Search

Background: Secale is an annual or perennial grasses from the Poaceae family represented in Iraq by three wild species, from which Rye (S.cereale) grew as a weed in Wheat fields. Rye represented a grain crop in the world used for different purposes such as alcoholic beverages, food, grazed forage. Methodology: This paper outlines the differences in concentrations of 10 different compounds determined by HPLC technique in three species of the genus Secale L. in Iraq. The content of most compounds are variable in the species. Results: High content of Gentisic acid are recorded in S.montanum Guss. and S.cereale while less content are observed for Luteolin-7-glucopyranoside. S.afghanicum (Vav.) Rozhev. reveals high content of Coumaric acid and less content of Anthocyanins. So the results indicate that the three species of the genus Secale represent a valuable source of biologically active constituents which can enhancing the separation of species by means of chemotaxonomic techniques. Conclusion: The situations of differences in concentrations of phenolic compounds play an important role in identification and separation between species studied which can be easily used as a chemotaxonomic tool. [ABSTRACT FROM AUTHOR]

An experiment was conducted to investigate the effects of dietary inclusion of rye, a model ingredient to increase gut viscosity, between 14 and 28 d of age on immune competence-related parameters and performance of broilers. A total of 960 day-old male Ross 308 chicks were weighed and randomly allocated to 24 pens (40 birds per pen), and the birds in every 8 replicate pens were assigned to 1 of 3 experimental diets including graded levels, 0%, 5%, and 10% of rye. Tested immune competence-related parameters were composition of the intestinal microbiota, genes expression in gut tissue, and gut morphology. The inclusion of 5% or 10% rye in the diet (d 14 to 28) resulted in decreased performance and litter quality, but in increased villus height and crypt depth in the small intestine (jejunum) of the broilers. Relative bursa and spleen weights were not affected by dietary inclusion of rye. In the jejunum, no effects on number and size of goblet cells, and only trends on microbiota composition in the digesta were observed. Dietary inclusion of rye affected expression of genes involved in cell cycle processes of the jejunal enterocyte cells, thereby influencing cell growth, cell differentiation and cell survival, which in turn were consistent with the observed differences in the morphology of the gut wall. In addition, providing rye-rich diets to broilers affected the complement and coagulation pathways, which among others are parts of the innate immune system. These pathways are involved in eradicating invasive pathogens. Overall, it can be concluded that inclusion of 5% or 10% rye to the grower diet of broilers had limited effects on performance. Ileal gut morphology, microbiota composition of jejunal digesta, and gene expression profiles of jejunal tissue, however, were affected by dietary rye inclusion level, indicating that rye supplementation to broiler diets might affect immune competence of the birds. [ABSTRACT FROM AUTHOR]

The structure of repetitive sequences of the JNK block present in the pericentromeric region of the 2RL chromosome was studied in Secale vavilovii. Amplification of sequences present between the JNK sequences led to the identification of seven abnormal DNA fragments. Two of these fragments showed high similarity to the glutamate 5-kinase gene and putative alcohol dehydrogenase gene of trypanosomatid from the genus Leishmania, whose presence can be explained by horizontal gene transfer (HGT). Other fragments were similar to mitochondrial gene for ribosomal protein S4 in plants and to the glycoprotein (G) gene of the IHNV virus. Presumably, they are pseudogenes inserted into the JNK heterochromatin region. Within this region, also fragments similar to the rye repetitive sequence and chromosome 3B in wheat were found. There is no known mechanism that would explain how foreign sequences were inserted into the block region of tandem repetitive sequences of the JNK family. [ABSTRACT FROM AUTHOR]

Due to the X-shape formation at somatic metaphase, the arrangement of the sister chromatids is obvious in monocentric chromosomes. In contrast, the sister chromatids of holocentric chromosomes cannot be distinguished even at mitotic metaphase. To clarify their organization, we differentially labelled the sister chromatids of holocentric Luzula and monocentric rye chromosomes by incorporating the base analogue EdU during replication. Using super-resolution structured illumination microscopy (SIM) and 3D rendering, we found that holocentric sister chromatids attach to each other at their contact surfaces similar to those of monocentrics in prometaphase. We found that sister chromatid exchanges (SCEs) are distributed homogeneously along the whole holocentric chromosomes of Luzula, and that their occurrence is increased compared to monocentric rye chromosomes. The SCE frequency of supernumerary B chromosomes, present additionally to the essential A chromosome complement of rye, does not differ from that of A chromosomes. Based on these results, models of the sister chromatid arrangement in mono- and holocentric plant chromosomes are presented. [ABSTRACT FROM AUTHOR]

Till this day, there is not much known about the phylogeny of the Secale genus; therefore, in our research, we tried to shed some lights on the issue of rye ( Secale genus) taxonomy. The genetic diversity and phylogenetic relationships were evaluated using 13,842 DArTseq™ polymorphic markers. The model-based clustering (STRUCTURE software) separated our 84 samples into three main clusters: perennial cluster, annual cluster, and S. sylvestre cluster. The same result was obtained using Neighbour Joining tree and self-organizing maps. Secale sylvestre, S. strictum, and S. cereale are the three main species of the Secale genus. Three samples of rye are in basal positions in phylogenetic trees. These accessions share ancient morphological characters and are probably the ancestors of different lineages within Secale. Annual Secale taxa, with the exception of S. sylvestre, create one mutual taxon. We have found out that the semi-perennial taxa of S. cereale var. multicaule and S. strictum subsp. ciliatoglume are genetically closest to the annual species of S. cereale. Phylogenetic signals for semi-perennial and annual taxa are also present in S. strictum subsp. africanum. SNP-based analysis revealed that evolution of annual S. cereale has already begun in S. strictum subsp. africanum. The results showed that S. vavilovii cannot be considered as a separate species but a subspecies of S. cereale Secale cereale subsp. dighoricum is a hybrid. It is still not clear whether we can consider S. strictum subsp. strictum and S. strictum subsp. kuprijanovii as two separate species. [ABSTRACT FROM AUTHOR]

The objective of this study was to quantify the molecular diversity and to determine the genetic relationships among Secale spp. and among cultivars of Secale cereale using RAPDs, ISSRs and sequence analysis of six exons of ScMATE1 gene. Thirteen ryes (cultivated and wild) were genotyped using 21 RAPD and 16 ISSR primers. A total of 435 markers (242 RAPDs and 193 ISSRs) were obtained, with 293 being polymorphic (146 RAPDs and 147 ISSRs). Two RAPD and nine ISSR primers generated more than 80% of polymorphism. The ISSR markers were more polymorphic and informative than RAPDs. Further, 69% of the ISSR primers selected achieved at least 70% of DNA polymorphism. The study of six exons of the ScMATE1 gene also demonstrated a high genetic variability that subsists in Secale genus. One difference observed in exon 1 sequences from S. vavilovii seems to be correlated with Al sensitivity in this species. The genetic relationships obtained using RAPDs, ISSRs and exons of ScMATE1 gene were similar. S. ancestrale, S. kuprijanovii and S. cereale were grouped in the same cluster and S. segetale was in another cluster. S. vavilovii showed evidences of not being clearly an isolate species and having great intraspecific differences. [ABSTRACT FROM AUTHOR]

The specific features in behavior of the nuclei and chromatin migrating through cytomictic channels as well as in formation of micronuclei in the cereal microsporogenesis have been studied. Immunofluorescence microscopy has allowed for demonstration that the tubulin cytoskeleton does not play a significant role in the intercellular migration of nuclei. Potential involvement of the actin cytoskeleton and SUN-KASH linker complexes in cytomixis is discussed. Comparative analysis of the published and own data suggests that the cytological patterns of cytomixis in monocots and dicots are conserved. As has been shown, each higher ploidy level in the polyploid series of the family Gramineae is accompanied by an increase in the rate of cytomixis independently of individual species. The results confirm the assumption on a correlation between the rate of cytomixis, ploidy level, and genome balance. [ABSTRACT FROM AUTHOR]

