Acidic and neutral ribonucleases (RNases) were studied in embryos of Triticum durum cv. Cappelli and the effects of abscisic acid (ABA) and gibberellic acid (GA₃) were analysed. RNases activities increased during germination and were comparable in dormant and non-dormant embryos imbibed for 24 h. ABA generally inhibited ribonucleolytic activities, while GA₃ only affected dormant embryos. To assess whether changes in RNase activities during germination or following hormonal treatment required new transcriptional or translational action, cycloheximide or cordycepin were used. The action of inhibitors of acidic RNase activity was found only in non-dormant-embryos. Findings obtained in the present work concur with a change of the ribonucleolytic pattern in the shift from dormant to non dormant metabolism.

Gynogenesis of Chinese long cucumber (Cucumis sativus L.) was obtained from unpollinated ovules cultured on cucumber basal medium (CBM) supplemented with thidiazuron (TDZ) and in some experiments AgNO₃. High induction frequencies (7.85-12.14 %) were induced from unpollinated ovules at the time of anthesis at 0.03-0.07 mg dm^-3 TDZ. Histological analysis indicated that embryo sacs developed completely at the time of anthesis. Further, the highest plant regeneration rate was achieved at CBM supplemented with 0.05 mg dm^-3 a-naphthaleneacetic acid, 0.2 mg dm^-3 6-benzyladenine and 5-10 mg dm^-3 AgNO₃. Flow cytometry analysis showed that 80 % of the regenerated plants were haploid. Histological micrographs and ploidy level analyses clearly revealed initiation, development, and germination of embryos from the unpollinated ovules.

Effects of 28-homobrassinolide (HBR) and kinetin (KIN) on photosynthesis, nitrogen metabolism, and the seed yield were studied. The leaves of 25-d-old plants of Vigna radiata (L.) Wilczek were sprayed with 0.01, 1.0 or 100 μM aqueous solution of KIN, or 0.0001, 0.01 or 1.0 μM that of HBR. KIN and especially HBR increased the activities of nitrate reductase and carbonic anhydrase, chlorophyll and total protein contents and net photosynthetic rate in the leaves, and pod number and seed yield, at harvest.

We quantified inbreeding depression for fruit production, embryo vitality and seed germination in three deceptive orchids, Serapias vomeracea, S. cordigera and S. parviflora, which do not provide any reward to their pollinators, and are predicted to experience high outcrossing. Of the three species examined only S. parviflora was autonomously selfing. Both S. vomeracea and S. cordigera showed highly significant differences in fitness between selfed and outcrossed progenies, resulting in high levels of inbreeding depression, which increased in magnitude from seed set to seed germination. Inbreeding depression may promote outcrossing in Serapias by acting as a post-pollination barrier to selfing. Cumulative inbreeding depression across three stages in S. parviflora was lower that in both outcrossing species. The large difference in germination between selfed and outcrossed seeds is an important issue in conservation biology.

During germination and post-germinative growth of Pinus pinaster Ait. seeds, triglycerides are hydrolysed and concurrently the embryo accumulates starch. In this study, the spatio-temporal variation of starch accumulation was described in zygotic embryos associated (ZE⁺) or not (ZE^-) to their megagametophyte and in somatic embryos (SE). In germinating ZE⁺, starch was accumulated in the growing tissues, following closely the spatio-temporal pattern of triglycerides depletion. In contrast, in ZE^- and SE, starch was only found in cortical cells close to the culture medium. In germinating ZE⁺, the spatio-temporal variations of starch accumulation can be thus interpreted as the result of the changing contact between the megagametophyte and the growing tissues and also of the existing interactions between triglyceride hydrolysis and the allocation of sucrose exported from the megagametophyte.

The activities of superoxide-dismutase (SOD), catalase (CAT) and peroxidase (POD), and concentrations of glutathione and ascorbate have been studied during the first stages of germination in Chenopodium rubrum L. seeds. The highest CAT and SOD activity was found prior to radicle protrusion, while POD activity was maximal at the time of radicle protrusion and seedling development, new POD isozymes simultaneously appearing. The concentrations of total, reduced and oxidized glutathione showed similar changes during germination, the highest values being detected at the time of radicle protrusion. Ascorbic acid was present in the seeds in a detectable concentration only at the time preceding radicle protrusion, while its oxidized form dehydroascorbic acid was detected during the whole germination period studied. Gibberellic acid (GA₃, 160 μM) had no effect on germination percentage, but in presence of GA₃, SOD and CAT activity notably increased prior to radicle protrusion, and oxidized glutathione concentration decreased in further germination.

