Showing papers in "Biologia Plantarum in 1994"
TL;DR: The results of the study showed that the size of nuclear genome of Musa is smaller than previously estimated, and it was found that nuclear DNA content of M. balbisiana (genome BB) is significantly lower than that ofM.
Abstract: Cell nuclei were isolated from leaf tissues of wild banana (Musa balbisiana, M. acuminata ssp.banksii andM. acuminata ssp.errans) and of the two vegetative clones of diploid cultivar “Pisang Mas”. Relative fluorescence intensity was measured on propidium iodide-stained nuclei by flow cytometry. Nuclei isolated fromGlycine max with known nuclear genome size were used as internal standard to determine nuclear DNA content ofMusa in absolute units. The results of the study showed that the size of nuclear genome ofMusa is smaller than previously estimated. In general, it is smaller in comparison with many other angiosperms. Furthermore, it was found that nuclear DNA content ofM. balbisiana (genome BB) is significantly lower than that ofM. acuminata subspecies and cultivars (genome AA). This finding should permit estimation of genome composition in triploidMusa clones with expected hybrid composition. Flow cytometry is proposed as a useful technique with potential applications in taxonomy, breeding and biotechnology ofMusa.
250 citations
TL;DR: In this article, the results of a salt tolerant and a normal population of an oilseed crop were assessed after four weeks growth in sand culture salinized with 0 (control), 100, 200, or 300 mol m−3 NaCl.
Abstract: Responses of a salt tolerant and a normal population of an oilseed crop,Eruca sativa Mill. were assessed after four weeks growth in sand culture salinized with 0 (control), 100, 200, or 300 mol m−3 NaCl. The salt tolerant plants produced significantly greater dry biomass than the normal population. The populations did not differ significantly in leaf osmotic potential, relative water content and leaf soluble proteins. However, the tolerant population accumulated significantly greater amounts of soluble sugars, proline and free amino acids in the leaves compared with the non-tolerant population. It is established that leaf soluble sugars, proline, and free amino acids are important components of salt tolerance inEruca sativa.
126 citations
TL;DR: The concentrations of chlorophylls and carotenoids were increased in most cases in broad bean leaves while in pea plants they remained more or less unchanged with the rise of salinization up to 80mM NaCl, and a significant decrease in these contents was observed.
Abstract: Increasing salinity of growth medium induced a reduction in growth and transpiration rate. The concentrations of chlorophylls and carotenoids were increased in most cases in broad bean leaves while in pea plants they remained more or less unchanged with the rise of salinization up to 80mM NaCl. Thereabove a significant decrease in these contents was observed. A stimulation of the net photosynthetic rate of pea was observed at the lowest levels of NaCl but at the highest levels inhibitory effect was recorded. In broad bean all salinization levels inhibited photosynthetic activity, but dark respiration of both plant species was stimulated. The content of Na+ in the roots and shoots of both species increased at increasing salinity. In broad bean, Ca2+ concentration in shoots and K+ and Ca2+ contents of roots increased at increasing salinization, while in pea plants, the content of K+ and Ca2+ was almost unaffected by salinity. Salinity induced an increase in the content of these ions in pea roots. Mg2+ content in shoots and roots of both broad bean and pea decreased at increasing salinity except in roots of pea, where it was generally increased.
96 citations
TL;DR: The responses of seedlings of three fast growing tree species, Eucalyptus hybrid, Casuarina equisetifolia andMelia azedarach, to different levels of soil moisture in controlled glasshouse conditions were compared and the survival percentage, height of plants, number of leaves per plant,Number of branches, fresh mass and dry mass of roots, stems, branches and leaves decreased in the three species with increasing water stress.
Abstract: The responses of seedlings of three fast growing tree species,Eucalyptus hybrid(E. camaldulensis × E. teriticornis), Casuarina equisetifolia andMelia azedarach, to different levels of soil moisture in controlled glasshouse conditions were compared. The survival percentage, height of plants, number of leaves per plant, number of branches, fresh mass and dry mass of roots, stems, branches and leaves decreased in the three species with increasing water stress. Stomatal frequency and length of stomata inEucalyptus andMelia also decreased with increasing water stress. However, no significant difference was obtained in the width of stomata and the ratio of number of open stomata to total number of stomata per unit area. The leaf thickness decreased, but the thickness of palisade parenchyma increased with increasing water stress inEucalyptus hybrid andCasuarina. Leaf thickness ofMelia did not show any significant variation due to water stress.
