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1.
Changes in Tuberization and Assimilate Partitioning in Potato (Solanum tuberosum) During the First 18 Days of Photoperiod Treatment 总被引:1,自引:0,他引:1
Potato (Solanum tuberosum L.) plants were equilibrated under18-h days (LD) before a subset of the plants was transferredto 10-h photosynthetic periods with either a dark night (SD)or an 8-h dim photoperiod extension with incandescent lamps(DE). Plants were harvested at regular intervals for growthanalysis during the 18 d after transfer. Leaf area increasedrapidly under SD and LD but was inhibited under DE. Internodeelongation was similar under SD and LD, but much higher underDE. Stem d. wts were lowest under SD. Axillary branching wasgenerally greatest under LD. Total shoot weights were greatestunder LD. Total shoot weights were similar under SD to thoseunder DE, even though within 18 d of transfer as much as one-thirdof the biomass of SD plants was in tubers. Tuber initiationwas later under LD than under SD, and was delayed even moreby DE. High temperature increased the delay in tuberizationfrom LD. The early tuber initiation under SD was concurrentwith a rapid increase in leaf area under SD, not with an earlycessation of leaf growth. This was contrary to assumptions basedupon studies of long-term effects of photoperiod. The resultanthigh sink strength under SD contributed to the greater efficiencyof biomass production. Potato, Solanum tuberosum L. cv. Norchip, photoperiod, temperature, morphology, tuberization, growth analysis, biomass partitioning, sink strength, leaf area, short term effects 相似文献
2.
Rates of Growth and Cell Division in the Shoot Apex of Silene During the Transition to Flowering 总被引:1,自引:0,他引:1
The growth rates of the shoot apex during and after floral inductionwere measured in Silene, a long-day plant. Plants were inducedto flower with 4 or more long days (LD) but not with 3 longdays or with short days (SD). The rate of increase of cell numberin the apical dome, above the youngest leaf pair, was exponentialand in plants given 3 LD remained the same as in plants in SD.In plants induced to flower with 7 LD, until the end of theinductive period the rate of increase of cell number in theapical dome remained the same as in plants in SD. Only whenthe apex began to enlarge as the first stage in the formationof the flower did the growth rate of the apical dome increase.The rates of increase of cell numbers in the apex correspondedto mean cell generation times of 20 to 33 h for plants in SD,for plants given 3 LD, and during the 7 days of induction forplants given 7 LD, and 6 to 8 h for induced plants when flowerformation was beginning. The distribution of cell division in the apex was examined bytreating plants with colchicine and noting in sections the positionsof the resulting metaphases. In vegetative apices and also inapices undergoing transition to flowering the whole of the apicaldome appeared to consist of cells dividing at a similar rate. The rate of leaf initiation during induction was the same asin vegetative, non-induced plants. 相似文献
3.
Kulkarni, V. J. and Schwabe, W. W. 1985 Graft transmission oflongday-induced leaf senescence in Kleinia articulata.J.exp. Bot. 36: 16201633. Senescence of attached and detached rooted leaves in Kleiniaarticulata can be regulated by daylength, accelerated by longphotoperiods LD (> 16 h) and retarded by short days SD (8h). Using detached, rooted leaves as stocks in leaf to leafgrafts, senescence was readily transmitted from a LD donor leafto a SD receptor leaf even if the receptor was retained in SD(D8).However, no transfer could be detected where it had to passthrough any stem tissue. Senescence was reversible up to a certain stage, beyond whichgrafts senesced, pointing to an accumulation of the graft transmissiblefactor to a threshold level that causes irreversible death. Key words: Kleinia, leaf senescence, senescence factor, daylength, graft transmission 相似文献
4.
