Search Results

You are looking at 1 - 10 of 17 items for

  • Author or Editor: M. Molnár-Láng x
  • Refine by Access: All Content x
Clear All Modify Search

The multicolour genomic in situ hybridization (mcGISH) method was improved in order to visualize the U b and M b genomes of Aegilops biuncialis Vis. (2n=4x=28, U b U b M b M b ). Hybridization probes prepared from the diploid U and M genome donors, Ae. umbellulata and Ae. comosa , resulted in clear hybridization signals on the U and M chromosomes in Ae. biuncialis . The random primed labelling method made it possible to decrease the blocking ratio to 1:30. McGISH allowed the simultaneous discrimination of individual Ae. biuncialis genomes and wheat chromosomes in γ-irradiated Triticum aestivum-Ae. biuncialis amphiploids (2n=70; AABBDDU b U b M b M b ). Dicentric chromosomes, terminal and interstitial translocations and centric fusions were detected in the irradiated generation. The irradiation-induced wheat- Ae. biuncialis intergenomic translocations will facilitate the successful introgression of useful agronomic traits into bread wheat.

Restricted access

Fluorescence in situ hybridization (FISH) is the most versatile and accurate molecular cytogenetic technique for determining euchromatic-heterochromatic boundaries and the locations of repetitive and single-copy DNA sequences and of chromosome-specific BAC clones on chromosomes. The combination of cytogenetic and genetic methods yields a highresolution physical map. FISH allows direct mapping of specific DNA sequences inside the cell (interphase nuclei), along meiotic pachytene chromosomes and isolated chromatin (DNA fibres). The increased sensitivity of the technique and its ability to detect gene locations provide a powerful research tool for genetic and pre-breeding studies. FISH-based physical mapping plays an important role and is increasingly used for studies at the cytological level on the chromatin organization that controls gene expression and regulation. The present minireview describes some of the benefits of alternative FISH-based techniques and their application for studying plant chromosomes and genomes.

Restricted access

Several molecular markers have been reported for the detection of the 1RS chromosome arm. The aim of the present experiments was to study the reliability and reproducibility of six molecular markers specific to the 1RS rye chromosome (GPI, Bmac213, 5S, IAG95, SCM9 and RMS13) in distinguishing between wheat genotypes with and without the 1BL.1RS or 1AL.1RS translocations. In the course of the analysis, PCR products of the expected size were obtained with all the markers, which were found to give a reliable indication of the presence of the 1RS chromosome arm in the wheat genome.

Restricted access

Six different 1RS-specific molecular markers (RMS13, Bmac213, GPI, 5S, SCM9, IAG95) were tested in twenty rye cultivars of various origin. The aim of the experiments was to choose rye cultivars which give polymorphic PCR products with these 1RS-specific markers compared to the wheat cultivar Mv Magdaléna, which contains the 1BL.1RS translocation. The polymorphic rye cultivars can be presumed to differ from the 1BL.1RS translocation originating from the Petkus rye cultivar and will hopefully carry effective resistance genes which can be incorporated into the 1BL.1RS translocation in wheat. Twenty rye cultivars (at least two plants per cultivar) were analysed with these markers. Of fifty-two rye samples analysed, three plants were found to be polymorphic, one (Kisvárdai Alacsony from Hungary), for the 5S marker, one (Kriszta from Hungary) for the RMS13 marker and one (Porto from Portugal) for the SCM9 marker. The polymorphic plants were grown to maturity in the phytotron.

Restricted access

The present study was focused on the selection of S. cereale cultivars of different geographic origin showing polymorphism detectable by fluorescent in situ hybridization on their 1RS chromosome arms. One perennial and four annual genotypes were tested. FISH was carried out with the DNA probes pSc119.2 and (AAC) 5 . The pSc119.2 probe gave hybridization signals different from that of the rye ‘Petkus’ on the 1RS arms of all five rye cultivars examined. Differences were manifested mainly in the intensity of the labelling, but the complete lack of FISH signals and double signals were also observed.

