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1.
OLAVI JUNTTILA 《Physiologia plantarum》1980,49(2):127-134
Flower bud initiation in seedlings and vegetatively propagated plants of Salix pentandra from different locations has been studied under controlled conditions. In mature plants flower bud formation was induced by 2-chloroethyltrimethylammoniumchloride (CCC) and by short day treatment. The effect of CCC was antagonized by GA3. The critical photoperiod for flower bud formation was about 18 h for a southern clone (from 49°48'N), but cuttings of a northern ecotype (from 69°39'N) formed flower buds even at 24 h photoperiod. Generally, flower bud formation occurred simultaneously with apical growth cessation. However, apical growth cessation was not a prerequisite for floral initiation and flower buds were also found in elongating plants. Seedlings up to 60 days old did not form flower buds in growth chamber studies. The length of the juvenile phase has not been studied in detail, but cuttings taken from seedlings approximately 20 cm high and 60 days old were able to develop flower buds when treated with CCC. A gradual transition from the juvenile to the mature phase was obtained by repeated pruning of seedlings grown at 18°C and 24 h photoperiod. 相似文献
2.
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. 相似文献
3.
Summary The absorption and subsequent transport of foliar applied Rb86 labeled Rb Cl (10 mM) was studied on bean plants (Phaseolus vulgaris, L. cv. Black Seeded Blue Lake) exposed to physiologically tolerable levels of certain plant growth substances in the solution culture root media. Gibberellin A3 (10-5 M) increased Rb uptake but did not affect total translocation from the treated leaf. Translocation was directed to the upper vegetative parts and markedly reduced to the roots. Foliar influx of Rb and transport to the roots were greatly enhanced by 1-naphthaleneacetic acid (10-6 M) but mobilization of Rb into the leaves and upper stem was reduced. 2-Chloroethyltrimethylammonium chloride (10-3 M) and N,N-dimethylaminosuccinamic acid (3×10-4 M) decreased the mobility of Rb to the upper stem, increased it to the roots, and had no effect on initial uptake. Rb absorption was depressed by 2,4-dichlorobenzyltributylphosphonium chloride (10-5 M) with no effect on subsequent translocation. Both uptake and mobility were strikingly inhibited by N6-benzyladenine (10-6 M).These results suggest that absorption and the subsequent transport of foliar absorbed Rb are independent processes and that the distribution or mobilization of Rb in the various plant organs was not always a function of the chemically modified growth rate of the corresponding organ.Report No. COO-888-50 in cooperation with the Division of Biology and Medicine of the United States Atomic Energy Commission, Contract No. AT (11-1)-888. Journal Article No. 3643 of the Michigan Agricultural Experiment Station. 相似文献
4.
Sex expression in cucumber plants as affected by 2-chloroethylphosphonic Acid, ethylene, and growth regulators 总被引:8,自引:2,他引:6
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The effects of 2-chloroethylphosphonic acid (Ethrel), ethylene, and some growth retardants on sex expression of cucumber plants (Cucumis sativus L.) were investigated, with the use of a monoecious cultivar (Improved Long Green) which has a strong tendency toward maleness. 相似文献
5.
D. Klämbt 《Biologia Plantarum》1985,27(2-3):204-208
It is generally accepted that plant growth and development are regulated by the known plant hormones. Some objections to the
functions of auxins and cytokinins in the induction of shoot and root primordia are reported. Instead of them oligopeptides
of special amino acid sequences could be the endogenous signals. There exist structure relationships between auxins and parts
of the α-helical oligopeptides of defined amino acid sequences. The same is true for cytokinins.
The most difficult part of this hypothesis is its verification. Using protonemata ofFunaria hygrometrica bud induction by various oligopeptides was investigated. The most active peptide tested is leucine-tryptophan. On the other
hand endogenous oligopeptides containing [14C]-leucine in the moss protonemata during endogenous bud initiation were looked for. Three to four different oligopeptide
spots seem to be related to bud induction. 相似文献
6.
The effects of benzoquinone, naphthaquinone and anthraquinone on the growth of tomato callus, whole plants of tomato and on rooting of mungbean cuttings were studied. Naphthaquinone effects on some oxidases and on the isozyme patterns of peroxidases in all the three systems were also observed. Quinones increased callus growth, the number of roots initiated in mungbean cuttings and the growth of tomato plants, significant increases being obtained with 10–5
M naphthaquinone. Naththaquinone also decreased the activities of IAA oxidase, ascorbic acid oxidase and polyphenol oxidase, and led to the disappearance of one of the isozyme of peroxidase in all systems. 相似文献
7.
8.
