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1.
When apples which develop low temperature breakdown (LTB) at 32° F. are moved from 32° F. to 65° F. for 3 to 5 days at about the 7th to 8th week of storage, they subsequently develop within a given period of storage less LTB than apples kept at 32° F. continuously.

The respiration of apples susceptible to LTB increases steadily during storage at 32° F. If these apples are warmed to 65° F. during the period of exposure to 32° F., the subsequent rate of respiration at 32° F. is lower than before warming, and continues at a lower rate than for apples kept at 32° F. continuously.

If the apples are moved to 38° F., without an intermediate treatment at 65° F., the rate of respiration is higher than for apples at 38° F. continuously, and this higher rate persists.

If there is an intermediate wanning period at 65° F., the respiration of apples moved from 32° to 38° F. is of the same order as that for apples kept at 38° F. continuously.

The respiratory quotient of apples at 32° F. or at 38° F., which is indicative of the type of respiratory activity, is typical for the temperature at which it is measured, and is not affected by the warming treatment. The effects of wanning on both the incidence of LTB and respiration are similar for apples stored in air and in 2% oxygen: 98% nitrogen.  相似文献   

2.
Fruit pigmentation in ripening cv. Gala, Schniga’ apples was monitored under the influence of fertigation weekly during 21 July–31 August 2009, i.e. 34 days before and 7 days after the optimal harvest date in Slovenia. The soil was a heavy loam clay with high humus content (2.8 %) and high acidity (low pH 4.9). The spectral indices NDVI (Normalized Difference Vegetation Index) and NAI (Normalized Anthocyanin Index) were obtained by a PA 1101 on attached fruit on the transition between the ground and blush colour of the fruit surface. NAI increased slowly from 0.25 to 0.6 two weeks prior to optimum maturity. NDVI values fell from 0.9 to 0.2 before and during ripening, with significant changes starting ca. 3 weeks before and during the week after the optimum harvest date. Fertigation delayed fruit ripening viz harvest date by ca. 4 days. Fertigation delayed changes in the intensity of the fruit’s epidermal pigments, expressed as NDVI for 1 week and NAI for 4 weeks, respectively, but had no significant effect on fruit colour or NDVI and NAI values at the optimal harvest date. At this time, those fruits from the fertigated trees were firmer with a lower starch index compared with the un-fertigated control. Statistically, highly significant correlations were found (p?≤?0.01) (r?=?0.35 to r?=?0.91, R2?=?0.11–0.83) between all the studied spectral and standard parameters i.e. fruit fresh firmness, soluble solids content and starch index.  相似文献   

3.
4.
Yuri  José A.  Neira  Amalia  Fuentes  Mauricio  Sáez  Bárbara  Razmilic  Iván 《Erwerbs-Obstbau》2022,64(2):201-209

Total and specific phenolic compounds and antioxidant capacity were quantified over two seasons in flowers, leaves, fruitlets, and ripe fruit at harvest of the apple cultivars ‘Brookfield’, ‘Granny Smith’ and ‘Fuji’, as well the crabapple cultivars ‘Hillary’ and ‘Manchurian’. The results showed that leaves had the highest phenol concentrations and antioxidant capacity. Phenolic and antioxidant content was progressively lower from flowers, fruitlets, and ripe harvested fruit. There were high concentrations of phloridzin in flowers and leaves, while concentrations were lower in fruitlets, peel, and entire fruit at harvest. The phenolic compound with the highest concentration in peel was quercetin glycoside, while in the entire fruit it was flavanols. The studied crabapple cultivars did not present differences between them in phenolic compounds and antioxidant capacity.

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5.
Most of the frequency distributions of onion bulb weight throughout the growing period were found to be significantly and positively skewed. The positive skewness was significantly greater at high density than at low and increased significantly with time from sowing. A nomogram relating yield of various onion grade sizes to plant density was derived. For a particular cultivar grown in a known environment such a nomogram enables the plant density for optimum yield of a specified grade to be predicted.  相似文献   

6.
7.
Frank  Karin  Wissel  Christian 《Landscape Ecology》1998,13(6):363-379
The role of spatial configuration for metapopulation survival is analyzed by using a stochastic metapopulation model. This model reveals conditions which must be satisfied by the species' ecology and the landscape settings before a metapopulation can persist over a long term. Taking this as a basis, initial rules of thumb for landscape management are deduced. The following results are highlighted: (1) the critical correlation length dc of the extinction processes determines a spatial scale of the metapopulation dynamics. (2) Only species with a dispersal range dr above the correlation length dc are able to benefit from landscape management at all. (3) A certain metapopulation can only persist over a long term if no patch is inside the range of correlation of another one. (4) There is a hierarchy of importance in the characteristics of a spatial configuration (scale and type) and, hence, in the scopes of landscape management. To conclude, some general consequences for supporting species survival by management are discussed. Some prospects concerning the use of models for decision support in landscape planning are discussed.  相似文献   

