Search

Drought is one of the major threats to food security. Among several mechanisms involved in plant stress tolerance, one protein family—the plant metallothioneins (MTs)—shows great promise for enhancing drought resistance. Plant metallothioneins in oat (Avena sativa L.) have not yet been deeply analysed, and the literature lacks a comprehensive study of the whole family of plant MTs in response to drought. In this study, we showed that the number and nature of cis-elements linked with stress response in promoters of AsMTs1–3 differed depending on the MT type. Drought stress in oat plants caused an increase in the expression of AsMT2 and AsMT3 and a decrease in the expression of AsMT1 compared to well-watered plants. Moreover, the low values of relative water content, water use efficiency, net photosynthesis (PN), transpiration (E), stomatal conductance (gs), chlorophyll a, and carotenoid were accompanied by high levels of electrolyte leakage, internal CO2 concentration (Ci) and abscisic acid content, and high activity of antioxidants enzymes in plants under drought stress. The present study puts forward the idea that AsMTs are crucial for oat response to drought stress not only by regulating antioxidant activity but also by changing the plant water regime and photosynthesis. Our results support the hypothesis that structural differences among types of plant MTs reflect their diversified physiological roles. [ABSTRACT FROM AUTHOR]

Leucojum aestivum is known for its ability to biosynthesize alkaloids with therapeutic properties, among which galanthamine used for the treatment of Alzheimer's disease. New sources of this alkaloid are still being explored. In this study, a novel strain PLV of endophytic bacterium Paenibacillus lautus was isolated from in vitro L. aestivum plants. We report the whole genome sequence of that strain and its capacity to produce alkaloids and growth regulators. The effect of elicitation with autoclaved bacteria on the production of alkaloids was examined. Ten alkaloids were identified in bacteria extracts: galanthamine, lycorine, ismine, lycoramine, haemanthamine, tazettine, galanthine, homolycorine, 1,2-dihydrochlidanthine, and hippeastrine. The mean contents of galanthamine and lycorine were 37.51 µg/g of dry weight (DW) and 129.93 µg/g of DW, respectively. Moreover, isolated P. lautus strain synthesized: indole-3-acetic acid, t-zeatin, c-zeatin, kinetin, gibberellin A1, abscisic acid, salicylic acid, benzoic acid. In vitro elicitation of cultures with P. lautus increased dry biomass, stimulated galanthamine and lycorine production, contributed to 8,9-desmethylenebis (oxy)-7,9 dimethoxy-crinan biosynthesis, change pigments content, and antioxidant enzymes activities. Our findings for the first time point out that galanthamine can be synthesized by an microorganism. Moreover isolated strain can be used as a new elictor of Amaryllidaceae alkaloids biosynthesis. [ABSTRACT FROM AUTHOR]

Species from the genus Ocimum L. (basil) are among the most cultivated plants due to their large content of secondary metabolites, in particular essential oils and phenolic compounds. Still, different conditions of basil cultivation cause significant variations of quantitative and qualitative characteristics of material originating from basil plants. The application of plant tissue culture to produce biologically active compounds is a well-established alternative to the cultivation of whole plants. It provides the opportunity to obtain biotechnologically valuable plant characteristics, including a high content of secondary metabolites such as phenolic acids and flavonoids for the shortest period. The present paper summarizes the most cultivated basil genotypes worldwide and data about the mass propagation, somatic embryogenesis, basil cell and organ cultures, together with the main properties regarding the enhanced synthesis of secondary metabolites under tissue culture conditions. For most of the studies, increased synthesis of biologically active compounds (in particular phenolic acids, isoprenoids, and flavonoids) can be seen. However, for many of them, information regarding the used genotype or origin of plant material is missing. Considering the large number of species and cultivars belonging to the genus Ocimum L., appropriate utilization can provide maximal exploitation. Understanding how particular genotypes respond to specific conditions, treatments, and types of culture for enhancing the production of secondary metabolites could be the basis in designing protocols and further progress. Key message: In this review, we described recent progress in secondary metabolites production of Ocimum L. species. The content of secondary metabolites, mainly phenolics and flavonoids, can be enhanced by various types of in vitro cultures. [ABSTRACT FROM AUTHOR]

