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1.
《Electronic Journal of Biotechnology》2014,17(2):95-101
BackgroundWeedy rice (Oryza sativa L.) is a noxious form of cultivated rice (O. sativa L.) associated with intensive rice production and dry seeding. A cost-efficient strategy to control this weed is the Clearfield rice production system, which combines imidazolinone herbicides with mutant imidazolinone-resistant rice varieties. However, imidazolinone resistance mutations can be introgressed in weedy rice populations by natural outcrossing, reducing the life span of the Clearfield technology. Timely and accurate detection of imidazolinone resistance mutations in weedy rice may contribute to avoiding the multiplication and dispersion of resistant weeds and to protect the Clearfield system. Thus, highly sensitive and specific methods with high throughput and low cost are needed. KBioscience’s Allele Specific PCR (KASP) is a codominant, competitive allele-specific PCR-based genotyping method. KASP enables both alleles to be detected in a single reaction in a closed-tube format. The aim of this work is to assess the suitability and validity of the KASP method for detection in weedy rice of the three imidazolinone resistance mutations reported to date in rice.ResultsValidation was carried out by determining the analytical performance of the new method and comparing it with conventional allele-specific PCR, when genotyping sets of cultivated and weedy rice samples. The conventional technique had a specificity of 0.97 and a sensibility of 0.95, whereas for the KASP method, both parameters were 1.00.ConclusionsThe new method has equal accuracy while being more informative and saving time and resources compared with conventional methods, which make it suitable for monitoring imidazolinone-resistant weedy rice in Clearfield rice fields. 相似文献
2.
BackgroundAssessments of genetic diversity are essential for germplasm characterization and exploitation. Molecular markers are valuable tools for exploring genetic variation and identifying germplasm. They play key roles in a Xanthoceras sorbifolia breeding program.ResultsWe analyzed the genetic diversity of populations of this species using 23 simple sequence repeat (SSR) loci and data on kernel oil content. The 11 populations included in the study were distributed across a large geographic range in China. The kernel oil content differed significantly among populations. The SSR marker analysis detected high genetic diversity among the populations. All SSRs were polymorphic, and we identified 80 alleles across the populations. The number of alleles at each locus ranged from two to six, averaging 3.48 per primer pair. The polymorphism information content values ranged from 0.35 to 0.70, averaging 0.51. Expected heterozygosity, observed heterozygosity, and Shannon's information index calculations detected large genetic variations among populations of different provenance. The high average number of alleles per locus and the allelic diversity observed in the set of genotypes analyzed indicated that the genetic base of this species was relatively wide. The statistically significant positive correlation between genetic and geographic distances suggested adaptations to local conditions.ConclusionsMicrosatellite markers can be used to efficiently distinguish X. sorbifolia populations and assess their genetic diversity. The information we have provided will contribute to the conservation and management of this important plant genetic resource. 相似文献
3.
BackgroundCultivated peanut (Arachis hypogaea. L) represents one of the most important oil crops in the world. Although much effort has been expended to characterize microsatellites or Simple Sequence Repeats (SSRs) in peanut, the quantity and quality of the markers in breeding applications remain limited. Here, genome-wide SSR characterization and marker development were performed using the recently assembled genome of the cultivar Tifrunner.ResultsIn total, 512,900 microsatellites were identified from 2556.9-Mb genomic sequences. Based on the flanking sequences of the identified microsatellites, 7757 primer pairs (markers) were designed, and further evaluated in the assembled genomic sequences of the tetraploid Arachis cultivars, Tifrunner and Shitouqi, and the diploid ancestral species, A. duranensis and A. ipaensis. In silico PCR analysis showed that the SSR markers had high amplification efficiency and polymorphism in four Arachis genotypes. Notably, nearly 60% of these markers were single-locus SSRs in tetraploid Arachis species, indicating they are more specific in distinguishing the alleles of the A and B sub-genomes of peanut. In addition, two markers closely related with purple testa color and 27 markers near to FAD2 genes were identified, which could be used for breeding varieties with purple testa and high-oleic acid content, respectively. Moreover, the potential application of these SSR markers in tracking introgressions from Arachis wild relatives was discussed.ConclusionsThis study reported the development of genomic SSRs from assembled genomic sequences of the tetraploid Arachis Tifrunner, which will be useful for diversity analysis, genetic mapping and functional genomics studies in peanut.How to cite: Ma J, Zhao Y, Chen H, et al. Genome-wide development of polymorphic microsatellite markers and their application in peanut breeding program. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.004. 相似文献
4.
