共查询到20条相似文献,搜索用时 31 毫秒
1.
Tankersley C. G.; DiSilvestre D. A.; Jedlicka A. E.; Wilkins H. M.; Zhang L. 《Journal of applied physiology》1998,85(1):360-365
Genetic control ofdifferential inspiratory timing(TI) at baseline has beenpreviously demonstrated among inbred mouse strains. The inheritancepattern for TI between C3H/HeJ(C3; 188 ± 3 ms) and C57BL/6J (B6; 111 ± 2 ms) progenitors wasconsistent with a two-gene model. By using the strain distributionpattern for recombinant inbred strains derived from C3 and B6progenitors, 100% concordance was established betweenTI phenotypes and DNA markers onmouse chromosome 3. This genotype-phenotype hypothesis was tested bytyping 52 B6C3F2(F2) progeny by using simplesequence repeat DNA markers (n = 21)polymorphic between C3 and B6 strains on mouse chromosome 3. Linkageanalysis compared marker genotypes to baseline ventilatory phenotypesby computing log-likelihood values. A putative quantitative trait locuslocated in proximity to D3Mit119 wassignificantly associated with baselineTI phenotypes. At the peak(log-likelihood = 3.3), the putative quantitative trait locusdetermined 25% of the phenotypic variance inTI among F2 progeny. In conclusion, thisgenetic model of ventilatory characteristics demonstrated an importantlinkage between differential baseline TI and a candidate genomicregion on mouse chromosome 3. 相似文献
2.
Four families of sister inbred lines derived from a tropicalmaize variety have been evaluated for their ability to formcallus cultures with a morphogenetic response. Lines were homozygousfor heterochromatic knobs at 6L2, 6L3, 7L and 8L1but differedfor the presence or absence of K2L, K3L, K7S and K9S. Cleardifferences in embryogenic response were observed between thefamilies of inbreds. Only one family formed friable, highlyembryogenic type II calli; the other families formed slow growingnon-embryogenic or poorly embryogenic cultures. All the genotypesscreened showed a similar response to the two culture mediatested, suggesting that genetic factors are responsible forthe major differences among the families. Mitotic abnormalitieswere investigated in Feulgen preparations of most cultures.Anaphase bridges resulting from delayed chromatid separation,typical bridges and fragments were observed. In a previous study,delayed chromatids were shown to be held together at heterochromaticknob sites, while typical bridges would be formed by dicentricchromatids arising from breakage-fusion-bridge cycles initiatedby chromosome arms broken during the primary event. In the presentstudy, the frequency of both types of bridges was not strictlycorrelated with the knob content of the genotypes analysed.This suggests that knobs may undergo alterations in cultureleading to mitotic disturbance, and that this response may begenotype dependent.Copyright 1998 Annals of Botany Company Zea maysL., maize, plant tissue culture, somatic embryogenesis, somaclonal variation, heterochromatin, C-banding, breakage-fusion-bridge cycle. 相似文献
3.
Peroxidase activity was measured at three stages, from seedlingto maturity, in stem tissue of two genotypes of Linum usitatissimum,and their reciprocal F1 hybrids. The plants were grown throughoutin growth chambers, allowing close control over the environmentalconditions. There were large and consistent differences betweenthe activities of the parental genotypes, and between dialysedand undialysed extracts. Activities in both parents and theF1 were expressed on a logarithmic scale. The activity of theF1 fell, with one exception, between the activities of the twoparents. The relationship of F1 activity to the mean of theparental activities fluctuated with the stage of growth. 相似文献
4.
