Germination Of Tomato Seeds Research Articles

RNA Populations in Tomato Seeds Imbibing in the Presence or Absence of Abscisic Acid

The RNA content of tomato seeds was shown to increase when the seeds were imbibed in water. This increase was due mainly to an increase in nuclear RNA, the polysomal content declining and the ribonucleoprotein fraction remaining constant. The poly(A)+RNA population also showed a gradual increase, again due to a high de novo synthesis rate in the nucleus. In the presence of 200 μM abscisic acid (ABA), the total nuclear DNA failed to increase in the manner seen with water imbibition, leading to an overall decline in RNA during the first 1.5 h. The polysomal and ribonucleoprotein fractions were unaffected by ABA. The decline in total nuclear RNA was due primarily to a major decrease in the nuclear poly(A)+ content of seeds imbibing with ABA. This reduction in de novo transcription may be a factor responsible for the inhibitory effect that ABA has on germination of tomato seeds.

Matriconditioning Integrated with GA to Hasten Seed Germination and Improve Stand Establishment of Pepper and Tomato

Emergence and stand establishment of pepper and tomato seeds often are slow and erratic, particularly under stress conditions. Field emergence trials sometimes have not responded to priming in pepper. In this study, we examined the combining effect of matriconditioning with GA4+7 to hasten germination and improve stand establishment of pepper and tomato seeds. The results showed that, in all cases, even under stressful conditions, the combined matriconditioning plus GA treatment was effective in improving germination and emergence of pepper and tomato seeds. Emergence was improved in 20% when seeds were treated with GA4+7 up to 200 mM. Thus, matriconditioning during which germination is suspended, provides a unique means to rapidly and efficiently digest the endosperm by GA-induced enzymes and reduce not only the mechanical restraints but also provide the energy for embryo growth.

Involvement of Endomannanase in the Control of Tomato Seed Germination under Low Temperature Conditions

The cause of differences in germination rates in a cold-tolerant tomato line (PI341988), a control line (UC82B), and six progeny lines stemming from crosses and backcrosses between the two parent lines was investigated. Pursuant to earlier work showing that differences in germination ability at 12°C are due to the barrier imposed by the endosperm layer, we analysed the activity of cell-wall-hydrolysing enzymes extracted from these lines. A significant increase in endomannanase activity was found in plant line PI341988 prior to germination at 12°C. Extracts of PI341988 seeds that had imbibed at either 12 or 25°C exhibited higher endomannanase activity than their counterparts from plant line UC82B. Moreover, a positive relationship was found between germination ability at low temperature and endomannanase activity in the six progeny lines. Analysis of endomannanase activity in sub-regions of the seed indicated that the increase in activity prior to germination was higher in the micropylar endosperm cap than in the rest of the seed. Exogenous application of mannanase originating from soil-borne bacteria increased germination rates under both moderate and low temperature conditions. Cellulase (endo-1,4-β-glucanase) activity was also found to be higher in plant line PI341988. However, the activity of this enzyme probably increases after germination and it is therefore not considered as a key enzyme controlling germination at low temperatures.

Endo-beta-mannanases in the endosperm of germinated tomato seeds

Endo-beta-mannanases in the endosperm of germinated tomato seeds

Endo‐β‐mannanases in the endosperm of germinated tomato seeds

Three forms of galactomannan‐hydrolyzing enzymes (dyed galactomannan as substrate) were partially purified from germinated tomato [Lycopersicon esculentum (L.) Mill.] seed. Two of the enzymes were of the same molecular mass, 38 kDa, as judged by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE), but the points of elution from a CM‐Toyopearl column by a pH‐gradient were different between the two (pH 5.15 and 5.45. respectively). The molecular mass of the third form was slightly less (37.5 kDa) than that of the other two. These 3 enzymes showed no α‐galactosidase (EC 3.2.1.22) or β‐mannosidase (EC 3.2.1.25) activity. Thin‐layer chromatography (TLC) revealed that the products of the reaction were oligosaccharides and that free galactose and mannose were not released. These results indicate that the 3 galactomannan‐hydrolyzing enzymes are endo‐β‐mannanases (EC 3.2.1.78). Polyclonal antibodies raised against the 37.5‐kDa polypeptide cross‐reacted with the two 38‐kDa polypeptides, indicating that the 3 endo‐β‐mannanases are immunologically homologous. Activity staining and immunoblotting of native PAGE of endosperm extracts revealed that only two (38‐kDa. elution point pH 5.15 and 37.5‐kDa proteins) of the 3 forms were major endo‐β‐mannanases present in the endosperm of germinated tomato seeds.

