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Selection of powdery mildew resistant and susceptible grapevine genotypes with molecular markers
100-104Views:167Incorporation of competitive quality and resistance against the most important fungal diseases (powdery and downy mildew) in a cultivar is one of the most important aims of grapevine breeding. In the 20th century, the most advanced results in grapevine resistance breeding were achieved by French researchers. They used resistant cultivars in more than 30% of their growing areas. In these varieties, North American wild Vitis
species were the resistance gene sources. The discovery of immunity-like resistance of Muscadinia rotundifolia opened new perspectives in resistance breeding. M. rotundifolia harbours a dominant powdery mildew gene, providing resistance in highquality cultivars after back-crosses with V. vinifera varieties. M. rotundifolia has been involved in the Hungarian grape breeding programs since 1996, thanks to a French-Hungarian variety exchange. In addition to traditional selection methods, application of MAS (Marker Assisted Selection) based on various types of
molecular markers, can provide additional tools for these efforts. Run1 locus, responsible for powdery mildew resistance, was identified in Muscadinia rotundifolia. Molecular markers closely linked to this locus are very significant in screening progenies deriving from M. rotundifolia and V. vinifera crosses, making possible the discrimination between resistant and susceptible genotypes at DNA level. In our analyses BC5 progeny of {(M. rotundifola×V. vinifera) BC4}×Cardinal (V. vinifera) tested for powdery symptoms were analysed with PCR-RFLP (GLP1- 12P1P3) and microsatellite markers (VMC4f3.1, VMC8g9). Our results proved the applicability of the linked markers and reliability of marker assisted selection. -
Phylogenetic analysis of Phoma species
100-107Views:133The cosmopolitan Phoma genus contains mainly phytopathogenic, opportunistic parasites, and saprophyte fungal species. Up to now, the characterization of Phoma species and other taxa of Phoma has been determined on the basis of morphology on standardized media, and gene sequence analysis was only used as a confirmative or distinctive complement.
In this study, we tried to find molecular markers which can be used as phylogenetics markers in the molecular based classification in the Phoma genus.
We employed a part of the translation elongation factor 1 subunit alpha (EF-1α=tef1) containing both introns and exons and ITS region containing the internal transcribed spacer regions 1 and 2 and the 5.8S rDNA, as potential genetic markers to infer phylogenetic relationships among different Phoma taxa. Twelve different Phoma species sequences were analysed together with the closely related Ascochyta ones. The constructed phylogenetic trees, based on tef1 and ITS sequences, do not support the traditional Phoma sections based on morphological characterization. However, we managed to distinguish between the Phoma strains and Ascochyta species by comparing their tef1 sequences through parsimony analysis. We proved that a tef1 can be a useful phylogenetic marker to resolve phylogenetic relationships at species level in Phoma genus.
Both parsimony sequence analyses confirmed that the Phyllosticta sojicola species is identical to the Phoma exigua var. exigua species as Kövics et al. (1999) claimed. However, the evolutionary distance by ITS sequences within Phoma species is too small to get well based consequences for the phylogenetic relationships of Phoma genus.
Further investigations would be necessary to clarify whether the tef1 and ITS sequences as phylogenetic molecular markers are well suited for the classification of Phoma species. -
Study of alternative oxidase as possible molecular marker for phylogenetic analysis of the Botrytis cinerea
127-132Views:143Botrytis cinerea (teleomorph Botryotinia fuckeliana (de Bary) Whetzel) is able to attack several economically important plants causing gray rot. Botrytis cinerea species complex includes two cryptic species (B. cinerea and B. pseudocinerea) that tolerate fungicides differently. On the basis of classical taxonomic markers, the two related species are very difficult to be distinguished; therefore, their separation is usually performed using molecular methods based on the time-consuming molecular analysis of several markers. Our goal was to find markers, which are suitable for the differentiation. Testing the nucleotide sequences of the alternative oxidase encoding gene, B. cinerea and B. pseudocinerea strains were clearly differentiated. Moreover, the analysis of the protein sequences of the enzyme with the maximum likelihood method reflected well the taxonomic relationships of the different fungi.
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Use of molecular marker methods in the classification of bamboo taxa: A review
51-59Views:254Bamboo plants are currently attractive to researchers because of their versatile uses. Understanding the bamboos’ genetic level is needed to develop new varieties. Taxonomic identification is the basis for plant development. Bamboos were identified as their taxonomical morphological characters which are dependent on environmental factors. Molecular Marker techniques can be used to perform accurate genotype identification, which can be used for genetic diversity analyses. The RFLP, RAPD, AFLP, SSR, ISSR, iPBS, SCARS, SCoT, SRAP marker systems have been shown to be able to efficiently determine the genetic diversity of bamboo species based on genotyping. This paper summarizes research that aims to analyze the genetic diversity of bamboo species on a molecular basis.
