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1.
Programme of senescence in petals and carpels of Pisum sativum L. flowers and its control by ethylene 总被引:3,自引:0,他引:3
The role of ethylene in the control of senescence of both petals and unpollinated carpels of pea was investigated. An increase
in ethylene production accompanied senescence, and the inhibitors of ethylene action were effective in delaying senescence
symptoms in different flower verticils. Pollination did not seem to trigger the senescence syndrome in the corolla as deduced
from the observation that petals from pollinated and unpollinated flowers and from flowers whose carpels had been removed
senesced at the same time. A cDNA clone encoding a putative ethylene-response sensor (psERS) was isolated from pea flowers, and the pattern of expression of its mRNA was studied during development and senescence of
different flower tissues. The levels of psERS mRNA paralleled ethylene production (and also levels of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) mRNA) in both
petals and styles. Silver thiosulfate treatments were efficient at preventing ACO and psERS mRNA induction in petals. However, the same inhibitor showed no ability to modify expression patterns in pea carpels around
the anthesis stage, suggesting different controls for ethylene synthesis and sensitivity in different flower organs.
Received: 18 June 1998 / Accepted: 22 December 1998 相似文献
2.
The effect of cis-propenylphosphonic acid (PPOH), a structural analoge of ethylene, on flower wilting and ethylene production was investigated using cut carnation flowers which are very sensitive to ethylene. Wilting (petal in-rolling) of the flowers was delayed by continuously immersing the stems in a 5–20 mM PPOH solution. In addition, the continuous treatment with PPOH markedly reduced autocatalytic ethylene production of the petals accompanying senescence. This reduction of autocatalytic ethylene production was considered responsible for the inhibitory effect of PPOH on flower wilting. The inhibitory activity of trans-propenylphosphonic acid (trans-PPOH), on both flower wilting and the autocatalytic ethylene production accompanying senescence was markedly lower than that of PPOH, suggesting that PPOH action is stereoselective. PPOH may be of interest as a new, water-soluble inhibitor of wilting and autocatalytic ethylene production in cut carnation flowers. 相似文献
3.
The purpose of this paper is to investigate the differential responses of flower opening to ethylene in two cut rose cultivars,
‘Samantha’, whose opening process is promoted, and ‘Kardinal’, whose opening process is inhibited by ethylene. Ethylene production
and 1-aminocyclopropane-1-carboxylate (ACC) synthase and oxidase activities were determined first. After ethylene treatment,
ethylene production, ACC synthase (ACS) and ACC oxidase (ACO) activities in petals increased and peaked at the earlier stage
(stage 3) in ‘Samantha’, and they were much more dramatically enhanced and peaked at the later stage (stage 4) in ‘Kardinal’
than control during vasing. cDNA fragments of three Rh-ACSs and one Rh-ACO genes were cloned and designated as Rh-ACS1, Rh-ACS2, Rh-ACS3 and Rh-ACO1 respectively. Northern blotting analysis revealed that, among three genes of ACS, ethylene-induced expression patterns of
Rh-ACS3 gene corresponded to ACS activity and ethylene production in both cultivars. A more dramatic accumulation of Rh-ACS3 mRNA was induced by ethylene in ‘Kardinal’ than that of ‘Samantha’. As an ethylene action inhibitor, STS at concentration
of 0.2 mmol/L generally inhibited the expression of Rh-ACSs and Rh-ACO in both cultivars, although it induced the expression of Rh-ACS3 transiently in ‘Kardinal’. Our results suggests that ‘Kardinal’ is more sensitive to ethylene than ‘Samantha’; and the changes
of Rh-ACS3 expression caused by ethylene might be related to the acceleration of flower opening in ‘Samantha’ and the inhibition in
‘Kardinal’. Additional results indicated that three Rh-ACSs genes were differentially associated with flower opening and senescence as well as wounding. 相似文献
4.