NaCl-induced Senescence in Leaves of Rice (Oryza sativa L.) Cultivars Differing in Salinity Resistance 总被引:19,自引:0,他引:19
The influence of NaCl on senescence-related parameters (proteinand chlorophyll concentrations, membrane permeability and chlorophyllfluorescence) was investigated in young and old leaves of fiverice cultivars differing in salt resistance. NaCl hastened thenaturally-occurring senescence of rice leaves which normallyappears during leaf ontogeny: it decreased chlorophyll and proteinconcentrations and increased membrane permeability and malondialdehydesynthesis. Such an acceleration of deteriorative processes affectedall leaves in salt-sensitive cultivars while it was more markedin oldest than in youngest leaves of salt-resistant genotypes.NaCl-induced senescence also involved specific modifications,such as an increase in basal non-variable chlorophyll fluorescence(F 0) recorded in all cultivars or a transient increase in solubleprotein concentration recorded in salt-resistant genotypes only.Alteration of membrane permeability appeared as one of the firstsymptoms of senescence in rice leaves and allowed discriminationamong cultivars after only 7 d of stress. In contrast, F v/F mratio (variable fluorescence/maximal fluorescence) was thesame for all cultivars during the first 18 d of stress and thuscould not be used for identifying salt-resistant rice exposedto normal light conditions. Relationships between parametersinvolved in leaf senescence are discussed in relation to salinityresistance of rice cultivars. Chlorophyll concentration; chlorophyll fluorescence; electrolyte leakage; magnesium; malondialdehyde; membrane permeability; NaCl; Oryza sativa L.; protein; rice; salinity resistance; senescence; UV absorbing substances 相似文献
5.
F1 hybrids of Sorghum bicolor (L.) Moench and their inbred parentswere analysed for NADH-nitrate reductase activity during theearly stages of seedling growth. In all the hybrids both mid-parentaland better parental heterosis were discernible in shoots whereasin roots two hybrids out of the three tested, showed heteroticlevels. It is suggested that in sorghum nitrate reductase activityduring seedling stages can be used as a biochemical criterionfor evaluating hybrid vigour. Sorghum bicolor (L.) Moench, sorghum, hybrid vigour, nitrate reductase 相似文献
6.
Net photosynthetic rate, leaf area, tillering, shoot weight,and leaf area ratio for 35 F1 rice (Oryza sativa L.) hybridsduring the vegetative stage were compared with correspondingvalues for parental varieties. Shoot weight and leaf area showedheterosis. However, hybrid vigour was not reflected in net photosyntheticrate. Leaf area was closely correlated with heteroses in shootdry weight and tillering. Thus F1 rice hybrids grow vigorouslybecause of their high leaf area development, which is causedby high tillering. Key words: F1 rice hybrid, Net photosynthetic rate, Leaf area 相似文献
7.
A study was made of variation in the hypocotyl length of twoinbred lines of Brassica oleracea gemmifera (Brussels sprout).The pattern of means and variances obtained from parental, F1,F2 and backcross generations suggested polygenic control ofhypocotyl length. Measurements of parental seed weights, embryocell numbers, and the growth of seedlings from seeds of knownweight support the view that variation between the lines inhypocotyl length, when the seedlings were exposed to light,was determined by differential extension rather than by initialdifferences in seed weight. The effect of reduction in lightintensity on hypocotyl extension was studied and the differencesbetween the lines was maintained under all light intensities.Differential reaction of the lines was only observed when theperiod allowed for growth was short. The inbred line with thelonger hypocotyl was shown to suppress the other under competitiveconditions. 相似文献
8.
Three inbred lines of Antirrhinum majus and the F1 generationsof crosses between them were scored for flowering time in ninegreenhouse and garden experiments. The inbreds fell into twogroups, the difference between which showed a marked interactionwith environments. The two lines (An 105, An 106) which weresimilar were earlier flowering than the third line (An 101)in those environments which produced generally early flowering,but were later than An 101 when the environmental conditionsled to late flowering. In all cases the F1 generations wereat least as early as the earlier parent. Cabinet experiments identified temperature as the importantenvironmental factor when day length was kept constant at 16h. At 25°C, An 105 and An 106 were earlier than An 101 whileat 12°C, at which temperature the average flowering timewas much later, An 101 was earlier. The F1 generations werelike An 105 and An 106 at 25°C but showed heterosis at 12°C. The differences in flowering time between genotypes were inall cases established by the time the first reproductive budsbecame visible (budding time). Thus a temperature differencewell outside the range of vernalizing temperatures is havinga striking effect on the phenotypic expression of genotypicdifferences determining the transition from vegetative to floweringdevelopment. 相似文献
9.
