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1.
Abstract: In Polygonatum odoratum (Liliaceae), flowers located distally within the flowering shoot typically exhibit lower fruit set than flowers located proximally. In this study, experiments were performed to investigate whether the lower fruit set of distal flowers is due to pollen limitation, resource competition or "architectural" effects. We found that (1) fruit set and mean number of ovules per flower decline within the flowering shoot from proximal to distal position; (2) variations in the amount of pollen received do not explain the observed differences in fruit set; (3) the fruit set of the most distal flowers was significantly increased by removal of other flower buds in the flowering shoot just before flower opening, indicating that fruit set in these flowers is resource-limited; and (4) removal of proximal flowers increased the fruit set of later flowers to levels similar to those of early flowers of control shoots, arguing against the architectural effects hypothesis. 相似文献
2.
Background and Aims
The influence of temperature on the timing of budbreak in woody perennials is well known, but its effect on subsequent shoot growth and architecture has received little attention because it is understood that growth is determined by current temperature. Seasonal shoot development of grapevines (Vitis vinifera) was evaluated following differences in temperature near budbreak while minimizing the effects of other microclimatic variables.Methods
Dormant buds and emerging shoots of field-grown grapevines were heated above or cooled below the temperature of ambient buds from before budbreak until individual flowers were visible on inflorescences, at which stage the shoots had four to eight unfolded leaves. Multiple treatments were imposed randomly on individual plants and replicated across plants. Shoot growth and development were monitored during two growing seasons.Key Results
Higher bud temperatures advanced the date of budbreak and accelerated shoot growth and leaf area development. Differences were due to higher rates of shoot elongation, leaf appearance, leaf-area expansion and axillary-bud outgrowth. Although shoots arising from heated buds grew most vigorously, apical dominance in these shoots was reduced, as their axillary buds broke earlier and gave rise to more vigorous lateral shoots. In contrast, axillary-bud outgrowth was minimal on the slow-growing shoots emerging from buds cooled below ambient. Variation in shoot development persisted or increased during the growing season, well after temperature treatments were terminated and despite an imposed soil water deficit.Conclusions
The data indicate that bud-level differences in budbreak temperature may lead to marked differences in shoot growth, shoot architecture and leaf-area development that are maintained or amplified during the growing season. Although growth rates commonly are understood to reflect current temperatures, these results demonstrate a persistent effect of early-season temperatures, which should be considered in future growth models. 相似文献3.
Plants of Lamium amplexicaule, grown under short-day field conditionsin Northern California produce predominantly closed flowers.Under long-day field conditions, plants may produce up to 50per cent open flowers, the same total number of flowers beingproduced under each daylength regime. A 20 ml drop of GA3 or GA7 (100µM) was applied to themain shoot apex of plants growing under short-day conditions,and all subsequently produced flowers opened. CCC, an inhibitorof gibberellin synthesis, was applied (0.06 per cent) to thesoil of seedlings grown under long-day conditions. The CCC-treatedplants were dwarfed and bore only closed flowers. With GA7 appliedexogenously to the CCC-treated shoots, inhibition was released,resulting in elongated internodes and open flower production.The timing of flower production and internodal extension inLamium amplexicaule are positively correlated. When floral primordiawere removed from main shoots, the average internode lengthsdecreased. The number of nodes produced in treated plants wasincreased as a result of flower removal. Exogenous GA7 (10 µM)applied to the nodes from which flowers were removed resultedin internodal extension but had no effect on node number. Twoprocesses that may contribute to the control of the productionof open and closed flowers in Lamium amplexicaule are: (1) anincreasing anther sac size from lower to upper node flowersthat may exert control locally, via GN production, on corollaexpansion, and (2) a photoperiodic control. Lamium amplexicaule L, henbit, cleistogamy, chasmogamy, gibberellins, gibberellic acid (GA3), (2 chloroethyl) trimethylammonium chloride (cycocel) 相似文献
4.