BackgroundFragrance is one of the most important quality traits in rice, and the phenotype is attributed to the loss-of-function betaine aldehyde dehydrogenase (BADH2) gene. At least 12 allelic variations of BADH2 have been identified, and some of these have been applied to rice fragrance breeding using traditional molecular markers and Sanger sequencing techniques. However, these traditional methods have several limitations, such as being very expensive, imprecise, inefficient, and having security issues. Thus, a new molecular marker technology must be developed to improve rice fragrance breeding.ResultsIn this study, more than 95% of the cultivated fragrant rice varieties belonged to a 7-bp deletion in exon 2 (badh2-E2) or an 8-bp deletion and 3-bp variation in exon 7 (badh2-E7). Both allelic variations resulted in the loss of function of the badh2 gene. We developed two novel SNP molecular markers, SNP_badh2-E2 and SNP_badh2-E7, related to the alleles. Their genotype and phenotype were highly cosegregated in the natural variation of rice accessions, with 160 of the 164 fragrant rice varieties detected with the two markers. These markers cosegregated with the fragrance phenotype in the F2 population.ConclusionsTwo functional SNP molecular markers of badh2-E2 and badh2-E7 allelic variations were developed. These functional SNP molecular markers can be used for genotype and genetic improvement of rice fragrance through marker-assisted selection and will significantly improve the efficiency of fragrant rice breeding and promote commercial molecular breeding of rice in the future.How to cite: Li W, Zeng X, Li S, et al. Development and application of two novel functional molecular markers of BADH2 in rice. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.04.004. 相似文献
5.
本文对稻属Oryza L. 23种植物叶片表皮的结构特征进行了观察和研究,结果表明:叶表皮的某
些性状,如在叶片脉带之间长细胞中乳突的大小和分布以及叶表皮气孔器上小乳突的数目和着生位置
在稻属的各种之间有着一定的变异规律,这在稻属各种的分类和其系统关系的研究中有一定的价值。
综合这些性状的变异特征,按照叶片下表皮脉间长细胞中乳突的大小和分布特征以及气孔器中小乳突
的数目和着生位置可将稻属这23个物种分为3组。第一组包括长颖野稻、马来野稻、疣粒野稻和颗粒
野稻,这些种的叶表皮脉间长细胞中没有大乳突和中乳突,仅偶见极稀疏分布的小乳突,气孔器中均无
小乳突。第二组包括短药野稻、二倍体和四倍体药用野稻、小粒野稻、紧穗野稻、斑点野稻、阔叶野稻、高
株野稻、大颖野稻、根茎野稻和澳洲野稻,这些种的叶表皮脉间长细胞中通常没有大、中乳突,但密布小
乳突,且大多数种的气孔器保卫细胞的近两端各有2个小乳突。第三组包括栽培稻、一年生普通野稻、
多年生普通野稻、长雄蕊野稻、展颖野稻、南方野稻、矮舌野稻、非洲栽培稻和希来特野稻,这些种的叶
表皮脉间的长细胞中常有大乳突、中乳突和小乳突,而气孔器保卫细胞的近两端各有2个明显的小乳
突,并同时常在气孔器副卫细胞的近内缘还有2～4个小乳突。 相似文献
6.