56 citations
TL;DR: It is suggested that the ratio ofCFU of diazotroph bacteria to CFU of phytotoxic micromycetes can be used as an indicator of the degree of ARD and it may be assumed that the use of some VAM fungi can replace the chemcial treatment of the soil with ARD.
Abstract: Phytotoxic micromycetes appear to be responsible for the apple replant disease (ARD). This was suppressed by the inoculation of apple-tree seedlings with some species of vesicular-arbuscular mycorrhizal (VAM) fungi—Glomus fasciculatum andG. macrocarpum. After the inoculation, growth of apple-tree seedlings improved in dependence on the type of soil, on VAM fungus species and on the ARD appearance. After 12-month cultivation, plant biomass (height, shoot and root dry masses) was markedly increased by inoculation withG. fasciculatum. Similarly, the numbers of colony forming units per unit soil (CFU) of phytotoxic micromycetes and of diazotroph bacteria (associative dinitrogen-fixing bacteria) in the rhizosphere was affected; CFU of phytotoxic micromycetes decreased, whereas CFU of the genusAzospirillum was higher. These bacteria could also serve as antagonists against phytotoxic micromycetes. It is also suggested that the ratio of CFU of diazotroph bacteria to CFU of phytotoxic micromycetes can be used as an indicator of the degree of ARD. It may be assumed that the use of some VAM fungi can replace the chemcial treatment of the soil with ARD.
43 citations
TL;DR: In this article, wheat seedlings were grown hydroponically in the presence and absence of 100 mM NaCl for 7 d. The results extend previous data that cell membrane properties are different in salt sensitive and resistant genotypes and so cell permeability could be a potential trait indicating salt tolerance.
Abstract: 10-d-old wheat seedlings were grown hydroponically in presence and absence of 100 mM NaCl for 7 d. Salt stress decreased growth of shoots and roots of both cultivars; fresh mass of sensitive cultivar being more affected. NaCl increased membrane permeability to urea, methylurea and ethylurea and decreased membrane partiality in root cortex cells of sensitive cultivar. Neither parameter changed by NaCl in resistant cultivar. NaCl treatment decreased water permeability and osmotic potential in both cultivars; sensitive cultivar was more affected. The results extends our previous data that cell membrane properties are different in salt sensitive and resistant genotypes and so cell permeability could be a potential trait indicating salt tolerance.
38 citations
TL;DR: Investigation of chromosome association during metaphase I of meiosis revealed that the frequency of bivalents/cell was the highest among all investigated diploid, tetraploid and hexaploid accessions, indicating that segmental alloploidy has been the major process by which polyploid species have originated.
Abstract: The cytological investigation of 12 taxa ofPanicum L. revealed that the vast majority of them have the basic number x=9 at different ploidy levels. The basic number x=8 was recorded only in the tetraploid speciesP. maximum with 2n=32. The diploid number 2n=18 was encountered inP. capillare, P. laevifolium, P. antidotale andP. coloratum (2) with 3B-chromosomes recorded in the latter species. The tetraploid chromosome number 2n=36 was found to exist inP. miliaceum, P. miliare, P. coloratum (1) andP. virgatum. The hexaploid number 2n=54 was recorded inP. bulbosum, P. dichotomiflorum andP. esculentum. The karyotypes of all accessions were mostly symmetrical and mainly comprised of meta- and submetacentric chromosomes with little variation in length among them within each karyotype. Investigation of chromosome association during metaphase I of meiosis revealed that the frequency of bivalents/cell was the highest among all investigated diploid, tetraploid and hexaploid accessions. Univalents were also frequently encountered in various accessions. These results may indicate that segmental alloploidy has been the major process by which polyploid species have originated.
30 citations
TL;DR: C. rubrum plants of different age were treated with methyl jasmonate (JA-Me), in some cases in combination with photoperiodic flower induction, and showed inhibition of growth and flowering.
Abstract: C. rubrum plants of different age were treated with methyl jasmonate (JA-Me), in some cases in combination with photoperiodic flower induction. Plants treated with JA-Me (3×10−4, 3×10−5 and 5×10−7M) showed inhibition of growth and flowering. No effect of JA-Me application on ethylene formation was observed.
30 citations
TL;DR: Meristems from 25–90-year-old oak trees and seed embryos were pretreated with polyvinyl pyrrolidone, ascorbic acid, cysteine and citric acid solutions and showed a positive effect against the otherwise very rapid and harmful browning of the explants.