8.
The composition of fermentation medium for producing Cordyceps brasiliensis mycelium was optimized using response surface methodology. A Plackett-Burman design was applied to screen potential key factors selected on the basis of preliminary experiments, and the steepest ascent method was adopted to approach the approximate optimal medium composition. Finally, central composite design and response surface methodology were applied to define more precisely the optimal composition of the fermentation medium. Our data revealed glucose and beef extract to be the most influential parameters, and the composition of the optimal fermentation medium (100 mL) was determined to consist of 4.46 g glucose, 2 g soluble starch, 4 g silkworm powder, 2.93 g beef extract, 0.10 g KH2PO4 and 0.15 g MgSO4·7H2O.  相似文献   

9.
10.
Summary

In a previous study, the apple ‘Jonathan’ was shown to be semi-compatible with the ‘Topred’ sport of ‘Red Delicious’, the main cultivar in Israel. This incompatibility led to reduced pollination potency, explaining the low yield obtained from ‘Topred’ rows adjacent to ‘Jonathan’. Hence, the importance of identifying the level of compatibility for all ‘Topred’ pollinators became apparent. By analysing S-allele by PCR with primers for the various S-alleles of the cultivars in the ‘Topred’ orchard, including S10 and S28, which were cloned in this study, it was evident that apart from ‘Jonathan’, the common pollinators for ‘Topred’ are fully compatible with it. The ability to identify all S-alleles in the ‘Topred’ orchard was also utilized to resolve the observation that, although ‘Topred’ is considered self-incompatible, self-pollinated, net-caged, ‘Topred’ flowers set some fruit. Applying PCR-analysis of S-alleles to the progeny of the suspected self-pollinated ‘Topred’ fruit revealed that the fruit-set was the outcome of cross-pollination, perhaps the consequence of fertilization by wind carried pollen. Hence, the notion that ‘Topred’ is totally self-incompatible was confirmed and the efficiency of progeny PCR S-allele analysis for the determination of the pollen donor was exhibited.  相似文献   

11.
The present study focuses on small urban public parks, specifically on how they should be designed to promote a potential for psychological restoration and on what activities people could imagine doing in such parks. Students from Oslo University College were presented with visual stimuli depicting 74 small urban parks. They were asked to assess how likely it was that they could rest and recover in the parks presented in the photos. In addition, the participants were asked to write down what park components contributed to high versus low ratings on restoration likelihood, and what types of activities they could imagine doing in the parks presented in the photos. The components and activities the participants mentioned were grouped into categories describing similar properties. The categories mentioned most frequently and giving high ratings on restoration likelihood represented natural categories such as: ‘a lot of grass’, ‘a lot of flowers/plants’ and ‘water features’. In contrast, the categories contributing to low ratings on restoration likelihood represented lack of vegetation or disturbance from the surroundings such as: ‘a lot of hard surfaces’, ‘a lot of traffic’ and ‘poorly shielded from the surroundings’. The activities mentioned as being typically performed in the types of parks presented in the photos were ‘relax and philosophize’, ‘read’ and ‘eat/drink’. Conclusions drawn from the study: Small urban parks should be designed with natural components, shielded from disturbing surroundings and furnished with some seating to promote opportunities for restorative experiences and to function as social meeting places.  相似文献   

12.

Context

Recent research suggests that novel geodiversity data on landforms, hydrology and surface materials can improve biodiversity models at the landscape scale by quantifying abiotic variability more effectively than commonly used measures of spatial heterogeneity. However, few studies consider whether these variables can account for, and improve our understanding of, species’ distributions.

Objectives

Assess the role of geodiversity components as macro-scale controls of plant species’ distributions in a montane landscape.

Methods

We used an innovative approach to quantifying a landscape, creating an ecologically meaningful geodiversity dataset that accounted for hydrology, morphometry (landforms derived from geomorphometric techniques), and soil parent material (data from expert sources). We compared models with geodiversity to those just using topographic metrics (e.g. slope and elevation) and climate data. Species distribution models (SDMs) were produced for ‘rare’ (N?=?76) and ‘common’ (N?=?505) plant species at 1 km2 resolution for the Cairngorms National Park, Scotland.

Results

The addition of automatically produced landform geodiversity data and hydrological features to a basic SDM (climate, elevation, and slope) resulted in a significant improvement in model fit across all common species’ distribution models. Adding further geodiversity data on surface materials resulted in a less consistent statistical improvement, but added considerable conceptual value to many individual rare and common SDMs.