BackgroundPomegranate (Punica granatum L.), one of the most important tropical fruits in Azad Jammu and Kashmir regions of Pakistan, is highly valued for its nutrition and medicinal purposes. Although pomegranate is native to this region, the genetic diversity among wild pomegranate accessions is currently unknown. Such information would be vital for germplasm conservation and breeding efforts. In the current study, genetic diversity among forty-eight wild pomegranate accessions collected from different agro-ecological zones of Azad Jammu and Kashmir was assessed using 41 simple sequence repeat (SSR) markers.ResultsThe markers revealed 303 alleles averaging 7.39 alleles per marker. Polymorphic information content ranged from 0.12 (PGCT093B) to 0.88 (Pom006), with a mean of 0.54. The average genetic distance (GD) across all genotypes was 0.52, and was lowest between Chattar Class and Thorar genotypes (GD = 0.27), but highest between Khun Bandway and Akhor Ban (GD = 0.74). A neighbor-joining dendrogram separated the genotypes into three major clusters, with further sub-clustering within each cluster.ConclusionsOverall, the results presented here show significant genetic diversity among wild pomegranate accessions in Azad Jammu and Kashmir region of Pakistan. These accessions present a valuable genetic resource to breeding and cultivar improvement programs within the region.How to cite: Aziz S, Firdous S, Rahman H, et al. Genetic diversity among wild pomegranate (Punica granatum) in Azad Jammu and Kashmir region of Pakistan. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.06.002. 相似文献
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《Electronic Journal of Biotechnology》2014,17(6):268-274
BackgroundGenetic diversity and genetic variation of 10 populations and subpopulations of Magnolia wufengensis, a new and endangered endemic species, were examined by inter simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) molecular markers. Compared with other endangered endemic Magnolia taxa, M. wufengensis holds a relatively high level of genetic variation.ResultTotal genetic diversity was found to be 87.7% for ISSR and 88.0% for SRAP markers. For polymorphic loci (P), the effective mean number of alleles (Ae) was 1.414 for ISSR markers and 1.458 for SRAP markers, while the mean expected heterozygosity (H) was 0.256 using ISSR and 0.291 for SRAP markers. Within-population variation was estimated for P as 74.9% using ISSR and 74.6% with SRAP markers; the number of alleles Ae was 1.379 with ISSR and 1.397 for SRAP and H 0.235 with ISSR and 0.247 for SRAP markers.ConclusionThe analysis of molecular variation of both ISSR and SRAP marker systems indicated that most genetic variation is within populations, with values of 90.64% and 82.92% respectively. Mantel tests indicated a moderate association between the two marker systems and a low correlation between genetic and geographic distances. High levels of genetic diversity and low levels of population divergence suggest that genetic drift is not currently of great concern for this species. Severe habitat loss and fragmentation, predominantly ascribed to anthropogenic pressures, caused in-situ developing restriction of this species. Action for conserving this rare species for its long-term survival should be taken immediately. 相似文献
9.
稻属分类的现状及存在问题 总被引：1，自引：0，他引：1
稻属(Oryza L．是禾本科中重要的植物类群，该属含20余种，广泛分布于全球热带和亚热带地区。未来水稻育种的重大突破还将有赖于对稻属基因库中丰富种质资源，特别是野生稻资源的利用和开发。由于稻属植物在农业生产中的重要作用，引起了众多的植物分类学家、遗传学家、育种学家和分子生物学家的广泛研究。稻属自Linnaeus于1753年建立以来的200多年中，无论在物种的数量和分类系统上都产生了很大的变化。多位学者对稻属的属以下等级和种间的分类都做了详细的工作，对稻属现代分类系统的建立起到了重要的作用。Roschevicz(1931)对稻属全面深入的研究为后来的稻属系统分类奠定了基础。Sharma &; Shastry (1965) 建立的稻属分类系统在很大程度上受了 Roschevicz(1931)工作的影响，对属以下种以上的分类等级也处理得较合理，但是他们对稻属的分类定义较为广泛，包括了好几个如今已不放在稻属的物种。Vaughan(1989)对全球的稻属标本进行了较为全面的查证和研究，他建立的稻属系统不仅在属的界定上更为合理，而且对稻属中各物种的形态变异、地理分布和种间的关系，都有更清楚的描述。遗憾的是，Vaughan (1989)采用的属下等级——“复合体”(complex)，不符合国际植物命名法规(ICBN)的规定。Lu(1999)在对前人大量工作的基础上，结合现代对稻属的研究成果并包括了近年来发表的一些新种，建立了稻属3组7系24种的分类系统。本文结合最新的研究成果对稻属作了进一步的修订，列出了以形态特征为基础的分种检索表，并对稻属分类中仍存在的一些问题进行了讨论。 相似文献
10.