A critical step in the production of doubled haploids is a conversion of the haploid embryos into plants. Our study aimed to recognize the reasons for the low germination rate of Avena sativa haploid embryos obtained by distant crossing with maize. Oat cultivars of 'Krezus' and 'Akt' were investigated regarding embryo anatomy, the endogenous phytohormone profiles, and antioxidant capacity. The zygotic embryos of oat were used as a reference. It was found that twenty-one days old haploid embryos were smaller and had a less advanced structure than zygotic ones. Morphology and anatomy modifications of haploid embryos were accompanied by extremely low levels of endogenous auxins. Higher levels of cytokinins, as well as tenfold higher cytokinin to auxin ratio in haploid than in zygotic embryos, may suggest an earlier stage of development of these former. Individual gibberellins reached higher values in 'Akt' haploid embryos than in the respective zygotic ones, while the differences in both types of 'Krezus' embryos were not noticed. Additionally to the hormonal regulation of haploid embryogenesis, the poor germination of oat haploid embryos can be a result of the overproduction of reactive oxygen species, and therefore higher levels of low molecular weight antioxidants and stress hormones. [ABSTRACT FROM AUTHOR]

Androgenic responsiveness in anther (AC) and isolated microspore cultures (MC) was analysed using 15 lines of Polish winter rye (Secale cereale L.). The effect of low temperature (LT) alone or in combination with osmotic stress induced by mannitol treatment (MAN) and/or with reduced glutathione (GSH) on the effectiveness of the process was studied. Interestingly, each treatment had a different effect on microspore (mcs) vitality and capability to divide symmetrically. The first criterion for successful embryogenesis was to exceed the threshold number of at least 25% dividing microspores, which determined 'embryogenic suspension culture'. In some configurations a spectacular effect was achieved, especially in lines highly recalcitrant to androgenesis induction. Relatively high effectiveness of androgenesis induction (up to 4.58 AS per 105 mcs per spike in MC and 21.29 AS per spike in AC) showed that the developed protocol with GSH and/or MAN tiller pre-treatments overcomes the genotypic barrier for androgenesis initiation in rye. Moreover, relatively high, spontaneous genome diploidization (55%) of regenerated plants demonstrated that the described protocols could be effectively integrated into conventional rye breeding programmes. Key message: Glutathione and mannitol break the barrier of androgenesis initiation by increasing the dividing and vital microspores ratio. This marker is useful for screening material in breeding programs utilizing DH technology. [ABSTRACT FROM AUTHOR]

The efficiency of embryogenesis of anther culture was compared using four cultivars of oat (Avena sativa L.): 'Akt', 'Bingo', 'Bajka', and 'Chwat'. Despite the high resistance of oat to the process of androgenesis, all tested cultivars produced embryo-like structures and only two of them, 'Akt' and 'Chwat', produced fertile doubled haploid plants. A strong cultivar dependency was observed during induction of androgenesis. Further, cold pretreatment together with high temperature shock enhanced the efficiency of this technique. The highest number of embryo-like structures and haploid plants was obtained from cv. 'Chwat' (3.6% and 0.8%, respectively). Embryo-like structure formation also depended on the distance from the base of the flag leaf to the penultimate leaf of the panicle. Most of them were observed on anthers harvested from panicles of which the distance from the base of the flag leaf to the penultimate leaf was less than 4 cm. The presence of the induction medium supplemented with different plant growth regulators was essential for the induction of embryo-like structures but did not increase the production of haploid plants and doubled haploid lines. The highest number of embryo-like structures and plants was obtained on W14 medium with the addition of 2.0 mg/dm3 2,4-dichlorophenoxyacetic acid and 0.5 mg/dm3 kinetin (2.7%). The low haploid plant regeneration rate (from 0.03 to 0.05%) still limits the practical application of anther culture for the production of doubled haploid lines in oat. [ABSTRACT FROM AUTHOR]