Somatic embryos differentiated from hypocotyl explant in cotton (Gossypium hirsutum L.) exhibited very divergent morphologies. Six different types of somatic embryos based on cotyledon development were observed. The growth hormones (2,4-dichlorophenoxyacetic acid and kinetin) used in induction and maintenance media did not affect embryo rooting and germination. The 95 % conversion of normal embryos (with two cotyledons) was achieved, while an overall conversion was only 38 %. Horn shaped embryos failed to exhibit shoot growth. Poorly developed apical meristems were responsible for lower conversion percentages in some of embryo classes. However, regenerated plants phenotypically resembled to seed grown control plants regardless of somatic embryo morphology.

Activities of alcohol dehydrogenase, hexokinase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase were significantly inhibited by cadmium in germinating pea (Pisum sativum L. cv. Bonneville) seeds. The effect was concentration dependent in the range of 0.25 to 1.0 mM CdCl₂. The magnitude of detrimental effect on these enzymes was reduced during later stage of germination (9 d) largely because of fall in the activities of these enzymes in the control seeds germinated in water. In vitro, activities of hexokinase, glucose-6-phosphate dehydrogenase, and alcohol dehydrogenase were inhibited at 0.5 mM Cd²⁺ in the reaction mixture by 62, 67, and 36 %, respectively, however, 6-phosphogluconate dehydrogenase was insensitive to Cd²⁺.

An effort has been made to assess the role of reactive oxygen species in germination and subsequent growth of Amaranthus lividus under elevated temperature. Transfer of A. lividus seeds from 25 to 45 °C for 4, 8 and 12 h, during early imbibitional period reduced percentage of germination, relative germination performance, relative growth index and seedling length. Heat shock during early germination decreased also the activities of free radical scavenging enzymes like catalase, peroxidase and superoxide dismutase, increased the accumulation of superoxide, hydrogen peroxide and induced lipoxygenase mediated membrane lipid peroxidation. Membrane injury index and relative leakage ratio revealed a rise with concomitant reduction in membrane protein thiol content in heat shock raised seedlings. The results indicate that heat shock in A. lividus seeds induced an excessive generation of ROS and led to an oxidative membrane damage, causing early growth impairment.

Changes in ascorbate and glutathione contents and the activities and isoenzyme patterns of enzymes of the ascorbate-glutathione cycle were investigated in embryo axes and cotyledons of germinating lupine (Lupinus luteus L.) seeds. Ascorbate content was not significantly affected over the initial 12 h of imbibition in embryo axes, but afterwards increased, with the most rapid accumulation coinciding with radicle emergence. A somewhat similar trend was observed for glutathione with significant increase in embryo axes shortly before radicle protrusion followed by decline in the next hours. In cotyledons the ascorbate pool rose gradually during germination but the amount of glutathione showed fluctuations during a whole germination period. The activity of ascorbate peroxidase (APX) rose progressively in embryo axes, while activities of dehydroascorbate reductase (DHAR) and glutathione reductase (GR) showed transient increase during germination. New isoforms of APX and GR were synthesized, suggesting that they play a relevant role during germination. All analyzed enzymes were already present in dry seeds which allowed them to be active immediately after imbibition.

Black gram [Vigna mungo (L.) Hepper] cv. IPU 94 plants grown in sand culture with deficient zinc (0.1 µM Zn) nutrition and those deprived of normal (1 µM) Zn supply at the initiation of flowering, showed decrease in dry matter production and especially seed yield. These plants showed a decrease in the size of anthers and stigmatic heads, pollen producing capacity of the anthers and stigmatic exudations. Zn deficiency caused structural alterations in exine and retarded germination of pollen grains and tube growth. The pollen extracts and stigmatic exudates of the Zn-deficient plants showed increase in activity of acid phosphatase isoforms and inhibition of esterase isoforms. Zn deficiency led to decrease in number of pods, seeds per pod and seed mass, altered seed coat topography and reduced seeds germinability. Low seed yield under Zn deficiency is attributed to a role of Zn in pollen function, as also in pollen-pistil interaction conducive to fertilization and development of seeds.