Developmental and photobiological factors affecting photoperiodic induction in Arabidopsis thaliana Heynh. Landsberg erecta 总被引:1,自引:0,他引:1
We have tested whether the promotion of flowering by long days(LD) in Arabidopsis thaliana is a consequence of photoperiodicinduction. To achieve this, the flowering responses of Arabidopsisthaliana (L.) Heynh. Landsberg erecta (Ler) and the long-hypocotylmutants hy2, hy3 and hy4 were determined with respect to age,daylength and light quality. Ler was capable of distinguishingbetween short days (SD) and long days (LD) from about 4 d aftersowing at 20 C, the time at which cotyledons were expandingand greening. At this stage, the critical daylength was between8 h and 10 h. At 7 d, seedlings required five LD for inductionand, as the seedlings aged, they became more sensitive so thatby day 20, one LD was fully inductive. The response to SD innewly germinated seedlings was to delay flowering without alteringleaf number, but after about 10 d, delay of flowering by SDwas accompanied by extra leaves. In light quality experiments,blue light (B) was inductive for 5-d-old plants and in all subsequenttreatments, far-red (FR) caused induction in treatments at 12d and 18 d and low pressure sodium, equivalent to red, was notinductive at 5 d and 12 d, but partially inductive at day 18.Hence, both a specific blue-light photoreceptor and phytochromeA in High Irradiance Response mode promote floral induction.In daylength transfer experiments all three hy mutants respondedto LD by earlier flowering. Both hy2 and hy3 produced substantiallyfewer leaves than Ler in SD and hy3 flowered slightly earlierthan Ler. The hy4 mutants flowered later than Ler in SD andhad a higher leaf number. A scheme is proposed in which photoperiodicinduction depends on the ability of the plant to sense photoperiod,the stage of development and the photobiological input. We alsopropose that phytochrome A and the blue photoreceptor promoteflowering whereas phytochrome B promotes vegetative development. Key words: Arabidopsis thaliana, blue-absorbing photoreceptor, flowering, photoperiodic induction, phytochrome 相似文献
5.
Effects of Soil Temperature on the Growth and Hormone Content of Dactylis glomerata L. (Cocksfoot) in Controlled Environments 总被引:1,自引:0,他引:1
A comparison was made of effects of low and highsoil temperature (LST and HST, about 9 and 21·5 °Crespectively) on shoot growth of Norwegian and Portuguese populationsof Dactylis glomerata. In experiments lasting 8 short days (SD,8 h photoperiods) LST decreased leaf extension more markedlyin the Portuguese population. No differential effect of LSTon leaf growth was recorded in experiments lasting 20 or 21SD or in experiments of 8 d duration in long days (LD, 16 hphotoperiods). Since the meristem and region of cell extensionis close to the soil surface LST could directly influence bothroot and shoot growth. The application of gibberellic acid enhanced leaf extension,particularly in plants grown at HST. 6-Benzylaminopurine tendedto decrease leaf length. Extractable gibberellin levels wererelatively low after 8 SD in shoots of both races grown at LST.Cytokinin levels increased at LST, more so in shoots of Portugueseplants which sustained the greater reduction in leaf extension. The data suggest that LST may reduce the production of endogenousgibberellins important for leaf growth in Dactylis glomerata.Cytokinins are probably necessary for growth processes but theirlevel may reflect, rather than direct, the rate of leaf growth. 相似文献
6.
For Lolium perenne cv. Cropper, a system which resulted in 100%flowering comprised 90 short days (SD) at 4 ?C (vernalization)and 30 SD at 18 ?C followed by 8 long days (LD). The mitoticindex and G1 and G2 percentages were measured in the shoot androot apices of plants following 2, 5 or 8 LD and in SD controlssampled at the beginning and end of induction. Identical measurementswere made in plants given 48 SD at 18 ?C followed by 2, 5 or8 LD; plants remained vegetative in response to this treatmentlacking vernalization. Significant increases in both mitoticindex and meristem size occurred in the shoot apex in LD followingthe vernalizing, but not the non-vernalizing, treatment. A clusterof mitoses in the apical dome of the shoot apex was unique tothe vernalized plants given 5 or 8 LD. However, an increasein root meristem size occurred regardless of vernalization,but a significant increase in the mitotic index was limitedto vernalized plants given 5 or 8 LD. Whilst the vernalization-LDtreatment resulted in an increase in the G2 percentage in theshoot apex following 2, 5 or 8 LD, no such alteration was observedin the root meristem. Thus, the changes to the cell cycle whichcorrelated with flowering were increased mitotic indices andG2 percentages in the shoot apex at each sampling time and increasedmitotic indices in the root apex following 5 and 8 LD. Key words: Cell division, flowering, Lolium perenne L. 相似文献
7.
