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In the presented hybridization programme of barley cultivars and rye inbred lines including 48 cross combinations the seed set ranged from 3.13 to 92.98%, while embryos were formed in 0.74 to 36.36% in successful pollinations. Sixty five plants were generated by embryo callus culture and one - by embryo culture without callus formation. The hybrids had somatic chromosome numbers 2n=14 (60 plants) and 2n=28 (6 plants). Plants obtained via embryo callus culture showed good vegetative vigour and well-developed root system. Spike morphology of all plants resembled that of rye. Meiosis in 17 diploids showed 0.13-0.63 barley-barley and rye-rye bivalents with a chiasma frequency of 0.14-0.69 per cell. The heteromorphic bivalent-like configurations occurred in five plants in 0.01-0.02 per cell. The amphidiploids had 7.79-10.71 barley-barley and rye-rye bivalents with a chiasma frequency of 9.36-17.75 per cell. All plants, with 14 and 28 chromosomes, were completely sterile both in backcrosses and when selfed.
The effect of germination on the rate of formation of some endo- and exohydrolases, important in baking, in rye kernels was examined. Germination of the rye gave increase in a-amylase, endo-b-xylanase, endo-b-glucanase, b-xylosidase, a-arabinosidase, b-glucosidase as well as endo- and exopeptidases activities. The most intensive changes of activities in the group of examined enzymes were observed for a-amylase. b-amylase activity did not significantly increase on germination. The increase of endohydrolases activities in germinating rye kernels was much more markedly compared with activities of exohydrolases.
This study was conducted in order to identify quantitative trait loci (QTLs) for the in vitro culture response of winter rye (Secale cereale L.) immature embryos and immature inflorescences. A genetic linkage map comprising 67 SSRs, 9 ISSRs, 13 SAMPLs, 7 RAPDs, 2 SCARs and one EST marker was created based on the analyses of 102 recombinant inbred lines from the cross between lines L318 (which has a good response in tissue cultures) and L9 (which is unable to regenerate plants from somatic tissues and anthers). The map spans 979.2 cM, and the average distance between markers is 9.9 cM. Two characteristics were evaluated: callus induction (CI) and somatic embryogenesis ability (SE). They were expressed as the percentage of immature embryos/inflorescences producing callus (designated ECI/ICI) and the percentage of explants producing somatic embryos (ESE/ISE). All the analysed traits showed continuous variation in the mapping population but a non-normal frequency distribution. We identified nine putative QTLs controlling the tissue culture response of rye, explaining up to 41.6% of the total phenotypic variation: two QTLs for ECI — eci-1, eci-2; 4 for ESE — ece-1, ese-2, ese-3, ese-4; 2 for ICI — ici-1, ici2; and 1 for ISE — ise-1. They were detected on chromosomes 1R, 4R, 5R, 6R and 7R.
RFLP analysis of mitochondrial DNA was carried out with eight restriction enzymes BamHI, EcoRI, HaeIII, HindIII, MspI, PstI, SalI and XhoI, from which nine mitochondrial gene probes (atp6, atp9, atp1, cox1, nad3, nad6, nad9, pol-r, orf25) were hybridized, by means of digestion products, for seven species of the genus Secale. RFLP EcoRI/pol-r specific markers were determined for all the species of rye. To estimate the relationships among species, genetic pairwise similarities between them were estimated and a UPGMA dendrogram was constructed. The analysis separated the species into two groups. The first comprises the pair Secale sylvestre Host and S. cereale subsp. segetale Zhuk., exhibiting the greatest genetic similarity, that is, closest relationships. The second group is composed of S. strictum/Presl/Presl, S. strictum/Presl/Presl subsp. kuprijanovii/Grossh./ Hammer, S. strictum/Presl/Presl subsp. africanum/Stapf/Hammer, Secale cereale L. and S. vavilovii Grossh., with one clear subgroup comprising Secale strictum/Presl/Presl and S. strictum/Presl/Presl subsp. kuprijanovii/ Grossh./Hammer. The latter two species showed the highest genetic similarity to each other and relatively high genetic similarity to the remaining species in the group.
The occurrence of ergot [Claviceps purpurea (Fr.) Tul.] was studied in eight Lithuania-grown winter rye varieties at Šiauliai University’s Botanical Garden during the years 2002–2004. The source of infection consisted of ergot sclerotia incorporated in superficial layer of the soil between experimental plots of rye. Germination of ergot sclerotia and formation of ascocarps were assessed every three days from the first emergence of ascocarps over the soil surface. Percentage of flowering ears of rye was recorded every three days from the beginning of flowering of the first ears to the end of flowering. Percentage of ergot-infected ears and number of sclerotia per 1 m2 were estimated at rye hard maturity stage (BBCH 87). Averaged data from three experimental years suggest that local winter rye tetraploid variety Rûkai, characterised by late and lengthy flowering, exhibited the highest ergot susceptibility. Diploid varieties Duoniai and Joniai, flowering at a similar period as Rûkai, but having less expressed peak of flowering, were significantly less ergot – infected in 2002 and 2004, but in 2003 the occurrence of ergot on all the three varieties was similar. In our tests we did not reveal any increased ergot-susceptibility of the hybrid variety Esprit, although many authors indicate that hybrid varieties are the most susceptible to this pathogen. From the tested rye varieties, Walet, Motto and Hacada were found to be the least infected varieties, whose flowering was short and only a small number of ears flowered simultaneously. A strong negative correlation between crop density and ergot infection was established.
The aim of this study was to identify the genetic changes in rye seeds induced by natural aging during long-term storage and successive regeneration cycles under gene bank conditions. Genomic DNA from four rye samples (cv. Dańkowskie Złote), varying in their initial viability and having gone through one or three reproduction cycles, were analysed using specific PCR targeting of a secalin locus, and various repetitive fragments defined by the R173 sequence. A statistical analysis of the band frequencies for both secalin and R173.3 primer pairs revealed no changes in their frequencies. Similar data on R173.1 demonstrated significant changes between samples of different initial viability showing a lack of a band of the expected length (987 bp) in progeny originating from low viability seeds lots. These changes were inherited even after three regeneration cycles. Our results may indicate that long-term storage that leads to loss of viability also generates heritable changes in the preserved germplasm. However, it remains to be discovered where these changes occur and whether they are connected with coding or with non-coding DNA regions.
Four F2 mapping populations derived from crosses between rye inbred lines DS2×RXL10, 541×Ot1-3, S120×S76 and 544×Ot0-20 were used to develop a consensus map of chromosome 6R. Thirteen marker loci that were polymorphic in more than one mapping population constituted the basis for the alignment of the four maps using the JoinMap v. 3.0 software package. The consensus map consists of 104 molecular marker loci including RFLPs, RAPDs, AFLPs, SSRs, ISSRs, SCARs, STSs and isozymes. The average distance between the marker loci is 1.3 cM, and the total map length is 135.5 cM. This consensus map may be used as a source of molecular markers for the rapid development of new maps of chromosome 6R in any mapping population.
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