Abstract: Meristems from 25–90-year-old oak (Quercus robur L. andQ. petraea Matt.) trees and seed embryos were pretreated with polyvinyl pyrrolidone, ascorbic acid, cysteine and citric acid solutions. Tissues were cultured mostly on a WPM medium supplemented with different combinations and concentrations of growth regulators. All the different pretreatments showed a positive effect against the otherwise very rapid and harmful browning of the explants but ascorbic acid (100 mg dm−3) proved to be the most effective. Shooting was induced from seed embryos and meristems originating from adult trees. Rooted plantlets were obtained from explants of seed embryos.
29 citations
TL;DR: The results suggest that high ethylene production rates are not essential for germination of chick-pea seeds but that certain quantities of ethylene may be required.
Abstract: The germination percentage of chick-pea (Cicer arietinum) Seeds was greatly reduced by temperatures of 30°C and 35°C. This thermoinhibition was overcome by ethylene (ethrel). Both ABA and PEG diminished ethylene production and germination percentage in a parallel way. FC, MGBG and CHA stimulated both ethylene production and germination. AVG reduced ethylene production to some extent but did not inhibit germination. CoCl2 and PG completely prevented both ethylene production and germination; this effect was reversed by ethylene but not by its immediate precursor ACC. NBE prevented both germination and ethylene production. Our results suggest that high ethylene production rates are not essential for germination of chick-pea seeds but that certain quantities of ethylene may be required.
29 citations
TL;DR: Contents of phenolic acids, peroxidase activities and growth curves showed significant differences in embryogenic (EC) and nonembryogenic (NEC) suspension cultures of Medicago sativa L. NEC while in EC the distinct phases were absent.
Abstract: Contents of phenolic acids, peroxidase activities and growth curves showed significant differences in embryogenic (EC) and nonembryogenic (NEC) suspension cultures ofMedicago sativa L. NEC gave a typical growth curve while in EC the distinct phases were absent. The total content of phenolic acids was higher in NEC (related to EC), changed during the growth cycle and most of the acids occurred in ester-bound methanol soluble form. The level of phenolic acids in EC was significantly lower and did not change during 12-d cultivation. The major fraction was formed by phenolic acids ester-bound to the cell wall. The cytoplasmic peroxidase activity in NEC increased continuously during the growth and reached the maximum value at the end of exponential phase. In EC the extremely low cytoplasmic peroxidase activity did not change during cultivation. Ionically bound peroxidases in NEC represented 14 to 30% of the total extracted activity in dependence on the growth phase while in EC formed about 50% of the total activity and did not change during studied period. A possible participation of ionic peroxidase in the incorporation of phenolics into the cell wall is discussed.
TL;DR: Paclobutrazol, the gibberellin biosynthesis inhibitor, acceleratedin vitro tuber initiation of potato cv.
Abstract: Paclobutrazol, the gibberellin biosynthesis inhibitor, acceleratedin vitro tuber initiation of potato cv. Rema and increased the uniformity of tuberization period. However, the high concentrations (10–1000 mg l−1) of this retardant, strongly decreased mass and/or number of microtubers. The microtubers were harvested and stored in darkness (22±2°C) for 250 d. After this period both sprouting and growth of sprouts were affected by previous paclobutrazol treatment.
TL;DR: Osmotic priming of aged onion seeds with 25% polyethylene glycol-8000 for 5 d resulted in a marked increase in the rate of germination and early seedling growth and a diminution of response in terms of changes in the levels of antioxidants and scavenging enzymes.
Abstract: Osmotic priming of aged onion seeds with 25% polyethylene glycol-8000 for 5 d resulted in a marked increase in the rate of germination and early seedling growth. Priming reduced electrolyte leakage as well as lipid peroxidation in seeds implying the activation of membrane repair processes. Priming was also associated with increased levels of antioxidants,i.e. ascorbic acid and tocopherols particularly the latter and the activities of catalase and peroxidase involved in the mitigation of oxidative damage. In comparison with the priming of unaged seeds, the aged seeds experienced a diminution of response in terms of changes in the levels of antioxidants and scavenging enzymes.
Journal Article•
TL;DR: Calcium ions, calcium ionophores A23187 and ionomycin, as well as caffeine, stimulated the flowering of Pharbitis nil when applied just before and 2 h after starting a subinductive, 14-h long dark period, suggesting that an increase in free Ca 2+ before and during the first 2 h of the dark period increases the flowering responses, whereas after the 6th hour it decreases.
