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The F1 AABBRHch hybrids studied here were produced by crosses between the Portuguese triticale cultivar ‘Douro’ (AABBRR) and the tritordeum line HT9 (AABBHchHch). Fluorescent in situ hybridization performed with genomic DNA probes genomic in situ hybridization (GISH) from rye and Hordeum chilense allowed the unequivocal parental genomes discrimination in all hybrids. Among 55 plants, one presented a spontaneous wheat–rye translocation which was successfully detected after GISH. Recombinant chromosomes identification was made after reprobe with pTa71 and pSc119.2. Nine rDNA loci were detected by pTa71 and pSc119.2 identified the chromosome arms involved in the translocation, after comparing the observed hybridization patterns with those described by several authors. We identified the spontaneous wheat–rye translocation as being the 7BS/7RL. Many wheat–rye translocations have been found (e.g. 1BL.1RS and 1AL.1RS), but as far as we know, this is the first time that this translocation is reported. We considered it helpful for wheat breeding programmes as it could provide the transference of interesting agronomic characteristics from rye (e.g. leaf rust resistance) to wheat. [ABSTRACT FROM AUTHOR]

Chromosome identification is essential in oyster genomic research. Fluorescence in situ hybridization (FISH) offers new opportunities for the identification of oyster chromosomes. It has been used to locate satellite DNAs, telomeres or ribosomal DNA sequences. However, regarding chromosome identification, no study has been conducted with simple sequence repeats (SSRs). FISH was used to probe the physical organization of three particular SSRs, (GGAT)4, (GT) 7 and (TA) 10 onto metaphase chromosomes of the Pacific oyster, Crassostrea gigas. Hybridization signals were observed in all the SSR probes, but the distribution and intensity of signals varied according to the oligonucleotide repeat. The intercalary, centromeric and telomeric bands were observed along the chromosomes, and for each particular repeat every chromosome pair presented a similar pattern, allowing karyotypic analysis with all the SSRs tested. Our study is the first in mollusks to show the application of SSR in situ hybridization for chromosome identification and karyotyping. This technique can be a useful tool for oyster comparative studies and to understand genome organization in different oyster taxa. [ABSTRACT FROM AUTHOR]

The DNA hypomethylation effect of 5-azacytine (5-AC; a cytosine analog) is widely known. This agent has been used for rRNA gene expression studies of Triticeae amphiploids and hybrids regarding rye rRNA genes suppression caused by the wheat nucleolar dominance phenomenon. However, this situation is reverted by 5-AC treatment which activates rye rRNA gene expression as it has been intensively observed in triticale. For nucleo|ar dominance studies, we produced F1 multigeneric hybrids (AABBRHCh; 2n=6x=42) from crosses between the triticale cultivar 'Corgo' (AABBRR; 2u=6x=42) and the tritordeum cultivars HT9 and HT31 (AABBHchHch; 2n=6x=42). The hybrid seeds were germinated in a low concentration of 5-AC (treatment) and in distilled water (nontreated control plants). Silver nitrate staining performed in one 5-AC-treated F1 hybrid revealed a reduced number of interphase cells with seven nucleoli, metaphases with eight Ag-NORs, and neocentromeres in the long arm of three wheat chromosomes. Nontreated hybrids presented six Ag-NORs per mitotic metaphase cell and a maximum of six nucleoli per interphase because of the 1R Ag-NOR suppression. No neocentromere was found in the control F1 hybrid plants. Both treated and nontreated seedlings were subsequently evaluated by fluorescent in situ hybridization performed with genomic and repetitive DNA probes to identify Hch and rye genomes, to confirm Ag-NORs location, and to detect inactive rDNA loci. DAPI counterstaining was also helpful for the detection of neocentromeres in the lung arm of three wheat chromosomes. This study allowed us to suggest that 5-AC treatment specifically induced wheat neocentromeres in the F1 multigeneric triticale x tritordeum hybrids. [ABSTRACT FROM AUTHOR]