Rood, S. B. and Larsen, K. M. 1988. Gibberellins, amylase, andthe onset of heterosis in maize seedlings.J. exp. Bot.39: 223233. The possible involvement of gibberellins and amylase in heterosisof maize seedlings was investigated in two parental inbreds,CM7 and CM49, and their single cross F1 hybrid, CM7xCM49. Germinationof all three genotypes was complete within 36 h after the onsetof imbibition. By 48 h, heterosis (hybrid vigour) for increasedshoot and root length was consistently observed. The endogenousconcentration of gibberellin A1 (GA1) was measured in 48 h seedlingsby gas chromatography-mass spectrometry with selected ion monitoring(GC-SIM) using [2H2]-GA1 as an internal standard. The GA1 concentrationwas highest in the hybrid (59 ng g1 dry wt.), intermediatein CM49 (9.0 ng g1), and lowest in CM7 (<5.0 ng g1).Amylase activities in all three genotypes were very low at 24h, but increased during the next 24 h, after which time amylaseactivity in the hybrid was significantly higher than that ofeither parental inbred. Inhibitors of gibberellin (GA) biosynthesis,AMO-1618 or CCC, inhibited germination, shoot and root growth,and amylase activity in all three genotypes. Conversely, exogenousgibberellic acid (GA3) increased amylase activity, particularlyin the inbred CM7. Amylase isozymes were separated through polyacrylamidegel electrophoresis and generally similar profiles of starchdegrading enzymes were observed in the three genotypes. SinceGA is known to control a-amylase biosynthesis in some cereals,these results are consistent with the hypothesis that GAs areinvolved in the regulation of heterosis in maize. A higher endogenousGA1 concentration in the hybrid could result in increased amylaseactivity in the hybrid seedlings and consequently, more rapidstarch hydrolysis which fuels heterosis for early growth. Key words: Amylase, germination, gibberellic acid, Gibberellin A1, heterosis, hybrid vigour, Zea mays 相似文献
10.
The net assimilation rate (EA), relative growth-rate (Rw), andleaf-area ratio (FA) were measured for rape (Brassica napus),sunflower (Hetianthus annuus), and maize (Zea mays) at varioustimes of year in an arid climate, using young plants grown widelyspaced on nutrient culture. Multiple regression analysis accountedfor 9095 per cent of the variation in EA and RW in termsof two climatic variables: mean temperature and radiation receipt. EA rose linearly with radiation in all three species; increasein EA with temperature was greatest in maize and least (notsignificant) in rape. RWrose with radiation and temperature,the latter being the more important variable especially in coolweather; a temperature optimum was shown at 24° C in rape.FA rose with increase in temperature or decrease in radiation;its variation was due to change in leaf area/leaf weight ratherthan in leaf weight/plant weight. Multiple regression analyses can lead to faulty interpretationif the independent variables are correlated (as are climaticvariables in nature), but conclusions can be checked by controlled-environmentstudies in which climatic factors are not correlated. The presentconclusions are supported by such studies. The regression equations, coupled with average weather records,indicate seasonal cycles of growth parameters. EA is maximalnear midsummer and minimal near midwinter, following the radiationcycle. Maxima and minima in RW are about a month later, becauseRW is affected by the temperature cycle and this lags behindthe radiation cycle. FA is maximal in autumn and minimal inspring. EA is highest where radiation receipts near 750 cal cm2day1 coincide with high temperatures. This combinationoccurs only in clear midsummer weather at low latitudes, andis maintained over long periods only in arid regions. The fact that EA rose linearly with radiation suggests thatleaf water deficits arising under high radiation had littleeffect on EA and that saturating levels of light were very high. 相似文献
11.