Studies in 1963–65 of the phytotoxic effects, on leaves, flowers and yields of blackcurrants, of sprays containing sulphur, particularly lime sulphur, showed that there was considerable variation in degree of effect between years and between experiments in the same year. It was difficult to damage flowers except at low temperatures, but if fruit set was affected then yield was depressed. Leaf scorching has to be very severe before yields are depressed. There was no evidence from preliminary experiments that sprays of seaweed extract reduced sulphur shock if used up to 3 days before lime sulphur application. The growth rate of shoots was reduced by 1/4–4% lime sulphur for short periods, dependent on concentration, but total bud numbers, flower/ vegetative bud ratios and yield were unaffected. It was found that no adverse effects of lime sulphur were carried over into the following year. 相似文献
5.
Eggplants (Solanum melongena L. cv. Bonica) were grown in a glasshouse during summer under natural light with one unbranched shoot or one shoot with 3
to 4 branches and with or without fruit in quartz sand buffered and not buffered with 0.5% CaCO3 (w : v), respectively. Nutrient solutions supplied contained nitrate or ammonium as the sole nitrogen source.
Compared with nutrient solutions containing nitrate (10 mM), solutions containing ammonium (10 mM) caused a decrease in net photosynthesis of eggplants during early stages of vegetative growth when grown in quartz sand
not buffered with CaCO3. The decrease was not observed before leaves showed interveinal chlorosis. In contrast, net photosynthesis after bloom at
first increased more rapidly in eggplants supplied with ammonium than with nitrate nitrogen. However, even in this case, net
photosynthesis decreased four weeks later when ammonium nutrition was continued. The decrease was accompanied by epinasty
and interveinal chlorosis on the lower leaves and later by severe wilting, leaf drop, stem lesions, and hampered growth of
stems, roots, and fruits. These symptoms appeared later on plants not bearing fruits than on plants bearing fruits. If nutrient
solutions containing increasing concentrations of ammonium (0.5–30 mM) were supplied after the time of first fruit ripening, shoot growth and set of later flowers and fruits were promoted. In
contrast, vegetative growth and reproduction was only slightly affected by increasing the concentration of nitrate in the
nutrient solutions.
In quartz sand buffered with CaCO3 ammonium nutrition caused deleterious effects only under low light conditions (shade) and on young plants during rapid fruit
growth. If eggplants were supplied with ammonium nitrogen before bloom, vegetative growth was promoted, and set of flowers
and fruit occurred earlier than on plants supplied with nitrate. Furthermore, the number of flowers and fruit yield increased.
These effects of ammonium nutrition were more pronounced when plants were grown with branched shoots than with unbranched
shoots.
The results indicate that vegetative and reproductive growth of eggplants may be manipulated without causing injury to the
plants by supplying ammonium nitrogen as long as the age of the plants, carbohydrate reserves of the roots, quantity of ammonium
nitrogen supplied, and pH of the growth medium are favourable. T W Rufty Section editor 相似文献
6.
Factors Affecting Flower Abortion and Malformation in Roses 总被引:2,自引:1,他引:1
ROAR MOE 《Physiologia plantarum》1971,24(2):291-300
The formation of blind shoots and malformed flowers in rose plants grown under various temperatures and light intensities, and subjected to different cut back procedures has been studied. Low temperature, low light intensity and low cut back promoted blind shoot formation. Hybrid tea cultivars are more sensitive for unfavourable temperature, light and cut back treatments than Floribunda cultivars. The process of floral abortion is initiated during the early stages of shoot growth before the differentiation of floral parts has been completed. Low temperatures (12–15°C) in this critical stage of development strongly promote blind shoot formation, but have no effect when stamen and pistil primordia had been formed in the apical flower bud. The formation of malformed flowers, so-called “bullheads”, which have significantly more petals than normal flowers, is also promoted by low temperature and low cut back. Light intensity seems to have no effect. Shoots subjected to low temperature (12°C) during the early stages of development, before the differentiation of the floral organs are fully completed, produce malformed flowers to a greater extent than shoots subjected to high temperature (18–24°C) during this period. It is suggested that blind shoot formation in roses is subject to hormonal control. 相似文献
7.