We produced 15 dissection lines of common wheat carrying segments of chromosome 1R of wild rye (Secale montanum) (1Rm) by the gametocidal system. Using the 1Rm dissection lines and previously established 24 dissection lines of chromosome 1R from cultivated rye (Secale cereale cv. 'Imperial') (1Ri), we conducted cytological mapping of 97 markers that were amplified in the 1Ri addition line. Sixty-eight of the 97 markers were amplified in the 1Rm addition line. To reveal what structural differentiation occurred in chromosome 1R during domestication, we compared the cytological map of chromosome 1Ri with that of chromosome 1Rm, and also with the previously published cytological map of chromosome 1R from wheat cultivar 'Burgas 2' (1RB). There was one discrepancy in marker order in the satellite region between chromosomes 1Ri and 1RB, while there were four discrepancies in marker order between chromosomes 1Ri and 1Rm. These results suggested that during the domestication of rye, some intrachromosomal rearrangements had occurred in chromosome 1R, although this chromosome is regarded as the most stable chromosome in the rye genome. [ABSTRACT FROM AUTHOR]

The JNK motif is repeated 4 000 times in an additional heterochromatin band. Flanking sequences of a JNK region, which form extra heterochromatin in 2R rye ( Secale vavilovii Grossh.) chromosomes, were studied using a genome walking technique. The results clearly indicate that there were blocks of JNK sequences adjacent to the R173 family of repeated sequences. Moreover, it appears that the R173 are sequences flanking in both directions, i.e., upstream and downstream. Downstream, the R173 is adjacent to the JNKs in an anti-parallel orientation, whereas upstream it is adjacent in a parallel orientation. In order to confirm the presence of the R173 sequence, fluorescence in situ hybridization was carried out. Using both JNK and R173 molecular probes, overlapping hybridization signals in the 2RL pair of chromosomes were observed, indicating an identical location of the two sequence elements. [ABSTRACT FROM AUTHOR]

The unique 75 K -secalins encoded by Sec2 loci in Secale species is composed of almost half rye storage proteins. The chromosomal location of Sec2 loci in wild Secale species, Secale africanum, was carried out by the wheat--S. africanum derivatives, which were identified by genomic in situ hybridization and multi-color fluorescence in situ hybridization. The Sec2 gene-specific PCR analysis indicated that the S. cereale Sec2 was located on chromosome 2R, while the S. africanum Sec2 was localized on chromosome 6Rafr of S. africanum. A total of 38 Sec2 gene sequences were isolated from S. africanum, S. cereale and S. sylvestre by PCR-based cloning. Phylogenetic analysis showed that S. africanum Sec2 diverged from S. cereale Sec2 approximately 2-3 million years ago. The illegitimate recombination of chromosome 2R-6R involving the Sec2 loci region may accelerate sequence variation during evolutionary process from wild to cultivated Secale species. [ABSTRACT FROM AUTHOR]

We aim to improve diversity of domesticated wheat by transferring genetic variation for important target traits from related wild and cultivated grass species. The present study describes the development of F1 hybrids between wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum and production of new amphidiploids. Amphidiploid lines were produced from 20 different distant relatives. Both colchicine and caffeine were successfully used to double the chromosome numbers. The genomic constitution of the newly formed amphidiploids derived from seven distant relatives was determined using genomic in situ hybridization (GISH). Altogether, 42 different plants were analysed, 19 using multicolour GISH separating the chromosomes from the A, B, and D genomes of wheat, as well as the distant relative, and 23 using single colour GISH. Restructuring of the allopolyploid genome, both chromosome losses and aneuploidy, was detected in all the genomes contained by the amphidiploids. From the observed chromosome numbers there is an indication that in amphidiploids the B genome of wheat suffers chromosome losses less frequently than the other wheat genomes. Phenotyping to realize the full potential of the wheat - related grass germplasm is underway, linking the analyzed genotypes to agronomically important target traits. [ABSTRACT FROM AUTHOR]

Breeding work using European rye populations has resulted in a considerable reduction of genetic variation in breeding materials of that species. Many taxa from the genus Secale may constitute a potential source of genetic variation in rye breeding. A source of new genetic variation can be found in such species as Secale montanum and Secale vavilovii, which are sources of resistance to fusarium ear blight and septoria leaf blotch, while Secale vavilovii may also be a source of sterilising cytoplasm. The aim of this study was to assess the efficiency of crossing the wild species Secale vavilovii and the rye subspecies Secale cereale subsp. afghanicum, Secale cereale subsp. ancestrale, Secale cereale subsp. dighoricum, Secale cereale subsp. segetale with the crop species Secale cereale ssp. cereale, and to produce F1 hybrids and describe selected morphological traits. Observations of biometric traits indicate that the F1 crosses produced may be potential sources of variation for common rye. The greatest variation in terms of all analysed phenotypic traits combined was found for the cross combinations S. c. ssp. cereale cv. Amilo × S. c. ssp. ancestrale and S. c. ssp. cereale cv. Dańkowskie Diament × S. c. ssp. dighoricum. The hybrids showed considerable variation in the analysed biometric traits within individual cross combinations. [ABSTRACT FROM AUTHOR]

To prevent unbalanced chromosome segregation, meiotic metaphase I - anaphase I transition is carefully regulated by delaying anaphase until all kinetochores are well oriented (anaphase checkpoint) in mammals and insects. In plants this has not yet been established. In heterozygotes of two reciprocal translocations of Secale cereale, with one chromosome replaced by its two telocentric arms, anaphase delay was correlated with the orientation of the kinetochores of the complex of five chromosomes. The terminal kinetochores of the half chromosomes were readily elongated and pole oriented. Chains of five chromosomes with all five kinetochores orienting on alternate poles where the first to start anaphase. Kinetochores of two adjacent chromosomes when oriented on the same pole were partly shielded and less well pole directed. Anaphase was delayed. Cells with this configuration accumulated during anther development. Kinetochores in metacentric chromosomes lacking chiasmata in one arm (in trivalents and bivalents) were slightly better pole oriented and delayed anaphase less. Release of chromatid cohesion as triggered by kinetochore stretch is apparently delayed by inadequate exposition and pole orientation of the kinetochores. It is a mild form of an anaphase checkpoint, in normal material synchronizing bivalent segregation. [ABSTRACT FROM AUTHOR]

Inter-simple sequence repeat (ISSR) and inter-retrotransposon amplified polymorphism (IRAP) techniques were used to investigate the genetic diversity among species of the genus Secale L. Chromosomal distribution of the AAC simple sequence repeat was examined by means of the fluorescent in situ hybridization technique. Comparative analysis revealed differences in the distribution of analyzed sequences in the genomes of Secale species. Using ISSR and IRAP data, a similarity matrix was constructed based on Dice's coefficient, and the unweighted pair-group method with arithmetic mean clustering was used to create dendrograms. Secale sylvestre Host and Secale strictum C.Presl were separated from a cluster consisting of the rest of the Secale taxa. The similarity for Secale sylvestre and Secale strictum reached over 85%. For Secale strictum subsp. africanum (Stapf) K.Hammer and Secale strictum subsp. kuprijanovii (Stapf) K.Hammer, which were clustered together, the similarity reached a value of 75%. The remaining taxa formed a large cluster, in which the highest value of similarity was assigned to Secale cereale L. and the Secale vavilovii Grossh. 121 inbred line (80%). The distribution patterns of the AAC repeat in chromosomes support these results. The pattern found in Secale vavilovii resembles that of Secale cereale and its subspecies. The most unique pattern of AAC distribution was observed in Secale sylvestre. [ABSTRACT FROM AUTHOR]

Physiological effect of six levels of water stress (0, -0.1, -.03, -0.6, -0.9 and -1.2 MP) was studied on seed germination and plumule as well as radicule growth length in three species namely: Agropyron elongatum, Agropyron desertourm and Secale montanum. Polyethylene glycol (PEG) was used to provide appropriate water potentials. A total of 100 seeds in four replications (Petri dishes) were sown from each species. Experimental design was a factorial one of complete randomized design. Maximum germination rate was obtained at 0 MP. Germination rate and plumule and radicule growth declined with water potential level. The most resistance species to water stress are Secale montanum, Agropyron elongatum and Agropyron desertorum respectively. [ABSTRACT FROM AUTHOR]