The effects of 50 mM NaCl and 5, 10, 15 and 20 mM boron on the rate of germination, growth rate, contents of boron, sodium, potassium and chloride, and membrane permeability in maize (Zea mays L.) and sorghum (Sorghum bicolor L.) were studied. Germination rate, lengths of roots and shoots as well as dry matter production in the two tested plants, decreased with the increasing B concentration in nonsaline conditions, and markedly under salinity. Membrane permeability increased by increasing B concentration only under salinity. Increase in B concentration of sorghum was lower under salinity when compared to nonsaline conditions. Contrary to this, increase in B concentration of maize was higher under salinity. Under salinity Na and Cl concentrations increased and K concentration decreased in the both tested plants. Potassium concentration was decreased by B treatments under salinity.

Hexaploid triticale introgressive lines developed after recombination of A-genome with A^m-genome of diploid wheat (Triticum monococcum) were analysed in respect of grains responsiveness to exogenous ABA treatment. This was assessed by in vivo bioassay as grain germination indices, and by α-amylase assay as quantity of synthesised α-amylase measured with the technique of radial diffusion in agarose gel. The results showed an important diminishing of seedling length caused by ABA (variable in different lines) as well as genotype dependant variability of α-amylase synthesis inhibition. The differences of ABA responsiveness were seen both in whole grains and in embryoless half-grains as a direct reaction of the aleurone layer. Variation of grain sensitivity to ABA treatment compared with two sprouting resistance indices showed a significant correlation with Falling Number values in grains, but not with a dormant grains germination in spikes. This is an evidence that in triticale precocious starch decompose in unripened and ungerminated grains is dependent on genotype ABA-responsiveness of the aleurone layer.

Acyl carrier protein (ACP), as an essential protein cofactor, plays an important role in de novo synthesis of fatty acids in plastids. In this study, the expression profile of peanut (Arachis hypogaea) AhACP1-1 and AhACP1-2 was analyzed in different tissues. The expression level of AhACP1-1 was highest in the seed, whereas expression was barely detected in the shoot, and AhACP1-2 was expressed in every tissue analyzed with the highest expression level detected in the leaf and seed. Overexpression (OE) and antisense-inhibition (AT) of AhACP1 in transgenic tobacco modified the transcript level of endogenous NtACPs, and the content of total lipids and composition of fatty acid in leaves were altered compared with the wild-type control. Transgenic OE-AhACP1 or AT-AhACP1 tobacco exhibited a significant increase or decrease in polyunsaturated C18:2 and C18:3 fatty acid content, and were more tolerant or sensitive to cold stress, respectively. It is suggested that AhACP1 bound with C18:1 might be the specific substrate of oleoyl-ACP thioesterase or glycerol-3-phosphate acyltransferase, and participates in membrane lipid synthesis.

To evaluate the genetic diversity of some Vicia species, seed proteins of 160 accessions (30 of Vicia faba, 15 of V. narbonensis, 82 of V. sativa and 25 of V. ervilia and 8 accessions of other Vicia species) were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The dendrogram showed that the two outcrossing species V. faba and V. villosa were the most distant among all species (average percent disagreement value PDV 0.47 and 0.45, respectively). The tree was divided into small clusters of two species each. V. narbonensis fell in one cluster with V. michausai (at PDV = 0.35) and V. lutea (var. hirta) fell in one cluster with V. serococorpes (at PDV = 0.32) whereas, V. ervilia fell in one cluster with V. sativa (at PDV = 0.27). The V. sativa subspecies, however, were closely related (PDV < 0.1). In general, this study did not prove any relationship between the studied storage proteins and the geographical distribution or ecological needs of the studied accessions.

The present study was carried out to contribute to our knowledge of the mechanism of seed deterioration in two cotton (Gossypium hirsutum L.) cultivars (HS6 and H1098) during natural ageing. The seeds were sealed in polythene bags and stored at 25 ± 1 °C for 3, 6, 9, 12 and 18 months. In both the cultivars, germinability decreased whereas membrane deterioration assayed as electrical conductivity of the seed leachates increased with storage period. The decrease in germinability was well correlated with increased accumulation of H₂O₂ and malondialdehyde content. The activities of peroxidase, catalase, ascorbate peroxidase, glutathione reductase and superoxide dismutase decreased with ageing. Seeds of cv. H1098 were more susceptible to ageing than HS6.