Potato (Solanum tuberosum L.) plants were grown under long days(LD) of 18 h before a subset of the plants was transferred to10-h photosynthetic periods with either a dark night (SD) oran 8-h dim photoperiod extension with incandescent lamps (DE).Temperature was constant at 21 °C. Leaves were sampled atthe beginning and end of the high density light period for starchanalyses. Potato leaves accumulated starch more rapidly underSD than under LD; and this difference continued after a secondmajor sink, the tuber, began to develop. Starch accumulationover 10 h in SD leaves was three times higher than in LD leaves,even after 17 d of treatment. By this time SD gave higher wholeplant relative growth rates than LD, and the tuber mass of SDplants exceeded 30% of their total plant biomass. The DE treatmentresulted in starch accumulation intermediate to the LD and SDtreatments. Genotypes likewise differed: the earlier genotype,more strongly induced to tuberize, had higher leaf starch accumulationthan the later genotype. The effects of photoperiod and genotypewere also present when potatoes were grown at 27 °C, a temperatureunfavourable for tuberization under LD. Thus the formation ofa strong tuber sink was consistently associated with more rapidleaf starch accumulation. Potato, Solanum tuberosum L., cv. Norchip, photoperiod, temperature, genotype, starch accumulation, partitionin 相似文献
8.
The environmental control of flowering in some arctic-alpineCarexspecies has been studied in controlled environments.Carex nigra,C. brunnescens, C. atrata, C. norwegica andC. serotina all hada dual induction requirement for flowering. In all exceptC.nigra either low temperature (12 °C or lower) or short days(SD) over a wider range of temperatures were needed for primaryfloral induction and inflorescence formation. InC. nigra primaryfloral induction took place in SD only (921 °C),810 weeks of exposure being required for a full response.In all these species long days (LD) were required for, or stronglypromoted, culm elongation and inflorescence development (secondaryinduction). Quantitative ecotype differences in both primaryand secondary induction were demonstrated. Unlike the otherspecies,C. bicolor proved to be a regular LD plant which requiredLD only for inflorescence initiation and development. In allspecies leaf growth was strongly promoted by LD, especiallyin the higher temperature range (1521 °C). In SDand temperatures below 15 °C the leaves became senescentand the plants entered a semi-dormant condition which was immediatelyreversed by LD. The results are discussed in relation to growthform and life history of shoots. Carex ; dual induction; ecotypic diversity; flowering; growth; photoperiod; sedges; temperature 相似文献
9.
The cell cycle in Silene coeli-rosa shoot apices was measuredto test whether or not early components of the floral stimulus,produced during the 2nd and 3rd long days (LD) of an inductiveLD treatment, resulted in an increase in the duration of G2phase in constant 2024 h cell cycles. Plants were grownat 20°C in short days (SD) of 8 h light and 16 h darknessfor 28 d (day 0). Starting on day 0, plants were given SD or3 LD each comprising an identical 8 h day and 16 h photo-extension,or 3 dark-interrupted (d.i.) non-inductive LD, interrupted at1700 h of each day with 1 h of darkness. The cell cycle (percentagelabelled mitoses method) and changes in cell number were determinedin the shoot apical meristem. During days 12 of the SDtreatment, the cell cycle and mean cell generation time (MCGT)was 18 and 32 h, respectively, giving a growth fraction of 56%.During days 23, the cell cycle and MCGT shortened to15 and 23 h, respectively (growth fraction = 65%). During days12 of the LD and d.i. LD treatments, cell cycles andMCGTs were 910 and 2729 h, respectively, resultingin smaller growth fractions (about 33%). Thus, shortened cellcycles and altered growth fractions occurred regardless of whetheror not the treatment was inductive. The LD treatment resultedin a marked shortening of G1 and, to a lesser extent, S-phase,whilst G2 remained constant. These changes were consistent withincreases in the proportion of cells in G2 during the photoextensionof each LD which were suppressed during the comparable periodsof the d.i. LD treatment. The latter treatment resulted in eachphase occupying virtually identical proportions of the cellcycle as in the SD treatment. Thus, the unique cell cycle responsesto the initial part of the inductive LD treatment were increasesin the proportion of cells in G2 coupled with G1 and G2 beingof similar duration. Cell cycle, mean cell generation time, shoot apex, Silene coeli-rosa 相似文献
10.