Wild Secale species, Secale africanum Stapf., serve as a valuable source for increasing the diversity of cultivated rye (Secale cereale L.) and provide novel genes for wheat improvement. New wheat - S. africanum chromosome lRafr addition, lRafr(lD) substitution, lBL.lRafrS and lDS.lRafrL translocation, and 1 RallL monotelocentric addition lines were identified by chromosome banding and in situ hybridization. Disease resistance screening revealed that chromosome lRafrS carries resistance gene(s) to new stripe rust races. Twenty-nine molecular markers were localized on S. africanum chromosome lRafl by the wheat - S. africanum introgression lines. Twenty markers can also identically amplify other reported wheat - S. cereale chromosome 1R derivative lines, indicating that there is high conservation between the wild and cultivated Secale chromosome 1R. Nine markers displayed polymorphic amplification between S. africanum and S. cereale chromosome lRafl derivatives. The comparison of the nucleotide sequences of these polymorphic markers suggested that gene duplication and sequence divergence may have occurred among Secale species during its evolution and domestication. [ABSTRACT FROM AUTHOR]

Meiotic metaphase I configuration frequencies were determined in different tillers of genetically related plants of rye ( L.) heterozygous for reciprocal translocation T248W (between chromosome arms 1RS and 6RS) and with an additional (telocentric) arm 1RS. Seventeen different configurations could be recognized, grouped into three categories. Very different configuration frequencies were found not only between sister plants from the same parents but also between tillers of the same plant grown under identical conditions (climate chambers at 15 °C and 20 °C). The heterogeneity reflects variation in chromosome pairing and crossing over, and is variable and unpredictable. Anthers within florets were homogeneous. Between tiller heterogeneity is insufficient to explain differences between sister plants. It is ascribed to random somatic variation in the conditions of the chromatin which, at meiosis, govern chromosome pairing. During sexual differentiation, these conditions are fixed and subsequent cell lineages have the same pairing and crossing over characteristics. As homology search is an activity of DNA, this control of pairing and crossing over, consistent over long cell lineages, may be considered to be epigenetic even when no realistic suggestions concerning its character can be given. [ABSTRACT FROM AUTHOR]

Extreme morphological variation in the land snail Abida secale has been categorized in 17 currently recognized subspecies. Fourteen of these occur in a relatively small area of the species' range. Within this subspecies complex, based on shell morphological analyses, a ‘ring-species’ scenario has been postulated. To evaluate this scenario and to define (sub)species boundaries within the complex, the mitochondrial marker cytochrome oxidase I was analysed. The phylogeny reconstruction reveals two clades in Abida secale. These clades do not correspond to subspecies definitions based on shell morphological analyses. One clade of A. secale has A. attenuata, a morphologically well-defined species, as its sister taxon. These results could be explained by either incomplete lineage-sorting of the mitochondrial genome and/or by introgression of the A. attenuata mitochondrial genome into A. secale. Circumstantial evidence favours the second scenario. Whichever scenario has caused the observed pattern, the results of the mitochondrial DNA analyses do not show evidence of reduced gene flow between A. s. cadiensis and A. s. cadica. Since these two subspecies are the postulated ‘ends’ of the ring, there was no support for a ring-species scenario in Abida secale. [ABSTRACT FROM PUBLISHER]

With 3 figures and 3 tables Abstract A search was carried out for allelopathic sources among accessions of Triticum, Secale, Triticosecale and wheat-rye substitution and translocation lines to be used in breeding programmes to improve weed suppression ability of wheat. A bioassay with mustard as target plants was used for the screening. Mustard was chosen among seven tested target plants because it showed a particular high root growth inhibition when grown together with rye compared with wheat. None of the Triticum accessions studied showed potential allelopathic activity of interest for breeding, but most Triticosecale did. Several of the wheat-rye substitution and translocation lines also showed high allelopathic activity. The highest activity was found in lines with a substitution of 1R or 2R. Some multiple substitution lines and lines with only rye chromatin also showed high allelopathic activity. It is suggested that in vitro selection of wheat-rye substitution lines with high allelopathic potential with a bioassay with mustard as target plants could be used to improve weed suppression ability of wheat. [ABSTRACT FROM AUTHOR]

Chromosomal rearrangements, including reciprocal translocations, may prevent recombinational transfer of genes from a donor genotype to a recipient, especially when the gene is located in an interstitial segment. The effect of trisomy of chromosome arm 1RS on recombination was studied in translocation heterozygote T248W of rye (Secale cereale), involving chromosome arms 1RS and 6RS. (Pro)metaphase I configuration frequencies were analyzed. Crossing over, estimated as chiasma parameters, in five genetically different euploid heterozygotes was compared with those of 10 different single arm trisomics. The addition of 1RS greatly altered the crossing over pattern around the translocation break point, with a special increase in the interstitial segment of 6RS and adjoining regions, normally hardly accessible to recombination. Furthermore, there was considerable variation between plants of closely related genotypes. Heterogeneity widens the distribution of crossing overs, including segments normally not accessible to recombination, but decreases average recombination in other segments. The extra chromosome and abnormal segregants are eliminated by using the trisomic as the pollen parent. [ABSTRACT FROM AUTHOR]

Abstract: The supramolecular reorganization of LHCII complexes within the thylakoid membrane in Secale cereale leaves under low and high light condition was examined. Rye seedlings were germinated hydroponically in a climate chamber with a 16h daylight photoperiod, photosynthetic photon flux density (PPFD) of 150μmolm−2 s−1 and 24/16°C day/night temperature. The influence of pre-illumination of the plants with high light intensity on the PSII antenna complexes was studied by comparison of the structure and function of the LHCII complexes and organization of thylakoid membranes isolated from 10-day-old plants illuminated with low (150μmolm−2 s−1) or high (1200μmolm−2 s−1) light intensity. Aggregated and trimeric with monomeric forms of LHCII complexes were separated from the whole thylakoid membranes using non-denaturing electrophoresis. Analyses of fluorescence emission spectra of these different LHCII forms showed that the monomer was the most effective aggregating antenna form. Moreover, photoprotection connected with LHCII aggregation was more effective upon LHCII monomers in comparison to trimer aggregation. Light stress induced specific organization of neighboring LHCII complexes, causing an increase in fluorescence yield of the long-wavelength bands (centered at 701 and 734nm). The changes in the organization of the thylakoid membrane under light stress, observed by analysis of absorbance spectra obtained by Fourier transform infrared spectroscopy, also indicated light-induced LHCII aggregation. [Copyright &y& Elsevier]

ABSTRACT Carbon and oxygen isotope discrimination of CO2 during photosynthesis (Δ13 Cobs and Δ18 Oobs) were measured along a monocot leaf, triticale ( Triticum × Secale). Both Δ13 Cobs and Δ18 Oobs increased towards the leaf tip. While this was expected for Δ18 Oobs, because of progressive enrichment of leaf water associated with the Péclet effect, the result was surprising for Δ13 Cobs. To explore parameters determining this pattern, we measured activities of key photosynthetic enzymes [ribulose bis-phosphate carboxylase-oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPC) and carbonic anhydrase) as well as maximum carboxylation and electron transport rates ( Vcmax and Jmax) along the leaf. Patterns in leaf internal anatomy along the leaf were also quantified. Mesophyll conductance ( gm) is known to have a strong influence on Δ13 Cobs, so we used three commonly used estimation methods to quantify variation in gm along the leaf. Variation in Δ13 Cobs was correlated with gm and chloroplast surface area facing the intercellular air space, but unrelated to photosynthetic enzyme activity. The observed variation could cause errors at higher scales if the appropriate portion of a leaf is not chosen for leaf-level measurements and model parameterization. Our study shows that one-third of the way from the base of the leaf represents the most appropriate portion to enclose in the leaf chamber. [ABSTRACT FROM AUTHOR]