Although much investigated, the factors constraining cereal grain protein accumulation are not well understood. As a result of the development of a new technique, new approaches to this question are now possible. A peduncle perfusion system was used to deliver a range of plant growth regulators (PGRs) and/or N solutions into barley (Hordeum vulgare) plants during the grain-filling period. The perfusion technique floods the peduncle interior with a treatment solution for periods of weeks to months, allowing the plant to take up administered substances from the perfused solution. The objectives of the present work were to determine: (1) whether some PGRs could alter the overall pattern of N allocation within barley plants, perhaps leading to higher protein accumulation in the seeds, (2) whether the addition of N through the peduncle could increase the seed N concentration even when the concentration of N in the rooting medium was high, and (3) whether or not PGR-stimulated elevations in grain protein levels and peduncle-added N increases in grain protein levels were additive. Three experiments were conducted to determine the physiological effects of (1) peduncle-administered PGRs (2) combinations of soil- and peduncle-applied N and (3) selected combinations of soil- and peduncle-administered N, and peduncle-applied PGRs on photosynthetic rate, dry matter partitioning and N accumulation of barley plants during grain filling. The first experiment tested four PGRs: abscisic acid (ABA), kinetin, gibberellic acid (GA3), and 2,4-dichlorophenoxy acetic acid (2,4-D) each at three concentrations. The second experiment tested three levels of soil N (NH4NO3) fertility, and two concentrations of peduncle-added N (urea). The third experiment tested four PGRs: ABA, kinetin, GA3, and 2,4-D with two soil N concentrations and two concentrations of peduncle-added N. ABA and 2,4-D decreased total seed weight of the perfused spike. The addition of peduncle-perfused N increased seed protein concentration and content under conditions of high soil N fertility, suggesting that seed protein accumulation is more limited by the ability of roots to take up N from the soil than by the seed to take up N from the rest of the plant. The effects of the PGRs on N allocation among plant parts varied with the amount of N available to the plant. Because it resulted in less protein stored in the flag leaf and more in the seeds, GA3 perfusion caused an overall change in the allocation of N among plant parts. Peduncle perfusion of kinetin and ABA affected some aspects of photosynthetic physiology. 相似文献
9.
Plant growth regulating activity of dehydrocostus lactone possessing an α-methylene-γ-lactone moiety has been compared with its two derived C-16 lactones, in which a trisubstituted double bond and a cyclopropane ring are conjugated with the lactone carbonyl. The results show that the two latter compounds are slightly more active than dehydrocostus lactone. 相似文献
10.
Regeneration of garlic callus as affected by clonal variation, plant growth regulators and culture conditions over time 总被引:3,自引:0,他引:3
A long-term regeneration system for garlic (Allium sativum L.) clones of diverse origin was developed. Callus was initiated on a modified Gamborg's B-5 medium supplemented with 4.5 μM 2,4-D and maintained on the same basal medium with 4.7 μM picloram+0.49 μM 2iP. Regeneration potential of callus after 5, 12 and 16 months on maintenance medium was measured using several plant growth
regulator treatments. The 1.4 μM picloram+13.3 μM BA treatment stimulated the highest rate of shoot production. Regeneration rate decreased as callus age increased, but healthy
plantlets from callus cultures up to 16-months-old were produced for all clones. Regeneration of long-term garlic callus cultures
could be useful for clonal propagation and transformation.
Received: 24 September 1998 / Revision received: 27 January 1999 / Accepted: 26 February 1999 相似文献
11.
A multi-fan system (MFS) for single culture beds was developed to improve the airflow in a plant factory with artificial light. The MFS had seven fans which were installed on both the front and back sides of culture beds to generate airflow from two opposite horizontal directions. The fans that push the air into the culture bed were air inlets while those that pull the air out of the culture bed were air outlets. In this study, three airflow patterns were evaluated: T1, the front and back sides of the culture bed were air inlets; T2, the front side was an air inlet and the backside was an air outlet; and T3, both the front and back sides were air outlets. A culture bed with no MFS was used as a control (T4). Lettuce growth and tipburn occurrence were evaluated and leaf boundary layer resistance (1/gbv), sensible heat flux (Sh), and latent heat flux (Lh) of lettuce plants were estimated. The airflow pattern in T1 improved the air velocity (Va) by an average of 0.75 m s-1 and a variation coefficient of 65%. The 1/gbv decreased significantly with the increase in Va, and the lowest value of 54.0 s m-1 was observed in T1. The low resistance to heat and moisture transfer enhanced the Sh and Lh of lettuce plants. The average Sh and Lh were 40% and 46% higher in T1 compared with those in T4. The fresh and dry weights of lettuce plants in T1 were 1.13 and 1.06 higher than those in T4, respectively. No tipburn occurrence was observed in lettuce plants grown under the MFS while five leaves per plant were injured with tipburn in T4. The results indicated that improving the airflow can improve the growth of indoor cultured lettuce and alleviate the occurrence of tipburn due to the decrease in the 1/gbv and the increase in the transpiration rate. 相似文献
12.