Abstract: Summary Calcium ions, calcium ionophores A23187 and ionomycin, as well as caffeine, stimulated the flowering of Pharbitis nil when applied just before and 2 h after starting a subinductive, 14-h long dark period. Effectiveness of all the mentioned compounds decreased over successive hours and when used from 6 h after the onset of the dark period they had no effect or inhibited flowering. Intracellular calcium modulators, ryanodine and thapsigargicin, which are active in animal cells had no effect on flowering. These results suggest that an increase in free Ca 2+ before and during the first 2 h of the dark period increases the flowering responses, whereas after the 6th hour it decreases it. We postulate that the targets for calcium action are stomata, which are open before the dark period and remain closed during the first 4-5 h of the dark period. The significance of stomata in flower induction was confirmed in experiments with abscisic acid (ABA), a plant hormone which regulates stomatal movements. Treating the cotyledons of plants with ABA at the 8th and 10th hour of the dark period, resulted in plants with about 50% less flower buds than the control, however, this phytohormone had no effect on flowering when used before the subinductive dark period.
TL;DR: Three anionic peroxidases (EC 1.11.7), named Prx1, 2, and 3, which are rapidly accumulated in cucumber reacting hypersensitively to tobacco necrosis virus, were purified to homogeneity and close serological relationships have been demonstrated.
Abstract: Three anionic peroxidases (EC 1.11.1.7), named Prx1, 2, and 3, which are rapidly accumulated in cucumber (Cucumis sativus L., cv. Laura) reacting hypersensitively to tobacco necrosis virus, were purified to homogeneity. The three enzymes had an isoelectric point about 4.3, and the relative molecular masses of Prx1, 2, and 3 estimated by SDS-PAGE were 40 700, 38 000, and 37 100, respectively. These peroxidases had a similar pH stability, but differed in their specific activity, pH optimum, and thermal stability By Ouchterlony double diffusion tests with antisera raised against the three purified enzymes, close serological relationships have been demonstrated between the three peroxidases.
TL;DR: Growth analysis indicated that carbon gain in the alpine succulent succulentSedum album tended to take place early during the growing season, and increased levels of proline and betaine towards the end of thegrowing season appeared to reflect seasonal changes.
Abstract: Growth analysis indicated that carbon gain in the alpine succulentSedum album tended to take place early during the growing season. Leaf water potential remained unchanged for a considerable length of time after the imposition of water stress in the field. Induction of crassulacean acid metabolism (CAM) by protracted water stress occurred before any signs of stress could be observed in the leaves, and appeared to be influenced by a complex interaction of environmental conditions including temperature and duration of sunshine. Increased levels of proline and betaine towards the end of the growing season appeared to reflect seasonal changes.
TL;DR: In this paper, the effect of combinations of different concentrations of copper (Cu) and mercury (Hg) ions with different constant temperatures (T) onPhaseolus vulgaris plants was studied.
Abstract: The effect of combinations of different concentrations of copper (Cu) and mercury (Hg) ions with different constant temperatures (T) onPhaseolus vulgaris plants was studied. Criteria investigated included shoot and root length, dry mass, chlorophyll content (Chl) and stability index (CSI), and contents of soluble (SS) and hydrolysable saccharides (HS), soluble proteins (SP) and total free amino acid (AA). Each of the factors (T, Cu and Hg) significantly affected the parameters tested with exception of T effect on Chlb content as well as on Chla/b ratio. Bifactorial interactions (T×Cu) or (T×Hg) were also significant, except the interaction (T×Hg) in shoot elongation, Chlb content and Chla/b ratio. Statistical treatment of the data lead to three findings: (1) temperature was dominant in affecting CSIa, shoot AA and root SS, (2) Cu and Hg had the predominant effect on growth parameters and Chl content, and (3) interactions (T×Cu and T×Hg) were dominant in affecting CSIb, shoot SP, and root HS.
TL;DR: The enzyme activities of the proline metabolic pathways were determined in control and satt-treated calli derived from cotyledons of the domestic saltsensitive tomato and the wild salt-tolerant L. pennellii.