A stable, highly fertile wheat Secale africanum substitution line LF24, derived from the F generation of a cross between Mianyang11 (MY11) and Triticum durum, S. africanum amphiploid (YF) was identified through molecular cytogenetic analysis. Application of C-banding, in situ hybridization and molecular markers analysis showed that LF24 was a wheat S. africanum 2R(2D) substitution line. When inoculated with stripe rust isolates, T. durum and MY11 were highly susceptible, while S. africanum, YF and LF24 were immune. It is confirmed through molecular cytogenetic analysis that the stripe rust resistance of LF24 was derived from S. africanum chromosome 2R. We compared the banding patterns and disease resistance of reported chromosomes 2R from different S. cereale introduced into wheat background, and found that there was new stripe rust resistance gene(s) on S. africanum 2R. LF24 is a new substitution line which can be used as stripe rust resistant source in wheat improvement. [ABSTRACT FROM AUTHOR]

We present the first characterization of 360 sequences in six species of the genus Secale of both cultivated and wild accessions. These include four distinct kinds of dispersed repetitive DNA sequences named pSc20H, pSc119.1, pSaO5411, and pSaD15940 belonging to the Revolver family. During the evolution of the genus Secale from wild to cultivated accessions, the pSaO5411-like sequences became shorter mainly because of the deletion of a trinucleotide tandem repeating unit, the pSc20H-like sequences displayed apparent homogenization in cultivated rye, and the second intron of Revolver became longer. In addition, the pSc20H-, pSc119.1-, and pSaO5411-like sequences cloned from wild rye and cultivated rye could be divided into two large clades. No single case of the four kinds of repetitive elements has been inherited by each Secale accession from a lone ancestor. It is reasonable to consider the vertical transmission of the four repetitive elements during the evolution of the genus Secale. The pSc20H- and pSaO5411-like sequences showed evolutionary elimination at specific chromosomal locations from wild species to cultivated species. These cases imply that different repetitive DNA sequences have played different roles in the chromosome development and genomic evolution of rye. The present study adds important information to the investigations dealing with characterization of dispersed repetitive elements in wild and cultivated rye. [ABSTRACT FROM AUTHOR]

Eleven weedy or wild species or subspecies of the genus Secale L. were compared with a set of cultivated rye accessions, based on inter-simple sequence repeat (ISSR) markers to analyze their phylogenetic relationships. A total of 846 bands were amplified from reactions using 12 screening primers, including 79 loci with a mean of 10.1 alleles per locus. The number of amplified bands for each primer ranged from 12 to 134, with a mean of 70.5 amplified bands per primer. The presence and distribution of amplified bands in different accessions demonstrate that a rapid evolutionary trend of microsatellite repeats occurred during the speciation process from the perennial wild form to annual cultivated rye. In addition, variation, amplification, and deletion of microsatellites in genomes revealed phylogenetic relationships in the genus Secale. Analysis of the presence, number, and distribution of amplified bands in genomes, as well as the comparison with genetic similarity (GS) indices based on ISSR, indicate that Secale strictum subsp. africanum (Stapf) Hammer, Secale strictum anatolicum (Boiss.) Hammer, Secale sylvestre Host, and Secale strictum subsp. strictum (C. Presl) Hammer emerged in succession from a common ancestor of Secale following geographic separation and genetic differentiation. The annual weedy rye evolved from S. strictum subsp. strictum, which was domesticated as present-day cultivated rye. Data from ISSR analyses separated all investigated accessions of the genus Secale into three distinct groups. These results support the division of the genus Secale into three species: the annual wild species S. sylvestre; the perennial wild species S. strictum, including several differential subspecies forms such as strictum, africanum, and anatolicum; and S. cereale, including cultivated and weedy rye as subspecies forms. [ABSTRACT FROM AUTHOR]

Genomic in situ hybridization (GISH) with Secale cereale cv. ‘Jingzhou rye’ DNA as a probe to chromosomes of hexaploid triticale line Fenzhi-1 revealed that not only were all chromosomes of rye strongly hybridized along the entire chromosome length, but there were also stronger signals in terminal or subtelomeric regions. This pattern of hybridization signals is referred to as GISH banding. After GISH banding, sequential fluorescene in situ hybridizaion (FISH) with tandem repeated sequence pSc200 and pSc250 as probes showed that the chromosomal distribution of pSc200 is highly coincident with the GISH banding pattern, suggesting that GISH banding revealed chromosomal distribution of pSc200 in rye. In addition, FISH using pSc200 and pSc250 as probes to chromosomes of 11 species of the genus Secale and two artificial amphiploids ( Triticum aestivum- S. strictum subsp. africanum amphiploid and Aegilops tauschii- S. silvestre amphiploid) showed that (1) the chromosomal distribution of pSc200 and pSc250 differed greatly in Secale species, and the trend towards an increase in pSc200 and pSc250 binding sites from wild species to cultivated rye suggested that pSc200 and pSc250 sequences gradually accumulated during Secale evolution; (2) the chromosomal distribution of pSc200 and pSc250 presented polymorphism on homologous chromosomes, suggesting that the same species has two heterogeneous homologous chromosomes; (3) the intensity and number of hybridization signals varied differently on chromosomes between pSc200 and pSc250, suggesting that each repetitive family evolved independently. [ABSTRACT FROM AUTHOR]

Simple sequence repeat (SSR) analysis was performed on five Secale species, four Triticum species and a Triticale line Fenzhi-1 using 102 pairs of microsatellite primers. A 387-bp specific DNA fragment FZ387 (GenBank accession no. EF179137) was obtained from the Triticale Fenzhi-1 with primer Xgwm614, without amplification in Secale. NCBI BLAST revealed that this FZ387 sequence had 94% and 95% similarity to part of the Gypsy Ty3-LTR retrotransposon Fatima in Triticum monoccocum (AY485644) and Triticum turgidum (AY494981), respectively. A pair of specific polymerase chain reaction (PCR) primers, FaF and FaR, was designed based on the conserved region of this FZ387 sequence. The amplification of primer pair Xgwm614F and FaR revealed that a specific 350-bp band (designation as A350) was obtained from the species containing A chromosomes. Furthermore, PCR on Langdon Chinese Spring substitution lines was performed, and the results found that this segment was located on both long and short arms of all A chromosomes. However, the amplification of primer pair FaF and Xgwm614R gave rise to a specific DNA band of about 350 bp (designated AB350) from materials containing A and/or B chromosomes. The wild species of wheat and the relatives were amplified using the two pairs of primers, and revealed that only A350 and AB350 were found in Chinese Spring (CS). Sequence comparison and variation of SSR primers binding regions of FZ387 indicated that significant diversity might exist in the internal sequence of this Fatima-like element among triticeae genomes. Meanwhile, both A350 and AB350 can be used as molecular markers for the detection of A and AB genomes. [ABSTRACT FROM AUTHOR]

To clarify whether silicon application could improve root growth of rye (Secale cereale L.) under drought, a pot experiment was conducted under two soil water regimes (soil water contents were kept at 0.015-0.030 or above 0.050 g g-1 for dry and well-watered conditions, respectively). Silicon increased dry weight of rye but did not affect shoot/root ratio under the well-watered condition, while it lowered the ratio under the dry condition. Water use and leaf water potential were increased by silicon under the well-watered condition, although photosynthetic rate, stomatal conductance and water use efficiency were not affected. Under the dry condition, silicon-supplied ryes showed higher photosynthetic rate, stomatal conductance, water use and leaf water potential than silicon-deficient ones. These results suggested that silicon increased dry matter production of ryes under drought, enabling them to allocate more assimilates to root. This resulted in lowering of the shoot/root ratio and better adaptation to drought. [ABSTRACT FROM AUTHOR]