The growth responses of Actinidia chinensis raised from cuttingswere compared in 8 h short days (SD) and 16 h long days (LD)at 15, 20 and 25 °C, as well as under varying day and nighttemperatures The data obtained reveal effects on stem elongation,apparent plastochrons, leaf area and shape, as well as dry matteraccumulation and water contents of different plant parts Theseinvestigations were supplemented by studies on the effects ofapplied GA3 and ethephon Alternating day/night temperatures(thermoperiodicity) increased leaf area and d wt accumulationin LD Effects on sugar and starch contents, are described anddiscussed Unexpected effects such as very high petiole watercontents and their continuous growth, increased twisting ofthe climbing stem in SD and other findings are also reportedand discussed Actinidia chinensis, Kiwi fruit, gibberellic acid, ethephon, temperature, photoperiod, themoperiodicity 相似文献
11.
VREUGDENHIL DICK; XU XIN; JUNG CHUN S.; van LAMMEREN ANDRE A. M.; EWING ELMER E. 《Annals of botany》1999,84(5):675-680
Cell division and cell expansion during early stages of tuberdevelopment were studied using developing axillary buds on single-leafcuttings from potato (Solanum tuberosum L.). Cuttings takenfrom plants induced to form tubers, by short day (SD) treatment,were compared with cuttings from non-induced (long day, LD)plants. In the apical zone of the buds, cell division occurredfrom the first day after cutting, in both LD and SD cuttings.The planes of these divisions were transverse, associated withelongation of the buds. At day 5, a new orientation of celldivision was observed in the subapical zone of SD cuttings only.These divisions were longitudinal, associated with radial growth.Cell expansion occurred in both SD and LD cuttings, and wasnot uniquely related to the onset of tuber formation. Copyright1999 Annals of Botany Company Solanum tuberosum L., potato, tuber formation, cell division, cell expansion. 相似文献
12.
Graft transmission of the floral stimulus was studied in homograftsof Kleinia articulata (SDP) and heterografts between K. articulataand K. repens (LSDP). While receptor shoots of K. repens graftedonto induced donor plants of K. articulata flowered readilyin LD (16 h) as well as SD (8 h), graft-induced flowering failedto take place in LD receptors of K. articulata. Neither theinduced shoots and detached leaves from induced plants of K.articulata nor the induced shoots of K. repens could evoke theflowering response in the K. articulata receptors. Increasingthe donor pool of induced leaves even up to ten per receptoralso had no effect. It is known that the very young leaf primordiaof K. articulata are photoperiodically sensitive, and it seemsthat they may prevent the stimulus from reaching the apex. Key words: Kleinia, Flowering stimulus, Graft transmission 相似文献
13.
肖翊华;徐孟亮;刘文芳 《武汉植物学研究》1992,10(2):128-132
本文报道了农垦58s和农垦58幼穗发育期长短日下吲哚乙酸氧化酶和过氧化物酶的活性变化。结果表明:58s LD叶片中吲哚乙酸氧化酶活性从花粉母细胞形成期至花粉内容物充实期显著低于58s SD,与游离IAA的积累密切相关,可能影响花粉育性;但过氧化物酶的活性在上述时期显著高于58s SD,与游离IAA的积累无关,其作用尚不清楚。58s LD幼穗及花药中两酶活性在减数分裂期和花粉内容物充实期均较58s SD高,与同期幼穗及花药中游离IAA的亏缺有一定联系,从而可能在一定程度上影响花粉育性。对照农垦58叶片和幼穗及花药中两酶活性变化都不呈现上述现象。 相似文献
14.
Exogenous gibberellin A3(GA3) reduced the number of leaf nodesat flowering and time to flowering and increased the stem heightat flowering in three genotypes of spring rape (Brassica napusvar.annua L.). The responses to GA3were similar to those forlong days (LD) and low-temperature treatments, suggesting thatthe effect of photoperiod and the vernalization response areprobably mediated through gibberellins. The response to exogenousGA3was greatest in non-cold-treated plants in short days (SD)suggesting that endogenous GAs are limiting in these conditions.CCC, an inhibitor of gibberellin biosynthesis, caused a smallincrease in the number of leaf nodes at flowering and time toflowering and a small decrease in the stem height at flowering,but unexpectedly, its effect was hardly influenced by the applicationof exogenous GA3. Genotypes that showed the clearest responsesto the treatments with regard to the number of leaf nodes atflowering and time to flowering did not show the clearest responseswith regard to the stem height at flowering; the pattern ofresponses of the number of leaf nodes at flowering and timeto flowering was distinct from that of stem height at flowering.This indicates that flower formation and stem elongation areseparable developmental processes which may be controlled bydifferent endogenous gibberellins, different levels of a specificendogenous gibberellin, or different responses to gibberellin.Copyright 1999 Annals of Botany Company Brassica napus var. annua, gibberellin, photoperiod, spring rape, vernalization. 相似文献
15.