The development of embryos requires interaction of many endogenous hormones. The aim of the study was to determine which endogenous phytohormones are involved in the process of oat (Avena sativa L.) haploidization. Oat haploids were obtained by wide crossing with Zea mays L. The hormonal profiles of the ovaries with (OE) and without developed embryo (OWE) were compared. Phytohormone contents were measured by UHPLC coupled with mass spectrometer. The total content of indole-3-acetic acid (IAA), trans-zeatin (tZ), and kinetin (KN) in OE was significantly higher than in OWE. 4-Chloroindole-3-acetic acid was detected only in OWE. There were no differences between OE and OWE in the content of gibberellins (GA1, GA3, GA4, GA6, GA7) and stress hormones (abscisic, salicylic, jasmonic acids). Content of endogenous KN was highly negatively correlated with the percentage of haploid embryos, germinated haploid embryos, haploid plants on MS (in vitro), haploid plants in soil (ex vitro), and doubled haploid lines. The tZ content negatively correlated with the frequency of haploid embryo formation, germination, and haploid plants obtained in vitro, as opposed to GA1, which correlated positively. A positive correlation was found between IAA and tZ in OE, whereas in OWE it was a negative correlation. The profiles of phytohormones in OE and OWE were determined; however, their mode of action needs to be clarified. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the effect of indole-3-butyric acid (IBA) and exogenous sucrose concentrations on in vitro rooting, soluble sugar, starch and phenolic production, and ex vitro survival of four magnolia cultivars. There was a significant linear increase in rooting of most magnolia genotypes with an increase in IBA concentration in the medium from 1 to 6 mg L−1. A further increase of IBA concentration to 10 mg L−1 decreased ('Elizabeth', 'Burgundy') or had no effect on rooting frequency ('Spectrum'). The effect of IBA on rooting of magnolia shoots was modified by sucrose supply. The three out of four magnolia cultivars showed the highest rooting efficiency in the presence of 6 mg L−1 IBA and 30 g L−1 of sucrose. Generally, decreasing and increasing the sucrose supply from 30 g L−1 significantly lowered the rooting frequency. In 'Yellow Bird', sucrose at 40 g L−1 totally blocked root formation. It has been found that the poor rooting ability of 'Yellow Bird' coincided with a low soluble sugar content, and high production of starch and phenolics in the shoot bases during the whole rooting period as compared to easy-to-root cultivars. After 5 weeks of the growth on IBA medium, rooted and unrooted shoots were transferred to ex vitro conditions. Both types of shoots showed a high survival and rooting rate (85.4-100%), but they differed in their growth activity and quality. Sucrose concentration in the rooting medium had a post-effect on ex vitro root formation and survival of magnolia plantlets. Ex vitro establishment (13.3%) of recalcitrant 'Yellow Bird' was obtained only when the shoots were taken from rooting medium containing the lowest level of sucrose (20 g L−1). [ABSTRACT FROM AUTHOR]