Iino M Nomura T Tamaki Y Yamada Y Yoneyama K Takeuchi Y Mori M Asami T Nakano T Yokota T 《Phytochemistry》2007,68(12):1664-1673
Progesterone is a mammalian gonadal hormone. In the current study, we identified and quantified progesterone in a range of higher plants by using GC-MS and examined its effects on the vegetative growth of plants. The growth of Arabidopsis (Arabidopsis thaliana) seedlings was promoted by progesterone at low concentrations but suppressed at higher concentrations under both light and dark growth conditions. The growth of the gibberellin-deficient mutant lh of pea (Pisum sativum) was also promoted by progesterone. An earlier study demonstrated that progesterone binds to MEMBRANE STEROID BINDING PROTEIN 1 (MSBP1) of Arabidopsis. In this work, we cloned the homologous genes of Arabidopsis, MSBP2 and STEROID BINDING PROTEIN (SBP), as well as of rice (Oryza sativa), OsMSBP1, OsMSBP2 and OsSBP and examined their expression in plant tissues. All of these genes, except OsMSBP1, were expressed abundantly in plant tissues. The roles of progesterone in plant growth were also discussed. 相似文献
13.
Hydrogen peroxide-scavenging enzymes and antioxidants in Echinochloa frumentacea as affected by triazole growth regulators 总被引:2,自引:0,他引:2
Paclobutrazol (PBZ)- and uniconazole (UCZ)-treated plants of Echinochloa frumentacea were shorter but had much wider leaves than untreated controls 10 days after treatment. Leaves of treated plants had a slightly higher concentration of soluble protein than the controls and exhibited enhanced activities of ascorbate peroxidase, monodehydroascorbate (MDHA) reductase, and glutathione (GSH) reductase. The triazoles did not influence the activity of dehydroascorbate (DHA) reductase. The leaves of treated plants had increased concentrations of water-soluble sulfhydryls and ascorbic acid. In contrast, the concentration of malondialdehyde (MDA), a by-product of lipid peroxidation, was lower in the leaves of treated plants than in controls. These results suggest that triazole growth regulators increased the activity of the endogenous H2O2-scavenging system in E. frumentacea. 相似文献
14.
P. A. Balatti J. J. Guiamet E. R. Montaldi 《World journal of microbiology & biotechnology》1990,6(3):295-298
Long-day photoperiods and applications of gibberellic acid promoted shoot growth by stimulating leaf enlargement as a result of increasing avaliable photosynthates, which was also reflected in the higher leaf, stem and nodule plant dry weights. Short-day plants had more nodules, but they were smaller (by weight) than those of long-day plants. Gibberellic acid at 1.5×10–6
m enhanced nodule growth without preventing nodule formation. Factors other than just gibberellic acid are concluded to be involved in the responses of nodulation and nitrogen fixation to day length.
Résumé Des photopériodes de longue journée et l'application d'acide gibbérellique a promu la croissance des pousses en stimulant l'élargissement des feuilles. Celle-ci résuitalent d'un accroissement de photosynthates disponibles. Cet effet s'est aussi réflecté dans un accroissement de la masse de feullies, de tiges et de nodules chez la plante. Des plants soumis à des photopériodes de courte journée présentaient plus de nodules mais ceux-ci étaient plus petits et de masse moindre que ceux de plants soumis à des photopériode de longue journée. L'acide gibbérellique à la dose de 1.5 10–6 m a accru la croissance des nodules sans empêcher la formation des nodules. On a conclu que des facteurs autres que le seul acide gibbérellique sont mêlés aux réponses de la nodulation et de la fixation d'azote à la longueur de la journée.相似文献
15.
In severely disturbed soils, such as those that have been recently land leveled, the interactions among soil properties are accentuated because of the disruption of pre-leveling equilibrium, and manifest their controlling influence on growth and production of sensitive crops, such as soybean [Glycine max (L.) Merr.]. The objective of this study was to identify pre-plant soil properties that influence first-year soybean growth and production following shallow land leveling in an alluvial soil commonly used for rice and soybean production in the Mississippi Delta region in eastern Arkansas, USA. Soil physical (i.e., bulk density and particle-size fractions), chemical (i.e., organic matter, pH, electrical conductivity, and extractable soil nutrients) and biological (i.e., bacterial and fungal biomass) properties were evaluated in the top 10 cm of soil following land leveling. Soybean leaf area index at the R5-6 growth stage, plant population, above-ground dry matter, seed yield and harvest index were also measured at 50 grid points spaced evenly within a 0.36-ha study area. Post-leveling soil properties were significantly correlated with first-year soybean growth and production parameters. Variations in soil chemical properties, particularly extractable soil nutrient contents, organic matter concentrations and biological properties (i.e., microbial activities) accounted for the largest percentage of the variability in first-year soybean growth and production parameters. Results from this study indicate that factors other than those measured in this study, such prolonged soil moisture conditions and poor internal drainage, may contribute to the resulting variability of first-year soybean growth and productivity following land leveling.
