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1.
Ma  Zonghuan  Yang  Shijin  Mao  Juan  Li  Wenfang  Li  Wei  Zuo  Cunwu  Chu  Mingyu  Zhao  Xin  Zhou  Qi  Chen  Baihong 《Journal of Plant Growth Regulation》2021,40(2):679-693
Journal of Plant Growth Regulation - Light is a vital environmental factor that can affect the synthesis of volatile organic compounds (VOCs) in grape berries. However, the mechanism through which...  相似文献   

2.
Liu  Jianlong  Yue  Rongrong  Si  Min  Wu  Meng  Cong  Liu  Zhai  Rui  Yang  Chengquan  Wang  Zhigang  Ma  Fengwang  Xu  Lingfei 《Journal of Plant Growth Regulation》2019,38(3):1161-1169

Melatonin (MT) modulates a wide range of physiological functions with pleiotropic effects in plants. In this study, we studied the effect of exogenous applications of MT to pear trees on indicators of pear fruit quality. The results showed that MT increased the size of pear fruit by improving the net photosynthetic rate and maximal quantum efficiency of photosystem II photochemistry during the late stage of pear fruit development. Overall, MT increased fruit weight by 47.85% compared to the control. During the period of fruit maturation, MT increased the content of soluble sugars, particularly sucrose and sorbitol, likely as a result of improved starch accumulation. Expression levels of the invertase gene Pbinvertase 1/2 were lower in MT-treated fruit that resulted in lower enzyme activity, whereas activity of sucrose phosphate synthase was greater due to enhanced levels of expression of PbSPS1/2/3. Thus, application of melatonin improved sucrose content. This study shows that the application of MT to pear trees may be utilized for the production of larger and sweeter fruit of higher economic value.

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3.
The effect of hydrogen cyanamide (HC) on dormancy release, antioxidant enzyme’s activity and proline and free polyamine contents were investigated in ‘Superior Seedless’ grapevine buds. HC application caused a sharp decrease of catalase (CAT, EC 1.11.1.6) activity and a transient stimulation during the 5 days following treatment of peroxidase (POD, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11) activities. This coincided with an accumulation of total free polyamines, especially putrescine (Put). Proline content increased dramatically. There was a strong correlation between APX and POD activities and total free PAs and Put contents implying a possible stimulating effect of the latter compounds on these enzymes. These observations indicate that HC triggers an oxidative stress leading to bud endodormancy release. Afterward, as budbreak started, we observed a rapid proline and Put degradation; this could be responsible for reactivation of growth. Indeed, the decline in Put to (Spd + Spm) ratio, reported here, may be considered as a reliable biochemical marker of bud growth resumption.  相似文献   

4.
The possible role of salicylic acid (SA) and methyl jasmonate (MJ) treatments on the physiology responses and growth of strawberry (Fragaria?×?ananassa) cv. ‘Camarosa’ subjected to the different levels of salinity stress were investigated. Root and shoot growth as well as their Na+/K+ ratio, photosynthetic-related factors, and activity of some important antioxidant enzymes were determined in the salt-treated plants. Results indicated that salt stress reduced plant performance especially at higher concentrations. By increasing the levels of salinity stress, fresh and dry weight of shoot and roots, net photosynthetic rate (Pn), and stomatal conductance (Gs) significantly decreased, whereas intercellular CO2 (Ci) increased. Application of exogenous SA and MJ significantly improved the plant physiological characters as well as fresh and dry weight of shoots and roots. Moreover, the ratio of Na+/K+ was elevated in the leaves and roots concomitantly with salinity levels, whereas SA and MJ treatments significantly reduced this ratio. Results of enzymatic assays showed that activity of ascorbate peroxidase, peroxidase, and superoxide dismutase enzymes increased in the salt-stressed plants. In addition, SA and MJ treatments reduced the destructive effects of salinity in strawberry plant. In general, among the tested concentrations, 0.5 mM SA and 0.25 mM MJ best increased the activity of antioxidant enzymes and hence alleviated the detrimental effects of salinity stress.  相似文献   

