygotes with the use of standard primers. Removal of null alleles eliminated the excess homozygotes in the
chum salmon samples described. In addition to the exclusion of false homozygosity, the use of modified primers makes it possible
to introduce polymorphic primer variants associated with certain microsatellite alleles into population studies. 相似文献
18.
In the present study we report on the exploitation of expressed sequence tags (ESTs); (1) to investigate whether microsatellite
densities are significantly differed among Pleurotus ostreatus, Lentinula edodes and Agaricus bisporus ESTs, (2) between development stages of mycelia and fruiting bodies and (3) to identify microsatellite primer pairs that
could be used in mushroom genetic studies. Analyses of ESTs indicated that three mushroom species and tissues showed statistically
significant microsatellite densities. A total of 23 EST-microsatellite primer pairs were developed and tested on two species
of mushrooms. The use of these microsatellite primer pairs could be used in genetic studies of mushroom species. 相似文献
19.
A Simple Method for Developing Microsatellite Markers using Amplified Fragments of Inter-simple Sequence Repeat (ISSR) 总被引:21,自引:0,他引:21
10 A primer IP1 designed from the sequenced region at one end of the microsatellite and for nested PCR another primer IP2 based
on the sequence between IP1 and the microsatellite were prepared. These two primers were used to determine the other sequence
flanking the microsatellite by a “walking” method. With this approach, we developed several microsatellite markers from Salix reinii, Pinus densiflora and Robinia pseudoacacia, respectively. The absence of enrichment processes and screening procedures makes it easier to develop microsatellite markers,
and this approach provides an alternative for the development of microsatellite markers in any organism.
Received 23 April 2001/ Accepted in revised form 11 June 2001 相似文献
20.
E. FUKATSU K. ISODA T. HIRAO M. TAKAHASHI A. WATANABE 《Molecular ecology resources》2005,5(2):378-380
We developed 14 microsatellite loci from an enriched genomic DNA library of a broad‐leaved deciduous tree, Zelkova serrata. Of 198 clones from the library, 112 contained microsatellite repeat regions. The M13‐tailed primer method was used for economy. Sequence‐specific primer pairs were designed for 58 of 76 candidate clones. Fourteen of these primer pairs successfully amplified polymorphic single loci among 34 individuals collected from the Kanto breeding region in Japan. The expected heterozygosity for the 14 microsatellite markers ranged from 0.378 to 0.876, suggesting that these will prove valuable for breeding and ecological studies on Z. serrata. 相似文献