K. Manning 《Planta》1986,168(1):61-66
The relationship between ethylene production and the CN--assimilating enzyme -cyanoalanine synthase (CAS; EC 4.4.1.9) was examined in the carnation (Dianthus caryophyllus L.) flower. In petals from cut flowers aged naturally or treated with ethylene to accelerate senescence the several hundred-fold increase in ethylene production which occurred during irreversible wilting was accompanied by a one- to twofold increase in CAS activity. The basal parts of the petal, which produced the most ethylene, had the highest CAS activity. Studies of flower parts (styles, ovaries, receptacles, petals) showed that the styles had a high level of CAS together with the ethylene-forming enzyme (EFE) system for converting 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene. The close association between CAS and EFE found in styles could also be observed in detached petals after induction by ACC or ethylene. Treatment of the cut flowers with cycloheximide reduced synthesis of CAS and EFE. The data indicate that CAS and ethylene production are associated, and are discussed in relation to the hypothesis that CN- is formed during the conversion of ACC to ethylene.Abbreviations ACC
1-aminocyclopropane-1-carboxylic acid
- AVG
aminoethoxyvinylglyoine
- CAS
-cyanoalanine synthase
- CHI
cycloheximide
- EFE
ethylene-forming enzyme 相似文献
5.
R. Nichols 《Planta》1977,135(2):155-159
Production of endogenous ethylene from the styles, ovary and petals of pollinated and unpollinated flowers of Dianthus caryophyllus L. was measured. The rate of ethylene production of cut, unpollinated flowers aged in water at 18°C was low until the onset of petal wilting, when a rapid surge of ethylene occurred in all tissues. The flower ethylene production was evolved mostly from the styles and petals. The bases of petals from unpollinated, senescing flowers evolved ethylene faster and sometimes earlier than the upper parts. Treatment of cut flowers with propylene, an ethylene analogue, accelerated wilting of flower petals and promoted endogenous ethylene production in all flower tissues. Pollination of intact flowers also promoted endogenous ethylene production and caused accelerated petal wilting within 2–3 days from pollination. Although the data are consistent with the hypothesis that ethylene forms a link between pollination of the style and petal wilting, in the unpollinated flower the style and petals can evolve a surge of ethylene independently of each other, about the time when the petals irreversibly wilt. The results are discussed in relation to the role of ethylene in flower senescence. 相似文献
6.
We determined the effects of phosphorus (P) concentration and mycorrhizal colonization on ethylene production by flowers
of snapdragons (Antirrhinum majus L.). Mycorrhizal colonization in a soil-less medium did not significantly affect the total number of flowers per spike or
flower P concentration, but it significantly increased flower vase-life and significantly decreased flower ethylene production.
This demonstrates for the first time that mycorrhizal colonization can have a non-localized effect on host ethylene production.
The reduction in ethylene production caused by mycorrhizal colonization was as large as the variation in ethylene production
among snapdragon cultivars. Thus, mycorrhizal colonization may be a viable alternative to toxic ethylene inhibitors such as
silver thiosulfate. Increased fertilizer P concentration (15 versus 3 μg P ml–1) significantly increased plant fresh weight and the total number of flowers per spike. In contrast to mycorrhizal colonization,
increased fertilizer P concentration resulted in an increase in ethylene production. There was no significant effect of fertilizer
P concentration on vase-life. This suggests that factors other than ethylene have at least partial control over vase-life.
Postharvest amendment of individual flowers with phosphate also significantly increased flower ethylene production. Phosphorus
apparently does not mediate the mycorrhizal effect because mycorrhizal colonization decreased ethylene production without
significantly influencing flower P concentration. Moreover, treatment with phosphate increased flower ethylene production.
Mycorrhizal colonization did not significantly influence response to exogenous ethylene.
Accepted: 14 June 1999 相似文献
7.
Mitsuhiro Obara Wataru Tamura Takeshi Ebitani Masahiro Yano Tadashi Sato Tomoyuki Yamaya 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(3):535-547
Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients
more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci
(QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable
growth conditions for estimating the root length were first established to renew nutrient solutions daily and supply NH4
+ as a single nitrogen source. Thirty-eight chromosome segment substitution lines derived from a cross between ‘Koshihikari’,
a japonica variety, and ‘Kasalath’, an indica variety, were used to detect QTL for seminal root length of seedlings grown in 5 or 500 μM NH4
+. Eight chromosomal regions were found to be involved in root elongation. Among them, the most effective QTL was detected
on a ‘Kasalath’ segment of SL-218, which was localized to the long-arm of chromosome 6. The ‘Kasalath’ allele at this QTL,
qRL6.1, greatly promoted root elongation under all NH4
+ concentrations tested. The genetic effect of this QTL was confirmed by analysis of the near-isogenic line (NIL) qRL6.1. The seminal root length of the NIL was 13.5–21.1% longer than that of ‘Koshihikari’ under different NH4
+ concentrations. Toward our goal of applying qRL6.1 in a molecular breeding program to enhance rice yield, a candidate genomic region of qRL6.1 was delimited within a 337 kb region in the ‘Nipponbare’ genome by means of progeny testing of F2 plants/F3 lines derived from a cross between SL-218 and ‘Koshihikari’. 相似文献
8.