Plants were grown at either 350 or 1000 µl l-1CO2and inone of three photoperiod treatments: continuous short days (SD),continuous long days (LD), or short switched to long days atday 41 (SDLD). All plants received 9 h of light at 450µmol m-2s-1and LD plants received an additional 4 h oflight at 8 µmol m-2s-1. Growth of SD plants respondedmore positively to elevated CO2than did LD plants, due largelyto differences in the effect of CO2on unit leaf rate. High CO2increasedheight and decreased branching under SD conditions, but hadno effect under LD conditions. Elevated CO2also increased thenumber of buds and open flowers, the effect for flower numberbeing greater in short than in long days. The specific leafarea of plants grown at 1000 µl l-1CO2was reduced regardlessof daylength. High CO2also decreased leaf and increased reproductiveallocation, the magnitude of these effects being greater underSD conditions. Bud formation and flower opening was advancedunder high CO2conditions in SD plants but bud formation wasdelayed and there was no effect on flower opening under LD conditions.The effects of CO2on plants switched from SD to LD conditionswere largely intermediate between the two continuous treatments,but for some parameters, more closely resembled one or the other.The results illustrate that daylength is an important factorcontrolling response of plants to elevated CO2. Petunia hybridaHort. ex Vilm; carbon dioxide; photoperiod; functional growth analysis; daylength; global change; development; phenology 相似文献
16.
The response of leaf area expansion to atmospheric saturationdeficit (SD) and soil moisture deficit was examined in termsof leaf water potential (1) and turgor potential (p), as partof a wider study of the effects of SD on groundnut growth. Standsof plants were grown at four levels of SD and without irrigationin controlled environment glasshouses. A fifth stand was grownat low SD on soil kept irrigated to field capacity. Large saturation deficits accelerated the depletion of soilmoisture reserves in the unirrigated stands and greatly reducedleaf area index, particularly in the driest treatment. Leafnumber per plant and leaf size both decreased as SD increased,but the effect on leaf size was greater than on number. SD hadless effect than soil water deficit on leaf production. Turgorpotential and leaf extension rate (R) were both reduced at highsaturation deficits and R was linearly related to p between0900 and 1600 h. However, leaf extension rate and turgor potentialwere poorly correlated between 0400 and 0700 h in the driesttreatment. Arachis hypogaea L., groundnut, saturation deficit, leaf growth, canopy development 相似文献
17.
Nitrogen Assimilation and Leaf Development in Indeterminate Soybeans as Influenced by Post-Flowering Photoperiod 总被引:1,自引:0,他引:1
Guiamét, J. J., Balatti, P. A. and Montaldi, E. R. 1986.Nitrogen assimilation and leaf development in indeterminatesoybeans as influenced by post-flowering photoperiod.J.exp. Bot. 37: 16111618. The effects of photoperiod on nitrogen fixation and leaf developmentin indeterminate soybeans were studied during early reproductivegrowth. Soybean plants cv. Williams were grown under short days(SD: 8 h-natural daylight (N.D.)+16 h-darkness) or long days(LD: 8 h-N.D. + 8 h-low intensity artificial light+ 8 h-darkness)from full bloom until mid pod filling. Long days greatly increased plant growth, both on the basisof leaf area or weight, mainly due to higher net assimilationrate. Average daily rates of N2-fixation increased under LD;however, average N2-fixation rates on a nodule weight or N basisdid not vary, suggesting that changes were not in nodule efficiencybut in nodule biomass. As compared to SD, LD reduced N contentin vegetative parts (pooled roots, stems and leaves), individualleaf blades and fruits. This seemed to be due to greater drymatter accumulation relative to N2-fixation. The 2nd and 5th trifoliolate leaves showed larger specific leafweight (SLW) under LD. Soluble protein content on a dry weightbasis was higher in the 5th (younger) leaf than in the 2nd,but did not vary due to photoperiod. On the other hand, chlorophylland Fraction I protein content decreased in terms of dry weightunder LD. A larger proportion of leaf N was allocated to solubleproteins under LD, thus compensating for the lower N content.On the whole, growth enhancement by LD seemed unrelated to increasedavailability of N or to greater leaf soluble protein or FractionI content. Key words: Photoperiod, leaf development, soybean, nitrogen fixation 相似文献
18.