Abstract: The enzyme activities of the proline metabolic pathways were determined in control and satt-treated (140 M NaCl) calli derived from cotyledons of the domestic saltsensitive tomatoLycopersicon esculentum and the wild salt-tolerantL. pennellii. Glutamate, glutamine, asparagine, and aspartate levels increased in both genotypes under salt stress, while proline accumulation increased markedly only in the salt sensitive tomato. Activity of glutamine synthetase (GS) decreased in the salt-treated calli of the domestic species, whereas both NADH- and NADPH-glutamate synthase (GOGAT) activities increased; GS and NADPH-GOGAT decreased together in the salinized calli of the wild species. Decreasing ornithine levels were found due to NaCl in both tomato populations, while ornithine transaminase (OT) decreased in the wild type only. Increasing NADPH-Δ-pyrroline-5-carboxylate reductase (P5CR) and decreasing proline oxidase (Pro oxi) occurred in the salinized calli of the wild type. Conversely, Pro oxi and proline dehydrogenase (Pro dH) decreased highly in the salinized calli of the domestic population, while no significant changes in P5CR were found.
TL;DR: An ameliorative effect of Ca2+ pretreatment in droughted cells was found as membrane stability index was improved and K+ leakage was reduced, and higher chlorophyll content and stability was observed, which might increase survival of C. fusca cells subjected to drought through membrane stabilization.
Abstract: Chlorella fusca was subjected to evaporative dehydration under air humidity of 72%. Ca2+ pretreated cultures lost water as rapidly as untreated cultures. Nevertheless, an ameliorative effect of Ca2+ pretreatment in droughted cells was found as membrane stability index was improved and K+ leakage was reduced. In addition, higher chlorophyll content and stability was observed. These parameters enabled droughted cells to recommence growth upon rewatering. Thus Ca2+ might increase survival ofC. fusca cells subjected to drought through membrane stabilization.
TL;DR: For clonal propagation ofAsparagus cooperi, shoot tips and node explants of 7, 20 and 35 d old spear from the region within 10 cm and below 25 cm from the apex were cultured in modified Murashige and Skoog's medium containing 6-benzylaminopurine (BAP).
Abstract: For clonal propagation ofAsparagus cooperi, shoot tips and node explants of 7, 20 and 35 d old spear from the region within 10 cm and below 25 cm from the apex were cultured in modified Murashige and Skoog's (1962) medium containing 6-benzylaminopurine (BAP). The required concentration of BAP varied in explants of different ages and types. In shoot tip culture, the rate of shoot multiplication was higher after 40 d than 60 d of culture. The maximum mumber (62–65) of shoots were obtained from shoot tip explants of 20 d old spear in the medium containing 2.0 mg dm−3 of BAP, 80 mg dm−3 of adenine and 0.02 mg dm−3 of α-naphthalene acetic acid after 60 d of culture. From node cultures, high number of shoots were obtained after 30 d. Pretreatment with BAP in liquid medium for 48 h was effective for semirejuvenescence. The individual shoots produced roots in presence of indole-3-butyric acid and also in potassium salt of indole-3-butyric acid, the later being more effective. All regeneratns were cytologically stable.
TL;DR: In this article, the authors showed that increasing soil acidity (from pH 6.5 to pH 2.0) decreased chlorophyll (Chl)a and b contents, dry matter accumulation by plants and the transpiration coefficient.
Abstract: Increasing soil acidity (from pH 6.5 to pH 2.0) decreased chlorophyll (Chl)a andb contents, dry matter accumulation by plants and the transpiration coefficient. Chl stability to heat significantly increased with increased soil acidity. The Chla/b ratio was increased significantly at pH 5 and 4 and decreased at pH 3 and 2. SprayingSorghum shoots with kinetin solutions counteracted the above adverse effects on Chl content and dry matter accumulation. Kinetin-treated plants showed a lower transpiration coefficient than the untreated plants.
TL;DR: The considerable decrease in the amount of cinnamic acid derivates and broader spectrum of hydroxybenzoic acids suggest in tolerant cell lines the activation of alternative pathway not regulated by phenylalanine ammonia lyase.