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Molecular studies on Cryphonectria parasitica isolates from Carpathian-basin
76-80Views:105Chryphonectria parasitica, the casual agent of chestnut blight, is one of the most important fungal pathogens of chestnut (Castanea spp.) in Europe and Hungary. In this study we analyzed the diversity of 14 Cryphonectria parasitica strains isolated from different location of Carpathian-Basin. For the analyses we used the partial sequences of the translation elongation coding gene, tef1. Our results showed that the tef1 gene, contrary to other fungal species, is not suitable for the molecular analyses of C. parasitica. In the future, for the molecular studies of C. parasitica, we need to use other molecular markers like microsatellites.
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Phylogenetic studies of soybean pathogen Phoma species by Bayesian analysis
53-61Views:193We carried out phylogenetic study analyzing sequences of genetic markers in the taxonomy of Phoma and Phoma-like fungi. Different species of Phoma and Phoma-like fungi occurring on soybean (Phoma pinodella, Phoma sojicola, Phyllosticta sojicola, Phoma exigua var. exigua) are difficult to identy because of their high morphological and symptomatic similarities.
Twenty-two isolates of nine different Phoma species were obtained from reference culture collections. Seven of them were isolated from soybean, the others were collected from different hosts.
The Phoma isolates were firstly characterised by morphologically, and then we employed a part of the gene responsible for the synthesis of translation elongation factor 1 subunit alpha protein (tef1), ITS region, as well as β-tubulin partial sequences as potential genetic markers to infer
phylogenetic relationships among different Phoma species..Finally, their ITS and tef1 sequences were sequenced and analysed by Bayesian approaches.
According to phylogenetic trees inferred by Bayesian analysis of tef1, ITS and β-tubulin sequences, different Phoma species can be separated proving that these phylogenetic markers are well suited for phylogenetic studies of Phoma species. However, the phylogenetic tree does not support the traditional Phoma sections based on morphological characterization.
Bayesian analyses of the three sequences confirmed that the Phyllosticta sojicola species is clustered with the Phoma exigua var. exigua group and the Phoma sojicola is grouped with Phoma pinodella group. The molecular data provide evidence for reclassification of formerly mentioned soybean pathogens. -
Examination of microsatellite markers of Dorper sheep breed
57-61Views:229Number of not woolly and molty sheep exceeds 60 million throughout the world. Their numbers and their importance is growing, still they have appeared in the past two decades all over in North-America, Australia, New-Zealand and also in Europe. The South African Dorper has been a pioneer among them in Hungary. It was introduced in 2006 in the country. The Dorper sheep is the second largest breed in South Africa, which was developed from the crossing of Dorset Horn and the Blackhead Persian. The aim of the EU Member States in terms of this specific breed is increasing the small populations, improving the productive qualities, in addition to this avoiding inbreeding. However, finding appropriate breeding stock is difficult due to the small size of available populations and also to the suspected common of origin. With the help of various molecular genetic methods we could get a total view of the genetic background of these flocks. Nowadays the most commonly known and used genetic markers are microsatellites, because their applications give fast, accurate and easily reproducible results. There is no specific descriptive information on the genetic background of Dorper populations in the various EU countries , also regarding diversity between populations. Therefore in our work we want to optimize the conditions of applicability of 31 selected microsatellite reactions as a first step of mapping the entire genetic background of the different EU Dorper populations.
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Coincidences between molecular genetic and studbook data of gidrán mare families on the basis of mtDnA
69-73Views:232The traditional Hungarian horse breed, Gidran has been close to the edge of extinction several times. Despite the multiple bottleneck effect, the breed has retained a part of its genetic variability, and performed prominently in carriage driving and show-jumping competitions. Maintaining of the Gidran breed is important in the point of view of world heritage; because besides Hungary, smaller Gidran populations exist only in Bulgaria and Romania. Taking advantage of the special inheritance features of mtDNA, our study focused on two mtDNA regions of Gidran mares. Altogether, 251 hair samples from various Hungarian studs were examined. The analysis was successfully made in case of 251 samples of the cytochrome b and in case of 246 samples of D-loop regions. Because of the distinct mutation rates of the two mtDNA markers, the number of the haplotypes and the way of grouping samples into haplotypes was different. Our key finding was that most haplotypes may be compatible with mare families of the stud book; however incidental mistakes in stud book have occurred only in a few cases. Our results indicate the importance of the preservation and breeding those mare families, which are molecular genetically more diverse than the others, and are in the edge of extinction.