Polyamines (PAs) are related to many physiological processes, including soil drought stress. Two yellow lupin 'Morocco 4' (drought tolerant) and 'Taper' (drought sensitive) were exposed to soil drought for 2 weeks. The half of the examined plants were additionally sprayed with a solution of polyamine biosynthesis inhibitor- dl-α-difluoromethylarginine (DFMA). Yellow lupin leaves showed a 19% increase and seeds a 54% decrease in the total PA contents. The seeds contained fourfold less PAs than the leaves under drought conditions. The highest amount of spermidine and lack of agmatine were found in the leaves, while in the seeds the highest content of spermine and the presence of agmatine was confirmed. The use of DFMA under drought conditions decreased the content of spermine in 'Morocco 4' and 'Taper' (41 and 19%, respectively) and spermidine in 'Taper' (by 13%), as well as reduced two out of three of the yield components. More tolerant 'Morocco 4', after DFMA treatment was characterized by a higher spermidine and spermine content and a smaller decrease in yield components compared to the less tolerant 'Taper'. Simultaneously subjecting plants to soil drought and DFMA treatment caused in 'Morocco 4' a decline in the number of pods and seeds per plant and seeds dry weight per plant (64, 50 and 54%, respectively), while in 'Taper' a reduction of the number of pods per plant and seeds per pod (32 and 27%, respectively) was observed. These results confirm that PAs are involved in yellow lupin tolerance and may play a protective function under soil drought conditions. [ABSTRACT FROM AUTHOR]

Functionality of the photosynthetic system under water stress is of major importance in drought tolerance. Oat ( Avena sativa L.) doubled haploid (DH) lines obtained by pollination of F oat crosses with maize were used to assess the differences in plant genotypic response to soil drought. The investigations were based on the measurements of gas exchange and chlorophyll a fluorescence kinetics. Drought was applied to 17-day-old seedlings by withholding water for 14 days and subsequent plant recovery. Non-stressed optimally watered plants served as controls. Yield components were determined when plants reached full maturity. It was shown differences among the oat lines with respect to drought stress susceptibility (SI) and stress tolerance index mean productivity and drought susceptibility index. Sensitivity to drought of individual DH lines was significantly different, as demonstrated by the correlation between drought susceptibility index and yield components, such as dry weight (GW) or grain number (GN) of the harvested plants. GW and GN were lower in drought-sensitive genotypes exposed to drought stress compared to those resistant to drought. The principal component analysis allow to separate three groups of lines differing in their sensitivity to drought stress and indicated that tolerance to drought in oat has a common genetic background. [ABSTRACT FROM AUTHOR]

Obtaining oat DH lines is only effective via wide crossing with maize. Seven hundred haploid embryos from 21 single F progeny obtained from wide crosses with maize were isolated, divided into four groups according to their size (<0.5 mm, 0.5-0.9 mm, 1.0-1.4 mm, and ≥1.5 mm), and transferred into 190-2 regeneration medium with different growth regulators: 0.5 mg L kinetin (KIN) and 0.5 mg L 1-naphthaleneacetic acid (NAA); 1 mg L zeatin (ZEA) and 0.5 mg L NAA; or 1 mg L dicamba (DIC), 1 mg L picloram (PIC), and 0.5 mg L kinetin (KIN). Among all isolated embryos, approximately 46.1% were between 1.0-1.4 mm, while the smallest group of embryos (7.1%) were those <0.5 mm. The ability of haploid embryos to germinate varied depending on oat genotypes and the size of embryos. Haploid embryos <0.5 mm were globular and did not germinate, whereas embryos ≥1.5 mm had clearly visible coleoptiles, radicles, and scutella, and were able to germinate. Germination of oat haploid embryos varied depending on growth regulators in the regeneration medium. Most haploid embryos germinated on medium with 0.5 mg L NAA and 0.5 mg L KIN, while the fewest germinated on medium with 1 mg L DIC, 1 mg L PIC, and 0.5 mg L KIN. One hundred thirty germinated haploid embryos converted into haploid plants. Fifty oat DH lines were obtained after colchicine treatment. [ABSTRACT FROM AUTHOR]