Abstract: Glyphosate tolerant cell lines were selected from highly embryogenic cell suspension culture ofMedicago sativa L. Resistant cell lines showed significant reduction of embryogenic ability and during long-term culture in the presence of glyphosate gradual loss of this ability was observed. After glyphosate treatment the increased activity of 5-enolpyruvylshikimate-3-phosphate synthase in tolerant cell lines overcame the block in aromatic amino acid synthesis which was observed in control cell lines. Glyphosate caused marked increase in the content of shikimic acid in both control and tolerant cell lines but the accumulation of shikimic acid was considerably lower in tolerant calli. Significant qualitative and quantitative differences were found in the content of individual phenolic acids. The considerable decrease in the amount of cinnamic acid derivates and broader spectrum of hydroxybenzoic acids suggest in tolerant cell lines the activation of alternative pathway not regulated by phenylalanine ammonia lyase. The possible role of altered pool of phenolic acids on the embryogenic ability is discussed.
TL;DR: In this article, the length of roots and shoots, fresh and dry matter yield, and the contents of insoluble saccharides and free amino acids were reduced with the rise in NaCl concentration.
Abstract: The lengths of roots and shoots, fresh and dry matter yield, and the contents of insoluble saccharides and free amino acids were reduced with the rise in NaCl concentration. However, under combination of NaCl with Ca2+ ions, these parameters generally raised. Contents of soluble saccharides, proline and quaternary ammonium compounds increased with increasing NaCl concentration, but under addition of CaCl2 or CaSO4, contents of these compounds were decreased. Low concentrations of NaCl stimulated soluble proteins, production, but higher concentrations decreased the content of soluble proteins. Addition of Ca2+ in the media did not improve the soluble protein production. Insoluble proteins content was increased with the rise of salinity level, but these effects were more pronounced with NaCl and CaCl2 or CaSO4 than with NaCl only.
TL;DR: The results show that although UV-C did not produce significant changes in peroxidase activity in susceptible species, and only minor changes in resistant species, treatment with UV-light induces an acidic isoperoxidases A1, capable of oxidising 4-hydroxystilbenes inresistant species.
Abstract: The effect of shortwave (250 nm) UV radiation (UV-C) on the level of peroxidase activity and peroxidase isoenzyme patterns in leaves of resistant ([Vitis vinifera x Viris riparia] x Vitis rupestris andVitis rupestris) and susceptible (Vitis vinifera) grapevine species toPlasmopara viticola (downy mildew) was studied. The results show that although UV-C did not produce significant changes in peroxidase activity in susceptible species, and only minor changes in resistant species, treatment with UV-light induces an acidic isoperoxidase (isoperoxidase A1), capable of oxidising 4-hydroxystilbenes in resistant species. It was named HSPrx 2. Since peroxidase is apparently the enzyme responsible for e-viniferin synthesis from resveratrol in grapevines, a close relationship between this peroxidase isoenzyme and e-viniferin synthesis which occurs in grapevine leaves after UV-C treatment must be expected.
TL;DR: Addition of either abscisic acid (ABA) or kinetin to salinized media (20–120mM NaCl) induced remarkable effects on growth ofPhaseolus vulgaris plants.
Abstract: Addition of either abscisic acid (ABA) or kinetin at 10−6 M to salinized media (20–120mM NaCl) induced remarkable effects on growth ofPhaseolus vulgaris plants. Whereas ABA inhibited the plant growth and the rate of transpiration, kinetin induced stimulation of both parameters. Moreover, ABA increased proline and phosphorus concentrations in the salinized plants whilst kinetin decreased them. ABA induced stimulation of the transport of K, Ca and Cl from root to shoot, accumulation of K, Na and Cl in root cells and inhibits the transport of Na and accumulation of Ca. Kinetin appeared to inhibit the transport and accumulation of Na and Cl, transport of K, and stimulates the accumulation of K and Ca as well as the transport of Ca. The highest influence of both ABA and kinetin was mostly observed when these hormones were used in combination with the highest concentration of NaCl (120 mM) in the medium.
TL;DR: A fully habituated (H) nonorganogenic sugar beet callus, subcultured in the light, did not contain detectable chlorophyll nor carotenoid, but a green hormone-dependent callus of the same sugar beet had normal fluorescence spectra and kinetics comparable to those of a green leaf.
Abstract: A fully habituated (H) nonorganogenic sugar beet callus, subcultured in the light, did not contain detectable chlorophyll (Chl) nor carotenoid (Car). It accumulated some Car in the dark. Fluorescence spectra indicated that this H callus also accumulated some protochlorophyllide which, however, was not well integrated into the protochlorophyllide-NADPH-photoreductase complex, and therefore not transformed into chlorophyllide in the light. The H callus showed no variable fluorescence which indicated absence of photosynthesis, and therefore it suggested a full heterotrophic behaviour of this peculiar callus line. A green hormone-dependent callus of the same sugar beet had normal fluorescence spectra and kinetics comparable to those of a green leaf.