Mantisia spathulata Schult. and M. wengeri Fischer, two critically-endangered, endemic and rare species of the genus Mantisia (Zingiberaceae), have been rediscovered from Lunglei province of Mizoram, India, after two decades. For sustainable conservation and utilization of the Mantisia species, in vitro seed and clonal propagation methods have been developed earlier by our research group and plantlets have been reintroduced to their natural habitat for species recovery. To comprehend the plausible reasons for endemism and endangeredness of both the species at DNA level, they were analyzed to assess natural genetic variation using three different polymerase chain reaction (PCR) based DNA markers viz. random amplified polymorphic DNA (RAPD), inter simple sequence repeat (ISSR) and directed amplification of minisatellite DNA regions (DAMD), both individually and cumulatively, which are popularly regarded as single primer amplification reaction (SPAR) methods. A total of 107 primers belonging to three SPARs are used which collectively endow low genetic variation (15 and 20 %, respectively) in both M. spathulata and M. wengeri. The use and efficacy of SPAR methods to reveal the natural genetic variation in Mantisia species at intra-specific level has been recorded for the first time. To impede the extinction risk of these two species of genus Mantisia, large scale conservation strategies including in situ and ex situ conservation are recommended.

The allelopathic potential of Pueraria thunbergiana was investigated under laboratory conditions. The powder of freeze-dried leaves of P. thunbergiana inhibited the germination and the growth of roots and shoots of cress, lettuce, timothy and ryegrass. Significant reductions in the germination and growth of roots and shoots were observed as the powder concentration increased in all bioassays. The putative compounds causing the inhibitory effect of the powder were isolated and determined by their spectral data as cis.trans- and trans,trans-xanthoxin

Capsaicin, a possible allelochemical, caused growth inhibition of roots and shoots of alfalfa (Medicago sativa), cress (Lepidium sativum), lettuce (Lactuca sativa), crabgrass (Digitaria sanguinalis), timothy (Phleum pratense) and ryegrass (Lolium multiflorum), and suppressed their germination. Increasing the dose of capsaicin increased the inhibition. The concentrations for 50 % inhibition of the root growth were 2.7, 0.32, 2.1, 0.27, 0.29 and 0.57 mM for alfalfa, cress, lettuce, crabgrass, timothy and ryegrass, respectively, and the concentrations for 50 % inhibition of the shoot growth were 17, 0.87, 6.7, 2.3, 1.4 and 6.2 mM for alfalfa, cress, lettuce, crabgrass, timothy and ryegrass, respectively. Germination percentage was inhibited 50 % at the concentrations 82, 88, 68, 4.8, 22 and 11 mM for alfalfa, cress, lettuce, crabgrass, timothy and ryegrass, respectively. Thus, effectiveness of capsaicin on the plant growth differed with species and targets, and suggests that capsaicin may act as an allelochemical to other plants.

Ferns present two alternant generations: sporophyte and gametophyte. In the present work we address the question of whether fern gametophytes have the potential to acclimate to different irradiances as vascular plants do. We studied the gametophytes of three different fern species belonging to the Aspleniaceae family with different ecological requirements (Asplenium trichomanes, Asplenium scoloprendrium and Ceterach officinarum). Fern spores were germinated and the gametophytes cultivated under photon flux density (PFD) of 10, 50 or 100 μmol m^-2 s^-1. From the early stages of spore germination (the formation of the 5-celled germinal filament), photosynthetic apparatus acclimates showing the typical patterns of photochemical responses to high or low PFD. In agreement with the photochemical pattern of acclimation, higher contents of xanthophyll cycle pigments and α-tocopherol was observed in plants grown under high PFD. The α/β-carotene ratio, used as indicator of the acclimation of the photosynthetic apparatus, also sustained the initial hypothesis except for A. trichomanes. We conclude that fern gametophytes display a complete array of photosynthetic and photoprotective traits that allow an effective acclimation to PFD.