《Electronic Journal of Biotechnology》2014,17(5):217-223
BackgroundIn the present study populations, representing different rounds of recombination were used for the analysis of phenotypic effects associated with the sdw1/denso locus. Other studies have mostly focused only on one type of population. Many different QTLs mapped at the same position as the sdw1/denso locus may indicate a pleiotropy of this gene or a tight linkage between genes conditioning quantitative traits. To date, results of studies have not unequivocally proven either of these two phenomena.ResultsBoth breeding and molecular mapping experiments were undertaken to examine 200 single seed descent (SSD) and 60 doubled haploid (DH) lines obtained from the Maresi (with a semi-dwarfing gene) and Pomo cross combination. They were evaluated for the type of juvenile growth habit and certain agronomic traits were measured after harvesting. The estimates of mean values, standard errors and significance of effects were analyzed. In terms of the analyzed characteristics, the greatest variability was obtained for genotypes with the prostrate growth habit. Microsatellite markers (SSR) were also used to identify co-segregation with the sdw1/denso locus and Bmag0013, Bmag0877, Bmag0306b markers were linked the closest. A partial linkage map of chromosome 3H with the sdw1/denso semi-dwarfing gene was constructed and QTLs were identified.ConclusionsOur experiments confirmed the impact of the semi-dwarfing gene on plant height, heading and flowering date both in SSD and DH populations, which may indicate pleiotropy. Moreover, a partial linkage between sdw1/denso locus and grain weight per spike and 1000-grain weight was found in the SSD population. 相似文献
11.
BackgroundWheat is one of the most important crops cultivated all over the world. New high-yielding cultivars that are more resistant to fungal diseases have been permanently developed. The present study aimed at the possibility of accelerating the process of breeding new cultivars, resistant to eyespot, by using doubled haploids (DH) system supported by marker-assisted selection.ResultsTwo highly resistant breeding lines (KBP 0916 and KBH 4942/05) carrying Pch1 gene were crossed with the elite wheat genotypes. Hybrid plants of early generations were analyzed using endopeptidase EpD1 and two SSR markers linked to the Pch1 locus. Selected homozygous and heterozygous genotypes for the Pch1-linked EpD1b allele were used to produce haploid plants. Molecular analyses were performed on haploids to identify plants possessing Pch1 gene. Chromosome doubling was performed only on haploid plants with Pch1 gene. Finally, 65 DH lines carrying eyespot resistance gene Pch1 and 30 lines without this gene were chosen for the eyespot resistance phenotyping in a field experiment.ConclusionsResults of the experiment confirmed higher resistance to eyespot of the genotypes with Pch1 in comparison to those without this gene. This indicates the efficiency of selection at the haploid level.How to cite: Wiśniewska H, Majka M, Kwiatek M, et al. Production of wheat doubled haploids resistant to eyespot supported by marker-assisted selection. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.003 相似文献
12.