Rose plants (Rosa hybrida ‘Sonia’=‘Sweet Promise’) were grown in heated (minimum night temperature 17°C), and unheated greenhouses with or without
root heating to 21°C. These trials covered 6 growth cycles extending over two winter seasons. In the heated greenhouse, root
heating did not increase yield, flower quality or plant development. In the unheated greenhouse, root-heated plants grew as
well as those in the air-heated greenhouse as long as the air temperature did not fall below 6°C. When minimum night temperatures
fell below 6°C, growth, yield and quality were reduced, irrespective of root temperature.
Daytime plant water relations were studied in plants growing at 6 different root temperatures in the unheated greenhouse.
Leaf resistance to water diffusion was lowest at optimal root temperature. Total leaf water potential was not significantly
affected by root temperature. 相似文献
8.
Frederick D. Hempel Lewis J. Feldman 《The Plant journal : for cell and molecular biology》1995,8(5):725-731
Within wild-type Arabidopsis populations, a subset of the plants were found to have a single chimeric shoot on their primary shoot axes. The chimeric shoots were located below the lowest primary-axis flower; and they exhibited features of both flowers and paraclades (lateral flowering shoots). Morphological analyses of chimeric shoots indicated that they developed from single primordia. In each chimeric shoot, the side furthest from the apical meristem was specified as 'flower'—while the side closest to the meristem was specified as 'paraclade'—suggesting that a stimulus from outside the apical meristem can directly induce primordia to develop as flowers. It is concluded that the development of the teratological chimeric shoots resulted from the overlap of the vegetative and floral specification processes within single primordia. 相似文献
9.
Carbon autonomy of current-year shoots in flowering, and of current-year shoots plus 1-year-old shoots (1-year-old shoot system)
in fruiting of Siberian alder (Alnus hirsuta var. sibirica) was investigated using a stable isotope of carbon, 13C. The current-year shoot and 1-year-old shoot systems were fed 13CO2 and the atom% excess of 13C in flowers and fruits was determined. The majority of photosynthate allocated to flower buds was originally assimilated
in the leaves of the flowering current-year shoots. Of all the current-year shoots on fruiting 1-year-old shoots, only those
nearest to the fruits allocated the assimilated photosynthate to fruit maturation. These results indicate that the current-year
shoots and 1-year-old shoot systems are carbon-autonomous units for producing flowers and maturing fruits, respectively. 相似文献
10.
Dieback of Passion Fruit in Surinam 总被引:1,自引:0,他引:1
In Surinam, the commercial cultivation of the yellow passion fruit (Passiflora edulis f. flavicarpa) is difficult due to the occurrence of dieback. Symptoms referred to as dieback include a decrease in elongation of the shoot end internodes after a period of normal growth leading to wilting and death of the shoots. Fruits from plants showing dieback symptoms are much smaller than those from healthy plants. From shoots with dieback symptoms, three fungi were isolated including Colletotrichum gloeosporioides. However, inoculation experiments with these fungi on shoots of vigorously growing plants were negative, even after wound inoculation. It appeared that plants with dieback symptoms had a poorly developed root system, From these roots Fusarium solani was isolated, which appeared to be highly pathogenic to roots of the yellow passion fruit. After inoculation of the roots of 3-month-old plants, roots became infected and the aerial plant parts showed typical dieback symptoms. Plants with their root system reduced either by inoculating with F. solani or by clipping, and subsequently inoculated with C. gloeosporioides on the aerial parts 2 weeks later, showed dieback symptoms and infection by C. gloeosporioides in shoots with these symptoms. Thus, a badly functioning root system, for example caused by infection of F. solani leads to dieback and predisposes plants to infection by C. gloeosporioides. The latter fungus itself is not a primary pathogen of shoots of the yellow passion fruit in Surinam. 相似文献
11.
The effects of heating at 38°C of whole cucumber (Cucumis sativus L.) seedlings or local heating of their shoots and roots on ABA content and heat tolerance of leaves and roots were investigated. During the initial period of the high-temperature treatment of whole seedlings, the ABA concentration in leaves and roots increased considerably. Local heating of the shoot or root resulted in an increase in the ABA concentration not only in the heated organ, but also in unheated seedling parts. A high-temperature treatment of the whole seedlings and the local treatment of shoots or roots caused an increase in the heat tolerance of leaf cells. The heat tolerance of root cells virtually did not change after heating of the whole seedlings or shoots, but decreased after heating of roots. The possible role of ABA in changing the heat tolerance of leaf and root cells by local heating of the seedling is discussed. 相似文献
12.