Taraxacum pieninicum is an extremely threatened species. It seems that traditional protection methods of this species are insufficient and it is necessary to use biotechnology tools that allow the in vitro storage of plant material. The present study describes in vitro conservation of T. pieninicum by slow-growth storage. Various light conditions and abscisic acid (ABA) treatments and combinations thereof were tested. Viability, proliferation rate and ability of shoots to root were evaluated during regrowth. Moreover, the effect of shoot storage conditions on the ABA level was analysed. The results showed that light during 3-months' storage increased the level of endogenous ABA. Similar results were observed when storage at a low temperature was prolonged to 9 months. Changes in ABA level had a negative effect on shoot condition. However, these changes were related to leaves and did not affect the ability of shoot tips to proliferate after long-term storage. Addition of ABA to storage medium increased several folds the level of ABA in plant tissues, which resulted in a reduction in the visual rating and proliferation rate. Shoots obtained after post-storage regrowth were able to root. All rooted shoots survived adaptation to field conditions and were able to flower in the second year after acclimatization. The analysis of DNA content indicated that all the regenerants had the same ploidy level independent of treatments during storage. Cold storage of T. pieninicum as used in this study enabled the interval between subcultures to be extended to 9 months. [ABSTRACT FROM AUTHOR]

In this study, the seedlings of two wheat cultivars were used: drought-resistant Chinese Spring (CS) and drought-susceptible (SQ1). Seedlings were subjected to osmotic stress in order to assess the differences in response to drought stress between resistant and susceptible genotype. The aim of the experiment was to evaluate the changes in physiological and biochemical characteristics and to establish the optimum osmotic stress level in which differences in drought resistance between the genotypes could be revealed. Plants were subjected to osmotic stress by supplementing the root medium with three concentrations of PEG 6000. Seedlings were grown for 21 days in control conditions and then the plants were subjected to osmotic stress for 7 days by supplementing the root medium with three concentrations of PEG 6000 (D1, D2, D3) applied in two steps: during the first 3 days of treatment −0.50, −0.75 and −1.00 and next −0.75, −1.25 and −1.5 MPa, respectively. Measurements of gas exchange parameters, chlorophyll content, height of seedlings, length of root, leaf and root water content, leaf osmotic potential, lipid peroxidation, and contents of soluble carbohydrates and proline were taken. The results highlighted statistically significant differences in most traits for treatment D2 and emphasized that these conditions were optimum for expressing differences in the responses to osmotic stress between SQ1 and CS wheat genotypes. The level of osmotic stress defined in this study as most suitable for differentiating drought resistance of wheat genotypes will be used in further research for genetic characterization of this trait in wheat through QTL analysis of mapping population of doubled haploid lines derived from CS and SQ1. [ABSTRACT FROM AUTHOR]

We propose that oxidative stress resulting from an imbalance between generation and scavenging hydrogen peroxide contributes to tissue regeneration efficiency during somatic embryogenesis of hexaploid winter wheat ( Triticum aestivum cv. Kamila) and organogenesis of faba bean ( Vicia faba ssp. minor cv. Nadwislanski). Endogenous hydrogen peroxide content and antioxidant capacity of cells were determined in initial explants and callus cultures derived from these explants. Regeneration-competent explants (immature embryos) contained more endogenous HO than explants initiated from regeneration-recalcitrant tissue (mature wheat embryos and faba bean epicotyls). Higher HO levels were observed despite the higher activity of antioxidative enzymes (superoxide dismutase and catalase) and the induction of their gene expression. Calli originating from immature embryos retained the capacity of the initial explants: high HO production was observed during the whole culture period. Low temperature treatment (4°C) was found to be an effective factor, which improved both regeneration ability and HO production. Exogenous application to the medium of HO and catalase blocker (3-aminotriazole), but not FeEDTA and superoxide dismutase blocker (diethyldithiocarbamate), also resulted in the enhancement of regeneration efficiency. These results clearly indicate that plant regeneration is specifically regulated by endogenous HO and by factors, which improve its accumulation. Moreover, a study of the activity of various SOD isoforms suggests that not only the absolute concentration of HO, but also its localisation might be responsible for controlling regeneration processes. [ABSTRACT FROM AUTHOR]