Erin M. O’Donoghue Sheryl D. Somerfield Lyn M. Watson David A. Brummell Donald A. Hunter 《Planta》2009,229(3):709-721
Galactose was the major non-cellulosic neutral sugar present in the cell walls of ‘Mitchell’ petunia (Petunia axillaris × P. axillaris × P. hybrida) flower petals. Over the 24 h period associated with flower opening, there was a doubling of the galactose content of polymers
strongly associated with cellulose and insoluble in strong alkali (‘residual’ fraction). By two days after flower opening,
the galactose content of both the residual fraction and a Na2CO3-soluble pectin-rich cell wall fraction had sharply decreased, and continued to decline as flowers began to wilt. In contrast,
amounts of other neutral sugars showed little change over this time, and depolymerisation of pectins and hemicelluloses was
barely detectable throughout petal development. Size exclusion chromatography of Na2CO3-soluble pectins showed that there was a loss of neutral sugar relative to uronic acid content, consistent with a substantial
loss of galactose from rhamnogalacturonan-I-type pectin. β-Galactosidase activity (EC 3.2.1.23) increased at bud opening,
and remained high through to petal senescence. Two cDNAs encoding β-galactosidase were isolated from a mixed stage petal library.
Both deduced proteins are β-galactosidases of Glycosyl Hydrolase Family 35, possessing lectin-like sugar-binding domains at
their carboxyl terminus. PhBGAL1 was expressed at relatively high levels only during flower opening, while PhBGAL2 mRNA accumulation occurred at lower levels in mature and senescent petals. The data suggest that metabolism of cell wall-associated
polymeric galactose is the major feature of both the opening and senescence of ‘Mitchell’ petunia flower petals. 相似文献
9.
Transgenic Kalanchoe blossfeldiana Poelln. with reduced ethylene sensitivity in flowers was obtained by Agrobacterium tumefaciens-mediated transformation using the plasmid pBEO210 containing the mutant ethylene receptor gene etr1-1 from Arabidopsis thaliana under the control of the flower-specific fbp1-promoter from Petunia. Three ethylene-resistent T0 lines, 300, 324 and 331, were selected and analyzed for postharvest-performance and morphological
characteristics. Line 324 was found to be infertile and only slightly less ethylene-sensitive than control-plants, but lines
300 and 331 had significantly increased ethylene-resistance and were fertile. These two lines were analyzed for copy-number
of the etr1-1 gene by Southern blotting and were crossed with the ethylene-sensitive cultivar ‘Celine’ to create T1 progeny. Line 300 contains
two T-DNA copies per nucleus, one of which is rearranged, and these are unlinked according to segregation data from the crossing
to ‘Celine’ and PCR-analysis of progeny plants. For control plants all flowers were closed after 2 days at 2 μl l−1 ethylene, but for line 300 only 33% were closed after 10 days. Line 331 contains three T-DNA copies per nucleus and is more
sensitive to ethylene than line 300. In the line 300 the etr1-1 gene was found by RT-PCR to be expressed in petals and stamens but not in carpels and sepals. Both lines 300 and 331, and
their progeny, appear morphologically and physiologically identical to control plants except for the higher ethylene resistance.
Line 300 and its progeny with only one T-DNA copy have very low ethylene sensitivity and may be useful in future breeding. 相似文献
10.
11.