5.
BackgroundResearches on diagnosis and treatment of Alzheimer's disease, the most common type of dementia, are still ongoing. Taurine is frequently used in Alzheimer's disease models due to its protective effects. Metal cation dyshomeostasis is an important etiological factor for Alzheimer's disease. Transthyretin protein is thought to act as a transporter for the Aβ protein that accumulates in the brain and is eliminated in the liver and kidneys via the LRP-1 receptor. However, the effect of taurine on this mechanisms is not fully known.Methods30 male rats, aged 28 ± 4 months, were divided into 5 groups (n = 6) as follows: control group, sham group, Aβ 1–42 group, taurine group and taurine+Aβ 1–42 group. Oral taurine pre-supplementation was given as 1000 mg/kg-body weight/day for 6 weeks to taurine and taurine+Aβ 1–42 groups.ResultsPlasma copper, heart transthyretin and Aβ 1–42, brain and kidney LRP-1 levels were found to be decreased in the Aβ 1–42 group. Brain transthyretin was higher in taurine+Aβ 1–42 group and brain Aβ 1–42 was higher in Aβ 1–42 and taurine+Aβ 1–42 groups.ConclusionTaurine pre-supplementation maintained cardiac transthyretin levels, decreased cardiac Aβ 1–42 levels and increased brain and kidney LRP-1 levels. Taurine may have a potential to be used as a protective agent for aged people at high risk for Alzheimer's disease.  相似文献   

6.
Effects of the dietary glycaemic load on postprandial blood glucose and insulin response might be of importance for fat deposition and risk of obesity. We aimed to investigate the metabolic effects, acceptance and tolerance of a follow-on formula containing the low glycaemic and low insulinaemic carbohydrate isomaltulose replacing high glycaemic maltodextrin. Healthy term infants aged 4 to 8 completed months (n = 50) were randomized to receive the intervention follow-on formula (IF, 2.1g isomaltulose (Palatinose™)/100mL) or an isocaloric conventional formula (CF) providing 2.1g maltodextrin/100mL for four weeks. Plasma insulinaemia 60min after start of feeding (primary outcome) was not statistically different, while glycaemia adjusted for age and time for drinking/volume of meal 60min after start of feeding was 122(105,140) mg/dL in IF (median, interquartile range) and 111(100,123) in CF (p = 0.01). Urinary c-peptide:creatinine ratio did not differ (IF:81.5(44.7, 96.0) vs. CF:56.8(37.5, 129),p = 0.43). Urinary c-peptide:creatinine ratio was correlated total intake of energy (R = 0.31,p = 0.045), protein (R = 0.42,p = 0.006) and fat (R = 0.40,p = 0.01) but not with carbohydrate intake (R = 0.22,p = 0.16). Both formulae were well accepted without differences in time of crying, flatulence, stool characteristics and the occurrence of adverse events. The expected lower postprandial plasma insulin and blood glucose level due to replacement of high glycaemic maltodextrin by low glycaemic isomaltulose were not observed in the single time-point blood analysis. In infants aged 4 to 8 completed months fed a liquid formula, peak blood glucose might be reached earlier than 60min after start of feeding. Non-invasive urinary c-peptide measurements may be a suitable marker of nutritional intake during the previous four days in infants.Trial registration: ClinicalTrials.gov NCT01627015  相似文献   

7.
Mediterranean beaches are very crowded during summer and, because of the high values of solar UV radiation, the potential risk for human health is relevant. In this study, all-day measurements of biologically effective global and diffuse UV radiation for skin (UVBEeryt) and eye (UVBEpker, UVBEpconj, UVBEcat) disorders were carried out on differently tilted surfaces on a summers day on a Mediterranean beach. The role played by beach umbrellas in protection from excessive sun exposure was also investigated. Erythema, photokeratitis and cataract seem to require almost the same exposure time to reach the risk threshold dose. Under full sunlight, the highest global and diffuse UV values are reached on surfaces normally oriented towards sunlight and on horizontal surfaces, respectively. Over vertical surfaces, at this northern hemisphere site, global and diffuse UV radiation reaches maxima values in the south-facing direction around noon, while maxima values are reached early in the morning and late in the afternoon over surfaces facing east and west, respectively. The quality of the beach umbrellas protection (efficiency in blocking solar UV radiation) varies with surface orientation; the highest efficiency for our specific site and geometrical conditions occurs over horizontal surfaces, with efficiency being least over vertical surfaces when incident radiation values are still relevant.  相似文献   