Susana M.P. Carvalho Ep Heuvelink Jeremy Harbinson Olaf van Kooten 《Physiologia plantarum》2006,128(2):263-273
The present work was aimed at understanding and quantifying the effect of sink–source relationships on flower size, using chrysanthemum as a model system. Sink/source ratio was manipulated by flower bud removal (leaving one, two or four flowers, and a control), axillary shoot removal, and varying daily light integral. Furthermore, the influence of flower position within the stem on the flower size was investigated. All means applied to reduce sink/source ratio resulted in a significantly higher individual flower dry mass and area in plants with a fixed number of flowers. Nevertheless, control plants responded to supplementary assimilation light with an increased number of flowers rather than producing larger flowers. Flower position had a negligible effect on flower size in both disbudded and control plants, except that the second-order lateral flowers were significantly smaller than the first-order ones. Singly flowered plants without side shoots represented the greatest potential flower size; they had flowers up to 2.4 times heavier than the control plants. Total aerial plant dry mass was only reduced at very low sink strength treatments, whereas flower mass ratio showed a saturating response to the number of flowers per plant. The results indicate that individual flower size is very sensitive to total plant sink strength, but it does not change with plant source strength when the number of flowers is not manipulated. 相似文献
13.
Flowering plant density can increase number of visits and fruit set in multi-flowering plants, however this aspect has not been studied on few flower species. We studied the effects of individual floral display and plant density on the fruit production of the epiphytic, moth-pollinated orchid, Ryncholaelia glauca, in an oak forest of Chavarrillo, Veracruz, Mexico. Species is non-autogamous, and produced one flower per flowering shoot each flowering season. We hypothesized that orchids with more flowering shoots and those on trees with clumps of conspecific should develop more fruits than isolated ones. R. glauca population flowers synchronouly, and individual flowers last up to 18 days, with flowers closing rapidly after pollination. Individuals produced few flowers per year, although some plants developed flowers in both seasons and fewer of them developed fruits both years. There was no relationship between flower number per orchid, or per host tree, with the number of fruits developed per plant. Host trees with flowering and fruiting orchids were randomly dispersed and the pattern of distribution of flowering and fruiting plants was not related. Apparently, pollinators visit the flowers randomly, with no evidence of density dependence. The fruit set of R. glauca was as low as fruit set of multi-flowered orchids moth pollinated, suggesting that fruit set on moth pollinated orchids could be independent of the number of flowers displayed. 相似文献
14.
Morphogenesis of floral structures, dynamics of reproductive development from floral initiation until fruit maturation, and leaf turnover in vegetative short-stem shoots of Saxifraga oppositifolia were studied in three consecutive years at an alpine site (2300 m) and at an early- and late-thawing subnival site (2650 m) in the Austrian Alps. Marked differences in the timing and progression of reproductive and vegetative development occurred: individuals of the alpine population required a four-month growing season to complete reproductive development and initiate new flower buds, whereas later thawing individuals from the subnival sites attained the same structural and functional state within only two and a half months. Reproductive and vegetative development were not strictly correlated because timing of flowering, seed development, and shoot growth depended mainly on the date of snowmelt, whereas the initiation of flower primordia was evidently controlled by photoperiod. Floral induction occurred during June and July, from which a critical day length for primary floral induction of about 15 h could be inferred. Preformed flower buds overwinter in a pre-meiotic state and meiosis starts immediately after snowmelt in spring. Vegetative short-stem shoots performed a full leaf turnover within a growing season: 16 (+/-0.8 SE) new leaves per shoot developed in alpine and early-thawing subnival individuals and 12 (+/-1.2 SE) leaves in late-thawing subnival individuals. New leaf primordia emerged continuously from snowmelt until late autumn, even when plants were temporarily covered with snow. Differences in the developmental dynamics between the alpine and subnival population were independent of site temperatures, and are probably the result of ecotypic adaptation to differences in growing season length. 相似文献
15.