Abstract: Using a PCR-based strategy, four new 75K γ-secalin genes were isolated from Secale cereale, Secale vavilovii, Secale sylvestre, and Secale strictum in genus Secale (rye). Based on amino acid sequences, the primary structure of the 75K γ-secalin subunits was demonstrated, which was composed of four main structural regions: (a) a conservative 19 amino acids signal peptide, (b) a steady short N-terminal region of 12 amino acids containing a cysteine residue, (c) a repetitive domain, which began with the conservative tetrapeptides PQ3 and was rich in glutamine and proline. PFPQ1−2(PQQ)1−2 was the core repeat motif in the repetitive region. Besides amino acid substitutions, this region showed variations in length due to the insertion and deletion events. In the repetitive region of EF432549 (Secale strictum), there were two octapeptides (PFPQQPQQ and PVPQQSQQ) insertions. On the contrary, deletion events of two residues (QT) took place in EF432546 (Secale sylvestre). Accounting for the amino acid replacement, an extra cysteine residue appeared in the repetitive region of EF432546, which did not exist in other genes, and (d) a conserved 143 amino acids C-terminal domain including eight cysteine residues. The implications of the results for quality improvement are discussed. [Copyright &y& Elsevier]

Telocentric trisomics (telotrisomics; one arm of a metacentric chromosome present in addition to two complete genomes) are used in theoretical studies of pairing affinities and chiasma formation in competitive situations and applied in genome analysis, gene localization, gene transfer, and breakage of close linkages. These applications require knowledge of the recombination characteristics of telotrisomics. Appropriate cytological and molecular markers and favorable chromosome morphology are not always available or applicable for quantitative analyses. We developed new mathematical models for extracting the maximum information from simple metaphase I observations. Two types of telotrisomics of the short arm of chromosome 1R of rye (Secale cereale), including several genotypes, were used as test material. In simple telotrisomics, pairing between morphologically identical complete chromosomes was more frequent than pairing between the telocentric and either of the normal chromosomes. In the telocentric substitution, morphologically identical telocentrics paired less frequently with each other than either one with the normal chromosome. Pairing partner switch was significant. Interaction between the two arms was variable. Variation within plants was considerable. Telotrisomics without markers are suitable for analyzing pairing preferences, for gene localization and gene transfer, and for breaking tight linkages, but less so for genome analysis. Les trisomiques télocentriques (télotrisomique : deux génomes complets additionnés d’un bras d’un chromosome métacentrique) sont utiles en recherche fondamentale pour étudier les affinités d’appariement et la formation de chiasmas en présence de compétition et en recherche appliquée pour l’analyse du génome, la cartographie génétique, le transfert de gènes et le bris de liaisons fortes. Ces applications nécessitent une connaissance de leurs caractéristiques lors de la recombinaison. Des marqueurs cytologiques et moléculaires ainsi qu’une morphologie chromosomique favorable ne sont pas toujours disponibles ou applicables pour des analyses quantitatives. Les auteurs ont développé de nouveaux modèles mathématiques pour extraire le maximum d’information à partir de simples observations des métaphases I. Deux types de trisomiques télocentriques impliquant le bras court du chromosome 1R du seigle (Secale cereale), incluant plusieurs génotypes, ont été employés comme matériel test. Chez des télotrisomiques simples, l’appariement entre les chromosomes complets identiques sur le plan morphologique était plus fréquent qu’entre le télotrisomique et l’un ou l’autre des chromosomes normaux. Chez les substitutions télocentriques, les télocentriques identiques sur le plan morphologique s’appariaient moins fréquemment ensemble qu’avec le chromosome normal. Les changements de partenaires d’appariement étaient significatifs. L’interaction entre les deux bras était variable. La variation au sein des plantes était considérable. Les télotrisomiques dépourvus de marqueurs étaient adéquats pour l’analyse des préférences d’appariement, pour la cartographie génétique, le transfert de gènes et pour briser les liaisons fortes, mais moins pour l’analyse génomique. [ABSTRACT FROM AUTHOR]

One of the intriguing issues concerning the dynamics of plant genomes is the occurrence of intraspecific variation in nuclear DNA amount. The aim of this work was to assess the ranges of intraspecific, interspecific, and intergeneric variation in nuclear DNA content of diploid species of the tribe Triticeae (Poaceae) and to examine the relation between life form or habitat and genome size. Altogether, 438 plants representing 272 lines that belong to 22 species were analyzed. Nuclear DNA content was estimated by flow cytometry. Very small intraspecific variation in DNA amount was found between lines of Triticeae diploid species collected from different habitats or between different morphs. In contrast to the constancy in nuclear DNA amount at the intraspecific level, there are significant differences in genome size between the various diploid species. Within the genus Aegilops, the 1C DNA amount ranged from 4.84 pg in A. caudata to 7.52 pg in A. sharonensis; among genera, the 1C DNA amount ranged from 4.18 pg in Heteranthelium piliferum to 9.45 pg in Secale montanum. No evidence was found for a smaller genome size in annual, self-pollinating species relative to perennial, cross-pollinating ones. Diploids that grow in the southern part of the group’s distribution have larger genomes than those growing in other parts of the distribution. The contrast between the low variation at the intraspecific level and the high variation at the interspecific one suggests that changes in genome size originated in close temporal proximity to the speciation event, i.e., before, during, or immediately after it. The possible effects of sudden changes in genome size on speciation processes are discussed. La variation intraspécifique du contenu en ADN nucléaire représente une des questions intrigantes en matière de dynamique des génomes végétaux. Le but de ce travail était de mesurer l’étendue de la variation du contenu en ADN nucléaire aux niveaux intraspécifique, interspécifique et intergénérique chez les espèces diploïdes de la tribu des triticées et d’examiner la relation entre la morphologie ou l’habitat et la taille du génome. Au total, 438 plantes représentant 272 lignées appartenant à 22 espèces ont été analysées. Le contenu en ADN nucléaire a été estimé par cytométrie en flux. Une très faible variation intraspécifique a été observée entre les lignées des espèces diploïdes de triticées ayant des morphologies ou des habitats différents. Contrairement à la constance observée pour le contenu en ADN nucléaire au niveau intraspécifique, des différences significatives ont été observées entre les diverses espèces diploïdes. Le contenu 1C au sein du genre Aegilops variait entre 4,84 pg, chez l’A. caudata, et 7,52 pg chez l’A. sharonensis tandis qu’au niveau intergénérique il variait entre 4,18 pg chez l’Heterantheliumpiliferum et 9,45 pg chez le Secale montanum. Aucune évidence n’a été observée d’un génome plus petit chez les espèces annuelles autofécondées que chez les espèces pérennes allofécondées. Les espèces diploïdes poussant dans la portion méridionale de l’aire de distribution avaient des génomes plus grands que les espèces poussant dans les autres régions de l’aire de distribution. Le contraste d’une faible variation intraspécifique et d’une grande variation interspécifique suggère que les changements dans la taille des génomes seraient survenus quasi-simultanément avec la spéciation, c’est-à-dire avant, durant, ou immédiatement après celle-ci. Les effets possibles de changements soudains dans la taille du génome sur les processus de spéciation sont discutés. [ABSTRACT FROM AUTHOR]

Artificial autotetraploids of diploid perennial rye (Secale montanum guss) plants were obtained by colchicine treatment. C1, C2 and C3 generations of autotetraploid perennial rye were compared for seed set and cytological characteristics such as irregularities in metaphase i (univalents) and anaphase I and II (lagging chromosomes and/or chromatids and bridge formation) and micronuclei in tetrads. In the three generations (C1, C2 and C3) the percentage of cells with univalents was 18.51, 14.56 and 9.38% respectively. The percentage of cells with irregular anaphase i with univalents was 23.43, 15.93 and 7.85%, and for anaphase II cells it was 20.93, 16.47 and 7.16. The percentage of tetrads with micronuclei was 18.17, 14.07 and 6.17% and seed set was 27.72, 43.51 and 59.59% respectively. A negative correlation was found between seed set and the cytological characteristics investigated. The correlations among the characters investigated during meiosis division were statistically significant. Selection of vigorous plants of autotetraploid perennial rye increased seed setting by increasing the cytological balance. However, abnormalities in the early stage of meiosis division were reflected in the later stages of meiosis. [ABSTRACT FROM AUTHOR]