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A 3-year field study was conducted to determine the influence of mode of application of the gibberellin-inhibitor paclobutrazol (PP333), [(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4 triazol-1-yl)pentan-3-ol], on PP333 soil residue levels and vegetative growth retardation of 10-year-old Starkrimson Delicious (Malus Domestica Borkh.) spur-type apple trees. Treatments were applied in March, 1986 and consisted of foliar or soil sprays (200 ppm, 7 × applications at petal fall (+) 2, 4, 6, 8, 10 and 12 weeks) or a single soil drench (8.2 g A.I./tree) applied to the collar at petal fall. Foliar sprays were applied with and without a plastic ground cover to evaluate the influence of foliar runoff on the degree of soil absorption and its subsequent effect on vegetative growth. PP333 was extracted over a 3 year period (1986–88) from 400 cm2 soil patches located at the drip line of each tree, with the exception of soil drenches which were sampled near the collar. PP333 soil extracts were purified and quantitatively analyzed by HPLC. PP333 soil residue levels following foliar sprays were comparable to the soil spray treatment for each year and decreased at a rate of 50% per year from 1986–1988. Foliar sprays retarded terminal growth in the year of application, whereas the soil spray did not inhibit growth until the following year. PP333 residue levels were highest in the soil drench where growth retardation was evident in 1987 and 1988. The greatest carry-over effect occurred in the soil treatments, especially the soil drench application which resulted in the highest soil residue rates throughout the 3 year period.  相似文献   

10.
Lodging can be a serious problem in oilseed Brassica napus. Dwarf genes have been used to reduce lodging in other crops, and their use in wheat and rice was a major factor in the success of the ‘Green Revolution’. We previously reported on a single, semi-dominant, gibberellin insensitive dwarf mutant of B. rapa (Brrga1-d), and provided evidence for homology of this gene to the wheat ‘Green Revolution’ dwarf gene. In this paper, we report using interspecific hybridization of B. rapa and B. oleracea and embryo rescue to resynthesize B. napus containing the Brrga1-d dwarf gene. The dwarf gene was backcrossed into two parents of a commercial hybrid combination and evaluated as inbred and hybrid lines in field experiments. The Brrga1-d gene reduced plant height and lodging in inbred and hybrid lines of B. napus, even when present as a single dose in heterozygous genotypes. Seed yields of inbred lines homozygous for Brrga1-d were reduced compared to near isogenic wild-type inbreds, presumably due to damage by insects caused by a slight delay in flowering time. However, yields of hybrids that were homozygous or heterozygous for Brrga1-d were similar to those of near isogenic wild-type hybrids. In addition, we report on a ‘perfect’ PCR marker for selection of the Brrga1-d gene that is based on detecting the nucleotide mutation causing the dwarf phenotype.  相似文献   

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13.
Ectomycorrhizae (ECM) are obligate symbiotic associations between higher fungi and most tree species of the temperate and boreal forests, and of some tree families in tropical areas. As the anatomical features of these symbiotic organs are very diverse and suggested to improve tree growth differently efficient, their frequency and natural distribution in the soil, as well as the differentiation and amount of their substrate exploiting extramatrical mycelia, are of special ecological interest. The soil with its heterogeneous assemblage of micro-niches certainly provokes ectomycorrhizal fungi to compete for such microsites. We therefore applied the method ‘micromapping’ to record the ECM in their natural position with the following question in mind: Do indicators exist for an exclusion of or an association with other ectomycorrhizal species or not? Thoroughly excavated and carefully cleaned ectomycorrhizae of the OF horizon of a Picea abies stand were drawn in their natural position on perspex plates of 5 × 5 cm mapping area (McMp) with ink of different colours. They were afterwards removed and specified. Following scanning of the McMp, a special computer program was applied to analyse their distribution. The spatial relations of the ECM were calculated according to the ‘growing grid method’. The preliminary results suggest that the ECM of Russula ochroleuca and Piceirhiza internicrassihyphis show no common occurrence within short distances. This possibly applies also for Russula ochroleuca in comparison to Piceirhiza cinnbadiosimilis, for Elaphomyces granulatus in comparison to Xerocomus badius, and Lactarius decipiens in comparison to Piceirhiza cinnbadiosimilis. Cortinarius obtusus with Piceirhiza internicrassihyphis, and Piceirhiza internicrassihyphis with Xerocomus badius, indicate, however, rather high values of common occurrence. Due to the small number of replications, the standard deviations are high. More detailed investigations are therefore necessary before definite conclusions can be made. This method, however, apparently provides a useful tool to analyse spatial relations of ECM in the soil. Possible reasons for exclusions and associations of ECM are briefly discussed.  相似文献   

14.
Drawing on ethnography from central Greece, this article is about the way people narrate their encounters with the devil. Although it echoes the idea that life as told and life as lived are structured in the same way, it takes the argument a step further by suggesting they are structured through a narrative plot wherein the present and the future of the story-tellers pre-date the past of which their stories tell. It also foregrounds the link between this structure and a particular kind of morality which replicates the narrative logic of the stories, giving rise to an inherently relational personhood – a personhood that, just like the way in which its narration destabilizes the logic of before and after, destabilizes the distinction between self and other. Lastly, contextualizing the current economic crisis in the lives of such persons, the article suggests we need to think of it in relation to the devil and the stories people tell of him.  相似文献   

