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1.
Physiological responses and fruit quality of ‘d’Anjou’ pear fruit from five orchard lots were evaluated after cold storage in air or controlled atmospheres (CA) with the O2 concentration based on assessment of fruit chlorophyll fluorescence (CF) or standard conditions (1.5 kPa O2). The pCO2 for all CA fruit was 0.5 kPa. Softening, acid loss, and peel degreening of all lots were delayed at one or more evaluation dates (2, 4, 6, 8 months) by previous storage at the CF pO2 compared with fruit stored in 1.5 kPa O2 or in air. Superficial scald developed on fruit previously stored in air but not on fruit stored in a CA. Pithy brown core developed on fruit from all lots stored at the CF pO2 and on fruit stored at 1.5 kPa in 3 of the 5 lots. Pithy brown core incidence decreased with advanced harvest maturity. Post-storage ethylene and CO2 production were in most instances lowest for fruit stored at the CF pO2. A significant relationship between fruit ethanol content and pithy brown core incidence was observed. Results indicate low pO2 storage based on CF monitoring slows fruit ripening relative to fruit stored at 1.5 kPa O2, prevents superficial scald development compared with fruit stored in air, however, development of pithy brown core in fruit stored at the CF pO2 was not accompanied by a change in CF.  相似文献   

2.
We focus our research on this question: Does an expansion in the percentage of labour employed in the manufacturing sector lead to reductions in the poverty rate? While some research suggests that regional differences in the employment share of the manufacturing sector explain variation in poverty rates, we do not find empirical evidence of this poverty‐ameliorating effect in our regression analysis of Canadian Census Districts between the years 2001 and 2006.  相似文献   

3.
Pre-storage application of 40% CO2 at 0 °C for 24 or 48 h and controlled atmosphere (12% O2 + 12% CO2) storage at 0 °C for up to eight weeks on decay control and quality of organic ‘Flame Seedless’ and ‘Crimson Seedless’ table grapes were studied as a postharvest disease control alternative. To simulate different potential field conditions, these organic treatments were applied to organic-grown grapes that were naturally infected (without inoculation), surface inoculated (berries inoculated by spraying with a conidia suspension), and nesting inoculated (clusters inoculated by placing in the middle an artificially infected berry) with the pathogen Botrytis cinerea, the cause of grape gray mold. Under these three conditions, a 40% CO2 for 48 h pre-storage treatment followed by controlled atmosphere reduced the gray mold incidence from 22% to 0.6% and from 100% to 7.4% after four and seven weeks, respectively. High CO2 pre-storage alone limited botrytis incidence in both naturally and artificially infected grapes, but was more effective when combined with CA. These treatments did not affect visual or sensory fruit quality. Exposure to high CO2 for 24 or 48 h effectively inhibited mycelial growth of B. cinerea in PDA plates incubated at 22 °C for up to 72 h. Conidia germination in PDA plates was reduced ∼60% after 12 h incubation. In vitro studies demonstrated a fungistatic effect, but further studies on the mechanism of action could improve treatment performance. This novel high CO2 initial fumigation followed by controlled atmosphere during storage or transportation could be a commercially feasible alternative for postharvest handling of organic and conventional table grapes. Our results encourage validating this combined physical treatment in other cultivars and under commercial conditions.  相似文献   

4.
The aim of this paper is to examine the relationship between social capital and entrepreneurship in deprived urban neighbourhoods (DUNs). While there is a great deal of research on social capital, its usage and value in deprived areas is an under‐researched topic. Drawing on survey data, it is found that social capital in the form of network ties within a DUN is linked to how entrepreneurship develops in these places. The breadth and variety of network ties that individuals are able to identify as sources of advice is related to the probability of considering an entrepreneurial career, and is even more strongly related to the conversion of entrepreneurial intentions into full engagement. If entrepreneurship is to be harnessed in DUNs a starting point is the enhancement of initiatives for developing social capital incorporating local businesses, residents, and local government agencies.  相似文献   