Restricted access

One way of incorporating useful traits from Aegilops biuncialis (2n=4x=28, U b U b M b M b ) into wheat ( Triticum aestivum L. 2n=6x=42, AABBDD) is to develop first addition then translocation lines. The 2M b , 3M b , 7M b , 3U b , 5U b and 5U b /6U b wheat- Ae. biuncialis addition lines were produced in Martonvásár. To facilitate the exact identification of the addition lines, it was necessary to analyse the fluorescence in situ hybridisation patterns of the parental wheat genotype, Ae. biuncialis and its diploid progenitors ( Ae. umbellulata 2n=2x=14, UU and Ae. comosa 2n=2x=14, MM). The great genetic variability of the Aegilops species causes polymorphism in the fluorescence in situ hybridisation (FISH) patterns of the individual chromosomes. Due to the high level of FISH polymorphism, it is advisable to confirm the identification of the Ae. biuncialis chromosomes with the help of molecular (microsatellite, SSR) markers, so 119 wheat SSR markers were tested on Aegilops biuncialis , on Ae. geniculata (2n=4x=28, U g U g M g M g ), on five wheat- Ae. biuncialis addition lines (2M b , 3M b , 7M b , 3U b , 5U b ) and on an addition series of wheat- Ae. geniculata in order to select SSR markers specific to the U and M genomes of Ae. biuncialis and Ae. geniculata .

Restricted access

Acta Agronomica Hungarica, 48(3), pp. 227–236 (2000) OCCURRENCE OF THE 1RS/1BL WHEAT–RYE TRANSLOCATION IN HUNGARIAN WHEAT VARIETIES B. K Ő SZEGI, G. LINC, A. JUHÁSZ, L. LÁNG and M. MOLNÁR-LÁNG AGRICULTURAL RESEARCH INSTITUTE OF THE HUNGARIAN ACADEMY OF SCIENCES, MARTONVÁSÁR, HUNGARY Received: August 15, 2000; accepted: October 15, 2000 The translocation which involves the substitution of the short arm of the 1R rye chromosome for the short arm of the 1B wheat chromosome by means of centric fusion has exercised an enormous influence on the world’s wheat breeding. Since the first mention of this translocation in 1937 the incidence of the 1RS/1BL translocation has been reported in connection with several hundred wheat varieties. Varieties carrying the translocation possess a chromosome segment which includes the resistance genes Sr31 (stem rust, Puccinia graminis), Lr26 (leaf rust, P. recondita), Yr9 (yellow rust, P. striiformis), Pm8 (powdery mildew, Erysiphe graminis) and Gb (aphid, Schizaphis graminum). The present paper investigates the occurrence of the 1RS/1BL translocation in wheat varieties bred in Hungary in recent years. It was found that 35 (53%) of the 66 Hungarian-bred wheat varieties registered in Hungary between 1978 and 1999 carried the 1RS/1BL translocation.

Restricted access

The safety of wheat production in Hungary requires the propagation of droughttolerant cultivars because of the regular occurrence of water deficiency. Hybridization between related species makes it possible to transfer desirable traits from one species to another. Introgression lines developed from wheat/barley hybrids were investigated together with the parental wheat and barley cultivars to determine how the added barley chromosome (segment) influences drought tolerance in wheat. The plants were grown in the field at the UP Georgikon Faculty, Keszthely. Sowing and harvest were done by hand. Half the length of the 12 m rows was covered with a plastic rain shelter on 2 nd April (EC: 30–31) to protect the plants from rain, resulting in a 163 mm difference in water supplies between the control (not covered) and stressed (covered) treatments. Data were obtained for anthesis and maturity date, plant height, root/shoot ratio, leaf water potential, grain yield and grain yield components. The plants adapted to water deficiency by increasing the root/shoot ratio and decreasing the water potential and the duration of grain filling. The grain yield was reduced by 12%, averaged over the genotypes, mainly due to a decrease in the number of spikes per plant.

Restricted access

The aim of the present study was to test the efficiency of gamma irradiation in inducing translocations between wheat and barley genomes using addition lines. The Martonvásári 9 kr1-Igri disomic addition set, previously produced in Martonvásár, was irradiated with gamma rays. The pattern of irradiation-induced intergenomic chromosome rearrangements was analysed in the mutagenized (M0) generation by genomic in situ hybridization (GISH). Centric fusions and a wide variety of reciprocal, terminal and interstitial translocations were frequently induced. The intergeneric translocations produced here are expected to be stabilized in later backcross progenies as a set of introgression lines carrying few but distinct rearrangements.

Restricted access