BackgroundGenetic diversity studies are important for the selection of parents with a greater combination capacity that, when crossed, increase the chances of obtaining superior genotypes. Thus, 26 polymorphic simple sequence repeat (SSR) primers were used to assess the genetic diversity of 140 individual samples from 12 diploid sugar beet pollinators (pollen parents) and two cytoplasmic male sterile (cms) lines (seed parents). Eight pollinators originated from three research centers in the United States Department of Agriculture, while four pollinators and cms lines were from the Institute of Field and Vegetable Crops, Novi Sad, Serbia.ResultsIn total, 129 alleles were obtained, with a mean of 3.2 alleles per SSR marker. The observed heterozygosity ranged from 0.00 to 0.87 (mean = 0.30). Expected heterozygosity and Shannon's information index were the lowest for marker BQ590934 and the highest for markers SB15s and FDSB502s; the same markers were the most informative, with PIC values of 0.70 and 0.69, respectively. Three private alleles were found in pollinator EL0204; two in pollinator C51; and one in pollinators NS1, FC221, and C93035. Molecular variance showed that 77.34% of the total genetic variation was attributed to intrapopulation variability. Cluster and correspondence analysis grouped sugar beet pollinators according to the breeding centers, with few exceptions, which indicate that certain amount of germplasm was shared, although centers had their own breeding programs.ConclusionsThe results indicate that this approach can improve the selection of pollinators as suitable parental components and could further be applied in sugar beet breeding programs. 相似文献
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BackgroundPearl oyster Pinctada fucata martensii is cultured for producing round nucleated pearls. Pearl production involves a surgical operation where a mantle tissue graft from a donor oyster and a round nucleus are implanted in the gonad of a host oyster. Whether the mantle graft implanted in the gonad of a host oyster contributes to the formation of a pearl sac that secretes pearl nacre to form a pearl should be determined. In April 2012, two full-sib families were separately used as donor and host oysters for a nucleus insertion operation. The pearl sac was sampled from the host oysters at day 60 after nucleus operation. A large number of simple sequence repeat (SSR) markers were developed using Illumina HiSeq™ 2000 platform. The two full-sib families were also used to mine diagnostic SSR markers for genotyping donor oyster, host oyster, and pearl sac.ResultsA total of 3168 microsatellite loci were identified in 39,078 unigenes, and 1977 SSR primers were designed by Primer 3.0. Forty-seven SSR primers were validated, and the rate of successful amplification was 72.3%. Two diagnostic SSR primers could successfully genotype pearl sac, donor oyster, and host oyster. Donor and host oysters were both homogenous, and the alleles in pearl sac were identical to those in donor and host oysters.ConclusionsThe present results confirmed that the mantle graft implanted in the gonad of host oyster contributed to the formation of the pearl sac in pearl oyster P. fucata martensii. 相似文献
15.
BackgroundProsopis, or mesquite (Prosopis juliflora (Sw.) DC.), was introduced in Saudi Arabia several decades ago and is heavily used in street, roadside, and park plantations. It shows great adaptation to the prevailing climatic conditions such as high temperature, severe drought, and salinity and spreads naturally in many parts of the Kingdom. This research was conducted to isolate allergen proteins and biogenic amines from the pollen grains of P. juliflora genotypes in Saudi Arabia from two regions, namely Al-Qassim and Eastern regions.ResultsThe results showed that 18 different allergen proteins were detected in P. juliflora genotypes, with molecular weight ranging from 14 to 97 kDa. Moreover, P. juliflora genotypes from the two studied regions contained eight biogenic amines, namely histamine, tyramine, tryptamine, β-phenylethylamine, butricine, codapherine, spermidine, and spermine. All genotypes from the Al-Qassim region were found to contain all eight amines, while in the Eastern region, histamine was absent in three genotypes, spermine was absent in six genotypes, and spermidine was absent in three genotypes. Genotypes B23, E20, and E21 had the lowest biogenic amine quantity.ConclusionsAll identified proteins from mesquite trees from both regions (Eastern and Al-Qassim) cause allergies in patients who are sensitive to pollen grains. Bioamines, except histamine and tyramine, were recorded at varying concentrations in different genotypes. 相似文献
16.