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Identification of Hucul mare families by mtDNA markers
75-79Views:232Hundred animal species have disappeared during the last century. By this time, approximately one-third of domestic animals have been in the endangered category. Hucul horses are also in this category; furthermore saving the genetic diversity beside the race preservation is an important challenge as well. The number of mares and stallions is only one of the expressive elements of genetic diversity; together with their quality determine the genetic variability of this breed. Beyond that, if an exact breed can originates from more founders, it can be more renewed genetically. Stud book documents these data by registering the mare families and stallions’ genealogical lineage. Molecular genetics, especially mitochondrial DNA analysis can make the precise identification of mare families possible. As a result of these molecular based methods, protection of genetic diversity, as well as breed preservation became more reliable. After the primer designing, the optimal primer pair was chosen which targets a 1092 bp length DNA sequence in the cytochrome b region. After the successful PCR optimalisation, we determined 170 Hucul mares’ sequences. According to our results, the samples compose ten haplotypes, which are much less, than the registered number of mare families in the stud book. Further investigations are needed to reach more representative results, and drawn the further consequences.
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Single nucleotide polymorphism analysis in meat-production related genes in broiler chickens
79-82Views:184In broiler chickens, the intensive selection for growth rate, feed efficiency, body composition (breast muscle weight) traits in the last decades was successful. To improve economically important characteristics, it is possible to use molecular markers associated with meat production traits. The aim of this study was to examine genotype polymorphisms in ROSS 308 broilers for thyroid hormone responsive Spot14α, insulinlike growth factor 1 (IGF1), IGF-binding protein 2 (IGFBP2), somatostatin (SST) and prolactin (PRL) genes. A further goal of this investigation was to study the relationship between the polymorphisms and phenotypic characteristics.
In the investigated broiler population, the frequency for CC homozygous genotype was 0.77 in Spot14α (AY568628), AA homozygous genotype was 0.80 in IGF1 (M74176), GG homozygous genotype was 0.85 in IGFBP2 (U15086), DD homozygous genotype was 0.60 in PRL (FJ663023 or FJ434669). Only the AA homozygous genotype was found in SST (X60191). Chickens with AC genotype in Spot14α, and with GG genotype in IGFBP2 had higher body weight (BW) and carcass weight (CW), compared to CC and GT genotypes. However, the differences were not significant (P>0.05). There was significant association (P<0.05) between PRL genotypes and body and carcass weight, where chicken with homozygous DD surpassed individuals with homozygous II genotypes.
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Comparison of RAPD and AFLP Analysis in Some Maize (Zea mays L.) Lines and Hybrids
3-7Views:114The use of molecular markers to enhance plant breeding efforts is being widely studied. DNA-based fingerprinting technologies (RAPD and AFLP) have proven useful in genetic similarity studies. We estimated different maize (Zea mays L.) inbred lines and hybrids originated from mutant ones based on their genetic differences.
We carried out RAPD analysis with different primers and the 707 (CCCAACACCC) and 792 (CAACCCACAC) primers with 50% similarities provided quite good DNA fragments. By applying the DNA based-AFLP technique, we had very dense DNA fingerprinting. We differentiated 15-32 polymorphic bands, the highest number of bands were found in P-T/H-CA (32). AFLP seems to be the more efficient method of comparing genetic similarities/differences among different genotypes. -
Phylogenetic studies of Phoma species by maximum likelihood analysis
37-46Views:133The cosmopolitan Phoma genus contains mainly phytopathogenic, opportunistic parasite, and saprophyte fungal species. Up to now the characterization of Phoma species and other taxa of Phoma has so far been determined on the basis of morphology on standardized media, and gene sequence analysis was only used as a confirmative or distinctive complement.
In this study we have tried to study phylogenetic relationships by maximum likelihood method in the Phoma genus. We employed a part of the gene responsible for the synthesis of translation elongation factor 1 subunit alpha protein (tef1) containing both introns and exons, a part of the gene responsible for synthesis of tubulin protein and ITS region containing the internal transcribed spacer regions 1 and 2 and the 5.8S rDNA as potential genetic markers to infer phylogenetic relationships among different Phoma taxa. Twenty-four isolates of eleven different Phoma species were firstly characterised by morphologically, and then their tef1, tubulin and ITS sequences were sequenced and analysed by maximum likelihood method carried out by PAUP*4.0b program. According to constructed phylogenetic trees, the different Phoma taxons are well separated. However these trees do not support the traditional Phoma sections based on morphological characterization.
The maximum likelihood analyses of all three sequences confirmed that the Phyllosticta sojicola species is clustered with the Phoma exigua var. exigua group and the Phoma sojicola is grouped with Phoma pinodella group. The experienced molecular evidences initiate the demand of reclassification of formerly mentioned soybean pathogens.