5.
This study investigated the effects of passive modified atmosphere packaging (MAP), storage temperature (5, 10 and 15 °C) and duration of 14 days on the postharvest quality attributes, compositional change in flavour attributes and microbiological quality of minimally processed pomegranate arils (Punica granatum L.), cvs ‘Acco’ and ‘Herskawitz’. Volatile compounds were extracted via headspace solid phase micro-extraction (HS-SPME) and analyzed by gas chromatography–mass spectrometry (GC–MS). A total of 17 and 18 volatiles were detected and identified in the headspace of pomegranate juices of ‘Acco’ and ‘Herskawitz’, respectively. Based on the physicochemical attributes and microbial evaluation, the postharvest life of MA-packaged ‘Acco’ and ‘Herskawitz’ was limited to 10 days due to fungal growth ≥2 log CFU g−1 at 5 °C. However, the concentration (%) and compositional changes in volatile compounds indicated that the flavour/aroma life (7 days) was shorter than the postharvest shelf-life based on appearance and other physicochemical (10 days) for both cultivars.  相似文献   

6.
Increasing air temperature due to changing climate is projected to decrease the length of the growing season, hasten vegetative development and maturation, and ultimately affect yield of many C3 crops. Previous multilocation trials highlighted strong relationships between thermal trends in the interval “beginning of flowering‐end of grain filling” and grain yield, and protein content in durum wheat (Triticum turgidum subsp. durum (Desf.) Husn.). With the aim to confirm these relationships, nine durum wheat genotypes, including old (Capeiti 8, Senatore Cappelli and Trinakria) and modern (Amedeo, Arcangelo, Mongibello, Simeto, and Svevo) varieties and a Sicilian landrace (Russello) were grown at three different sites representing a climate gradient in Sicily, Italy. Moreover, the effect of post‐anthesis heat stress on these durum wheats was further investigated in two contrasting environments: open‐field (control—C) and greenhouse heat stress (HS). HS shortened the interval “beginning‐end of flowering” of 1.5 days across genotypes, and the “end of flowering‐beginning of grain filling” and maturation of 4.9 days, with a range of 1 day in Arcangelo to 11 days in Cappelli. Advances in main phenophases significantly decreased kernel weight (KW) and grain yield (GY), whereas grain protein content (PC) increased. As expected, a negative relationship was observed between GY and PC, while positive relationships were found for GY and grain‐filling duration (GFD), and GY and KW. Genotypes responded differently to heat stress, as evidenced by the net photosynthesis, transpiration rate, instantaneous water use efficiency and dry matter accumulation in kernels. Genotypes were ranked according to the heat susceptibility index (HSI): Amedeo, Arcangelo, Capeiti 8, Svevo and Trinakria resulted heat‐tolerant. These varieties were characterized by an early trigger of dry matter accumulation in kernels under HS (Amedeo, Arcangelo and Trinakria), or showed similar length of the GFD (Capeiti 8) between environments. The multilocation trial confirmed a negative relationship between maximum temperatures and grain yield, and a positive relationship between minimum temperatures and protein content during grain–filling periods. Research focusing on agronomic strategies, phenology and breeding for tolerance to heat stress is of strategic importance to cope with the detrimental effect of global warming in semi‐arid climates.  相似文献   

7.
This paper simulated SO2 concentration at three different CLP diameters based on the mathematic model of heat and mass transfer of Ca(OH)2 Liquid Particles (CLP)in Spray Drying Desulfurization Absorber(SDDA), the transient characteristics of water and solid weight in CLP, the temperature of CLP, the temperature of flue gas. The results show that while the CLP diameter, the temperature change rate of CLP and flue gas in crease, the mass increasing rate of CLP decrease. At the same time, the absorbing time to stable state of CLP becomes longer, the stable mass and the vaporizing rate of CLP increase. On the other hand, coupling simulation between the numerical and transient simulation process, the transient characteristics of absorbing SO2 for CLP are finished for CLP in SDDA at different flue gas temperature with CLP diameter 80 μm.With increasing the flue gas temperature, the mass increasing rate of CLP changes slowly, and the absorbing time to stable state of CLP also becomes longer. The SO2 absorbing efficiency increases, and its changing rate becomes fast.  相似文献   