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The morphological, yield, cytological and molecular characteristics of bread wheat x tritordeum F1 hybrids (2n = 6x = 42; AABBDHch) and their parents were analysed. Morphologically, these hybrids resembled the wheat parent. They were slightly bigger than both parents, had more spikelets per spike, and tillered more profusely. The hybrids are self-fertile but a reduction of average values of yield parameters was observed. For the cytological approach we used a double-target fluorescence in situ hybridization performed with total genomic DNA from Hordeum chilense L. and the ribosomal sequence pTa71. This technique allowed us to confirm the hybrid nature and to analyse chromosome pairing in this material. Our results showed that the expected complete homologous pairing (14 bivalents plus 14 univalents) was only observed in 9.59% of the pollen mother cells (PMCs) analysed. Some PMCs presented autosyndetic pairing of Hch and A, B or D chromosomes. The average number of univalents was higher in the wheat genome (6.8) than in the Hch genome (5.4). The maximum number of univalents per PMC was 20. We only observed wheat multivalents (one per PMC) but the frequency of trivalents (0.08) was higher than that of quadrivalents (0.058). We amplified 50 RAPD bands polymorphic between the F1 hybrid and one of its parents, and 31 ISSR polymorphic bands. Both sets of markers proved to be reliable for DNA fingerprinting. The complementary use of morphological and yield analysis, molecular cytogenetic techniques and molecular markers allowed a more accurate evaluation and characterization of the hybrids analysed here. [ABSTRACT FROM AUTHOR]

The analytical results concerning the identifications of four different chromatographic profiles of Sambucus nigra based on HPLC analysis of the anthocyanins present in the berries are described. That information can be used to select the best plants for anthocyanin pigments production and also to determine the best harvest time. [ABSTRACT FROM PUBLISHER]

The evolution of chromosomes in species in the family Bovidae includes fusion and fission of chromosome arms (giving different numbers of acrocentric and metacentric chromosomes with a relatively conserved total number of arms) and evolution in both DNA sequence and copy number of the pericentromeric α-satellite I repetitive DNA sequence. Here, a probe representing the sheep α-satellite I sequence was isolated and hybridized to genomic DNA digests and metaphase chromosomes from various Bovidae species. The probe was highly homologous to the centromeric sequence in all species in the tribe Caprini, including sheep (Ovis aries ), goat (Capra hircus ) and the aoudad or Barbary sheep (Amnotragus lervia ), but showed no detectable hybridization to the α-satellite I sequence present in the tribe Bovini and at most very weak to species in the tribes Hippotragini, Alcelaphini or Aepycerotini. The sex chromosomes of sheep, goat and aoudad did not contain detectable α-satellite I sequence; in sheep, one of the three metacentric autosomal chromosomes does not carry the sequence, while in aoudad, it is essentially absent in three large autosomal pairs as well as the large metacentric chromosome pair. The satellite probes can be used as robust chromosome and karyotype markers of evolution among tribes and increase the resolution of the evolutionary tree at the base of the Artiodactyla. Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

In situ hybridization with cloned, repetitive DNA probes and total genomic DNA enables the parental origin of all chromosomes to be established in metaphases of triticale × tritordeum F1 hybrids (2n=6x=42). Nuclei contain seven chromosomes of Hordeum chilense origin, seven from Secale cereale and 28 of wheat origin. When used as a probe, total genomic rye DNA labelled the rye chromosomes strongly and uniformly along their lengths, with brighter regions coincident with the terminal heterochromatin. The probe labelled the wheat-origin chromosomes weakly and was almost undetectable on the H. chilense-origin chromosomes. In contrast, under the same conditions, H. chilense DNA hybridized strongly to the H. chilense- and, with intermediate strength, to the S. cereale-origin chromosomes, excluding the subtelomeric heterochromatin: it hybridized only weakly to the wheat chromosomes, in some experiments revealing characteristic bands on wheat chromosomes. Cloned repetitive DNA probes from rye and H. chilense were used as probes to identify the linkage groups of all of their own-species chromosomes. Analysis of hybridization patterns of various probes to prophase and interphase nuclei indicated that there are many non-random features in the localization of both repetitive DNA and whole chromosomes, although general patterns of nuclear organization have yet to emerge. Both the particular lines used and the techniques developed here are likely to be valuable for production and characterization of plant breeding material. [ABSTRACT FROM PUBLISHER]