TL;DR: Three fold multiplication rate was achieved during every subculture of regenerated shoots on the same medium producing an average of 230 shoots per node within 84 d and reduction in BAP concentration during subculture promoted shoot length without affecting the rate of multiplication.
Abstract: In vitro method has been developed for propagation ofWrightia tinctoria R.Br. using cotyledonary node segments. Murashige and Skoog's (MS) medium supplemented with 5.0 mg dm−3 of 6-benzylaminopurine (BAP) and 0.01 mg dm−3 of naphthaleneacetic acid (NAA) induced up to eight shoots per explant with an average shoot length of 1.4 cm in 21 d. Three fold multiplication rate was achieved during every subculture of regenerated shoots on the same medium producing an average of 230 shoots per node within 84 d. Reduction in BAP concentration from 5.0 to 1.0 mg dm−3 during subculture promoted shoot length without affecting the rate of multiplication. The differentiated shoots could be rooted by a dip treatment into preautoclaved indole-3-butyric acid (IBA-500 mg dm−3 for 5 min) followed by their implantation onto MS medium containing 1/4 salts. Rooting was observed within 8–10 d in approximately 80% of shoots inoculated after IBA treatment. 15 d after rooting, the plantlets were transferred to culture bottles containing soil-SoilriteTM (1∶1) and liquid nutrient solution comprising 1/4 MS salts. After their partial hardening in these bottles for 10 d they were transferred to pots containing soil-Soilrite (1∶1) mixture with 60% transplantation success. Methods are being standardized to improve the rate of survival and large scale field transfer.
TL;DR: The regeneration ability of primary explants derived from mericlones of two commercial Bohemian hops was investigated and high 2,4-D concentration pretreatment did not promote somatic embryogenesis, suggesting that HLVd infection did not impair organogenesis.
Abstract: The regeneration ability of primary explants derived from mericlones of two commercial Bohemian hops was investigated. It was found that these hops are able to regenerate shoots by direct organogenesis on media containing BAP or zeatin at concentrations 0.5–2 mg dm−3. The highest regeneration of shoots was achieved from either petioles or internodes at frequencies 21% and 52%, respectively, on the medium containing zeatin (2 mg dm−3), while relatively low amount of regenerated shoots (1.3%) was observed for leaf blade explants. On the other hand, more efficient rooting occurred on the leaf blades then on other explants. A similar pattern of regeneration we observed for HLVd-infected mericlones of clone Osvald 31 even though viroid concentration inin vitro cultures was about 8-fold higher than in field-grown plants and was 31.1 pg mg−1 of fresh mass in the average. These results suggest that HLVd infection did not impair organogenesis. We found that high 2,4-D concentration pretreatment (11 mg dm−3) did not promote somatic embryogenesis. Although this treatment suppressed direct organogenesis, the inhibition was not complete and in low frequency the shoot regeneration was seen. Sensitivity of hop explants to antibiotics commonly used inAgrobacterium-mediated transformation was assayed. It was found that kanamycin (100–200 mg dm−3) suppressed efficiently callogenesis, root formation and shoot proliferation. An estimation of effect of kanamycin (200 mg dm−3) and ticarcillin (500 mg dm−3) on morphogenesis was performed using regeneration medium. The inhibitory effects observed suggest that these conditions could be used inAgrobacterium transformation/selection system.
TL;DR: In the topmost leaves of low-irradiance (LI) tolerant CO 43 and LI susceptible IR 20 rice cultivars, the contents of chlorophyll (chl)a andb and carotenoids and the Hill reaction activity increased under LI while the content of non-reducing sugars increased due to shading.
Abstract: In the topmost leaves of low-irradiance (LI) tolerant CO 43 and LI susceptible IR 20 rice cultivars, the contents of chlorophyll (chl)a andb and carotenoids and the Hill reaction activity increased under LI. The increase was greater in cv. CO 43 than that in cv. IR 20, and in Chlb than in Chla. The contents of soluble proteins and reducing sugars and nitrate reductase activity of the leaves decreased while the content of non-reducing sugars increased due to shading. The decrease in reducing sugars was greater in cv. CO 43 than in cv. IR 20. On the other hand, the decrease in soluble proteins and nitrate reductase was much less in cv. CO 43 as compared with cv. IR 20.