8.
The article aims at discussing the rise of the green bonds in the context of the multilateral development banks, by problematizing their threats and potentialities to be an alternative to the existing financing system within the sustainable development agenda. It scrutinises the development rhetoric behind the emergence of multilateral development banks in the Global South, specifically in the Asian context, and attempts to foster alternatives to the Bretton Woods institutions. The two largest initiatives in that sense – the New Development Bank and the Asian Infrastructure Investment Bank – started in Asia and also target countries in the region, giving the growing influence of China and the enhancement of interregional cooperation through the BRICS countries, currently led by China, India and Russia. The paper argues that there is limited scope for the promised innovations in both project assessment and the role of private capital, given the prioritisation of infrastructure as the premise to achieving the right to development among emerging and least‐developed economies. The research departed from the quantitative and qualitative analysis of the projects funded by the New Development Bank and the Asian Infrastructure Investment Bank, from their inception until 2018, considering the approach that such institutions have taken to the social and environmental standards from their normative framework.  相似文献   

9.
Whitebacked planthopper (WBPH) along with brown planthopper (BPH) has emerged as a major pest of rice in several Asian countries. Development and cultivation of varieties resistant to both planthoppers is an ecologically acceptable strategy to manage these pests. Sinna Sivappu, a Sri Lankan landrace, was reported to be resistant to both planthoppers. While inheritance of BPH resistance has been reported, the genetics of WBPH resistance in this variety is not known. Using a mapping population of 255 F2:3 families from Taichung Native (TN)1/Sinna Sivappu cross and 128 polymorphic simple sequence repeat (SSR) markers, genes or quantitative trait loci (QTLs) for WBPH resistance quantified in ten phenotypic tests were identified, adopting classical Mendelian segregation, correlation and QTL analyses. The inheritance pattern suggested that a single recessive gene controlled regulation of seedling damage score. Antixenosis or nymphal preference was influenced by two complementary recessive genes, whereas tolerance in terms of days to wilt was under the influence of a single dominant gene. Several of these phenotypic tests recorded high degree of positive or negative correlation between them, suggesting dependence or redundancy of the tests. QTL analysis revealed 13 loci associated with nine traits. Five major-effect QTLs were detected for damage score (chromosome 6), nymphal survival (chromosome 12), and days to wilt (three QTLs on chromosome 4). We suggest involvement of four WBPH resistance genes in Sinna Sivappu, designated as wbph9(t), wbph10(t), wbph11(t), and Wbph12(t). One of the recessive genes could be allelic to any of the recessive genes reported in cluster C on chromosome 6 which might confer resistance to both BPH and WBPH.  相似文献   

10.
Summary The genetic basis of the resistance to a pepper strain of potato virus Y (PVY pathotype 1–2) was investigated in two lines: Capsicum annuum Criollo de Morellos 334 and Capsicum chinense PI 159236. F1, backcrosses, and F2 populations were produced using C. annuum Magda as the susceptible parent. Segregation ratios indicated that the resistance in C. annuum Criollo de Morellos 334 is governed by a nuclear, single dominant gene with a very high but incomplete penetrance. On the other hand, the resistant response of C. chinense PI 159236 is associated with the presence of a major recessive gene with an apparently complete penetrance. The failure in recovering or detecting PVY from/in the inoculated leaves of both resistant genotypes is strongly suggestive that both genes are acting by preventing the multiplication of the virus in the leaf tissue. Both mechanisms of resistance closely resemble either an operational immunity or a single-cell hypersensitive reaction to PVY pathotype 1–2. The name Ry 1–2 is suggested for the resistance gene from Criollo de Morellos 334. The gene for resistance to PVY pathotype 1–2 identified in C. chinense PI 159236 may be the same designated et c1, which is mentioned to be allelic to the et av locus. The phenotypic expression of the et av gene was characterized in C. annuum Avelar as a tolerant but not immune or hypersensitive reaction against some potyviruses in Florida. These data suggest that a critical reexamination of the allelic relationships at the locus et should be performed.  相似文献   