Rye (Secale cereale) is an important diploid (2n = 14, RR) crop species of the Triticeae and a better understanding of its organellar genome variation can aid in its improvement. Previous genetic analyses of rye focused on the nuclear genome. In the present study, the objective was to investigate the organellar genome diversity and relationships of 96 accessions representing diverse geographic regions using chloroplast (cp) and mitochondrial (mt) DNA PCR-RFLPs. Seven cpDNA and 4 mtDNA coding and noncoding regions were amplified using universal cpDNA and mtDNA primer pairs. Each amplified fragment was digested with 13 different restriction enzymes. mtDNA analysis indicated that the number of polymorphic loci (20) was low and genetic differentiation (GST) was 0.60, excluding the outgroups (hexaploid wheat, Triticum aestivum, 2n = 6x = 42, AABBDD; triticale, ×Triticosecale Wittmack, 2n = 6x = 42, AABBRR). cpDNA analysis revealed a low level of polymorphism (40%) among the accessions, and GST was 0.39. Of the 96 genotypes studied, 70 could not be differentiated using cpDNA PCR-RFLPs even though they are from different geographic regions. This is most likely due to germplasm exchange, indicating that genotypes might have a common genetic background. Two cpDNA and 3 mtDNA fragments were significantly correlated to the site of germplasm collection. However, there was no clear trend. These results indicate that the level of organellar polymorphism is low among the cultivated rye genotypes. The cpDNA and mtDNA PCR-RFLP markers used in the present study could be used as molecular markers in rye genetics and breeding programs. Le seigle (Secale cereale) est une importante culture diploïde (2n = 14, RR) au sein des hordées et une meilleure compréhension de la variation au sein des génomes des organites pourrait s’avérer utile en amélioration génétique. Les études génétiques antérieures ont porté sur le génome nucléaire du seigle. Dans le présent travail, l’objectif était d’investiguer la diversité au sein des génomes des organites et les relations entre 96 accessions représentant diverses régions géographiques à l’aide du polymorphisme PCR-RFLP au sein des ADN chloroplastiques (cp) et mitochondriaux (mt). Des régions codantes et non-codantes au sein de l’ADNcp (7) ou de l’ADNmt (4) ont été amplifiées à l’aide d’amorces chloroplastiques ou mitochondriales universelles. Chaque amplicon a été digéré avec 13 enzymes de restriction différentes. La variation au sein de l’ADNmt était faible avec 20 locus polymorphes et une différenciation génétique GST = 0,60, en excluant les groupes externes (blé hexaploïde (Triticum aestivum, 2n = 6x = 42, AABBDD) et le triticale (×Triticosecale Wittmack, 2n = 6x = 42, AABBRR)). L’analyse de l’ADNcp a révélé un faible polymorphisme (40 %) parmi les accessions et le GST était de 0,39. Les marqueurs PCR-RFLP sur l’ADNcp ne permettaient pas de distinguer 70 des 96 génotypes examinés même lorsqu’ils étaient d’origines géographiques distinctes. Une telle situation est vraisemblablement attribuable à l’échange de matériel génétique, ce qui indique que des génotypes pourraient avoir un fond génétique commun. Deux amplicons ADNcp et 3 amplicons ADNmt montraient une corrélation significative avec l’origine des accessions, mais il n’y avait pas de tendance nette. Ces résultats indiquent que le polymorphisme est faible au sein des organites chez les seigles cultivés. Les marqueurs ADNcp et ADNmt employés dans le présent travail pourraient s’avérer utiles comme marqueurs moléculaires pour des études génétiques ou en sélection. [ABSTRACT FROM AUTHOR]

The article is an attempt to summarize available information about the relationships within Dasypyrum ( Triticeae, Poaceae) and between Dasypyrum and other genera in the Triticeae. A relationship between the annual diploid D. villosum (L.) P. Candargy and the perennial tetraploid D. breviaristatum (L.) Frederiksen is discussed on the basis of cytological and molecular investigations. Although the relationship between the two Dasypyrum species seems to be quite close, D. breviaristatum is an autotetraploid with a basic genome different from that of D. villosum. The position of Dasypyrum in relation to other Triticeae is summarized, with special attention being paid to the Triticum and Secale. The closer relationship of Dasypyrum with Secale in comparison to Triticum seems to be reliable, even if only few intergeneric hybrids have been produced. It may be related to the fact that only a few experiments on production of those hybrids have been conducted till the present day, in contrast to experiments concerning hybrids with Triticum. [ABSTRACT FROM AUTHOR]

This work reports the molecular characterization of high molecular weight (HMW) glutenin subunits belonging to the diploid species Aegilops comosa, Aegilops uniaristata, and Aegilops speltoides, which represent three important genomes of the genus Aegilops: M, Un, and S, respectively. Besides improving our knowledge of Aegilops glutenins, which is useful in wheat breeding programs, this study examines the phylogenetic relationships between the glutenin genes of an important group of species of the tribe Triticeae. The new glutenin proteins examined (coded by Glu-Mx, Glu-My, Glu-Unx, Glu-Uny, and Glu-Sy) showed the same general characteristics as those previously described in other species of the tribe Triticeae. A phylogenetic study of the relationships between the new members of the Glu gene family and other known sequences of glutenin genes of the genera Aegilops, Triticum, and Secale was performed. In this analysis, the x- and y-type glutenin subunits showed similar interspecific relationships and differentiated rye from wheat and the Aegilops species. In both cases, the glutenin genes of Aegilops tauschii appeared closely related to the glutenins of the D genome, which, in turn, are closely related to those of Aegilops umbellulata. The homologous gene subunits of A. comosa and A. uniaristata from the section Comopyrum were grouped together. The glutenin gene of A. speltoides was grouped with the wheat B genome genes. This result reinforces the close relationships between the S and B genomes of Aegilops and Triticum, respectively. [ABSTRACT FROM AUTHOR]

Three low-molecular-weight (LMW) glutenin-like genes (designated as Ssy1, Ssy2, and Ssy3) from Secale sylvestre Host were isolated and characterized. The three genes consist of a predicted highly conservative signal peptide with 20 amino acids, a short N-terminal region with 13 amino acids, a highly variable repetitive domain and a less variable C-terminal domain. The deduced amino acid sequences of the three genes were the LMW-m type due to a methionine residue at the N-terminus. The phylogenetic analysis indicated that the prolamin genes could be perfectly clustered into five groups, including HMW-GS, LMW-GS, α/β-, γ-, and κ-prolamin. The LMW glutenin-like genes of S. sylvestre were more orthologous with the LMW-GS genes of wheat and B hordein genes of barley, which also had been confirmed by the homology analysis with the LMW-GS of wheat at Glu-A3, Glu-B3, and Glu-D3 loci. These results indicated that a chromosome locus (designated as Glu-R3) might be located on the R genome of S. sylvestre with the functions similar to the Glu-3 locus in wheat and its related species. [ABSTRACT FROM AUTHOR]

Amplified fragment length polymorphism (AFLP) data were utilized to analyze the phylogenetic relationships among 29 accessions representing 14 of the most commonly recognized ranked species or subspecies in the genus Secale. We observed 789 AFLP markers of 1130 fragments utilizing 18 P-/M- and E-/M- primer combinations. All polymorphic fragments were used to construct phenetic and phylogenetic trees. The resulting phenogram and cladogram had similar tree topologies. Cluster analysis showed that Secale sylvestre was the most distantly related to all other ryes. Annual forms were grouped together, and the perennial forms appeared more closely related to each other. This suggested that life cycle could have played an important role in determining the relationships among Secale species. Secale sylvestre was considered to be the most ancient species, whereas Secalecereale was the most recently evolved species. Amplified fragment length polymorphism analysis clearly separated all Secale species into only 3 major species groups, within the genus Secale: S. sylvestre, Secale montanum (syn. Secale strictum) for perennial forms, and S. cereale for annual forms. This study demonstrated that the AFLP approach is a useful tool for discriminating species differences, and also gave a much better resolution in discerning genetic relationships among Secale species as compared with previous studies using other approaches. [ABSTRACT FROM AUTHOR]