The root, vegetative shoot and fruit growth of November and January sown glasshouse tomato plants grown in flowing water culture was followed over 6–7 months. The relationship between vegetative and reproductive growth was examined after two-thirds of the flowers were removed from half the experimental plants. This resulted in larger plants which had fewer, larger fruits and eventually a fruit yield almost as large as the controls. In the control plants, fruit growth increased steadily until it reached 90% of the total incremental fresh weight of the plant 50–60 days after first anthesis. Leaf growth was markedly depressed at this stage and root growth ceased 4 wk after anthesis. Some root death was observed from anthesis onwards. When fruit growth subsequently diminished, vegetative growth recovered but to a lower rate than before fruiting commenced. Following partial flower removal, only 64% or less of the total increment of fresh weight went into the fruit. Although vegetative growth at this stage was thus greater than in the control plants, both shoot and root growth followed the same qualitative pattern with time. The ratio of vegetative shoot to root fresh weight remained essentially constant throughout the fruiting phase in plants of both sowings whether flowers were removed or not. This suggests that the fruit grew in competition with the vegetative organs as a whole, although, for a short period at early fruiting, root growth was more seriously affected. The pattern and amount of fruiting in this indeterminate plant was influenced by the size of the vegetative organs at fruiting, and by the effect of the existing developing fruit on further vegetative and reproductive growth. 相似文献
16.
Localization of the Site of Perception of Thermoinductive Temperatures in Thlaspi arvense L 总被引:2,自引:0,他引:2
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Metzger JD 《Plant physiology》1988,88(2):424-428
This paper describes attempts to localize the site of perception of low temperatures (0-10°C) during thermoinduction in Thlaspi arvense L. Reproductive development (stem elongation and flower formation) was observed when shoots were cooled to 4°C for 4 weeks and then returned to 21°C while maintaining the roots constant 21°C. However, chilling the roots was ineffective for initiating reproductive development. The apparent site of perception of thermoinductive temperatures was further localized to the shoot tip (apex and immature leaves) by controlling the temperature of the shoot tip independently of the rest of the plant. Furthermore, excised apices regenerated flowering plants in organ culture only if they were subjected to a 4 week cold treatment. Grafting experiments also support the notion that the shoot tip or the apex is the site of perception of thermoinductive temperatures: noninduced shoot tips grafted onto bolting donors remained as vegetative rosettes. Paradoxically, it was found that the cells of the shoot tip are not the only ones capable of being thermoinduced. Shoots regenerated from leaf cuttings excised from thermoinduced plants exhibited all signs of reproductive development, while regenerated shoots from control leaves developed into vegetative rosettes. It is suggested that many cell types are capable of being thermoinduced and that the shoot tip may appear to be the site of perception of thermoinductive temperatures because structures associated with reproductive development originate from this tissue. 相似文献
17.
Summary
Arthrocnemum fruticosum (L.)Moq., a halophyte from the shore of the Dead Sea in Jordan was grown in a greenhouse with nutrient solution supplemented
with various concentrations of NaCl. It was shown that with increasing salinity the plants became more succulent, mainly due
to an accumulation of sodium and water. Sodium was taken up into the roots in equal amounts to chloride, but in the shoots
far more sodium than chloride was found, suggesting a control of these ions either in the excretion into the xylem, or in
the uptake by the shoot out of the xylem.
Ammonium and nitrate in the plants decreased with time on nutrient solution more or less independently of the salt concentration.
However, more nitrate appeared again in the plants when they started flowering.
After an initial period of adaptation the nitrate reductase activityin vivo was not inhibited by a salinity of up to 2%, but at higher NaCl concentrations a shift of nitrate reductase activity occurred
from the roots to the shoots. This was consistent with earlier observations in the field. In the vegetative phase of the plants
the nitrate reductase in the roots was influenced by the soil water potential, but in the shoot it was mainly dependent on
the supply of nitrate from the roots.
High NaCl concentrations delayed flower initiation. During flowering the nitrate reductase was involved in the re-allocation
of nitrogenous compounds from the roots to the developing flowers, and it became effectively independent from salinity. 相似文献
18.
