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Effect of ethephon on sweet cherry pedicel-fruit retention force and quality is cultivar dependent 总被引:1,自引:0,他引:1
Ethephon (2-chloroethyl phosphonic acid) is effectively used to promote development of the pedicel-fruit abscission zone in
tart cherry (Prunus cerasus) for mechanical harvest. Our research program is investigating the use of ethephon to promote pedicel-fruit retention force
(PFRF) reduction on new sweet cherry (P. avium) cultivars to assist mechanized harvest and its affect upon fresh market quality fruit. Ethephon treatments were made at
different timings and rates to ‘Bing’ and ‘Chelan’ during the 2006 season. Ethephon applications to ‘Bing’ trees more than
10 days prior to harvest were effective at reducing PFRF and facilitating mechanical harvest, irrespective of rate (1.2, 3.5,
5.8 L ha−1 [1, 3, 5 pt A−1]). Ethephon applied fewer than 10 days prior to harvest did not reduce PFRF sufficiently. In contrast, no rate or timing
of ethephon studied induced a reduction in ‘Chelan’ PFRF sufficient for mechanical harvest. Accompanying PFRF analyses, fruit
quality was assessed by measuring firmness (g mm−1), soluble solids (oBrix), weight (g) and color (CTIFL, scale 1–7). Ethephon applied 22 days before harvest at a rate of 3.5 L ha−1 enhanced exocarp color in ‘Bing’ by 27%, while reducing firmness in both ‘Bing’ (−19%, 22 days prior to harvest) and ‘Chelan’
(−15%, 20 days prior to harvest). We observed a significant natural decline in ‘Skeena’ PFRF to levels acceptable for mechanical
harvest. This research documents genotypic-specific pedicel-fruit abscission characteristics and the potential to facilitate
mechanical harvest of fresh market quality sweet cherry fruit using ethephon. 相似文献
3.
Mokhtar Guerfel Alexandros Beis Tasos Zotos Dalenda Boujnah Mokhtar Zarrouk Angelos Patakas 《Acta Physiologiae Plantarum》2009,31(4):825-831
Differences in abscisic acid (ABA) accumulation between two olive cultivars were studied by enzyme-linked immunosorbent assay
in roots and leaves, leaf water potential (Ψl), stomatal conductance (g
s) as well as photosynthetic rate (A) were also determined in well-watered (WW) and water-stressed (WS) plants of two olive
cultivars ‘Chemlali’ and ‘Chetoui’. ‘Chemlali’ was able to maintain higher leaf CO2 assimilation rate and leaf stomatal conductance throughout the drought cycle when compared with ‘Chetoui’. Furthermore, leaf
water potential of ‘Chemlali’ decreased in lower extent than in Chetoui in response to water deficit. Interestingly, significant
differences in water-stress-induced ABA accumulation were observed between the two olive cultivars and reflect the degree
of stress experienced. Chemlali, a drought tolerant cultivar, accumulated lower levels of ABA in their leaves to regulate
stomatal control in response to water stress compared to the drought sensitive olive cultivar ‘Chetoui’ which accumulated
ABA in large amount. 相似文献
4.
Empathy entails the capacities to resonate with another person’s emotions, understand his/her thoughts and feelings, separate
our own thoughts and emotions from those of the observed and responding with the appropriate prosocial and helpful behavior.
While there is abundant research on the neurobiological mechanisms of some components of empathy (e.g., emotional contagion),
few studies have considered the neurobiological mechanisms underlying the empathic response. The present study explores psychophysiological
correlates (skin conductance level and the interbeat interval) as a function of the empathic response while participants watch
and respond to actors portraying emotionally laden vignettes. Forty undergraduate psychology students were each presented
with 40 emotional vignettes of positive or negative valence and asked to choose among three different empathic responses while
their electrodermal and cardiac responses were measured. Overall, the study shows that higher levels of additive empathy are
associated with increased cardiac activity (i.e., decreased Interbeat Interval) but not electrodermal activity. 相似文献
5.
