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1.
Consuming selenium (Se)‐rich fruit may play an important role in human health by supplementing Se. The aims of this study were to (1) determine the Se tolerance of pear trees and (2) explore the effects of different Se sources and spraying dates on Se concentrations and transformation of inorganic Se into organic Se compounds in various parts of the pear tree and on fruit quality. Spraying Se(IV) or Se(VI) at a concentration of > 40 mg L?1 resulted in leaf yellowing, marginal withering, and finally leaf abscission. Furthermore, fruit growth and appearance were adversely affected at high Se doses. At the same application stage, Se concentrations in different parts of the fruit were 1.1–4.7 times higher under Se(VI) compared to Se(IV) treatment. For the same Se source, Se concentrations under treatment at the fruit expanding stage were 1.9–2.5 times higher than under treatment at the fruit‐setting stage. Of the total Se in the fruit, 40% accumulated in the juice under Se(IV) treatment and > 70% under Se(VI) treatment. However, regardless of the Se source, the Se in the juice was almost all inorganic, while the transformation of inorganic Se into organic Se compounds was > 80% and 70% in the peel and pomace, respectively. Foliar Se application somewhat improved fruit quality by increasing the concentration of soluble solids. Compared to other species, Se tolerance in pear trees was relatively low. Given the high accumulation of Se and efficient transformation of inorganic Se into organic Se compounds in the peel, consumption of unpeeled Se‐rich pears is recommended.  相似文献   

2.
Despite the increasing interest in organic products, knowledge about how different levels of fertilization affect nutritionally relevant components is still limited. The concentration of polyphenols and the activity of polyphenoloxidase (PPO), together with the content in ascorbic acid, citric acid, and alpha- and gamma-tocopherol, were assayed in conventional and organic peach (Prunus persica L., cv. Regina bianca) and pear (Pyrus communis L., cv. Williams). 2-Thiobarbituric acid reactive substances and the tocopherolquinone/alpha-tocopherol ratio were used as markers of oxidative damage in fruits. A parallel increase in polyphenol content and PPO activity of organic peach and pear as compared with the corresponding conventional samples was found. Ascorbic and citric acids were higher in organic than conventional peaches, whereas alpha-tocopherol was increased in organic pear. The concentration of oxidation products in organic samples of both fruits was comparable to that of the corresponding conventional ones. These data provide evidence that an improvement in the antioxidant defense system of the plant occurred as a consequence of the organic cultivation practice. This is likely to exert protection against damage of fruit when grown in the absence of pesticides.  相似文献   

3.
Iron deficiency is a serious nutritional disorder in aerobic rice, causing chlorosis, poor yields and reduced grain nutritional quality. The problem can be managed by complementing the use of Fe-efficient plant type with a suitable Fe management strategy. In the present paper, we report the effect of eight iron management practices to resolve the problem of iron (Fe) chlorosis through the use of an iron deficiency tolerant (IDTR) and iron deficiency susceptible (IDSR) rice genotype, i.e. Pusa 33 and ADT 39, respectively. Fe deficiency tolerance of these genotypes was related to the root release of PS which enabled a higher uptake of Fe in the IDTR than the IDSR under Fe deficiency. In general, IDTR performed better than the IDSR as evident from a significant increase in total iron, active iron, chlorophyll content and grain and straw yield. IDSR produced the highest grain and straw yield under slow iron release nano clay complex source. Grain Fe content of the IDTR and IDSR increased by 18.9 and 13.4%, respectively, under recommended dose of Fe. The results identified the most effective soil management strategies for the alleviating Fe deficiency chlorosis and improving Fe nutrition of both IDTR and IDSR genotypes.  相似文献   

4.
Iron-deficiency chlorosis (IDC) is an important abiotic constraint affecting the growth and yield of groundnut in calcareous and alkaline soils worldwide. The present study investigated the inheritance of IDC resistance among four straight crosses of groundnut involving four IDC susceptible cultivars as females and a common IDC resistant male parent. The F1's of all the four crosses were resistant to IDC indicating the dominant nature of IDC resistance. The F2's of all the four crosses showed a good fit to the ratio of 15 (IDC resistant): 1 (IDC susceptible) and their behavior among the F3's was as per the expected ratio of 7:4:4:1. The IDC resistance in groundnut is under the control of duplicate dominant genes wherein, the presence of a dominant allele at either of the loci results in IDC resistance, while duplicate recessive results in IDC susceptibility. This information would facilitate development of IDC resistant cultivars of groundnut.  相似文献   