Yujie Sun Brian Christensen Fulai Liu Huiqun Wang Renate Müller 《Plant Growth Regulation》2009,59(1):83-91
Phalaenopsis frequently exhibits bud drop during production and in response to adverse postharvest conditions. The effect of exogenous
ethylene on bud drop of mini Phalaenopsis was studied and ethylene sensitivity of four cultivars was compared. Water content, membrane permeability and ABA (abscisic
acid) content in floral buds and flowers were determined after ethylene treatment. Exogenous ethylene induced flower bud drop
in all tested Phalaenopsis cultivars and the different cultivars showed distinct differences in ethylene sensitivity. The cultivar Sogo ‘Vivien’ exhibited
the highest bud drop, water loss and change in membrane permeability in floral petals, while Sogo ‘Berry’ showed the lowest
sensitivity. The ethylene inhibitor 1-MCP (1-methylcyclopropene) reduced ethylene-induced floral bud drop in the cultivar
Sogo ‘Yenlin’. ABA content in floral buds was increased in response to ethylene and 1-MCP pretreatment inhibited the ethylene-induced
increase in ABA levels efficiently. This finding suggests that the observed increase in ABA content during bud drop was mediated
by ethylene. The interaction between ABA and ethylene is discussed. 相似文献
12.
This study investigated the influence of different degrees of cross-linking of β-cyclodextrin-based nanosponges (β-CD-NSs)
on the activity of the incorporated 1-methylcyclopropene (1-MCP) to extend the postharvest longevity of carnation cut flowers.
The polymeric β-CD-NSs were synthesized from cyclodextrins at three varying reticulations, β-CD-NS 1:2, β-CD-NS 1:4, and β-CD-NS
1:8. These carriers were supplied to carry the nonvolatile formulations of 1-MCP at two different concentrations (0.25 and
0.5 μL L−1, ai) through stem and tissues of cut flowers of Dianthus caryophyllus L. ‘Idra di Muraglia’, both sprayed and in vase suspension. Treated cut flowers were compared to those receiving like concentrations
of commercially prepared gaseous 1-MCP and to neat β-CD-NS 1:2, β-CD-NS 1:4, and β-CD-NS 1:8. Visual checks for symptoms of
senescence alteration (VS), petal color variation, and endogenous ethylene production were registered daily. The β-CD-NS 1:2,
β-CD-NS 1:4, and β-CD-NS 1:8 complexes favored decorative value maintenance in carnation cut flowers. In particular, the lowest
suspended concentration (0.25 μL L−1) of the β-CD-NS 1:8 complex proved best for maintaining cut flower ornamental quality. β-CD-NS 1:8 treated flowers also appeared
longer-lived than those treated with both doses of commercial gaseous 1-MCP. Data on petal color variation and endogenous
ethylene production were strictly correlated with VS results. The potential for the formulated 1-MCP-loaded β-CD-NS suspension
to induce prolonged vase life was demonstrated. Its use could yield benefits, such as a reduction in total dose and frequency
of administration. 相似文献
13.
By the use of the Immobiline technique at pH ranges 7.0–7.6 and 6.9–7.9, 16 different hemoglobin (Hb) phenotypes were observed
in 61 English Saanen goats. They are explained in this breed by a genetic theory of five β-globin genes (A
4,A
6,A
8,E, andD) and two closely linked α-globin loci (′α and ″α) of which the ″α has a variant allele, provisionally called ″α
X
. Family data together with observed and expected Hb frequencies were in agreement with the genetic theory. Among six Barbary
sheep there were three Hb phenotypes explained by the occurrence of the β-chain allelesB andC
na. 相似文献
14.
To elucidate the role of the plant hormones—abscisic acid (ABA) and ethylene during flower senescence in roses, experiments
were conducted on two cultivars of cut-roses (Rosa hybrida L.), ‘Grandgala’ and ‘First Red,’ obtained from a commercial grower. An apparent similarity was observed during flower senescence
and accumulation of endogenous ABA in petal tissue. Several fold increase in ABA concentration was observed during the later
stages of senescence which was found to be associated with a drastic reduction of flower water potential and water uptake.
During the later stages of senescence (S5–S6) higher ABA concentration coincides with the elevated concentration of ethylene
production. ABA and ethylene both stimulate senescence and are suggested to interact during flower senescence under water
limitations. 相似文献
15.