C. D. Thron 《Bulletin of mathematical biology》1982,44(5):609-635
This paper deals with the unimodality of the ‘impulse response’ in compartmental systems, where the ‘impulse response’ in
any given compartment is the time course of the amount of diffusing substance in that compartment after an initial instantaneous
injection of the substance into that or some other compartment. It is shown that in certain compartmental structures, with
injection in certain compartments, the impulse response is always unimodal or monotonic in all compartments, regardless of
the numerical values of the various transfer rate coefficients. Structures with this property are here named ‘UM structures’,
and they include the familiar mammillary and catenary structures. In this paper, the set of all UM structures is described.
Structures which are not UM (NUM structures) are identified by showing that, by removal of certain connections and compartments
according to certain rules, they can be reduced to small structures which can be shown to be NUM by numerical computation.
Computations on two systems with bimodal impulse responses show that with constant infusions of a fixed amount of substance
the peak level may increase paradoxically with decrease in the infusion rate over a certain range. This effect is extremely
small, however.
Supported in part by U.S. Public Health Service Research Grant GM 21269 from the National Institute of General Medical Sciences,
and in part by Biomedical Research Support Grant S07 RR 05392 from the National Institutes of Health. 相似文献
6.
Moleón M Sánchez-Zapata JA Gil-Sánchez JM Ballesteros-Duperón E Barea-Azcón JM Virgós E 《Oecologia》2012,168(3):679-689
How predators impact on prey population dynamics is still an unsolved issue for most wild predator–prey communities. When
considering vertebrates, important concerns constrain a comprehensive understanding of the functioning of predator–prey relationships
worldwide; e.g. studies simultaneously quantifying ‘functional’ and ‘numerical responses’ (i.e., the ‘total response’) are
rare. The functional, the numerical, and the resulting total response (i.e., how the predator per capita intake, the population
of predators and the total of prey eaten by the total predators vary with prey densities) are fundamental as they reveal the
predator’s ability to regulate prey population dynamics. Here, we used a multi-spatio-temporal scale approach to simultaneously
explore the functional and numerical responses of a territorial predator (Bonelli’s eagle Hieraaetus fasciatus) to its two main prey species (the rabbit Oryctolagus cuniculus and the red-legged partridge Alectoris rufa) during the breeding period in a Mediterranean system of south Spain. Bonelli’s eagle responded functionally, but not numerically,
to rabbit/partridge density changes. Type II, non-regulatory, functional responses (typical of specialist predators) offered
the best fitting models for both prey. In the absence of a numerical response, Bonelli’s eagle role as a regulating factor
of rabbit and partridge populations seems to be weak in our study area. Simple (prey density-dependent) functional response
models may well describe the short-term variation in a territorial predator’s consumption rate in complex ecosystems. 相似文献
7.
Erick D. Smith Matthew D. Whiting David R. Rudell 《Metabolomics : Official journal of the Metabolomic Society》2011,7(1):126-133
Increasing costs and decreasing labor availability for sweet cherry harvest in Washington State, USA, has reinvigorated commercial
and research interest of mechanized harvest. Ethephon (2-chloroethyl phosphonic acid) can be used to improve fruit abscission
for mechanical harvest. Our previous work shows that 3.5 l ha−1 ethephon enhances red color and reduces firmness of the cultivar ‘Bing’. In the current study, we used metabolic profiling
of cultivars ‘Bing’, Chelan’, and ‘Skeena’ fruit meso and exocarp tissue to better understand underlying quality-related metabolism
associated with ethephon application. Trees were treated using air-blast sprayer 13–14 days prior to harvest and fruit samples
were harvested every 7–10 days starting at least 17 days prior to commercial harvest. Nearly 200 identified and partially
characterized metabolites from mesocarp and exocarp tissue were characterized and evaluated. Principal component analysis
models revealed changes in the metabolome associated with both natural ripening and ethephon-induced changes, including associations
to key color, acid, and sugar components, such as cyanidin 3-glucoside, malic acid and sugar metabolism. 相似文献
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9.