BackgroundProfilin proteins (PRFs) are small (12–15 kD) actin-binding protein, which play a significant role in cytoskeleton dynamics and plant development via regulating actin polymerization. Profilins have been well documented in Arabidopsis, Zea mays L. as well as Phaseolus vulgaris, however no such fully characterization of rice (Oryza sativa L.) profilin gene family has been reported thus far.ResultIn the present study, a comprehensive genome-wide analysis of rice PRF genes was completed and three members were identified. OsPRF1 and OsPRF2 shared 98.5% similarity (6 nucleotide divergence), but the deduced amino acid sequences of OsPRF1 and OsPRF2 are fully identical. In contrast, the OsPRF3 presents relatively lower similarity with OsPRF1 and OsPRF2. Phylogenetic analysis also support that OsPRF1 has a closer relationship with OsPRF2. Expression pattern analysis revealed the differential expression of OsPRFs in tissues of mature plant, which suggested the potential spatial functional specificity for rice profilin genes. Subcellular localization analysis revealed the OsPRFs were localized in cytoplasm and nucleus and all of them could bind actin monomers. Furthermore, abiotic stresses and hormones treatments assay indicated that the three OsPRF genes could be differentially regulated, suggesting that OsPRF genes might participate in different stress processes in rice.ConclusionsTaken together, our study provides a comprehensive analysis of the OsPRF gene family and will provide a basis for further studies on their roles in rice development and in response to abiotic stresses.How to cite: Zhang Y, Dong G, Wu L, et al. Identification and characterization of profilin gene family in rice. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.08.004. 相似文献
17.
BackgroundSargassum liebmannii is widely distributed throughout rocky, coastal upwelling areas in the tropical Mexican Pacific. This brown algae is of great environmental and industrial importance. However, no information is available that documents the genetic or phenotypic variability of the species, which is needed to determine how it may react to environmental variation related to climate change. In this study, S. liebmannii specimens were collected from the coast of Jalisco, Mexico, and molecular and morphological characterization was conducted. Intraspecific variability was estimated according to the study areas.ResultsThe inter-simple sequence repeat (ISSR) markers indicated a polymorphism percentage of 95%. The Shannon index and Nei index showed relatively low values among the populations (0.3569 and 0.081, respectively). On the other hand, the genetic differentiation coefficient indicated inter- and intrapopulation values of 36.69% and 63.31%, respectively. The Jaccard similarity coefficient was used to determine the degree of similarity among individuals by geographical area. The morphological characteristics and environmental variables that were used to correlate phenotypes and genotypes indicated that S. liebmannii showed low genetic flow because of the presence of geographical barriers due to substrate that was not optimal for algal development.ConclusionsThe ISSR markers were useful for detecting genetic differences among S. liebmannii individuals. The results indicate that a coupled genotypic-phenotypic study is beneficial for documenting the variation present in the little-studied algal species. These studies may be used in future research to clarify taxonomic controversies while generating additional genomic information.How to cite: Jung-Kim HW, Hernández-Herrera RM, Enciso-Padilla I, et al. Genetic variability of Sargassum liebmannii on the coast of Jalisco in the central Mexican Pacific revealed by molecular markers and morphological traits. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.08.003 相似文献
18.