11.
The effect of juvenile Crangon crangon L. (brown shrimp) on the microbial part of the food web of marine shallow-water sandy sediment was investigated in two experiments using an outdoor flow-through system. Biomass, composition and productivity of microalgae and bacteria, POC and PON content in the sediment, as well as nutrient and oxygen fluxes, were measured in the absence and presence of two natural densities (50 and 100 ind·m−2) of juvenile Crangon. Stimulating effects of the presence of juvenile Crangon on both microalgae and bacteria were observed after three weeks. However, the number of statistically significant effects was low, despite the conspicuous change in sediment characteristics caused by Crangon activity. To explain the possible trophic effect of Crangon via meiofaunal grazing, the results were compared with meiofaunal grazing rates (dual labelling by 14C-bicarbonate and 3H-thymidine) and changes in the meiofaunal and macrofaunal community. The reasons for the low number of significant trophic effects of Crangon on algae and bacteria were that the overall meiofaunal grazing pressure on microbiota was low, and that only part of the meiofauna (mainly harpacticoid copepods) was significantly affected by the predator. Meiofauna thus appeared to be a weak mediating link in the sandy sediment system investigated. No effect of Crangon on oxygen fluxes, or POC and PON content in the sediment was observed. Neither were the nutrient concentrations in the overlying water affected, but increased nutrient levels in the pore water were observed. According to theoretical calculations, excretion from the shrimp may imply a considerable nutrient addition which can be rapidly re-utilized by the microbes directly at the sediment/water interface. Bioturbation by Crangon appeared to counteract flaking of the microalgal mat.  相似文献   

12.
Kiwifruit is cold-sensitive and very susceptible to chilling injury (CI) during low temperature storage. In this study, kiwifruit (Actinidia chinensis cv. Hongyang) were pre-treated by water dip for 10 min at 20 (control) or 35, 45, or 55 °C (heat pretreatments) and then stored at 0 °C for 90 days to investigate the effect of hot water treatments (HWT) on chilling injury tolerance. Results showed that 35 °C and 45 °C HWT alleviated but did not completely prevent chilling injury development. By contrast, 55 °C HWT increased symptoms of chilling injury. The 45 °C HWT was the most effective at reducing chilling injury index and incidence. Compared with the other HWT, fruit treated at 45 °C exhibited higher firmness and soluble solids content (SSC), and lower malondialdehyde (MDA) content, lipoxygenase (LOX) activity and ethylene production rate. C-repeat/dehydration-responsive element binding factors (CBFs) are key regulators in cold response. To investigate the molecular regulation of HWT on chilling tolerance of kiwifruit, a 637 bp CBF gene was identified and the relative expression of AcCBF was measured by RT-qPCR. In accordance with the effects of HWT on physiological parameters of chilling injury, AcCBF expression level was highest in the 45 °C HWT. These results indicate that HWT at 45 °C for 10 min prior to low temperature storage is effective for alleviating symptoms of chilling injury in ‘Hongyang’ kiwifruit.  相似文献   