Xu P Yang Y Zhang Z Chen W Zhang C Zhang L Zou S Ma Z 《Journal of experimental botany》2008,59(6):1375-1381
Alterations of mitochondrial-encoded subunits of the FoF1-ATPsynthase are frequently associated with cytoplasmic male sterility(CMS) in plants; however, little is known about the relationshipof the nuclear encoded subunits of this enzyme with CMS. Inthe present study, the full cDNA of the gene TaFAd that encodesthe putative FAd subunit of the FoF1-ATP synthase was isolatedfrom the wheat (Triticum aestivum) fertility restorer 2114for timopheevii cytoplasm-based CMS. The deduced 238 amino acidpolypeptide is highly similar to its counterparts in dicotsand other monocots but has low homology to its mammalian equivalents.TaFAd is a single copy gene in wheat and maps to the short armof the group 6 chromosomes. Transient expression of the TaFAd–GFPfusion in onion epidermal cells demonstrated TaFAd's mitochondriallocation. TaFAd was expressed abundantly in stem, leaf, anther,and ovary tissues of 2114. Nevertheless, its expression wasrepressed in anthers of CMS plants with timopheevii cytoplasm.Genic male sterility did not affect its expression in anthers.The expression of the nuclear gene encoding the 20 kDa subunitof Fo was down-regulated in a manner similar to TaFAd in theT-CMS anthers while that of genes encoding the 6 kDa subunitof Fo and the subunit of F1 was unaffected. These observationsimplied that TaFAd is under mitochondrial retrograde regulationin the anthers of CMS plants with timopheevii cytoplasm. Key words: CMS, FAd subunit, FoF1-ATP synthase, retrograde regulation, wheat
Received 8 October 2007; Revised 9 January 2008 Accepted 28 January 2008 相似文献
12.
Potential Dry Matter and Water Import Rates in the Tomato Fruit in Relationship to Fruit Size 总被引:3,自引:0,他引:3
The tomato fruit was compared to a sphere with a radius R. Radialgrowth rates in the fruit (FIW and FID) due to water importor to dry matter import, respectively, which are also the waterimport rate or dry matter import rate per unit surface areaof fruit, were calculated from two sets of published results.This data referred to fruits which swelled in such a way thatthe availability of assimilates had little effect on growth.Two varieties differentiated the two series of results and inone series, three trials were differentiated by the salinityof the nutrient solution. In all trials, it was found that FIW and FID decreased whenR increased. Two phases were observed for FIW: after a firstphase, FIW decreased more quickly and almost linearly when Rincreased. FID was constant or decreased with respect to R.Except at the beginning of growth at the greatest salinity,there were clearly linear regressions between FIW and FID suchas FID = aFIW-b; where b was lower with higher salinity. Thechanges of the concentration of imported dry matter (FID/FIWwere examined in terms of R and FIW/R. The mechanisms controllingthe changes in FIW and FID were discussed. The results suggestedfruit radius was an important parameter of these mechanisms.Thus, water import rate and dry matter import rate could eachbe considered to be the product of two factors: fruit surfacearea, which is directly dependent on fruit radius, and waterimport rate or dry matter import rate per unit of fruit surfacearea.Copyright 1993, 1999 Academic Press Dry matter, fruit growth, logistic model, sink size, tomato, water transfer 相似文献
13.