Vigor and selected physiological parameters (content of phenolic compounds, soluble sugars, chlorophyll a and b, and carotenoids) of eight naked and two husked oat cultivars harvested at 15% moisture content were determined. Oat seeds were threshed using two rotational speeds of the threshing drum: 1.6 m s (LS) and 2.4 m s (HS). They were then inoculated with a medium pathogenicity strain of Fusarium culmorum, strain IPO 348-01. In naked cultivars, the use of HS resulted in more severe mechanical damage; in consequence, seedling vigor decreased by 16%. In naked cultivars chlorophyll a and b and carotenoids content were significantly reduced-by more than 64%-when the HS was used. The inoculation caused over a 100% increase of carbohydrates in roots at LS but only a slight increase at HS. Phenolic compound content was twice as high in roots than in leaves after inoculation for both LS and HS. Area of microdamage and reduction of root fresh weight (f.wt.) are significantly correlated with biochemical parameters. Smaller microdamage area and root f.wt. reduction are connected with higher physiological parameters, which confirms lower seedling susceptibility to pathogen infection. [ABSTRACT FROM AUTHOR]

The purpose of this study was to identify endogenous factors that induce gummosis and to show their role in gummosis in tulip (Tulipa gesnerianaL. cv. Apeldoorn) stems. Using procedures to detect endogenous factors that induce gum in the stem of tulips, jasmonic acid (JA) and methyl jasmonate (JA-Me) were successfully identified using gas-liquid chromatography-mass spectrometry. Total amounts of JA and JA-Me designated as jasmonates in tulip stems were also estimated at about 70-80 ng/g fresh weight, using deuterium-labeled jasmonates as internal standards. The application of JA and JA-Me as lanolin pastes substantially induced gums in tulip stems with ethylene production. The application of ethephon, an ethylene-generating compound, however, induced no gummosis although it slightly affected jasmonate content in tulip stems. These results strongly suggest that JA and JA-Me are endogenous factors that induce gummosis in tulip stems. [ABSTRACT FROM AUTHOR]

Haploidization is one of the methods of creating new cultivars that allows to shorten the production time of new cultivars. The aim of this study was to increase the efficiency of oat haploid embryos germination obtained by the wide crossing method. The experiments were performed on 40 oat (Avena sativa L.) F1 progeny derived from Strzelce Plant Breeding Ltd. Oat emasculation was done 8 weeks after sowing. Plants were pollinated with maize and treated with a 2,4-dichlorophenoxyacetic acid (2,4-D). Three weeks after pollination, enlarged ovaries were collected and surface sterilized. Next embryos were isolated and placed on four regenerating media: (1) - 190-2 (Wang and Hu, 1984) with 0.5 mg dm-3 kinetin, 0.5 mg dm-3 1-naphthaleneacetic acid (NAA), 9% maltose, 0.6% agar and pH 6.0, (2) - medium (1) with 50 mg dm-3 cysteine, (3) - medium (1) with 10% v/v coconut water and (4) - medium (1) with 50 mg dm-3 casein hydrolysate. Induction and regeneration of embryos were performed at 16 h photoperiod and light intensity of 130 μmol (photons) m2 s-1 and at 20/17 °C (day/night). Germinated embryos were transferred to MS medium (Murashige and Skoog, 1962) with 1.5% sucrose, solidified with 0.6% agar and pH 5.8. The obtained haploid plants were acclimated to ex vitro conditions. Well-rooted haploid plants were treated with colchicine in order to double the number of chromosomes. Ploidy level of plants was evaluated using a MACS Quant flow cytometer (MACS Quant, prod. Miltenyi Biotec). Of the 40 oats (F1) genotypes, 974 panicles (26960 florets) were emasculated. Seven hundred forty five haploid embryos were obtained, while 211 germinated. The highest number of haploid embryos germinated on medium (1) - 0.40%, and the lowest on medium (4) with casein hydrolysate - 0.09%. On medium (2) with cysteine and on medium (3) with coconut water the percentage of germinating embryos was similar (0.24% and 0.20%, respectively). Addition of cysteine, coconut water and casein hydrolysate inhibited embryos germination. As a result of haploid plants acclimatization to natural conditions and chromosome doubling, 67 doubled haploid (DH) lines were obtained. The number of embryos and regenerated plants depended on the genotype. The embryos were induced in 39 of 40 examined genotypes. The embryos of eight genotypes: 5.8514, STH5.8529, STH4.403/1, STH5.451/1, 5.8422, STH5.8528, 5.8430 and STH5.5046 did not develop into haploid plants. DH lines were obtained from 28 genotypes. The highest number of embryos per emasculated florets (over 5%) was obtained from the genotypes 5.8508, 5.8525 and STH5.8518/1. The most DH lines generated 5.8507, STH5.8504/1 and STH5.8518/1 genotypes. On average, of all tested genotypes, 2.69% of embryos, 0.76% of germinating embryos, 0.43% of haploid plants and 0.24% of DH lines per one hundred emasculated florets were obtained. [ABSTRACT FROM AUTHOR]