Relative Wilt‐Inducing Capacity of the Culture Filtrates of Isolates of Fusarium oxysporum f.sp. radicis‐lycopersici, the Tomato Crown and Root Rot Pathogen

AbstractCell‐free 30‐day‐old culture filtrates of 24 isolates of Fusarium oxysporum f.sp. radicis‐lycopersici (FORL) differed considerably in their capacity to induce wilting in 28‐day‐old tomato seedings and to inhibiting the germination of tomato seeds. The wilt effects ranged from mild on leaves and lateral stems, to total collapse of the seedlings in 24 h. Wilt, leaf curl and leaf chlorosis, appearing in this sequence, were the three symptoms clicited by the culture filtrates. Boiled and non‐boiled filtrates elicited similar sympotoms. The high wilt capacity filtrates were pH 7.2; the others were generally below pH 6. The high wilt capacity filtrates showed polyphenoloxidase activity but the overall pattern of this activity did not correlate consistently with wilt capacity. The majority of the lower wilt capacity filtrates showed a net inhibition of dihydroxy‐phenylalanine (DOPA) oxidation. The study suggests that the symptoms in the tomato seedlings were elicited by toxins in the culture filtrates. Further, it appears that the differences obtained in the wilt capacity of filtrates from the isolates were due, at least in part, to inherent differences in the concentration of the toxic factors. The rapidity of the onset of wilt, the total, collaps of filtrate‐treated seedlings and the absence of fungi in wilted seedlings suggest further that the operative mechanisms are physiological and biochemical and not impairment of the seedlings’ translocation system by physical blockage with mycelia.

Nuclear replication activities during imbibition of abscisic acid- and gibberellin-deficient tomato (Lycopersicon esculentum Mill.) seeds

The role of cis-abscisic acid (ABA) and gibberellins (GAs) in the induction of cell-cycle activities has been studied during imbibition and subsequent germination of tomato seeds. Using flow cytometry, nuclear replication activity was investigated in embryo root tips isolated from seeds of the ABA-deficient mutant sit w , the GA-deficient mutant gib-1, and the wild-type (MM) tomato (Lycopersicon esculentum Mill. cv. Moneymaker) upon imbibition in water, 10 μM GA4+7, 5 μM ABA or 5 μM ABA+10 μM GA4+7. The nuclei of fully matured dry MM, sit w and gib-1 seeds predominantly showed 2C DNA signals, indicating that the cell-cycle activity of most root-tip cells had been arrested at the G1 phase of nuclear division. However, ABA-deficient sit w seeds contained a significantly higher amount of G2 cells (4C DNA) compared with the other genotypes, suggesting that, during maturation, cell-cycle activity in sit w seeds is less efficiently arrested in G1. Upon imbibition in water, an induction of the 4C signal, indicating nuclear replication, was observed in the root tip cells of both MM and sit w embroys. The augmentation in the 4C signal occurred before visible germination. Gib-1 seeds did not show cell-cycle activity and did not germinate in water. Upon imbibition in GA4+7, both cell-cycle activity and subsequent germination were enhanced in MM and sit w seeds, and were induced in gib-1. In ABA, the germination of MM and sit w seeds was inhibited while nuclear replication of these seeds was not affected. It is concluded that GA influences germination by acting upon processes that precede cell-cycle activation, while ABA affects growth by acting upon processes that follow cell-cycle activation.