Margarita Pérez-Jiménez Antonio Carrillo-Navarro José Cos-Terrer 《Plant Cell, Tissue and Organ Culture》2012,108(1):55-62
Somatic peach plants were regenerated from callus derived from the base of stem explants of the scion cultivars ‘UFO-3’, ‘Maruja’,
‘Flariba’ and ‘Alice Bigi’, and the peach × almond rootstocks ‘Garnem’ and ‘GF677’. A protocol for organogenic plant regeneration
was developed using three culture media containing different concentrations of 6-benzyladenine (BA) and indolebutyric acid
to produce organogenic calli. Shoots were obtained from sliced calli after their transfer to a differentiation culture medium
containing 2 mg l−1 BA and 1 mg l−1 α-naphthalene acetic acid. Using this procedure, up to 29 regenerated plants per callus were obtained. The highest regeneration
rate was obtained with the peach × almond rootstocks. This work provides an effective protocol that could be utilized for
peach transformation research. 相似文献
10.
The significance of sound interception to males of the bicolor damselfish,Pomacentrus partitus,during courtship 总被引:1,自引:0,他引:1
Todd N. Kenyon 《Environmental Biology of Fishes》1994,40(4):391-405
Synopsis Playback experiments conducted in the field and the laboratory demonstrated the use of sound interception in bicolor damselfish,Pomacentrus partitus. Two courtship sounds produced by male bicolors: the ‘chirp’ which occurs at the initiation of courting and the ‘grunt’ which
occurs near the termination, just prior to spawning, were found to hold different meanings to intercepting male competitors.
Males responded to grunt playback with directional swimming towards the sound source and increased courtship behavior. No
directional response was observed during chirp playback. The grunt sound appears to indicate that a spawn-ready female is
present near the sound source. Males therefore move towards it, likely to interfere with the imminent spawning or to gain
a possible spawning partner. Such is not observed in response to chirps, as little advantage would be gained by moving to
the source of a sound which is known to serve as an ‘advertisement’ or ‘territorial keep-out’ signal. Thus, upon intercepting
a neighbor's chirps, males exhibit courting within their own territory, or directly court a nearby female. 相似文献
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Ying Li Yuping Song Gongjun Shi Jianjun Wang Xilin Hou 《Acta Physiologiae Plantarum》2009,31(1):155-162
Changes in ascorbic acid content and antioxidant enzyme activities were investigated in non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) leaves of ‘Wutacai’ and ‘Erqing’ exposed to excess copper (Cu). Cu treatment reduced the fresh weight of shoot and
root by 57% and 46% in ‘Wutacai’, and 60 and 54% in ‘Erqing’, respectively. The accumulation of copper in leaves was higher
in ‘Wutacai’ than that in ‘Erqing’. Compared to the control, ascorbic acid (AsA) contents were significantly decreased after
copper treatment in both cultivars, while they were higher in ‘Wutacai’ than in ‘Erqing’, which may explain the higher copper-tolerance
of ‘Wutacai’ with higher copper accumulation. The higher AsA contents of ‘Wutacai’ resulted from their lower activities of
degrading enzymes, such as ascorbate oxydase (AAO) and ascorbate peroxidase (APX), as well as the increasing activity of dehydroascorbate
reductase (DHAR) after copper treatment compared with ‘Erqing’. Copper stimulated superoxide dismutase (SOD) activity in both
cultivars, but for catalase (CAT), there was little difference between both cultivars. Peroxidases (POD) activity was decreased
after copper treatment in ‘Erqing’, while in ‘Wutacai’, it was significantly increased at 14 days, and POD activity was higher
in ‘Wutacai’ than that in ‘Erqing’ at 21 and 28 days. Therefore, the induced increasing activity of POD in ‘Wutacai’ also
played an important role in its copper tolerance. 相似文献
13.