Influence of pre-sowing chilling treatments to seeds on seed germination and accumulation of osmotics in Indian mustard [Brassica juncea (L.) Czernj & Cosson] under NaCl stress was investigated. Germination was 100 % in water soaked non-chilled (control) seeds upto 100 mM NaCl, whereas it was upto 200 mM NaCl in chilling treated seeds. Pre-sowing chilling treatments to seeds for 5, 10 and 15 d also enhanced the dry mass of 6-d-old seedlings, and concentrations of saccharides and amino acids. The alleviation of NaCl stress by pre-sowing chilling treatments was also associated with decrease in Na⁺ and proline accumulation and a slight increase in K⁺ and Ca²⁺ contents of seedlings.

Germination of two rice (Oryza sativa L.) cultivars (Ratna and IR 36) in the presence of 10 µM PbCl2 and 10 µM HgCl2 decreased germination percentage, germination index, shoot/root length, tolerance index and dry mass of shoots and roots. Mercury was more toxic than lead. Reduced glutathione (GSH), cysteine (Cys), ascorbic acid, and α-tocopherol alleviated the adverse effects of these metals on plants in the order GSH > Cys > ascorbic acid > α-tocopherol. The effects were more pronounced in tolerant cultivar IR 36 than in the relatively susceptible cultivar Ratna.

Histone H3 lysine 4 methylations catalyzed by histone lysine methyltransferases (HKMTs), like the Arabidopsis thaliana ATX1 and ATX2, are important epigenetic modifications related to chromatin decondensation and gene activation. In order to study this epigenetic mechanism in monocot cereal plants, we performed homology searches of ATX1 and ATX2 against the Brachypodium distachyon L. Beauv and rice (Oryza sativa L. spp. japonica) genomes, discovering single homologues for each cereal crop representing both Arabidopsis sequences. Using this information, we employed the rolling circle amplification - rapid amplification of cDNA ends (RCA-RACE) method to isolate, clone and characterize HvTX1 from RNA extracted from barley (Hordeum vulgare L.) tissues and studied its expression during seed development and under drought stress. The cloned cDNA sequence contained a 3 093 bp ORF homologous to ATX1 and ATX2. Characterization of the translated HvTX1 transcript sequence revealed the multi-domain nature of the putative protein, including all conserved regions characteristic for ATX1 and ATX2. By comparative genomic analysis and homology searches in EST databases we located, with high probability, the gene coding for HvTX1 on the barley chromosome 5H. Constant elevation of HvTX1 expression was observed during seed development. Expression of HvTX1 after drought stress was analyzed by quantitative real-time polymerase chain reaction (qPCR) in two different barley cultivars with varying drought stress tolerance, revealing HvTX1 drought-induction in a tolerance-specific manner.

Germination of Lepidium apetalum Wild. seeds is invariably arrested by cold stress. cDNA-amplified fragment length polymorphism (AFLP) technique was used to isolate genes relevant to chilling stress (4 °C) during seedling emergence. 43 transcript-derived fragments (TDFs) were found to be up-regulated and 17 down-regulated during chilling stress. Eighteen TDF of up-regulated genes were cloned and sequenced. Some of these genes are involved in the stress response, some play important roles in energy and substrate metabolism, and some encode unknown proteins such as TDF119. Two sequences, designated TDF217 and TDF223, may correspond to novel genes. The expression profiles of 6 from 18 TDFs were analyzed by quantitative real-time PCR under chilling and abscisic acid (ABA) stress. It was demonstrated that all 6 genes were significantly induced by chilling and their expression was decreased when the temperature was shifted from 4 to 25 °C. The transcriptional levels of 5 TDFs were strongly enhanced also in response to exogenous ABA. Based on the characteristics of genes isolated from seedlings exposed to cold stress, we conclude that Lepidium adapts to cold stress by regulating many signal transduction pathways, including both ABA-dependent and ABA-independent signaling pathways.

Twenty clones of the breeding population of Hevea brasiliensis were evaluated for phenetic diversity. The test-clones included six clones developed in Nigeria, ten Malaysian clones, two clones from Indonesia and a clone from each of Brazil and Sri Lanka. Data collected on fifteen seed characters in 1998 and 1999 were utilized for multivariate analysis. Cluster analysis of data matrix of clonal mean seed characters was conducted to produce principal component axes, dendrograms and Tocher's clusters in 1998, 1999 and the combined data. There was taxonomic isolation of the recent collection from Brazil (IAN 710) from the other clones that are either members or descendants of the Wickham collection of 1876. There was a continuum of phenetic diversity from the highly divergent to the closely related pairs of clones. The highly divergent clones are expected to produce heterotic progenies in crosses while crosses among clones with close phenetic similarity should be avoided. This will guide against inbreeding depression and genetic erosion.