Roles of different seed components in controlling tomato seed germination at low temperature

The role of different seed components in controlling the germination of tomato ( Lycopersicon esculentum) seeds under low temperature conditions was studied in cold-resistant plant line PI341988 and cold-sensitive commercial cultivar UC82B, as well as in eight progeny lines of these two parents. At 12°C, PI341988 and UC82B seeds had a mean time of germination (MTG) of 8.7 days and 19.7 days, respectively. Removal of seed testa by NaOCl treatment shortened the time required for germination by 3 days in both plant lines, but did not reduce the significant differences in germination rate between them. Removal of the seed coat and the endosperm layer in front of the embryo's radicle tip eliminated the differences in germination rate under low temperature conditions between the ten tested lines. All lines exhibited similar radicle elongation rates, both at 25°C and at 12°C. These results indicate that the main barrier to germination of tomato seed at low temperatures is imposed by the endosperm layer. At 12°C, plant line PI341988 exhibited a higher respiration rate than UC82B, indicating its higher metabolic activity under low temperature conditions.

Effect of the addition of activated charcoal to the nutrient solution on the growth of tomato in hydroponic culture

Abstract The addition of activated charcoal to a nutrient solution for the hydroponic culture of tomato resulted in both a considerable decrease in the carbon concentration in the solution and significant increases in the dry weight of plant and in fruit yield. No appreciable changes were brought about in the concentrations of major and trace elements both in the solution and in the plant by the addition of activated charcoal. The nutrient solution collected after the cultivation without activated charcoal was toxic to the growth of tomato seedlings and to the germination of tomato seeds. No toxic effect was observed for the residual nutrient solution treated with activated charcoal. These facts indicate that the growth of tomato in hydroponic culture is inhibited by organic substances which arise from the root exudates and are removed from the nutrient solution by adsorption on activated charcoal.

Chemotaxis of Fluorescent Pseudomonads Towards Seed Exudates and Germinating Seeds in Solarized Soil

We investigated the chemotaxis of fluorescent pseudomonads towards seeds exudates and germinating tomato seeds. Chemotaxis of Pseudomonas putida and P.fluorescens in a capillary tube was more pronounced towards exudates originating from seeds that were germinated in solarized soil than towards comparable exudates from seeds that were germinated in nonsolarized soil. Movement of these bacteria was enhanced also towards a mixture of either amino acids or amino acids and sugars, but not of sugars alone (...)

Relationships between chemical structure and inhibitory activity of C6 through C9 volatiles emitted by plant residues

Leaf, stem, flower, fruit, and root residues of a wide variety of plants have been reported to emit bioactiven-alkanes, 2-alkanols,n-alkanals, 2-alkenals, 2-alkanones, andn-alkanoic acids containing from six to nine carbon atoms. During a 72-hr exposure to the vapor phase of these compounds (6.9, 20.8 or 34.4μ M/liter), germination of onion, carrot, and tomato seeds was inhibited to varying degrees. The extent of inhibition caused by these plant residue volatiles depended upon the compound type and concentration, carbon-chain length, and the seed species tested. Tomato seeds recovered more fully from exposure to these volatile inhibitors than did those of carrot and onion. Degree of recovery in all three species depended on the type and concentration of volatile present. The C7 and C8 compounds were the most inhibitory among these 24 volatiles. Of the six classes of chemicals examined, the 2-alkenals were the most inhibitory, followed by the 2-alkanols,n-alkanals, and 2-alkanones, which were equally effective as seed germination inhibitors. The straight-chain alkanes and alkanoic acids were relatively noninhibitory. Tests of a C7 and C9 alkadienal indicated that the C7 compound was the more inhibitory.