A. N. G. Dabul H. Belefant-Miller M. RoyChowdhury J. F. Hubstenberger A. Lorence G. C. Phillips 《In vitro cellular & developmental biology. Plant》2009,45(4):414-420
Rice has emerged as a model monocot for studies in agriculture and biotechnology due to its relatively small genome and a
ready accessibility to plant material. Tissue culture is one of the tools required for genetic transformation and some breeding
programs, and the selection of high-frequency regenerator types is essential for success in these technologies. Thirty-three
rice entries with agricultural and biotechnological characteristics of interest were screened with the aim to identify the
best regenerators. Entries that exhibited between 50% and 90% regeneration frequencies include ‘Taipei-309,’ ‘Super Dwarf,’
‘Norin’ (japonica types), PI 312777, ‘Ali Combo’ (indica types), ‘STG-S,’ and ‘LA3’ (red rice types). One third of the entries
tested were at least two times better at regeneration than the often-cited regenerator ‘Nipponbare.’ Those entries showing
at least 85% frequency of greening or somatic embryo formation at 15 or 30 d on regeneration medium ultimately produced whole
plants after 45 d on regeneration medium at high frequency (at least 40%); those entries not reaching the 85% threshold of
greening by Days 15 or 30 exhibited moderate (15–40%) to low (less than 10%) frequency of whole plant regeneration. This greening
response suggests the means for an early prediction system for identification of useful rice regenerator lines, which would
be beneficial for high-throughput screening of germplasm as well as for decreasing the time and cost of in vitro culture. 相似文献
14.
J. Perry Gustafson Xue-Feng Ma Viktor Korzun John W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(4):793-800
A consensus map of rye (Secale cereale L.) was constructed using JoinMap 2.0 based on mapping data from five different mapping populations, including ‘UC90’ × ‘E-line’,
‘P87’ × ‘P105’, ‘I0.1-line’ × ‘I0.1-line’, ‘E-line’ × ‘R-line’, and ‘Ds2’ × ‘RxL10’. The integration of the five mapping populations resulted in a 779-cM map
containing 501 markers with the number of markers per chromosome ranging from 57 on 1R to 86 on 4R. The linkage sizes ranged
from 71.5 cM on 2R to 148.7 cM on 4R. A comparison of the individual maps to the consensus map revealed that the linear locus
order was generally in good agreement between the various populations, but the 4R orientations were not consistent among the
five individual maps. The 4R short arm and long arm assignments were switched between the two population maps involving the
‘E-line’ parent and the other three individual maps. Map comparisons also indicated that marker order variations exist among
the five individual maps. However, the chromosome 5R showed very little marker order variation among the five maps. The consensus
map not only integrated the linkage data from different maps, but also greatly increased the map resolution, thus, facilitating
molecular breeding activities involving rye and triticale. 相似文献
15.
The effects of post harvest application of ethylene, abscisic acid (ABA), indole-3-butyric acid (IBA) treatments or dark storage
on root induction and continued growth of regenerated roots in Pelargonium cuttings were investigated using hydroponics in the greenhouse. Ethylene markedly increased rooting percentage in ‘Greco’
and ‘Surfing’, reduced the number of roots per cutting in ‘Surfing’ and had no effect on the total root lengths in the two
cultivars. Ethylene treatment reduced fresh root mass in ‘Surfing’, increased dry root mass and reduced root water content
in both cultivars. ABA (50 μM) enhanced rooting percentage in ‘Greco’, reduced the number of roots per cutting, reduced total
root lengths and fresh root mass in both cultivars. ABA increased dry root mass and reduced root water content in ‘Surfing’
but this effect was not apparent in ‘Greco’. Storing cuttings in the dark for 4 days had no effect on rooting percentage and
number of roots per cutting in ‘Greco’ and ‘Surfing’. However, dark storage reduced total root lengths in ‘Surfing’ and reduced
fresh root mass in ‘Greco’. Dark storage had no effect on dry root mass and water content in both cultivars. Applying 4 μl l−1 IBA in the rooting solution induced maximum (100%) root induction in ‘Surfing’. However, IBA reduced the number of roots
per cutting in ‘Greco’, reduced total root lengths and fresh root mass in the two cultivars. IBA treatment profoundly increased
and reduced dry root mass and root water content, respectively, in ‘Greco’ and ‘Surfing’. The enhanced root induction observed
after IBA and ABA applications could be ascribed to their influence on ethylene biosynthesis, since ethylene treatment increased
rooting percentage in both cultivars. However, high ABA (100 μM) and IBA (12 μl l−1) levels or dark storage reduced the ability of induced roots to continue growth. We attribute our results to plant stress-response
mechanism and ethylene appears to play an important role in the process of root initiation and root growth in Pelargonium cuttings. 相似文献
16.