15.
Ecologists routinely use statistical models to detect and explain interactions among ecological drivers, with a goal to evaluate whether an effect of interest changes in sign or magnitude in different contexts. Two fundamental properties of interactions are often overlooked during the process of hypothesising, visualising and interpreting interactions between drivers: the measurement scale – whether a response is analysed on an additive or multiplicative scale, such as a ratio or logarithmic scale; and the symmetry – whether dependencies are considered in both directions. Overlooking these properties can lead to one or more of three inferential errors: misinterpretation of (i) the detection and magnitude (Type-D error), and (ii) the sign of effect modification (Type-S error); and (iii) misidentification of the underlying processes (Type-A error). We illustrate each of these errors with a broad range of ecological questions applied to empirical and simulated data sets. We demonstrate how meta-analysis, a widely used approach that seeks explicitly to characterise context dependence, is especially prone to all three errors. Based on these insights, we propose guidelines to improve hypothesis generation, testing, visualisation and interpretation of interactions in ecology.  相似文献   

16.
The effects of salinity and its combination with silicon (Si) were studied in ‘Nova’ mandarin plants grafted on Citrus aurantium L. or Swingle Citrumelo to determine: (1) which combination is more tolerant to salt stress and (2) the impact of Si in limiting the harmful effects of salinity. Six groups of plants were grown in a greenhouse for 120 days and irrigated with: (1) 50 % Hoagland’s solution (Control), (2) 50 % Hoagland’s solution plus 80 mM NaCl (NaCl), and (3) 50 % Hoagland’s solution plus 80 mM NaCl plus 0.5 mM Si (NaCl + Si). Grafted plants exhibited accumulation of Na and Cl in their tissues following exposure to salinity. The ability of S. Citrumelo to retain the toxic ions in the roots in corroboration with the observation that the dry weights (DWs) of S. Citrumelo tissues were not influenced by NaCl treatment indicates that this rootstock is more tolerant to salinity. Silicon supplementation into the saline medium promoted the accumulation of toxic ions, whereas, when compared to NaCl treatment, it increased the DW of S. Citrumelo roots. Mineral concentrations were significantly affected by rootstock, treatment, and their interaction with S. Citrumelo, which presented better nutrient status than Sour Orange; and Si which differed depending on citrus tissue. It appears that S. Citrumelo rootstock is the most tolerant for ‘Nova’ mandarin plants under salinity, whereas salt tolerance in grafted citrus plants is not improved by Si application, indicating that the beneficial role of Si depends on the cultivar or rootstock–scion combinations.  相似文献   

17.

Background

More than 1 billion people are currently infected with soil-transmitted helminths and schistosomes. The global strategy to control helminthiases is the regular administration of anthelmintic drugs to at-risk populations. However, rapid re-infection occurs in areas where hygiene, access to clean water, and sanitation are inadequate.

Methodology

In July 2011, inhabitants from two villages and seven hamlets of the Taabo health demographic surveillance system in south-central Côte d’Ivoire provided stool and urine samples. Kato-Katz and ether-concentration methods were used for the diagnosis of Schistosoma mansoni, soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura, and hookworm), and intestinal protozoa. Urine samples were subjected to a filtration method for the diagnosis of Schistosoma haematobium. A questionnaire was administered to households to obtain information on knowledge, attitude, practice, and beliefs in relation to hygiene, sanitation, and defecation behavior. Logistic regression models were employed to assess for associations between questionnaire data and parasitic infections.

Principal Findings

A total of 1,894 participants had complete data records. Parasitological examinations revealed prevalences of hookworm, S. haematobium, T. trichiura, S. mansoni, and A. lumbricoides of 33.5%, 7.0%, 1.6%, 1.3% and 0.8%, respectively. Giardia intestinalis and Entamoeba histolytica/E. dispar were detected in 15.0% and 14.4% of the participants, respectively. Only one out of five households reported the presence of a latrine, and hence, open defecation was common. Logistic regression analysis revealed that age, sex, socioeconomic status, hygiene, and defecation behavior are determinants for helminths and intestinal protozoa infections.