Using detached leaves, two cultivars of pearl millet [Pennisetumamericanum (L.) Leeke], B282 and Serere 39, were assessed forvariation in the capacity to accumulate ABA in response to waterstress. Significant differences in ABA accumulation were detectedbetween cultivars and between different inbred lines withina cultivar, but within lines there was much less variation inthis character. In crosses between individual lines of B282(low ABA) and Serere 39 (high ABA), ABA accumulation in theF1 was mid-way between parental values, indicating additivegenetic control and lack of dominance. Selfed progeny of a B282 x Serere 39 cross were selected forcontrasting ABA accumulation in the F2 to F4 generations. Asixfold range in ABA accumulation was found amongst 207 F2 progeny.This increased to nearly ninefold at F3 and F4. Regression analysisindicated high heritability of ABA accumulation and rapid approachto homozygosity. As the cross studied involved a dwarf (B282) and a tall (Serere39) parent, segregation occurred for height as well as for ABA,though not entirely independently. Tall F3 progeny had significantlyhigher ABA contents than dwarf progeny and high ABA was thereforeassociated with other traits (e.g. large leaves, high leaf percent d. wt) characteristic of tall plants. Nevertheless, therewas a substantial range of ABA content within both groups whichwas uncorrelated with height and other characters. The potential use of the selections in studies on drought responseis briefly discussed. Pennisetum americanum (L.), Leeke, pearl millet, abscisic acid accumulation, water stress, genetic differences, inheritance 相似文献
14.
Genetic Analysis of Growth in Tomato: Segregating Generations 总被引:1,自引:0,他引:1
Genetical control of certain aspects of plant development hasbeen studied in the segregating generations derived from a diallelcross involving three varieties of L. esculentum and one ofL. pimpinellifolium. In the first experiment, dry-weight relativegrowth-rate was found to be inherited additively with a largedominance component which, however, was probably overestimatedin the F1 by the inclusion of only one type of reciprocal cross.Gene association in the parents was suggested by the distributionof the points in the diallel regression graph. In a second experiment,the increase in leaf number with time was followed in parental,F1, F2, F3, and backcross generations. Genetical analysis forvarious parameters of rates of production of leaves showed thecontrol to be additive with various degrees of dominance, andsimilar results were found for analysis of results on time-to-floweringand fruit yields. There was, throughout the experiments, agreementbetween the results for each generation. It is believed thatcombined genetical and physiological studies of growth in cropplants will be of value in the selection of parents for breedingimproved varieties. 相似文献
15.
Kwa Siew-Hwa; Wee Yeow-Chin; Lim Tit-Meng; Kumar Prakash P. 《Journal of experimental botany》1995,46(10):1535-1542
Gametophyte-derived callus cultures of Platycerium coronariumcould be maintained under photoautotrophic conditions on Murashigeand Skoog medium supplemented with 2µM 2,4-dichlorophenoxyaceticacid (2,4-D) and with CO2 enrichment. Progressive reductionof sucrose from the medium resulted in a reduction in growth,but an increase in total chlorophyll content. When subculturingwas delayed beyond 2 weeks, callus cells differentiated intogametophytes on the medium with 0.2 sucrose and no CO2 enrichment.Enriching the photoautotrophic cultures on 2µM 2, 4-Dwith 1% CO2 resulted in about 1.7-fold increase in fresh weightwithin 42 d. Total chlorophyll content was generally higherwith 1% CO2 enrichment than with 10%. Fv/Fm ratio was higherfor callus on low levels of sucrose (>0.5%) than that onsucrose 1.0%. An increase in autofluorescence of chloroplasts,but not the size, was observed with decreasing sucrose levelsin the medium. Autofluorescence decreased with increase in CO2from 0.03%. Our data are in agreement with the view that long-termexposure to high levels of decrease in photosynthetic capacity. Key words: Platycerium coronarium, stag's horn fern, autofluorescence of chloroplasts, confocal laser scanning microscope, Fv/Fm ratio, photoautotrophic callus 相似文献
16.