Conclusions

The geodiversity data used here helped us capture the abiotic environment’s heterogeneity and allowed for explicit links between the geophysical landscape and species’ ecology. It is encouraging that relatively simple and easily produced geodiversity data have the potential to improve SDMs. Our findings have important implications for applied conservation and support the need to consider geodiversity in management.
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13.
Summary

The conventional organic growing medium used for anthurium (Anthurium andraeanum) production is peat. Quality peat, however, is costly and is a non-renewable natural resource. The current study compared the suitability of using charred and composted organic agricultural wastes (OAW) vs. sphagnum peat as components of various growth media for the ornamental plant, anthurium (A. andraeanum ‘Pink Lady’). Ten different media were prepared from composted corn cobs (C), charred corn cobs (CC), charred garden waste (CG), and Pindstrup? sphagnum peat moss (P) in various proportions. The media contained [on a % (v/v) basis]: C (100%), CC (100%), CG (100%), C (70%) + CG (30%), CC (70%) + CG (30%), C (35%) + CG (15%) + P (50%), CC (50%) + P (50%), CC (35%) + CG (15%) + P (50%), C (50%) + P (50%), or P (100%) as a control. After 15 months in a greenhouse, the growth and flowering of transplanted anthurium plants were optimal using P, CC+P, or CC+CG+P.These results indicate that mixing charred OAW with peat could provide a suitable medium for anthurium production, thereby reducing the need for peat and converting agricultural waste material into useful products.  相似文献   

14.
Summary

In order to confirm the hybrid origin of Phalaenopsis intermedia Lindl., internal transcribed spacers (ITSs) of ribosomal DNA (rDNA) and three fragments of chloroplast DNA (cpDNA) were studied. Nineteen clones of ITS sequences from three accessions of P. intermedia Lindl. were aligned with nine species of sections of Phalaenopsis and Stauroglottis that were candidate parents. A phylogenetic tree, derived from the ITS data, was constructed by the Neighbor-joining (NJ) method. Two major groups were shown for 19 clones of ITS sequences of P. intermedia based on the phylogenetic tree. The average genetic distance between the aforementioned two groups and the candidate parents was calculated based on the Kimura 2-parameter method. One group had the lowest genetic distance from the ITS repeat sequences of P. aphrodite Rchb.f., and another group had the lowest distance from that of P. equestris (Schauer) Rchb.f. The results indicated that both P. aphrodite and P. equestris are parents of P. intermedia based on the ITS data. In addition, analysis of three fragments of cpDNA, namely the trnL intron, the trnL-trnF intergenic spacer (IGS), and the atpB-rbcL IGS, showed that P. intermedia had the lowest genetic distance from P. aphrodite. Both the ITS and cpDNA data, as well as reference to the effects of maternal inheritance of cpDNA, suggest that P. aphrodite was the maternal parent and P. equestris was the paternal parent of P. intermedia. Therefore, molecular evidence supports P. intermedia being a natural hybrid derived from P. aphrodite and P. equestris.  相似文献   

15.
In 1983, a group of incipient landscape ecologists met to discuss the nature and future directions for landscape ecology. The themes emerging from this conference—movement of materials, organisms, and energy through a landscape; the genesis of landscape patterns; the effects of landscape structure on the spread of disturbances; and the potential contributions of landscape ecology to resource management—established a foundation for the development of landscape ecology in North America over the following decades. I discuss these contributions in the light of where landscape ecology is today.
John A. WiensEmail:
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16.
Trees in urban areas are pruned for several reasons. Each pruning cut causes a wound, which leads at least in the exposed wood at the wound surface to discoloration and decay. The extension of the resulting defect depends on wound diameter, tree species, time of wounding, wound treatment, and last but not least the attachment of the branch to the stem. The effects of different pruning cuts on urban trees has been investigated in Hamburg, Germany, since 1985. The study of 750 different pruning wounds on typical urban tree species lead to the Hamburg Tree Pruning System (Hamburger Schnittmethode). The system is described in this paper and answers the following questions: How should branches with and without a branch collar be removed? How should dead branches be removed? How should branches with included bark or codominant stems be removed? What are the differences between tree species in wound response? What is the maximum wound size which will be effectively compartmentalised by the tree?  相似文献   