Abbreviations: BD – bulk density; CV – coefficient of variation; DM – dry matter; EC – electrical conductivity; HI – harvest index; LAI – leaf area index; OM – organic matter; SE – standard error 相似文献
16.
17.
18.
A study was conducted to characterize changes in bermudagrass (Cynodon dactylon [L.] Pers.) and tall fescue (Festuca arundinacea Schreb.) root development over time and with depth, and to determine the effects of defoliation interval and chemical seedhead
suppression on root and shoot growth. Field plots were established on a fine-silty, mixed mesic Typic Fragiudult soil in Fayetteville,
AR, USA, and each plot contained three minirhizotrons (plexiglass observation tubes) to a depth of 40 cm. Images of roots
in 10-cm depth increments were periodically videorecorded, and total root length (RL) and root length density (RLD) were measured
with a computer-interfaced tracing probe. Treatments consisted of two cutting intervals, 3 and 6 weeks, and two plant growth
regulator (PGR) treatments, an untreated control and either 300 g ha-1 mefluidide on tall fescue in early spring of both years or 10 g ha-1 each of metsulfuron methyl (MSM) and sulfometuron methyl (SMM) applied in late May of both post-establishment years. Data
were analyzed separately for the establishment period (planting to the first date of PGR application) and the subsequent post-establishment
period. Bermulagrass exhibited a two-stage root establishment pattern characterized first by minimal root development in conjunction
with stolon proliferation and soil surface colonization, followed by accumulation of total RL over two subsequent forage production
seasons. There was a net accumulation of root mass during the winter dormancy period of 1986–87. Total RL of tall fescue peaked
one and a half years after planting. Cutting interval had no influence on RL and RLD. Application of a PGR did not affect
RL but did alter RLD of both species. Application of mefluidide to tall fescue stimulated RLD 64 days after application, whereas
bermudagrass RLD was retarded by MSM and SMM up to 50 days after application. Trends in root growth did not closely follow
patterns of shoot growth.
Published with the approval of the Director of the Arkansas Agricultural Experiment Station.
Published with the approval of the Director of the Arkansas Agricultural Experiment Station. 相似文献
19.
J. Stoyanova 《Biologia Plantarum》1996,38(4):537-544
Growth, nodulation and N2 fixation inGlycine max L. Merr., cv. Biison as affected by the relative humidity of air (RH) during the dark period (95 or 50 – 65 %) and day/night
root temperature (Tr) (28/28, 25/25, 18/18, 22/28, 22/18 °C) were studied. The growth parameters (plant fresh and dry mass, yield), nodulation
(nodule number and fresh mass) and N2 fixation abilities (total nitrogen content, nitrogenase activity) increased significantly with the increasing Tr. In addition, at the same Tr during the day all studied parameters were increased at the higher Tr during the dark period. Growth, nodulation and N2 fixation were significantly enhanced at low RH. The findings indicate that all studied parameters could be regulated by environmental
factors during the dark period. 相似文献
20.
Saunders, P. F. and Barros, R. S. 1987. Periodicity of bud bursting in willow ( Salix viminalis ) as affected by growth regulators.
Lateral vegetative buds of willow ( Salix viminalis L.) were only innately dormant for 3–5 weeks in October; during this time their apices were correlatively inhibited by the bud leaflets. Exogenous gibberellins stimulated the opening of cultured buds when the plants were dormant or entering dormancy. As dormancy was being released, however, cultured buds became more responsive to exogenous cytokinins. Thus the demand for gibberellins and cytokinins for bud opening seemed to be sequential rather than simultaneous. Dormant buds cultured in the presence of abscisic acid remained unopened, but they opened after a chilling treatment. Subsequent growth of such buds as measured by dry matter accumulation, was observed only if a cytokinin was added to the medium. 相似文献
Lateral vegetative buds of willow ( Salix viminalis L.) were only innately dormant for 3–5 weeks in October; during this time their apices were correlatively inhibited by the bud leaflets. Exogenous gibberellins stimulated the opening of cultured buds when the plants were dormant or entering dormancy. As dormancy was being released, however, cultured buds became more responsive to exogenous cytokinins. Thus the demand for gibberellins and cytokinins for bud opening seemed to be sequential rather than simultaneous. Dormant buds cultured in the presence of abscisic acid remained unopened, but they opened after a chilling treatment. Subsequent growth of such buds as measured by dry matter accumulation, was observed only if a cytokinin was added to the medium. 相似文献