Temporal and Nutritional Influences on the Response to Elevated CO2 in Selected British Grasses 总被引:3,自引:0,他引:3
To investigate the duration of the CO2 response and its interactionwith mineral nutrition, CO2-enrichment experiments were performedon four British grasses of differing ecology and functionaltype: Arrhenatherum elatius (L.) Beauv., Festuca ovina L., Festucarubra L. and Poa annua L. Naturally-lit, glasshouse cabinetswere used, with a non-limiting water supply and a daytime meantemperature of 18 °C. Two CO2 treatments were maintainedat nominal concentrations of 350 and 700 vpm and were combinedfactorially with two levels of balanced mineral nutrition atconductivities of 0·1 and 1 mS cm-1. Harvests took placeat planting-out, and at 16, 37 and 58 d thereafter. Fitted curves were used to derive instantaneous values of totaldry weight, relative growth rate (RGR), shoot weight fraction(SWF) and unit shoot rate (USR) for all combinations of species,CO2 level, nutrient level and time of harvesting. At the higher nutrient level there was a reasonably close agreementwith previous estimates of the CO2 response in the four species.The response, if any, most often arose from an increase in USRbeing accompanied by a less than proportionate decline in SWF.Responses were sustained throughout the period studied. At thelower nutrient level, all species showed a CO2 response initially,but this declined at a rate which was inversely related to theCO2-responsiveness of the species at the higher nutrient level. The underlying ontogenetic drift appeared to be markedly towardsadjustment in SWF and away from that of USR. However, this driftwas retarded, suspended or even reversed by low-nutrient conditionsand/or by high CO2 responsiveness in the species itself.Copyright1995, 1999 Academic Press Climate change, CO2 enrichment, plant strategies, mineral nutrition, growth analysis, relative growth rate, shoot weight fraction, unit shoot rate, functional equilibria 相似文献
17.
The principal axis model (PAM) uses a principal axis and anellipse to characterize the variation in the relationship betweenthe seed (SWT) and plant (PWT) weights of individual plantswithin a crop. The theoretical linkage between the magnitudeand variability of plant harvest index (PHI), and thereforeseed yield per unit area, and changes in the components of thePAM was examined using data from four field pea (Pisum sativumL.) genotypes sown at 9, 49, 100, 225 and 400 plants m-2. Astrong linear relationship (R 2>93.8%) between SWT and PWTand a negative SWT-axis intercept were confirmed for all crops.Analyses indicated that decreased variability of PHI withina crop would result from selection to: (a ) increase the SWT-axisintercept of the PAM; (b ) increase the slope of the PAM; (c) optimize the ellipse location; and (d ) minimize the deviationaround the principal axis. The first three methods were usedto explain yield differences (P <0.05) among genotypes ofdifferent populations. A potential strategy for single plant selection based on thePAM is proposed. This may enable early generation (F4) selectionof small, high performing plants that may be ideal crop ideotypes.A theoretical example of the strategy is presented, with differencesamong selections based on the PAM, SWT or harvest index highlighted. Field pea(Pisum sativum L.); genetic harvest index; minimum plant weight; plant harvest index; principal axis model; plant population; seed weight; selection criteria 相似文献
18.
褐飞虱对噻嗪酮抗性的遗传分析 总被引:1,自引:0,他引:1
害虫的抗性遗传特性是影响其抗性发展的一个重要因子,也是制订抗性治理对策的重要依据。我们采用稻茎浸渍法测定了褐飞虱Nilaparvatalugens (Stal)抗性和敏感亲本、正反交(F1、F12、F'2)及回交(BC)后代3龄若虫对噻嗪酮的剂量反应数据,研究了褐飞虱对噻嗪酮的抗性遗传特性。结果表明: 正反交后代的显性度分别为-0.3153(F1)和-0.376 3(F'1),表明抗性遗传为常染色体的不完全隐性;将自交及回交后代的剂量反应数据进行单个主基因假设的卡方(χ2)检验,其卡方值分别为42.11(F2)、5.44 (F'2)及93.57(BC),均大于χ20.05= 15.51(df=8),表明其抗性是多基因控制的。还讨论了褐飞虱对噻嗪酮的抗性治理策略。 相似文献
19.