Daniel J. Mullan Ghader Mirzaghaderi Esther Walker Timothy D. Colmer Michael G. Francki 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(7):1313-1323
Lophopyrum
elongatum (tall wheatgrass), a wild relative of wheat, can be used as a source of novel genes for improving salt tolerance of bread
wheat. Sodium ‘exclusion’ is a major physiological mechanism for salt tolerance in a wheat–tall wheatgrass amphiploid, and
a large proportion (~50%) for reduced Na+ accumulation in the flag leaf, as compared to wheat, was earlier shown to be contributed by genetic effects from substitution
of chromosome 3E from tall wheatgrass for wheat chromosomes 3A and 3D. Homoeologous recombination between 3E and wheat chromosomes
3A and 3D was induced using the ph1b mutant, and putative recombinants were identified as having SSR markers specific for tall wheatgrass loci. As many as 14
recombinants with smaller segments of tall wheatgrass chromatin were identified and low-resolution breakpoint analysis was
achieved using wheat SSR loci. Seven recombinants were identified to have leaf Na+ concentrations similar to those in 3E(3A) or 3E(3D) substitution lines, when grown in 200 mM NaCl in nutrient solution. Phenotypic
analysis identified recombinants with introgressions at the distal end on the long arm of homoeologous group 3 chromosomes
being responsible for Na+ ‘exclusion’. A total of 55 wheat SSR markers mapped to the long arm of homoeologous group 3 markers by genetic and deletion
bin mapping were used for high resolution of wheat–tall wheatgrass chromosomal breakpoints in selected recombinants. Molecular
marker analysis and genomic in situ hybridisation confirmed the 524-568 recombinant line as containing the smallest introgression
of tall wheatgrass chromatin on the distal end of the long arm of wheat chromosome 3A and identified this line as suitable
for developing wheat germplasm with Na+ ‘exclusion’. 相似文献
16.
Susana Manzano Cecilia Martínez Zoraida Megías Pedro Gómez Dolores Garrido Manuel Jamilena 《Plant Growth Regulation》2011,65(2):213-221
In this paper we compare the sensitivity of different squash genotypes to ethylene and brassinosteroids by studying the effects
of different ethylene and brassinosteroid treatments on the sexual expression and flower development of different C. pepo genotypes: Bolognese (Bog) and Vegetable Spaghetti (Veg), two contrasting lines for ethylene production and sensitivity, as well as Cora, a standard commercial hybrid. Results have demonstrated that ethylene has a much greater effect on sexual expression and
flower development in C. pepo than brassinosteroids. Ethephon increases the number of female flowers per plant and reduces the first male phase of development,
while treatments with the ethylene inhibitors AVG and STS reduce the number of female flowers per plant and expand the first
male phase of development. The differential response observed between genotypes appears to be related to ethylene production
and sensitivity. Bog, which produces more ethylene and is more sensitive to this hormone, responded much better to AVG and STS, reducing the number
of female flowers per plant, while Veg, which is characterised by lower production of and sensitivity to ethylene, responded better to ethephon by reducing the
first male phase of development and increasing the number of female flowers per plant. The differential abortion of female
and male flowers in ethephon, AVG and STS treatments, as well as the occurrence of bisexual flowers in the AVG and STS treated
plants of the more ethylene sensitive genotypes, demonstrate that ethylene is also involved in the development of female flowers.
Female flower buds require a minimal level of ethylene not only to complete their development and maturation without a premature
abortion, but also to arrest the development of stamens in the third whorl and to promote the appropriate growth of the carpels.
On the contrary, the role of brassinosteroids in the sexual expression of C. pepo was not so evident. The application of brassinazole, an inhibitor of brassinosteroid biosynthesis slightly changes the production
of ethylene in the three analysed genotypes, but those changes have little effect on their sexual phenotypes, and they do
not alter the development of the unisexual flowers. 相似文献
17.
So-Young Park Hosakatte N. Murthy Kee-Yoeup Paek 《In vitro cellular & developmental biology. Plant》2002,38(2):168-172
Summary An efficient and rapid in vitro method was developed for regeneration of Phalaenopsis using leaf segments derived in vitro from flower stalk nodes. Leaf segments of four cultivars Tinny Sunshine ‘Annie’, ‘Taisuco Hatarot’, Teipei Gold ‘Golden Star’,
Tinny Galaxy ‘Annie’ cultured on Murashige and Skoog medium supplemented with N
6-benzyladenine (BA; 88,8 μM) and α-naphthaleneacetic acid (NAA; 5,4 μM) produced an average of 10–13 protocorm-like bodies (PLBs) after 12 wk. PLB proliferation was achieved on a modified Hyponex
medium (1 gl−1 6.5N−4.5P−19K+20N−20P−20K+2gl−1 peplone +3% (w/v) potato homogenate +0.05% activated 1 gl−1 charcoal) and an optimal number of 13–18 PLBs developed from single PLB sections of different cultivars. Plantlet development
was also achieved on a modified Hyponex medium. By repeated subculture of PLBs on a proliferation medium, and culturing them
in the plantlet regeneration medium, plantlets could be produced continuously. Approximately 6 mo, were required from the
initiation of culture to the production of plantlets for transplant to community pots. 相似文献
18.