Genotypic differences in aluminum (Al) resistance in rye ( Secale cereale L.), triticale ( X Triticosecale Wittmack), wheat ( Triticum aestivum L.), and buckwheat ( Fygopyrum esculentum Moench) were examined using a compartmental hydroponic system. Four-day-old seedlings were grown for 24 h in 0.5 mM CaCl 2 (pH 4.5) containing 0 or 50 µM Al. Relative root elongation (RRE) at 50 µM Al. (as a percentage of that at 0 Al) was used as the index of Al resistance. On average, rye exhibited the highest Al resistance, followed by buckwheat, triticale, and wheat. However, triticale displayed the greatest genotypic differences. Al content in the root tips of triticale breeding lines negatively correlated with RRE (r = 0.5, P [ABSTRACT FROM AUTHOR]

Cover crop roots and shoots release carbon (C) and nitrogen (N) compoundsin situduring their decomposition. Depending upon the season, these C and N compounds may be sequestered, the C may be respired or the N may be leached below the root zone. A field study was established to identify the contributions of cover crop root and shoot N to different regions within aggregates in the A p horizon of a Kalamazoo loam soil. Fall-planted rye plants (Secale cerealeL.) were labeled the next May with foliar applications of solutions containing 99% atom (15NH4)2SO4. Isotopic enrichment of soil aggregates ranging from 2.0 to 4.0, 4.0-6.3 and 6.3-9.5 mm across was determined following plant residue applications. Concentric layers of aggregates were removed from each aggregate by newly designed meso soil aggregate erosion (SAE) chambers. Non-uniform distributions of total N and recently derived rye N in soil macroaggregates, across time, suggested that the formations and functions of macroaggregates are very dynamics processes and soil aggregates influence where N is deposited. Early in the season, more15N migrated to the interior regions of the smallest aggregates, 2-4 mm across, but it was limited to only surfaces and transitional regions of the larger aggregates, 6.3-9.3 mm across. Exterior layers of aggregates between 6.0 and 9.5 mm retained 1.6% of the Nderived from roots in July 1999, which was three times more than their interior regions. This was slightly greater than the % Nderived from shoot. One month later, as the maize root absorption of N increased rapidly, % Nderived from roots and % Nderived from shoot were nearly equal in exterior layers and interior regions of soil aggregates. This equilibrium distribution may have been from either greater diffusion of N within the aggregates and/or maize root removal form aggregate exteriors. Results supported that most of roots grew preferentially around surfaces of soil aggregates rather than through aggregates. Cover crop roots contributed as much N as cover crop shoots to the total soil N pool. Subsequent crops use N from the most easily accessible zones of soil structure, which are surfaces of larger soil aggregates. Therefore maintaining active plant roots and aggregated soil structure in the soil enhances N sequestration and maximize soil N availability. These studies suggest that the rapid and perhaps bulk flow of soil N solutions may bypass many of the central regions of soil aggregates, resulting in greater leaching losses. [ABSTRACT FROM AUTHOR]

Chromosome in situ hybridization (FISH and GISH) is a powerful tool for determining the chromosomal location of specific sequences and for analysing genome organization and evolution. Tricepiro (2n = 6x = 42) is a synthetic cereal obtained by G. Covas in Argentina (1972), which crosses hexaploid triticale (2n = 6x = 42) and octoploid Trigopiro (2n = 8x = 56). Several years of breeding produced a forage crop with valuable characteristics from Secale, Triticum, and Thinopyrum. The aim of this work is to analyse the real genomic constitution of this important synthetic crop. In situ hybridization using total DNA of Secale, Triticum, and Thinopyrum as a probe (GISH) labelled with biotin and (or) digoxigenin showed that tricepiro is composed of 14 rye chromosomes and 28 wheat chromosomes. Small zones of introgression of Thinopyrum on wheat chromosomes were detected. The FISH using the rye repetitive DNA probe pSc 119.2 labelled with biotin let us characterize the seven pairs of rye chromosomes. Moreover, several wheat chromosomes belonging to A and B genomes were distinguished. Therefore, tricepiro is a synthetic hexaploid (2n = 6x = 42) being AABBRR in its genomic composition, with zones of introgression of Thinopyrum in the A genome of wheat. [ABSTRACT FROM AUTHOR]

The association pattern of marked tetrasomes of Secale chromosome 1R at meiotic first metaphase was analyzed. Two of the four chromosomes were identical with terminal C-bands at both arms; the other two were also identical but lacked C-bands and were homologous or homeologous with the first two. Four different types of heterozygotes for 1R were studied: (i) autotetraploid hybrids between genetic variants within Secale cereale subsp. cereale, (ii) tetraploid hybrids between subspecies of Secale cereale, (iii) tetraploid hybrids between species of Secale, and (iv) autotetrasomes of S. cereale in a wheat background. Earlier observations that heterozygous associations (banded with unhanded) had consistently higher chiasma frequencies than homozygous associations were extended and confirmed. To analyze this phenomenon more closely, the possible relations between this correlation and several other meiotic phenomena were studied. For this analysis, three genetically different autotetraploid hybrids within S. cereale were selected that differed with respect to the relation between pairing type and chiasma frequency. Special attention was given to different patterns of interference and other meiotic phenomena in the two chromosome arms of chromosome 1R. No relations between such phenomena and the relation between pairing type and chiasma frequency could be established. A hypothesis is formulated assuming that long-distance homologue attraction is concentrated in a limited number of sites and that in different genotypes, different patterns of active sites are present. Moderately weak attraction sites can pair with strong homologous sites under favorable genetic conditions, but two weak sites cannot. Then, heterozygotes have more effective pairing initiation and consequently chiasma formation than homozygotes. Under less favorable conditions, only strong sites are effective, and then, homozygotes pair better, but the chiasma frequency is lower. A model of the forces... [ABSTRACT FROM AUTHOR]

In cold‐hardened leaves (CHL) of winter rye (Secale cereale L.) much higher levels of malate were detected by 13C‐NMR than in non‐hardened leaves (NHL). As this was not observed previously, malate metabolism of CHL was studied in more detail by biochemical assays. The activities of several enzymes of malate metabolism, NADP‐malate dehydrogenase, NAD‐malate dehydrogenase, phosphoenolpyruvate carboxylase, and NADP‐malic enzyme, were also increased in CHL. Short exposures to low temperature of 1–3 d did not induce increases in the malate content or in the activities of enzymes of malate metabolism in mature NHL. The malate content and the enzyme activities declined within 1–2 d after a transfer of CHL from their growing temperature of 4 °C to 22 °C. The malate content was further increased when CHL were exposed to a higher light intensity at 4 °C. In CO2‐free air the malate content of CHL strongly declined at 4 °C. Malate may thus serve as an additional carbon sink and as a CO2‐store in CHL. It may further function as a vacuolar osmolyte balancing increased concentrations of soluble sugars previously observed in the cytosol of CHL. Malate was not used as a source of reductants when CHL were exposed to photo‐oxidative stress by treatment with paraquat. However, the activities of enzymes of the oxidative pentose phosphate pathway were markedly increased in CHL and may serve as non‐photosynthetic sources of NADPH and thus contribute to the previously observed superior capacity of CHL of winter rye to maintain their antioxidants in a reduced state in the presence of paraquat. [ABSTRACT FROM PUBLISHER]

Genetic analysis of three semi-dwarf genotypes of rye (Secale cereale L.) -- 'Moskowskij Karlik', 'Gülzow kurz' and 'R 18', which were shown to be insensitive to applied gibberellic acid (GA3), has been carried out by using a seedling test. It could be demonstrated that all of the three genotypes are carrying recessive alleles for GA-insensitivity. Whereas the alleles of 'Moskowskij Karlik' and 'R 18' seem to have the same locus on chromosome 5R, the GA-insensitivity of 'Gülzow kurz' is governed by a different gene, most probably located on chromosome 7R. The relationship between the genes (alleles) for GA-insensitivity and semi-dwarfness, including the symbolization of the Gai-genes as well as their utilization in rye breeding is discussed. [ABSTRACT FROM AUTHOR]