Morphological and anatomical changes in shoots of vigorously growing cottonwood plants (Populus deltoides Bartr.) were studied during dormancy induction in 8-hr short days (SD) and in control plants grown in 18-hr long days (LD). Pronounced structural changes occurred in terminal buds after 4 wk and full dormancy was achieved in 7 wk of SD. Leaf expansion ceased after 5 wk of SD as foliage leaves matured to the terminal bud base at leaf plastochron index 0 (LPI 0). Within the bud, total leaf length (lamina + petiole) decreased and stipule length increased progressively each week; thus, the ratio total leaf length/stipule length decreased rapidly, especially at the position of incipient bud-scale leaves LPI - 1 and LPI - 2. These bud-scale leaves were fully developed by wk 6 and were derived from enlarged stipules and aborted laminae. The full complement of primordia within the bud at the start of SD eventually matured as foliage leaves and the first bud-scale leaf (LPI - 1) was initiated immediately following transfer to SD. Acropetal advance of the primary-secondary vascular transition zone (TZ) was associated with leaf maturation. However, it did not advance throughout the entire vascular cylinder as in LD, but only in those leaf traces serving mature leaves beneath the terminal bud. In both LD and SD treatments the same linear relationship was maintained between LPI of the TZ and LPI of the most recently matured leaf; both parameters simultaneously increased in LD and decreased in SD. Thus, the relationship between leaf maturation and advance of the TZ was maintained irrespective of environment. 相似文献
19.
Twenty-eight-day-old plants of Silene coeli-rosa L. were maintainedin short days (SD) for 9 d (08) or exposed to 7 longdays (LD), or 7 SD with a 5 min exposure at 1700 h of each dayto far-red (FR), red (R) or 5 min FR/5 min R, or 7 dark-interrupted(di = 17001720 h) LD. Treatments were followed by twofurther SD. The mitotic index and G1 and G2 proportions weremeasured in the shoot apices of plants sampled at 2000 h ofeach day of each replicated treatment. Exposure to 7 LD (= 100per cent flowering) resulted in significant increases, relativeto the SD controls, in both the G2 proportion and the mitoticindex on d 0 to 3, 7 and 8. Five minute FR (= 0 per cent flowering)resulted in cell cycle responses similar to those in LD onlyfrom d 0 to 2. R and FR/R (both = 0 per cent flowering) didnot result in any increases in the G2 proportion in the apexapart from d 3 of FR/R. However 5 min FR/5 min R, and to a lesserextent 5 min R, did result in significant increases in the mitoticindex on d 0, 1, 7, and 8. diLD (= 810 per cent flowering)also prevented any significant increases in the G2 proportionon d 0 to 3, and 5 to 8 but the mitotic index was again higheron these days compared with control data. Thus the transitionto floral growth for 90 per cent of the plants is associatedwith changes in the cell cycle in the shoot apex measured asincreases in the G2 proportion at 2000 h of LD 0 to 3 and 7to 8. Silene coeli-rosa L., cell cycle, flowering, phytochrome, shoot apex 相似文献
20.
Thermal time is used to analyse hourly differences in leaf extensionrate of pearl millet. The procedure enables the effects of theenvironment on leaf extension to be examined when temperatureis varying. The analysis was made on the results of two experimentsin which saturation vapour pressure deficit (SD) was controlledor allowed to vary with air temperature. In all treatments,temperature was the major environmental factor governing therate of leaf extension. The effect of SD was small in one experimentand negligible in the other. In the former, leaf extension wasalso limited by another factor, probably irradiance. Key words: Extension, Saturation deficit, Millet 相似文献