5.
The composition of phenolic compounds of a Portuguese pear cultivar (Pyrus communis L. var. S. Bartolomeu) was determined by HPLC after thioacidolysis. The average concentration of phenolic compounds in pear harvested at commercial maturity stage was 3.7 g per kg of fresh pulp. Procyanidins were the predominant phenolics (96%), with a mean degree of polymerization (mDP) of 13-44; hydroxycinnamic acids (2%), arbutin (0.8%), and catechins (0.7%) were also present. The most abundant monomer in the procyanidin structures was (-)-epicatechin (99%), which was found as extension and terminal units; (+)-catechin (1%) was found only as a terminal unit. Sun-drying of these pears caused a decrease of 64% (on a dry pulp basis) in the total amount of native phenolic compounds. Hydroxycinnamic acids and procyanidins showed the largest decrease; the B2 procyanidin was not found at all in the sun-dried pear. Less affected were arbutin and catechins. In the sun-dried pear, the procyanidins with high mDP became unextractable in the solvents used.  相似文献   

6.
Several studies suggest that the Fabaceae‐Rhizobium symbiosis is particularly sensitive to iron (Fe) deficiency with respect to NO3‐dependent plants. The aim of this study, which is part of a screening program for common bean tolerance to Fe deficiency, was to study genotypical differences in Fe requirement and Fe use‐efficiency of common bean cultivars depending on symbiotic nitrogen fixation (SNF). Results show that ARA14 produces more whole plant dry matter and particularly more nodule biomass than Coco blanc. ARA14 is characterized by a high capacity of nitrogen fixation and a better Fe use‐efficiency for the growth and the function of the nodules.  相似文献   

7.
黄瓜地上部水浸液对番茄的化感抑制效应   总被引:2,自引:0,他引:2  
采用培养试验研究了黄瓜地上部水浸液对番茄的化感作用及其生理生化机理,并用试管法对其水浸液的主要化学成分进行定性分析.结果表明,黄瓜地上部水浸液含有生物碱、酚类、有机酸、皂甙、甾体、多糖、蛋白质和油脂,不含鞣质.黄瓜地上部水浸液处理显著抑制番茄种子萌发过程中的呼吸速率和α-淀粉酶活性,使种子萌发率和萌发指数降低,其抑制作用随处理浓度提高而增强.在番茄幼苗生长过程中浇灌黄瓜地上部水浸液提高了番茄叶片中超氧阴离子(O2)、H2O2和丙二醛(MDA)的含量及质膜透性;降低了过氧化氢酶(CAT)和过氧化物酶(POD)活性,还原型谷胱甘肽(GSH)和抗坏血酸(ASA)含量提高,而超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性随处理浓度增加先升后降;叶绿素含量、净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)降低,胞间CO2浓度(Ci升高,幼苗干重下降.叶绿素荧光动力学资料显示,番茄叶片的初始荧光(Fo)随着处理浓度提高而增大,最大荧光(Fm)、PSⅡ潜在光化学效率(Fv/Fo)、PSⅡ原初光能转换效率(Fv/Fm)、PSⅡ光合电子传递量子效率(ΦPSⅡ)、光化学猝灭系数(qP)、表观光合电子传递速率(ETR)和光化学速率(PCR)下降,非光化学猝灭系数(NPQ)先升后降,表明叶片光合机构受到伤害.  相似文献   

8.
ABSTRACT

Red acid soil is generally distributed in humid tropical areas under high rainfall. The main constraint is usually the extremely low pH of the soil due to the very intensive leaching of the bases from the soil. At the same time, however, the soluble micro elements, such as iron, are high. This can cause plant toxicity. The liming of acidic soils is normally performed to reduce the iron toxicity as the first step toward providing a balanced nutrition for cultivated plants. The objective of this study is to determine the effects of liming on the soil pH, on the decrease of iron in the soil and on the growth of the pineapple. The research was done in the Greenhouse of the Research and Development Department, PT Great Giant Pineapple, Lampung, Indonesia, from November 2015 to April 2016. The design of the experiment was arranged as a completely randomized design with seven treatments and three replications, consisting of: No dolomite (D0), dolomite 1 t ha?1 (D1), dolomite 2 t ha?1 (D2), dolomite 3 t ha?1 (D3), dolomite 4 t ha?1 (D4), dolomite 5 t ha?1 (D5) with added Fe-EDTA and for the control treatment, no dolomite and no Fe-EDTA (C0). The results showed that an increase in the dolomite dose can increase the pH, potassium (K), calcium (Ca) and magnesium (Mg) in the soil and can decrease the iron (Fe) in the soil significantly. Increasing the pH, K, Ca and Mg and decreasing the Fe in the soil were seen to influence the growth of the pineapple. In particular, the leaf area of the pineapple plant increased considerably. The other parameters also increased, but not significantly.  相似文献   