The functions of cytosolic heat shock protein AtHsp90.3 in response to heavy metal stress were characterized by using expression of AtHsp90.3 gene in yeast and Arabidopsis thaliana. AtHsp90.3 supported the Saccharomyces cerevisiae Hsp90 knockout strain R0005 growth and maintaining cells membrane integrity under cadmium and arsenic stresses, which was compatible with the components of ScHsc82 machinery. However, constitutive overexpression of AtHsp90.3 in Arabidopsis impaired plant tolerance to Cd stress with lower germination rate and shorter root length, decreased contents of phytochelatins (PCs) and glutathione (GSH), inhibited activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), and increased content of malondialdehyde (MDA). These results suggested that proper homeostasis of Hsp90 was critical for cellular response and/or tolerance to heavy metal stress in plants.

Accelerated ageing of Dendrocalamus strictus Ness seeds at 42 ± 1°C and 100% relative humidity for 1 to 8 d was conducted. Seeds lost viability and changed their biochemical constituents. Reductions in the contents of sugars, starch, proteins and lipids were found. Decrease in the activity of the peroxidase as well as acid and alkaline phosphatase were also observed. Increase in total free amino acids content and the activity of amylase confirmed the degradation of seed reserves.

It is hypothesized that since protein α-amylase inhibitor (α-AI) and stimulator might be present together in red kidney bean (Phaseolus vulgaris L.) seeds, their in vitro interactions might influence their detection and quantification. Assay of α-AI using extracts from the embryonic axes revealed an unexpected finding in that the extracts stimulated rather than inhibited α-amylase activity. The cotyledon extracts exhibited inhibitory or enhancement effect on α-amylase activity depending on whether prior to the α-amylase assay they had been boiled for 10 min or not. Phytohemagglutinin (PHA-L in particular) is implicated in the present study as a stimulator of α-amylase activity co-extracted with α-AI from red kidney bean cotyledons. The importance of these findings is discussed in relation to the possible widespread occurrence of protein α-amylase stimulator in seeds and other plant parts.

Seedlings of Sorghum bicolor (L.) Moench were subjected to 180 mM NaCl with or without 0.25 mM spermine (SPM) for 7 d. NaCl treatment resulted in the inhibition of growth and increased the content of free proline, soluble protein and malondialdehyde (MDA). Additionally, it also enhanced the activity of catalase (CAT), peroxidase (POX) in both shoots and roots, while decreased that of glutathione reductase (GR). When exogenous spermine was added to the test solution, the growth of sweet sorghum seedlings was improved, and a smaller increase in the free proline and MDA contents was observed. The addition of spermine also partially increased the activities of POX and GR, but had no effects on soluble protein content or the activity of CAT.

The embryogenic calli (EC) were obtained from hypocotyl explants of groundnut (Arachis hypogaea L.) cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) in combination with 0.5 mg dm^-3 6-benzylaminopurine (BAP). The EC were exposed to γ-radiation (10-50 Gy) or treated with 1-5 mM of ethyl methane sulphonate (EMS) or sodium azide (SA). The mutated EC were subcultured on embryo induction medium containing 20 mg dm^-3 2,4-D. Somatic embryos (SE) developed from these calli were transferred to MS medium supplemented with BAP (2.0 mg dm^-3) and 0.5 mg dm^-3 2,4-D for maturation. The well-developed embryos were cultured on germination medium consisting of MS salts with 2.0 mg dm^-3 BAP and 0.25 mg dm^-3 naphthaleneacetic acid (NAA). Well-developed plantlets were transferred for hardening and hardened plants produced normal flowers and set viable seeds. The fresh mass of the EC, mean number of SE per explant and regeneration percentage were higher at lower concentrations of mutagens (up to 30 Gy/3 mM). Some abnormalities in regenerated plants were observed, especially variations in leaf shape.