Stocklin J 《American journal of botany》1997,84(6):763-768
I studied the effects of competition and soil fertilization on variation of seed yield components of the outcrossing perennial Epilobium dodonaei Vill. using a randomized complete block design. Fertilization as a main effect was not significant. Competition, however, reduced the number of flower buds per shoot (-29%), the number of ovules per fruit (-12%), and the number of ripe fruits per shoot (-51%). In addition, competition caused an increase in abortion of flower buds. Consequently the fruit/flower bud ratio decreased from 0.71 to 0.47. Average seed mass was not reduced significantly by competition. Some of the negative effects of competition on fruit production were mitigated by fertilization. However, competition considerably reduced the proportion of late-aborted seeds, which resulted in an increase of the seed/ovule ratio from 0.31 to 0.49 (+58%). As a consequence of this compensation, the reduction in the number of seeds per shoot due to competition was not significant. At the level of the genet, competition had a strong effect on seed yield due to decreases in the number of shoots produced. I discuss patterns of regulation at consecutive levels of reproduction. Shoots of plants suffering from competition initially invested less in reproductive structures than the control and showed a higher abortion rate of less costly structures early in reproductive development, but also had a lower abortion rate later in their development. The observed compensatory pattern in yield components illustrates the fine-tuning regulation capacity at different levels of reproductive development in plants. 相似文献
19.
Ethylene production by sorghum is rhythmic and the amplitude of the rhythm is increased both by dim, far-red enriched light and in mutant plants deficient in phytochrome B. The mechanisms involved in controlling ethylene production were examined in detail by measuring the rate of ethylene production among organs and tissues, examining the organ-specific levels of ACC (1-aminocyclopropane-1-carboxylic acid, the ethylene precursor) and investigating the contribution of the roots to shoot ethylene production. The results demonstrate that the expanding leaves were the major source of ethylene under dim, far-red enriched light and in the phytochrome B mutant. Enhanced ethylene production by the expanding leaf appeared to be the result of targeted delivery of ACC to this tissue. Root ACC levels were much higher than those in the shoot but roots converted much less of this endogenous ACC to ethylene. Applying ACC to the roots had only a marginal effect on their ethylene production, but greatly increased that of the shoots. Decapitated shoots continued to produce ethylene in a rhythmic pattern but the amplitude decreased with time compared to intact plants. The results collectively suggest that some, but not all, of the shoot ethylene rhythm depends on the transport of ACC from the roots to the shoots. 相似文献
20.
Grafting raises the salt tolerance of tomato through limiting the transport of sodium and chloride to the shoot 总被引:22,自引:0,他引:22
Estañ MT Martinez-Rodriguez MM Perez-Alfocea F Flowers TJ Bolarin MC 《Journal of experimental botany》2005,56(412):703-712
With the aim of determining whether grafting could improve salinity tolerance of tomato (Lycopersicon esculentum Mill.), and what characteristics of the rootstock were required to increase the salt tolerance of the shoot, a commercial tomato hybrid (cv. Jaguar) was grafted onto the roots of several tomato genotypes with different potentials to exclude saline ions. The rootstock effect was assessed by growing plants at different NaCl concentrations (0, 25, 50, and 75 mM NaCl) under greenhouse conditions, and by determining the fruit yield and the leaf physiological changes induced by the rootstock after 60 d and 90 d of salt treatment. The grafting process itself did not affect the fruit yield, as non-grafted plants of cv. Jaguar and those grafted onto their own root showed the same yield over time under non-saline conditions. However, grafting raised fruit yield in Jaguar on most rootstocks, although the positive effect induced by the rootstock was lower at 25 mM NaCl than at 50 and 75 mM NaCl. At these higher levels, the plants grafted onto Radja, Pera and the hybrid VolgogradskijxPera increased their yields by approximately 80%, with respect to the Jaguar plants. The tolerance induced by the rootstock in the shoot was related to ionic rather than osmotic stress caused by salinity, as the differential fruit yield responses among graft combinations were mainly related to the different abilities of rootstocks to regulate the transport of saline ions. This was corroborated by the high negative correlation found between fruit yield and the leaf Na(+) or Cl(-) concentrations in salt-treated plants after 90 d of salt treatment. In conclusion, grafting provides an alternative way to enhance salt tolerance, determined as fruit yield, in the tomato, and evidence is reported that the rootstock is able to reduce ionic stress. 相似文献