17.
Summary

A dot blot assay, based on the internal transcribed spacer of the ribosomal region, was developed for rapid diagnosis and identification of Botrytis cinerea, the causal agent of grey mould of greenhouse tomatoes. In this assay, DNA from fungal cultures and diseased plant tissue were amplified by PCR using primers specific to septate fungi, fixed to nylon membranes, and hybridized with digoxigenin-d-UTP labelled oligonucleotides specific to B. cinerea. The hybridized probes were detected by chemiluminescence. Six isolates of B. cinerea, four isolates of Botrytis species, one isolate each of B. fabae, B. squamosa, B. streptothrix, B. allii, B. porri, and B. tulipae and some common greenhouse pathogens were tested using this assay. Of four probes screened, probe Bot1 gave a positive reaction with all isolates of B. cinerea and with fresh or frozen plant tissue affected with grey mould from research centres and commercial greenhouses. All other greenhouse fungi tested negative with probe Bot1. This dot blot diagnoses infection by B. cinerea in large numbers of samples rapidly and reliably and distinguishes isolates of B. cinerea from other epiphyte fungi found on greenhouse crops.  相似文献   

18.
We argue for the landscape ecology community to adopt the study of poverty and the ecology of landscapes as a Grand Challenge Topic. We present five areas of possible research foci that we believe that landscape ecologists can join with other social and environmental scientists to increase scientific understanding of this pressing issue: (1) scale and poverty; (2) landscape structure and human well-being; (3) social and ecological processes linked to spatial patterns in landscapes; (4) conservation and poverty, and (5) applying the landscape ecologist’s toolkit. A brief set of recommendations for landscape ecologists is also presented. These include the need to utilize broad frameworks that integrate social and ecological variables, build capacity to do this kind of work through the development of strong collaborations of researchers in developed and developing countries, create databases in international locations where extreme poverty exists, and create a new generation of researchers capable of addressing this pressing social and environmental issue.  相似文献   

19.
AIM:To observe the effects of aortal angiotensin Ⅱ(AngⅡ)levels and AngⅡ receptor in the hypertensive rat models. METHODS: Intraperinoneal injection of L-Nω-nitro-arginine(L-NNA) into rats induced hypertensive model, the binding of aortal AngⅡ receptor and the contents of aortal tissue AngⅡ and plasma NO2-+NO3-(NOx) were determined.RESULTS:Compared with the control group, the blood pressure of the rats treated with L-NNA was significantly increased by 142%(P<0.01),the plasma NOx levels were decreased by 48%. However, in the rats treated for 4 weeks the ratio of cardial index was increased by 128%(P<0.01),the plasma AngⅡ levels weren't significantly changed, the contents of vascular tissue AngⅡ were increased by 612%(P<0.01) and the Bmax of [125I]-AngⅡ was increased by six times (P<0.01),the affinity was doubled respectively.CONCLUSIONS:Nitric oxide synthase (NOS) inhibition mostly influes the reninangiotensin system in regional tissue. The inhibition for long time up-regulates vascular AngⅡ and AngⅡ receptor, which can support the hypothesis "NOS inhibition can induce AngⅡ-depended hypertension".  相似文献   

20.
AIM: To explore the possible effect of UII in the process of remodeling after vascular injury. METHODS: The rat model of balloon injury in thoracic aorta was established. Male rats were randomized to 4 groups (n=5), including sham injury group, injury group, UII group (UII pumped into the rats after thoracic aorta balloon injury at 1.0 nmol·kg-1·h-1) and urantide group (urantide pumped into the rats after thoracic aorta balloon injury at 10 nmol·kg-1·h-1). At 21 days, the thoracic aortas were taken out to measure the changes of pathology, the expression of UII, the proliferation of VSMC and the expression of collagen. RESULTS: (1) At the 21 days after operations, the systolic blood pressure was higher in UII group than that in injury group [(140.0±10.0) mmHg vs (132.0±3.4) mmHg, P>0.05]. The systolic blood pressure was also obviously higher than that in urantide group [(140±10.0) mmHg vs (128.0±2.4) mmHg, P<0.05]. (2) Urotensin Ⅱ was expressed strongly in the injured area after thoracic aorta injury. (3) In contrast to injury group, the intimal thicken in urotensin Ⅱ group enhanced, the decrease in lumen area was marked (0.13±0.05 vs 0.07±0.02, P<0.05), the cell proliferation index was markedly increased (0.74±0.16 vs 0.40±0.11, P<0.01), and the expression of collagen was also markedly increased (counted as IOD, 318±127 vs 78±26, P<0.01). (4) In contrast to injury group, the decrease in lumen area was not abolished (0.09±0.03 vs 0.07±0.02, P>0.05) after chronic infusion of urotensin Ⅱ receptor antagonist urantide, the cell proliferation index was markedly increased (0.73±0.15 vs 0.40±0.11, P<0.01) and the expression of collagen was not statistically increased (counted as IOD, 200±79 vs 78±26, P>0.05). CONCLUSION: Urotensin Ⅱ expresses strongly in the myointimal cells after thoracic aorta injury in rat. The extra UII enhances the proliferation of VSMC and expression of collagen in the myointimal, increases the stenosis of injured vasculature, indicating that UII might take part in the process of repairing after vessel injury.  相似文献   

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