The survival at sub-zero temperatures of leaf blade cells of rye (Secale cereale L. cv. Voima), which had not been cold acclimated, was determined by measuring the efflux of ninhydrin-positive substances: 50% of the cells were dead at -4°C (LT50) and none survived at -12°C or below. Examination of ultrastructural changes during cold hardening and freezing injury requires frozen tissues prepared for transmission electron microscopy without thawing. Specimens were prepared from leaf blade segments at room temperature, -4°C or -12°C by plunge freezing at 3 m s-1 into a cooling medium at -170°C followed by freeze-substitution in acetone with OsO4 fixation. Comparisons of room temperature specimens were made with those prepared by chemical fixation using glutaraldehyde/paraformaldehyde/tannic acid. On freezing to -12°C, the cells were severely dehydrated and distorted, the vacuoles severely shrunken and the cytoplasm and mitochondria disorganized whereas the chloroplasts were little affected. On freezing to -4°C, some cells were as disorganized as those at -12°C, others were relatively intact, and some showed evidence of intracellular ice crystal formation. [ABSTRACT FROM AUTHOR]

The diploid hybrid Hordeum californicum x Secale vavilovü and the tetraploid hybrid H. parodü x S. anatolicum, were obtained through embryo rescue techniques at relative frequencies of 0.70 and 5.3% of pollinated florets, respectively. Means of 11.74[supI] + 1.13[supII] per cell at metaphase I of meiosis were obtained in the diploid hybrid and 14.74[supI] + 6.31[supII] + 0.22[supIII] + 0.02[supIV] in the terraploid hybrid with a maximum of 6.0[supI] + 4.0[supII] and 9.0[supII] + 2.0[supIII] + 1.0[supIV] respectively. In the diploid hybrid there was preponderance of intregenomic pairing (86.7%). Increased pairing in the tetraploid hybrid was attributed to autosyndesis among Hordeum chromosomes. [ABSTRACT FROM AUTHOR]

Secale is a small but very diverse genus from the tribe Triticeae (family Poaceae), which includes annual, perennial, self-pollinating and open-pollinating, cultivated, weedy and wild species of various phenotypes. Despite its high economic importance, classification of this genus, comprising 3–8 species, is inconsistent. This has resulted in significantly reduced progress in the breeding of rye which could be enriched with functional traits derived from wild rye species. Our previous research has suggested the utility of non-coding sequences of chloroplast and mitochondrial DNA in studies on closely related species of the genus Secale. Here we applied the SPInDel (Species Identification by Insertions/Deletions) approach, which targets hypervariable genomic regions containing multiple insertions/deletions (indels) and exhibiting extensive length variability. We analysed a total of 140 and 210 non-coding sequences from cpDNA and mtDNA, respectively. The resulting data highlight regions which may represent useful molecular markers with respect to closely related species of the genus Secale, however, we found the chloroplast genome to be more informative. These molecular markers include non-coding regions of chloroplast DNA: atpB-rbcL and trnT-trnL and non-coding regions of mitochondrial DNA: nad1B-nad1C and rrn5/rrn18. Our results demonstrate the utility of the SPInDel concept for the characterisation of Secale species. [ABSTRACT FROM AUTHOR]

The use of androgenetic doubled haploids in rye breeding is still limited by low regeneration rates. In this study we tested the influence of two modified MS-media on the number of reacting anthers and on plant regeneration. Picloram and 2,4-D were used as auxin components in the induction media. The highest induction rates (reacting anthers per 100 cultivated anthers) and the highest regeneration rates (number of green plants per 100 cultivated anthers) were reached on a modified MS-medium containing Picloram as auxin source, regardless of the donor plant material. The comparison of the results obtained with the single cross 'SC 35' which contains genes of Secale vavilovii and the true Secale cereale donor forms clearly show the genotypic influence of donor plant material on induction and regeneration ability. [ABSTRACT FROM AUTHOR]

Background: The recent development of next-generation sequencing DNA marker technologies, such as genotyping-by-sequencing (GBS), generates thousands of informative single nucleotide polymorphism markers in almost any species, regardless of genomic resources. This enables poorly resourced or “orphan” crops/species access to high-density, high-throughput marker platforms which have revolutionised population genetics studies and plant breeding. DNA quality underpins success of GBS methods as the DNA must be amenable to restriction enzyme digestion and sequencing. A barrier to implementing GBS technologies is access to inexpensive, high-throughput extraction methods that yield sequencing-quality genomic DNA (gDNA) from plants. Several high-throughput DNA extraction methods are available, but typically provide low yield or poor quality gDNA, or are costly (US$6–$9/sample) for consumables. Results: We modified a non-organic solvent protocol to extract microgram quantities (1–13 μg) of sequencing-quality high molecular weight gDNA inexpensively in 96-well plates from either fresh, freeze-dried or silica gel-dried plant tissue. The protocol was effective for several easy and difficult-to-extract forage, crop, horticultural and common model species including Trifolium, Medicago, Lolium, Secale, Festuca, Malus, Oryza, and Arabidopsis. The extracted DNA was of high molecular weight and digested readily with restriction enzymes. Contrasting with other extraction protocols we assessed, Illumina-based sequencing of GBS libraries developed from this gDNA had very uniform high quality base-calls to the end of sequence reads. Furthermore, DNA extracted using this method has been sequenced successfully with the PacBio long-read platform. The protocol is scalable, readily automated without requirement for fume hoods, requires approximately three hours to process 192 samples (384–576 samples/day), and is inexpensive at US$0.62/sample for consumables. Conclusions: This versatile, scalable and simple protocol yields high molecular weight genomic DNA suitable for restriction enzyme digestion and next-generation sequencing applications including GBS and long-read sequencing platforms such as PacBio. The low cost, high-throughput, and extraction of high quality gDNA from a range of fresh and dried source plant material makes this method suitable for many sequencing and genotyping applications including large-scale sample screening underpinning breeding programmes. [ABSTRACT FROM AUTHOR]

Botanical Garden in Warsaw was established by the Polish Academy of Sciences as a special research unit for plant genetic resources conservation in 1974. The first research studies and conservation efforts were devoted to rye, the leading at that time cereal crop in Poland. Our efforts were focused on the primitive germplasm of genus Secale: wild Secale species, local landraces and old cultivars of rye. Genetic resources of Secale were collected from all over the world. For the long-term storage of rye caryopses the seed bank was organized. Seeds desiccated to 7-8% moisture content were stored at -25 °C in vacuum conditions in hermetic sealed aluminum polyethylene bags. The Secale collection was established in very close collaboration with the USDA-ARS research units, especially with the National Center for Genetic Resources Preservation in Fort Collins, Colorado and rye germplasm was preserved in both places: in Warsaw and in Fort Collins. At present the Secale collection comprises 2.608 accessions, among them 89 wild Secale species, 1588 local landraces and 490 cultivars, as well as 380 accessions of genetic and breeding lines. In our seed bank 61 wild species related to cereals of Triticinae subtribe is also preserved. The second germplasm collection in Botanical Garden, started in 1985, was genus Malus, especially old or historical cultivars of apple trees. At the beginning the Malus collection was preserved as trees in pomological orchard opened for public display. Thanks to collecting efforts in Poland and in neighbouring countries: Ukraine, Lithuania and Slovakia 1046 accessions were collected, and 445 of them were identified as cultivars. Thanks to cooperation with the Kazakh Academy of Sciences the collection of Malus sieversii from natural localities in Kazakhstan was also established. In recent years the cryogenic storage was also developed for the preservation of dormant apple buds, as a supplementary conservation method for apple trees genetic resources. At present more than 100 accessions of historical apple cultivars are stored in liquid nitrogen. The long-term storage of seeds was also applied for ex situ conservation of rare and endangered species of Polish vascular flora. Seeds collected from natural localities are also preserved in cryogenic conditions at temperature ca. -150 °C in vacuum of liquid nitrogen. For this purpose, special studies on seed germination biology of wild species had to be developed. These studies were performed in the framework of two EU projects: ENSCONET and FLORNATUR. At present the seeds of 120 species of Polish native plants, represented by 385 natural populations are stored in our cryogenic seed bank. [ABSTRACT FROM AUTHOR]