Conclusions/Significance

We found that inadequate sanitation and hygiene behavior are associated with soil-transmitted helminths and intestinal protozoa infections in the Taabo area of south-central Côte d’Ivoire. Our data will serve as a benchmark to monitor the effect of community-led total sanitation and hygiene education to reduce the transmission of helminthiases and intestinal protozoa infections.  相似文献   

18.
Agricultural intensification leads to large-scale loss of habitats offering food and nesting sites for bees. This has resulted in a severe decline of wild bee diversity and abundance during the past decades. There is an urgent need for cost-effective conservation measures to mitigate this decline. We analysed the impact of five different high-quality habitats on species richness and abundance of wild bees in a complex landscape of north-western Switzerland at six sites. The five habitat types included 45 plots situated on eight organic farms and were composed of 16 low-input meadows, six low-input pastures, seven herbaceous strips adjacent to hedges, five sown flower strips and eleven organic cereal fields. All of them are financially subsidised by the Swiss agri-environmental scheme. Wild bees were sampled between the end of April and end of August 2014 by using trio-pan traps and complementary sweep netting on these five habitat types. On 45 plots we recorded 3973 bee specimens, belonging to 91 species, 16 of which are red listed, revealing a high bee species richness in the study area. Wild bee species richness and abundance were best explained by habitat type, number of flowering plants and site. A strong relationship of increasing number of flowering plants and bee species richness and abundance was found. Grassland habitats, especially low-input meadows, harboured the highest species richness and abundances. Organic cereal fields showed a potential to conserve bee species relevant to nature conservation (harbouring exclusively two red list species and four rare species). Ordination analysis of the bee communities showed a relative dissimilarity between the habitat types and indicates their complementary effects to benefit the diversity of wild bees. Our results demonstrate that a matrix of low-input habitats are needed to sustain rich assemblages of wild bees in agroecosystems.  相似文献   

19.
ABSTRACT

Five ruminally and duodenally cannulated Kazakh male lambs (30 ± 2.75 kg) maintained singly in a metabolic cage were used in a 5 × 5 Latin square experiment to investigate the effect of supplementing a ration with five different levels of distillers’ grape residue (DGR) on ruminal degradability, whole tract digestibility and nitrogen (N) metabolism of growing lambs. The rations were isoenergetic and isonitrogenous and contained 0, 3.85, 7.70, 11.55 and 15.41% DGR (DM basis). Each experimental period lasted for 18 d: 10 d for adaptation to the dietary treatment and 8 d for faecal, urinary, ruminal and duodenal digesta sample collections. The outflow rate of ruminal digesta increased (p = 0.032) linearly with the increased level of dietary neutral detergent fibre content, caused by the supplementation of DGR. As a result, the effective degradability of dry matter and crude protein decreased significantly with the treatments. Although the dietary intake of N, duodenal flow of total N, and the endogenous N at the duodenum were not affected by experimental treatments, N fractions in the digesta were altered. Ruminal microbial N decreased (p < 0.01) linearly; in contrast, ruminal un-degradable protein increased linearly (p < 0.01) in response to the increased addition of DGR. Although there was no significant difference in faecal N among treatments, N retention was increased linearly (p = 0.014), owing to the remarkable reduction (p = 0.016) of urinary N excretion with an increasing level of DGR. The results indicate that the DGR has some potential benefits of increasing the supply of bypass protein and of improving the utilisation efficiency of N for sheep. Therefore, the supplementation of DGR in ruminant feeding is recommended at levels not exceeding 10% of the diet.  相似文献   

20.
This study examined whether topography-induced gradients in water potential and leaf litter depth contribute to species coexistence in tropical forests through species-specific effects on seedling emergence and mortality. Seedling emergence and mortality were followed for a period of 12 months in 36 (1 × 2 m) plots on Barro Colorado Island (BCI), Panamá. Plots with and without litter were distributed on slope and plateau sites in three catchments. In the absence of manipulations, the lower litter depth on slopes resulted in approximately four times as many emergent seedlings than on plateau sites. However, litter depth had little effect on seedling community composition. By the end of the first dry-season, post-emergence, there were no significant differences in surviving seedling numbers between any treatments. There were differences in the emergent seedling community between slope and plateau sites within the same catchment as well as differences in composition between catchments, suggesting that both niche partitioning and dispersal limitation might play a role in structuring seedling community composition. During the wet-season seedling mortality was highest on slope sites although this pattern was reversed during the dry-season. In both seasons mortality was higher for small-seeded species. These results demonstrate that gradients in water potential related to topography impact on patterns of seedling emergence and mortality although processes in the first year after emergence may be insufficient to explain observed habitat preferences of adult plants.  相似文献   

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