BackgroundProcambarus clarkii produces high-quality, delicious meat that is high in protein, low in fat, and rich in calcium and phosphorus. It has become an important aquatic resource in China. Our objectives are (i) to analyze the level of genetic diversity of P. clarkii populations; (ii) to explore the genetic differentiation (Gst); and (iii) to propose appropriate strategies for the conservation.ResultsIn this study, Shannon's index (I) and Nei's gene diversity index (H) for P. clarkii were high (I = 0.3462 and H = 0.2325 on average and I = 0.6264, H = 0.4377 at the species level) based on the SSR markers. The expected heterozygosity value of 17 microsatellite loci in 25 crayfish populations was 0.9317, the observed heterozygosity value was 0.9121, and the observed number of alleles per locus was 2.000; and the effective number of alleles per locus was 1.8075. Among the P. clarkii populations, the inbreeding coefficient within populations (Fis) was 0.2315, overall inbreeding coefficient (Fit) was 0.4438, genetic differentiation coefficient among populations (Fst) was 0.3145 and gene differentiation (Gst) was 0.4785 based on SSR analyses. The cluster analysis results obtained by unweighted pair-group method with arithmetic mean (UPGMA) analysis, principal coordinate analysis (PCoA) and STRUCTURE analysis were similar. A mantel test showed that the isolation-by-distance pattern was not significant.ConclusionsThe high Gst among P. clarkii populations is attributed to genetic drift and geographic isolation. The results indicated that more P. clarkii populations should be collected when formulating conservation and aquaculture strategies.How to citeLiu F, Qu Y-K, Geng C, et al. Analysis of the population structure and genetic diversity of the red swamp crayfish (Procambarus clarkii) in China using SSR markers. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.06.007. 相似文献
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《Electronic Journal of Biotechnology》2014,17(1):6-13
BackgroundThe quality of wheat grain depends on several characteristics, among which the composition of high molecular weight glutenin subunits, encoded by Glu-1 loci, are the most important. Application of biotechnological tools to accelerate the attainment of homozygous lines may influence the proportion of segregated genotypes. The objective was to determine, whether the selection pressure generated by the methods based on in vitro cultures, may cause a loss of genotypes with desirable Glu-1 alleles.ResultsHomozygous lines were derived from six winter wheat crosses by pollination with maize (DH-MP), anther culture (DH-AC) and single seed descent (SSD) technique. Androgenetically-derived plants that originated from the same callus were examined before chromosome doubling using allele-specific and microsatellite markers. It was found that segregation distortion in SSD and DH-MP populations occurred only in one case, whereas in anther-derived lines they were observed in five out of six analyzed combinations.ConclusionsSegregation distortion in DH-AC populations was caused by the development of more than one plant of the same genotype from one callus. This distortion was minimized if only one plant per callus was included in the population. Selection of haploid wheat plants before chromosome doubling based on allele-specific markers allows us to choose genotypes that possess desirable Glu-1 alleles and to reduce the number of plants in the next steps of DH production. The SSD technique appeared to be the most advantageous in terms of Mendelian segregation, thus the occurrence of residual heterozygosity can be minimized by continuous selfing beyond the F6 generation. 相似文献
20.
《Electronic Journal of Biotechnology》2014,17(1):50-54
BackgroundRhizoctonia solani (teleomorph: Thanatephorus cucumeris) is one of the most important pathogens of rice (Oryza sativa L.) that causes severe yield losses in all rice-growing regions. Sclerotia, formed from the aggregation of hyphae, are important structures in the life cycles of R. solani and contain a large quantity of polysaccharides, lipids, proteins and pigments. In order to extract high-quality total RNA from the sclerotia of R. solani, five methods, including E.Z.N.A.™ Fungal RNA Kit, sodium dodecyl sulfate (SDS)–sodium borate, SDS–polyvinylpyrrolidone (PVP), guanidinium thiocyanate (GTC) and modified Trizol, were compared in this study.ResultsThe electrophoresis results showed that it failed to extract total RNA from the sclerotia using modified Trizol method, whereas it could extract total RNA from the sclerotia using other four methods. Further experiments confirmed that the total RNA extracted using SDS–sodium borate, SDS–PVP and E.Z.N.A.™ Fungal RNA Kit methods could be used for RT-PCR of the specific amplification of GAPDH gene fragments, and that extracted using GTC method did not fulfill the requirement for above-mentioned RT-PCR experiment.ConclusionIt is concluded that SDS–sodium borate and SDS–PVP methods were the better ones for the extraction of high-quality total RNA that could be used for future gene cloning and expression studies, whereas E.Z.N.A.™ Fungal RNA Kit was not taken into consideration when deal with a large quantity of samples because it is expensive and relatively low yield. 相似文献