Unopened leaves, petioles and fully opened leaves from micropropagation cultures of five Vitis rotundifolia Michx. varieties were cultured on induction medium to study their embryogenic response. Among the various explants tested,
the maximum number of varieties produced embryogenic cultures from unopened leaves followed by fully opened leaves and petioles.
Based on morphological differences, two types of embryogenic cultures were identified. Friable cultures typically arose as
proembryonic masses (PEM) on induction medium, whereas somatic embryo production without an intervening PEM stage was observed
in compact cultures. Of the five varieties tested, the highest frequency of embryogenic response was observed from fully opened
leaves of ‘Supreme’ and unopened leaves and petioles of ‘Delicious’. Attempts to initiate suspension cultures from varieties
resulted in proliferation and maintenance of ‘Alachua’ and ‘Carlos’ cultures in liquid medium for 16 weeks. Embryogenic potential
of varieties was studied on cultures growing on embryo development medium. The maximum number of cotyledonary stage somatic
embryos from 0.2 g proembryonic masses were observed in ‘Carlos’ (379.3) followed by ‘Alachua’ (350.0) and ‘Delicious’ (305.0).
Cotyledonary stage somatic embryos germinated when cultured on Murashige and Skoog medium containing 1 μM Benzyladenine (BA).
Although high embryo germination rates (80–100%) were observed in the varieties tested, plant recovery from germinated somatic
embryos ranged from 6–47%. Embryogenic cultures could be maintained on X6 medium and used in genetic engineering studies. 相似文献
17.
Marielle Merlino Philippe Leroy Christophe Chambon Gérard Branlard 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(7):1321-1337
Albumins and globulins of wheat endosperm represent 20% of total kernel protein. They are soluble proteins, mainly enzymes
and proteins involved in cell functions. Two-dimensional gel immobiline electrophoresis (2DE) (pH 4-7) × SDS-Page revealed
around 2,250 spots. Ninety percent of the spots were common between the very distantly related cultivars ‘Opata 85’ and ‘Synthetic
W7984’, the two parents of the International Triticeae Mapping Initiative (ITMI) progeny. ‘Opata’ had 130 specific spots while
‘Synthetic’ had 96. 2DE and image analysis of the soluble proteins present in 112 recombinant inbred lines of the F9-mapped
ITMI progeny enabled 120 unbiased segregating spots to be mapped on 21 wheat (Triticum aestivum L. em. Thell) chromosomes. After trypsic digestion, mapped spots were subjected to MALDI-Tof or tandem mass spectrometry for
protein identification by database mining. Among the ‘Opata’ and ‘Synthetic’ spots identified, many enzymes have already been
mapped in the barley and rice genomes. Multigene families of Heat Shock Proteins, beta-amylases, UDP-glucose pyrophosphorylases,
peroxydases and thioredoxins were successfully identified. Although other proteins remain to be identified, some differences
were found in the number of segregating proteins involved in response to stress: 11 proteins found in the modern selected
cultivar ‘Opata 85’ as compared to 4 in the new hexaploid `Synthetic W7984’. In addition, ‘Opata’ and ‘Synthetic’ differed
in the number of proteins involved in protein folding (2 and 10, respectively). The usefulness of the mapped enzymes for future
research on seed composition and characteristics is discussed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
Pâmela Fávero Francisco de Assis Alves Mourão Filho Liliane Cristina Libório Stipp Beatriz Madalena Januzzi Mendes 《Acta Physiologiae Plantarum》2012,34(2):471-477
The difficulty in adult tissue genetic transformation in woody species is still an obstacle to be overcome, including in most
sweet orange cultivars of the Brazilian citrus industry. This work reports that, after in vitro culture adjustments, transgenic
adventitious buds of ‘Hamlin’, ‘Pêra’, and ‘Valencia’ sweet oranges (Citrus sinensis L. Osbeck) were recovered using adult material as explant source, in genetic transformation experiments via Agrobacterium tumefaciens. The transgenic buds were identified by the GUS histochemical analysis and confirmed by PCR analysis, which indicated the
presence of an amplified fragment of 817 bp corresponding to the uidA gene sequence. The efficiencies of genetic transformation for ‘Hamlin’, ‘Pêra’, and ‘Valencia’ sweet orange cultivars were
2.5, 1.4, and 3.7%, respectively. Media supplemented with auxins and cytokinins during co-culture, and media with high concentrations
of cytokinins (3 mg L−1) during transgenic selection led to the transformation and, consequently, the regeneration of adequate number of adventitious
buds for the three cultivars. The use of sonication during the explant disinfection was not effective to reduce endophytic
contamination and reduced transformation efficiency. 相似文献
19.