13.
Brown planthopper(BPH) is one of the most serious and destructive insect pests of rice in most rice growing regions of the world. In this study, two major resistance genes against BPH have been identified in an Oryza rufipogon (Griff.) introgression rice line, RBPH54. Inheritance of the BPH resistance in RBPH54 was studied by screening the resistance in parents, F1, F2 and BC1 generations against BPH biotype 2. A population of BC3F2 lines was developed and SSR markers were employed for the gene mapping, and new markers were designed for fine mapping of the resistance genes, while sequence information of BAC/PAC clones was used to construct physical maps of the genes. The results showed that the BPH resistance in RBPH54 was governed by recessive alleles at two loci, tentatively designated as bph20(t) and bph21(t). The locus bph20(t) was fine mapped to the short arm of chromosome 6 about 2.7 cM to the upper marker RM435 and 2.5 cM to lower marker RM540 and in a 2.5 cM region flanked by two new SSR markers BYL7 and BYL8 which were developed in the present study. The other BPH resistance locus bph21(t) was initially mapped to a region 7.9 cM to upper marker RM222 and 4.0 cM to lower marker RM244 on the short arm of chromosome 10. For physical mapping, the bph20(t)-linked markers were landed on BAC/PAC clones of the reference cv., Nipponbare, released by the International Rice Genome Sequencing Project. The bph20(t) locus was physically defined to an interval of about 75 kb with clone P0514G1. Identification and location of these two genes in the present study have diversified the BPH resistance gene pool, which give benefit to the development of resistant rice cultivars, and the linkage PCR-based SSR markers for the bph20(t) and bph21(t) genes would help realize the application of the genes in rice breeding through marker-assisted selection.  相似文献   

14.
The paper aims at investigating the impact of the Great Recession on per capita GDP convergence process across European regions and countries. Using the time-varying factor model developed by Phillips and Sul for the period 2000–2015 and two different merging procedures to identify clubs, we provide evidence of the diverging impact of the Great Recession “between” the higher and the lower convergence clubs at both regional and country levels as well as of the strengthening of the convergence process “within” most clubs. In addition, we add further evidence to the common belief of a “multi-speed” Europe by contrasting Eastern European countries' and regions' behavior vis-à-vis original European members' one, and by identifying the factors that affect club membership and resilience to the recent economic downturn. We find that the membership in the higher clubs and resilience to the Great Recession are positively affected by the presence of several local-specific factors and macroeconomic characteristics.  相似文献   

15.
Pear and apple are among the main fruit crops worldwide. These species can be planted in mixed orchards, and they both depend on insect pollination for fruit set. As pollinating insects are attracted by the floral resources, we investigated nectar and pollen production and chemical composition in four pear (‘Concorde’, ‘Conférence’, ‘Doyenné du Comice’, ‘Triomphe de Vienne’) and five apple (‘Braeburn’, ‘Golden Reinders’, ‘Jonagored’, ‘Pinova’, ‘Wellant’) cultivars commonly grown in Belgium. We also investigated whether insect flower visitation rate and pollination efficiency are linked to floral resource quantity and quality. The pear cultivars flowered one week before the apple cultivars in early spring, and their flowers were about six times less visited by insects. The visitors foraged more on the pollen of the pear trees and the nectar of the apple trees. Pear flowers produced higher volumes of nectar than apple flowers (1.3–3.2 μl vs. 0.4-0.6 μl), but with lower sugar concentration (9.6%-10.8% vs. 28.3%-36.4%). Pear flowers also produced fewer pollen grains per anther than apple flowers (2425–4937 vs. 3284–7919), but these had higher polypeptide (346–362 μg/mg vs. 216–303 μg/mg), amino-acid (40–77 μg/mg vs. 12–18 μg/mg) and phytosterol (21–47 μg/mg vs. 15–43 μg/mg) concentrations. The foraging behavior of the insects is thus better explained by nectar and pollen quality rather than quantity. Despite the differences in flower visitation rates, pollination of both species resulted in valuable fruit production.  相似文献   

16.
The rice cultivar ASD7 (Oryza sativa L. ssp. indica) is resistant to the brown planthopper (BPH; Nilaparvata lugens Stål) and the green leafhopper (Nephotettix virescens Distant). Here, we analyzed multiple genetic resistance to BPH and the green rice leafhopper (GRH; Nephotettix cincticeps Uhler). Using two independent F2 populations derived from a cross between ASD7 and Taichung 65 (Oryza sativa ssp. japonica), we detected two QTLs (qBPH6 and qBPH12) for resistance to BPH and one QTL (qGRH5) for resistance to GRH. Linkage analysis in BC2F3 populations revealed that qBPH12 controlled resistance to BPH and co-segregated with SSR markers RM28466 and RM7376 in plants homozygous for the ASD7 allele at qBPH6. Plants homozygous for the ASD7 alleles at both QTLs showed a much faster antibiosis response to BPH than plants homozygous at only one of these QTLs. It revealed that epistatic interaction between qBPH6 and qBPH12 is the basis of resistance to BPH in ASD7. In addition, qGRH5 controlled resistance to GRH and co-segregated with SSR markers RM6082 and RM3381. qGRH5 is identical to GRH1. Thus, we clarified the genetic basis of multiple resistance of ASD7 to BPH and GRH.  相似文献   