Potassium (K+) and chloride (Cl−) are two essential elements for plant growth and development. While it is known that plants possess specific membrane transporters
for transporting K+ and Cl−, it remains unclear if they actively use K+-coupled Cl− cotransporters (KCC), as used in animals, to transport K+ and Cl−. We have cloned an Oryza sativa cDNA encoding for a member of the cation–Cl− cotransporter (CCC) family. Phylogenetic analysis revealed that plant CCC proteins are highly conserved and that they have
greater sequence similarity to the sub-family of animal K+–Cl− cotransporters than to other cation–Cl− cotransporters. Real-time PCR revealed that the O. sativa cDNA, which was named OsCCC1, can be induced by KCl in the shoot and root and that the expression level was higher in the leaf and root tips than in any
other part of the rice plant. The OsCCC1 protein was located not only in onion plasma membrane but also in O. sativa plasma membrane. The OsCCC1 gene-silenced plants grow more slowly than wild-type (WT) plants, especially under the KCl treatment regime. After 1 month
of KCl treatment, the leaf tips of the gene-silenced lines were necrosed. In addition, seed germination, root length, and
fresh and dry weight were distinctly lower in the gene-silenced lines than in WT plants, especially after KCl treatment. Analysis
of Na+, K+, and Cl− contents of the gene-silenced lines and WT plants grown under the NaCl and KCl treatment regimes revealed that the former
accumulated relatively less K+ and Cl− than the latter but that they did not differ in terms of Na+ contents, suggesting OsCCC1 may be involved in K+ and Cl− transport. Results from different tests indicated that the OsCCC1 plays a significant role in K+ and Cl− homeostasis and rice plant development. 相似文献
19.
Flowering plants of Begonia × cheimantha cv Emma and Begonia x hiemalis cv Schwabenland Red were exposed to different light levels (0, 40, 80 M m–2S–1) and to ethylene (150 nl 1–1) in growth cabinets. Increasing irradiance level increased the number of flower buds in both begonia species. The amount of 14C-assimilates translocated to flower buds and the acid invertase activity in flower buds and flowers also increased with increasing irradiance level. Conversely, treatment with ethylene decreased the accumulation of 14C in flowers and flower buds, but did not affect acid invertase activity. Ethylene accelerated abscission of flowers and flower buds and increased the number of cup shaped and small flowers. 相似文献
20.
Effects of elevated CO2 on flowering phenology and nectar production of nectar plants important for butterflies of calcareous grasslands 总被引:1,自引:0,他引:1
Effects of elevated CO2 on flowering phenology and nectar production were investigated in Trifolium pratense, Lotus corniculatus, Scabiosa columbaria, Centaurea jacea and Betonica officinalis, which are all important nectar plants for butterflies. In glasshouse experiments, juvenile plants were exposed to ambient
(350 μl l−1) and elevated (660 μl l−1) CO2 concentrations for 60–80 days. Elevated CO2 significantly enhanced the development of flower buds in C. jacea. B. officinalis flowered earlier and L. corniculatus produced more flowers under elevated CO2. In contrast, the number of flowers decreased in T. pratense. The amount of nectar per flower was not affected by elevated CO2 in the tested legumes (T. pratense and L. corniculatus), but was significantly reduced (!) in the other forbs. Elevated CO2 did not significantly affect nectar sugar concentration and composition. However, S. columbaria and C. jacea produced significantly less total sugar under elevated CO2. The nectar amino acid concentration remained unaffected in all investigated plant species, whereas the total of amino acids
produced per flower was reduced in all non-legumes. In addition, the amino acid composition changed significantly in all investigated
species except for C. jacea. The observed effects are unexpected and are a potential threat to flower visitors such as most butterflies which have no
alternative food resources to nectar. Changes in nectar production due to elevated CO2 could also have generally detrimental effects on the interactions of flowers and their pollinators.
Received: 12 September 1996 / Accepted: 9 September 1997 相似文献