Restoring plant species diversity and community composition in a ponderosa pine-bunchgrass ecosystem
Daniel C. Laughlin Jonathan D. Bakker Mark L. Daniels Margaret M. Moore Cheryl A. Casey Judith D. Springer 《Plant Ecology》2008,197(1):139-151
Monitoring of ecological restoration treatments often focuses on changes in community structure and function. We suggest that
long-term changes in community composition also need to be explicitly considered when evaluating the success of restoration
treatments. In 1992, we initiated an experiment in a ponderosa pine-bunchgrass ecosystem to evaluate responses to restoration
treatments: (a) thinning the overstory vegetation (‘thinning’), (b) thinning plus forest floor manipulation with periodic
prescribed burning (‘composite’), and (c) untreated ‘control.’ Treatments were further stratified by forest patch type: presettlement
tree clumps (trees that established prior to the onset of fire exclusion in 1876), patches of retained postsettlement trees,
patches where all postsettlement trees were removed, and remnant grass openings. Species richness did not differ among treatments
for 10 years, but was highest in the composite treatment in 11th and 12th year after initial treatment. Community composition
diverged among treatments 5 years after initial treatment, and compositional changes were greatest in the composite treatment.
Species richness and composition differed among patch types prior to treatment. Remnant grass patches were the most diverse
and presettlement patches were the least diverse. Following treatment, species richness in the postsettlement removed and
retained patches, gradually approached levels found in remnant grass patches. Compositional differences among patch types
changed a little by 2005. Species richness at the 2 m2 scale increased only where the overstory was thinned and the understory was burned. However, these changes may not be detectable
for many years, and can vary temporally in response to events such as severe droughts. Nonnative species establishment may
be reduced by scheduling longer burn intervals or by refraining from burning where fuel loads are not hazardous, though these
options may hinder goals of increasing diversity. Restoring species diversity and community composition continues to be more
difficult than restoring ecosystem structure and function. 相似文献
20.
Mustapha Ennajeh Ahmadou Mohamed Vadel Habib Khemira 《Acta Physiologiae Plantarum》2009,31(4):711-721
In this study, we compared the efficacy of defense mechanisms against severe water deficit in the leaves of two olive (Olea europaea L.) cultivars, ‘Chemlali’ and ‘Meski’, reputed drought resistant and drought sensitive, respectively. Two-year old plants
growing in sand filled 10-dm3 pots were not watered for 2 months. Changes in chlorophyll fluorescence parameters and malondialdehyde content as leaf relative
water content (RWC) decreased showed that ‘Chemlali’ was able to maintain functional and structural cell integrity longer
than ‘Meski’. Mannitol started to accumulate later in the leaves of ‘Chemlali’ but reached higher levels than in the leaves
of ‘Meski’. The latter accumulated several soluble sugars at lower dehydration. ‘Chemlali’ leaves also accumulated larger
quantities of phenolic compounds which can improve its antioxidant response. Furthermore, the activity of three antioxidant
enzymes catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) increased as leaf RWC decreased. However, differences
were observed between the two cultivars for CAT and POD but not for APX. The activity of the first two enzymes increased earlier
in ‘Meski’, but reached higher levels in ‘Chemlali’. At low leaf hydration levels, ‘Chemlali’ leaves accumulated mannitol
and phenolic compounds and had increased CAT and POD activities. These observations suggest that ‘Chemlali’ was more capable
of maintaining its leaf cell integrity under severe water stress because of more efficient osmoprotection and antioxidation
mechanisms. 相似文献