17.
In reaction to public dismay over the technological inadequacy of electoral equipment in the 2000 presidential elections, Congress quickly enacted the Help America Vote Act, legislation to fund the acquisition of advanced vote‐counting technology. The intention was to enable, rather than mandate, choices of new equipment. This paper utilizes a unique historical opportunity to test whether electoral equipment follows the pattern predicted by well‐established models of innovation diffusion, merging electoral data with census data on socio‐economic characteristics. We infer that fiscal constraints to acquisition are strong but not the only limitations to technology adoption, particularly within certain easily identifiable populations.  相似文献   

18.
Using insights gained from Jacobian externalities, we consider how a more diverse economic industrial base relates to business survival rates. While a low survival rate is often perceived negatively among policy-makers, evidence suggests that business exit is part of a dynamic and robust economy. The high opportunity cost of continuing with a struggling business in a more diversified economy may ultimately sway entrepreneurs with less competitive ventures to exit leading to lower survival rates. We model average 5-year survival rates at the county level annually from 1990 to 2012 employing a spatial panel Durbin specification. The data support the central hypothesis that more diversified economies increase the opportunity costs of operating an underperforming new business, thereby lowering survival rates.  相似文献   

19.
为了明确O157:H7(△hly △stx△toxB)口服能否减少亲本株O157:H7在山羊体内的定殖.选用3月龄山羊,首先口服接种O157:H7(△hly△stx△toxB),分别于第7,14天再次口服接种亲本株O157:H7,监测亲本株O157:H7的排菌持续时间和排菌量.结果表明:O157:H7(△hly △stx△toxB)口服后第7天攻击亲本株O157:H7,第4天检测不到亲本株O157:H7的排菌;第14天攻击亲本株O157:H7,第9天检测不到亲本株O157:H7的排菌.直接口服亲本株O157:H7,排菌一直持续到第25天.口服O157:H7(△hly △stx△toxB)能够减少O157:H7在山羊体内的定殖,为研制EHEC O157:H7基因缺失疫苗奠定了基础.  相似文献   

20.
An ideal legume for resource-poor farmers, grass pea [Lathyrus sativus] is a drought tolerant crop that thrives with minimal external inputs. It is grown on 1 million ha throughout South Asia, mainly as a relay crop after rice. It is also grown extensively in Ethiopia, where it is an important legume for human consumption. Traditionally used for human consumption and as a source of animal feed, this protein-rich legume is favoured for its excellent flavour. There is great potential for an expansion in the utilization of grass pea in drought-prone economies, such as Ethiopia. However, L. sativus produces small quantities of a neurotoxin, β-N-oxalyl –L-α-diaminopropanoic acid (ODAP), which, when consumed alone in large quantities, may cause ‘lathyrism’, an irreversible paralysis of the legs. Lathyrism is a medical condition closely associated with poverty in rural areas. Despite efforts in some countries to discourage production of L. sativus, poor farming communities continue to rely on the crop to supplement their meagre diets. As local land races with high toxin levels generally outperform introduced varieties with lower toxin levels, farmers have little option but to continue to grow their locally-adapted varieties. While there has been some success in breeding grass pea lines with low levels of ODAP, crop improvement programmes are scarce and under-resourced. Facing rising food prices and more frequent natural disasters associated with climate change, we should not neglect the ability of grass pea to provide human and animal feed, under conditions unsuitable for economic production of other legume crops.  相似文献   

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