A Comparison of Priming Agents for Tomato and Asparagus Seeds

Tomato (Lycopersicon esculentum Mill.) and asparagus (Asparagus officinalis L.) seeds were primed for 1 week in –0.8 MPa (20C, dark) polyethylene glycol 8000 (PEG), synthetic seawater (INO), or combinations of Ca+2, K+, or Na+ with Cl–, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\) \end{document}, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{H}_{2}\mathrm{PO}_{4}^{-}\) \end{document}, or \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{SO}_{4}^{-2}\) \end{document}) and then were placed in 0.5-fold Hoagland solution at 20C for germination. Priming did not affect percentage germination of tomato seeds; but asparagus germination increased from 85% in untreated seeds to 90% due to priming. All priming treatments reduced the time to 50% germination (G50) of both species but reduced the time between 10% and 90% germination (G10-90) of only tomato seeds. Salt solutions gave lower G50 values than PEG for tomato seeds but did not provide this advantage for asparagus seeds. The G50 and G10-90 of tomato seeds were lower after priming with nitrate salts than with other salts, but the reductions were greatest with sodium nitrate. The G50 of asparagus seeds was lowered with nitrate salts, but the G10-90 was unaffected.

Germination and Seedling Emergence of Primed Tomato and Asparagus Seeds under Adverse Conditions

Seeds of `Ace 55' tomato (Lycopersicon esculentum Mill.) and `Mary Washington' asparagus (Asparagus officinalis L.) were primed in -0.8 MPa (20C, 1 week, dark) polyethylene glycol 8000 (PEG), synthetic seawater (INO), or NaNO3. Primed seeds of both species had a higher percentage of germination than untreated seeds only at 10C in nonsaline (– 0.05 MPa) medium, while in saline medium (– 0.6 MPa) priming increased the percentage of germination of tomato seeds at 10 and 30C, and of primed asparagus seeds at 10 and 20C. Sodium nitrate was superior to PEG or IN0 for priming tomato seeds since it resulted in fewer days to 50% germination and higher final germination percentage in saline media at all temperatures. IN0 was a satisfactory alternative to PEG or NaNO3 for priming asparagus seeds since priming agent had little or no effect on germination. Seedling emergence from NaNO3-primed seeds of both species sown in a seedbed provided saline (– 0.39 MPa) irrigation was faster than from untreated dry-sown seeds. In the saline seedbed, priming increased final emergence percentage (FEP) from asparagus seeds, provided they were not subsequently dried, but had no effect on the percentage emergence of tomato seeds. Fluid-drilling primed or germinated seeds of either species enhanced seedling establishment in the saline seedbed by reducing time to 50% emergence and/or increasing FEP relative to primed, dried-b&k or untreated seeds.

The effect of light and exogenous gibberellic acid on respiration pathways during germination of tomato seeds

The effect of light and exogenous gibberellic acid on respiration pathways during germination of tomato seeds

The effect of light and exogenous gibberellic acid on respiration pathways during germination of tomato seeds

Tomato (Lycopersicon esculenlum Mill. cv. Taiwan Red) seeds are typical lightsensitive seeds where light requirement can be substituted by gibberellic acid (GA3). During the initial stage of germination, the hexose monophosphate pathway (HMP) in seeds incubated for 24 h under white light or 12 h in 0.3 mW GA3 solution acidified with 1 M HCI for 1 h in the dark (HCl→GA3) was much greater than in seeds incubated for 24 h in the dark. The results were obtained from measurements of the respiration rate by man metric method of Warburg with or without iodoacetic acid, and from activities of glucose‐6‐phosphate dehydrogenase (EC 1.1.1.49) and aldolase (EC 4.1.2.13). Although the HMP tended to decrease at the later stage (72 h under white light or in the dark, or 36 h in HCl→GA3), it remained greater in light‐ than in dark‐incubated seeds. CN‐resistant respiration increased from 27–30% to 57–64% of the total respiration in seeds incubated under white light or in HCI→GA3, while respiration of non‐germinating, dark‐incubated seeds remained zero. Benzohydrox–amic acid (BHAM), an inhibitor of the alternative pathway, inhibited both respiration and seed germination. It is concluded that the enhancement of HMP and the CN–resistant pathways are both controlled by Pfr, but there is no direct connection between them.