Doubled haploid (DH) technology in oat has not reached the same stage as in other cereals leading to its application in plant breeding. The objective of this investigation was to increase the effectiveness of Avena sativa L. haploid embryo germination obtained by the distant crosses with maize. Developed embryos (obtained from 22 genotypes) were transferred on five germination media: MS (Murashige and Skoog, Physiol Plant 15:473-497, 1962) with 3% sucrose, pH 5.8 (control medium), and 190-2 supplemented with 6 and 9% maltose. The pH of 190-2 was adjusted to 5.5 and 6.0. Of all tested genotypes, 591 haploid embryos were obtained, almost half of them (279) germinated. The rate of haploid embryo germination induced on 190-2 was 6.92%, while in MS it was 3.25%. The sugar and its concentration significantly affected the germination of haploid embryos. The highest percentage of haploid embryo germination (9.11%) and DH lines production (1.64%) was achieved on 190-2 with 9% maltose and pH 6.0. All DH lines are incorporated to breeding programs for the development of new cultivars. [ABSTRACT FROM AUTHOR]

Wide crossing of cereals with maize is often used to produce doubled haploids (DH). Usually in this method total elimination of maize chromosomes are commonly observed in most cereals, but oat can retain one of more maize chromosomes. The aim of the study was identification, morphological characterization and yield components analysis of the OMA (oat-maize addition) lines. In order to identify maize chromosomes retained in oat genome, oat genomic DNA was isolated from the flag leaf. DNA samples were analyzed by PCR method with using 5'-AAA GAC CTC ACG AAA GGC CCA AGG-3' and 5'-AAA TGG TTC ATG CCG ATT GCA CG-3' primers to detect the presence of maize chromatin. When the whole chromosomes or fragments of maize chromosomes were retained in oat genome, genomic DNA of 500 bp (specific maize retrotransposon fragment, Grande I) was amplified, and detected by electrophoresis. All OMA lines with detected Grande I were analyzed with genomic in situ hybridization (GISH) in order to detect and visualize maize chromosomes. To determine which maize chromosome was present in the OMA lines, DNA amplification using SSR-PCR with primers specific for maize chromosomes was performed. Of all the examined oat lines, in 47 OMA lines retrotransposon Grande I was detected. Twenty-six fertile OMA lines were analyzed with GISH. The whole maize chromosomes as well as a banding pattern probably colocalised with 25S rDNA sites in examined lines were found. Additional hybridization signals found in 2-3 pairs of chromosomes (depending on the analyzed line) might correspond 5S rDNA sequences (in the oat genome these sequences are located on 4 pairs of chromosomes). However, it can not be excluded that these signals came from other maize DNA sequences that have been incorporated into oat chromosomes. Studies based on SSR-PCR enabled the detection of 4, 5 and 6 maize chromosomes in three OMA lines. There were no significant morphological differences between OMA and DH lines. The obtained lines were varied mainly in number of grains and thousand grain weight. [ABSTRACT FROM AUTHOR]