Inhibition of growth and photosynthesis of freshwater phytoplankton by ultraviolet A (UVA) radiation and subsequent recovery from stress 总被引:2,自引:0,他引:2
The effect of ultraviolet A (UVA) on growth and photosyntheticrate was studied in diatoms (Melosira spp.) of the phytoplanktonof a eutrophic lake and a cultured green alga Chloretla ellipsoidea.The cells were incubated under photosynthetically active radiation(PAR) (UVA) or PAR + UVA conditions (+UVA). Growth ofC.ellipsoidea was retarded under +UVA, as shown by an increasein the lag period, but the rate of exponential growth was almostthe same in + and UVA conditions. The photosyntheticrate was depressed markedly by UVA in Chlorella cells grownunder UVA. In contrast, cells grown in +UVA showed onlyslight inhibition by UVA and after exposure to UVA for 6 daysthere was no inhibition. During the growth experiment, the cellularchlorophyll a content was higher in +UVA than +UVA grown cells.A similar effect was observed in diatoms from the eutrophicLake Suwa. In vivo fluorescence with (Fa) and without 3-(3,4-dichloropheny)-l,l-dimethylurea (DCMU) (Fb) and the photosynthetic rate were measured forC.ellipsoidea and the diatoms for 5 h under + and UVAconditions. Soon after C.ellipsoidea had been subjected to +UVA,Fb and Fa / Fb decreased quickly and reached minima after 40min and 1 h, respectively. The suppressed in vivo fluorescenceresumed and full recovery was achieved after 4 h. This suggeststhat reactivation of the photosystem is acquired under prolongedexposure to UVA. A similar shift of Fa + Fb, but no change inFb, was found in diatoms by exposure to UVA. Changes in photosyntheticoxygen evolution by C.ellipsoidea under +UVA were similar tochanges in Fa + Fb. Degradation of chlorophyll a extracted inmethanol was enhanced by UVA. The rate of degradation by UVAwas independent of temperature from 15 to 34°C, suggestinga photochemical reaction. The results indicate that C.ellipsoideaand Melosira spp. acclimatize to prolonged UVA exposure by reactivationof the photosystem and enhanced cellular chlorophyll a synthesis.The ecological importance of these results to phytoplanktonproductivity in natural aquatic environments is discussed. 相似文献
20.
以砂培菊芋(Helianthus tuberosus)幼苗作为试验材料,分别进行不同浓度NaCl (50、 100、150、200、250 mmol&;#8226;L-1)和Na2CO3 (25、50、 75、100、125 mmol&;#8226;L-1)胁迫处理,以1/2全营养液作为对照,处理7 d后研究NaCl和Na2CO3胁迫处理对菊芋幼苗叶片光合作用及叶绿素动力学 参数的影响。结果表明:1)在NaCl处理下,当浓度小于150 mmol&;#8226;L-1时,增加了菊芋的叶绿素含量、净光合速率(Net photosynthetic rate, Pn)和气孔导度(Stomatal conductivity, Gs),对荧光参数PSⅡ的电子传递情况( Fm/Fo)、PSⅡ原初光能转换效率(Fv/Fm)、PSⅡ量子效率 (Actual quantum yield of PSⅡ under actinic irradiation,φPSⅡ)和光化学猝灭系数(Photochemical quenching coefficient, qP)和非 光化学猝灭系 数(Non-photochemical quenching coefficient, NPQ)没有显著影响,随着浓度的增加,各项生理指标与对照相比除了NPQ显著 增加,其余均显著降低;2)在Na2CO3胁迫处理下,随着Na2CO3浓度的增加,与对照相比菊芋幼苗叶绿素含量、Pn、Gs以及叶绿素a荧光诱导动力 学参数Fm/Fo、Fv/Fm、φPSⅡ和qP均显著降低,NPQ显著增加;3)就NaCl和Na2CO3相比而言,在相同Na+浓度情况下,处于Na2CO3胁迫下的菊芋 幼苗的叶绿素含量、Pn、Gs以及叶绿素a荧光诱导动力学参数Fm/Fo、Fv/Fm、φPSⅡ和qP下降幅度和NPQ的增加幅度均显著大于NaCl,这说明 NaCl和Na2CO3胁迫均对菊芋幼苗造成不同程度的伤害,但在相同Na+浓度情况下,Na2CO3的伤害程度大于NaCl。由此说明菊芋对盐的忍耐程度高 于碱。 相似文献