The content of [formula omitted] in seeds and seedlings of plants

The content of N- malonyl- d-tryptophan (MTry) was determined in seeds and seedlings of some plants. MTry was present in dry seeds of tomato, sweet clover and alfalfa and absent in the seeds of pepper, maize, rose, horse bean, wheat and soybean. The germination of tomato, alfalfa and sweet clover seeds was accompanied by an increase in the MTry content. MTry was also identified in the seedlings of wheat and Lycopersicon peruvianum Mill. The MTry and IAA content in tomato seedlings increased during the first 6 days of growth and then decreased. The content of l-Try remained low during the period of tomato hypocotyl elongation and sharply increased when seedling growth ceased. MTry was mainly located in the meristematic zone of the tomato hypocotyl and was absent in the roots. Light-grown seedlings has slower rates of growth and MTry accumulation than dark-grown ones. The changes of MTry content during seedling growth are believed to reflect the change of the production of d-Try which is used both for IAA and MTry synthesis.

Production of a novel steroid sulfate metabolite [4,4,24-trimethylcholesta-8,14,24(28)-trien-2 alpha,3 beta,11 alpha,12 beta-tetrol 12-acetate, 3-sulfate] by Fusarium species and its biological activity

A novel steroid sulfate, 4,4,24-trimethylcholesta-8,14-24(28)-trien-2 alpha,3 beta,11 alpha,12 beta- tetrol 12-acetate, 3-sulfate, was discovered in Fusarium spp. Forty Fusarium strains belonging to F. sporotrichioides, F. chlamydosporum, E. equiseti, F. acuminatum, F. sambucinum, F. culmorum, and F. graminearum produced the steroid on white corn grits at 25 degrees C for 20 days. This steroid sulfate is one of the more abundant and easily attainable microbial steroids. At a concentration of 160 micrograms/ml, it inhibited the growth of six fungi, two gram-positive bacteria, and an alga, as well as the germination of both wheat and tomato seeds.

NaCl Effects on Tomato Seed Germination, Cell Activity and Ion Allocation

Summary Salinity effects on germination, ion allocation and cell activity in Lycopersicon esculentum were studied. NaCl concentrations up to 100 mM affected the speed but not the percentage of germination. Concentrations higher than 137 mM altered both parameters. Na + and Cl - contents in roots, hypocotyls and cotyledons progressively increased with NaCl concentration, whereas K+ content decreased. Ca ++ content decreased in hypocotyls and roots. Mg ++ concentration did not vary significantly with the different treatments. Transcriptional and translational activities were modified even with the minimal concentrations assayed.

Seed-germination inhibition by volatile alcohols and other compounds associated withAmaranthus palmeri residues

Effects of 3-pentanone and eight low molecular weight aliphatic alcohols and aldehydes identifed in the mixtures of volatiles released byAmaranthus palmeri S. Wats. (AMAPA) residues were determined on germination of onion, carrot, AMAPA, and tomato seeds. Three-day exposures to these volatiles significantly inhibited germination of these assay seeds, and the inhibition was dependent upon exposure time and concentration. Based on the degree of inhibition observed in both time- and concentration-dependent assays, the following activity series was obtained: 2-heptanol > 3-methyl-1-butanol, 1-hexanol > hexanal, 1-pentanol, 3-pentanone, acetaldehyde > ethanol, 2-methyl-1-propanol. The activities of this group of compounds with that of 2-heptanone appear to be additive and related to test compound volatility and hydrophilicity. 2-Heptanol and 2-heptanone also significantly inhibited the germination of other species, including shepherdspurse, soybean, lettuce, alfalfa, common purslane, oats, and lovegrass.

Germination and Priming of Tomato, Carrot, Onion, and Sorghum Seeds in a Range of Osmotica

Abstract In the article “Germination and Priming of Tomato, Carrot, Onion, and Sorghum Seeds in a Range of Osmotica”, by Anthony M. Haigh and E.W.R. Barlow (J. Amer. Soc. Hort. Sci. 112:202–208, March 1987), the term “ionic strength” has been inadvertently used throughout the paper where “ionic concentration” was meant.