9.
Effects of seed and root exudates obtained from common bean on the proliferation of Rhizobium sp. (Phaseolus) were examined in a combination of three plant cultivars with three Rhizobium strains. In the first experiment, seed or root exudate was mixed with an Andosol soil extract, and bacterial proliferation in the mixture was traced. Seed exudate was prepared from hydroponic solution used in seed imbibition for 24 h, and a series of root exudates was prepared from a hydroponic solution collected every 24 h from the initiation of rooting up to 96 h after rooting. Regardless of the common bean cultivars and Rhizobium strains used, Rhizobium population markedly increased of the 24 h of culture in the mixture containing seed exudates, whereas a negligible increase was detected in the mixture with root exudates. The mixture containing root exudates collected within a period of 72–96 h after initial rooting (96–120 h after seed imbibition) exerted an inhibitory effect on Rhizobium proliferation. The seed exudates contained large amounts of sugars, amino acids, nitrogen, phosphorus, potassium, and magnesium compared to any root exudates. In the second experiment, Rhizobium was inoculated directly to common bean seeds sowed in a vermiculite bed which was sterilized and moistened with a plant nutrient solution. Compared with the control (without seed), a remarkable increase in the number of bacterial cells was observed in all the combinations of plant cultivars and Rhizobium strains 24 h after sowing. These results reveal that seed exudates of common bean have a substantial potential to promote Rhizobium proliferation, and that root exudates in a particular period of culture contain some inhibitory factors.  相似文献   

10.
The effect of baobab ( Adansonia digitata L.) and néré ( Parkia biglobosa (Jacq.) Benth.) trees on soil water content and water infiltration was investigated in farmed parkland at Nobéré, Burkina Faso, West Africa. Soil infiltrability was measured using tension head infiltrometers under trees and in an open field. Soil water content was determined gravimetrically. Soil infiltrability was higher below the edge of tree crowns compared with the open. There were no differences in infiltrability between soil under both tree species and in the open field. However, soil infiltrability increased from tree trunks to crown edges. This is probably due to tillage and/or higher compaction under trees than in the open field. In contrast to soil infiltrability, soil moisture was higher under tree crowns compared with the open field, perhaps due to higher organic matter content and reduced evaporation under trees.  相似文献   

11.
Plants act as an important link between atmosphere and soil: CO2 is transformed into carbohydrates by photosynthesis. These assimilates are distributed within the plant and translocated via roots into the rhizosphere and soil microorganisms. In this study, 3 year old European beech trees (Fagus sylvatica L.) were exposed after the chilling period to an enriched 13C–CO2 atmosphere (δ13C = 60‰ – 80‰) at the time point when leaves development started. Temporal dynamics of assimilated carbon distribution in different plant parts, as well as into dissolved organic carbon and microbial communities in the rhizosphere and bulk soil have been investigated for a 20 days period. Photosynthetically fixed carbon could be traced into plant tissue, dissolved organic carbon and total microbial biomass, where it was utilized by different microbial communities. Due to carbon allocation into the rhizosphere, nutrient stress decreased; exudates were preferentially used by Gram-negative bacteria and (mycorrhizal) fungi, resulting in an enhanced growth. Other microorganisms, like Gram-positive bacteria and mainly micro eucaryotes benefited from the exudates via food web development. Overall our results indicate a fast turnover of exudates and the development of initial food web structures. Additionally a transport of assimilated carbon into bulk soil by (mycrorhizal) fungi was observed.  相似文献   

12.
In brown tea soil, the effects of ferrous sulfate with sulfuric acid on soil environment and tea plant (Camellia sinensis (L.) O. Kuntz) growth were examined by enzyme activity, microbe quantity, nutrients in rhizosphere soil, and the nutrients and dry matter weight in the tea plant. We found that the pH value in the brown soil was significantly decreased by ferrous sulfate with sulfuric acid treatments, compared with the value in unfertilized control (CK) or sulfuric acid treatments. The acid phosphatase activities of 3 g kg–1 ferrous sulfate with 0.05 mL L–1 sulfuric acid were increased by 210.53%. Interestingly, the quantities of fungi were increased by 19.76% and the bacteria and actinomyces were decreased in the CK treatment. Specifically, the nitrogen and magnesium in rhizosphere soil and leaves were significantly increased by the low concentrations of ferrous sulfate with 0.05 mL L–1 sulfuric acid, whereas the dry matter weight under 3 g kg–1 ferrous sulfate with 0.05 mL L–1 sulfuric acid was increased by 36.22% in the CK treatment. Thus, we concluded that ferrous sulfate with sulfuric acid affected not only the soil environment but also the growth of tea plants. Our results suggested that the concentration of ferrous sulfate at 3 g kg–1 soil diluted in 0.05 mL L–1 sulfuric acid could be considered a good soil conditioner to make a suitable soil environment for tea production.  相似文献   

13.
为促进永兴县冰糖橙产业的持续快速发展,采用层次分析法、德尔斐法以及GIS空间叠加方法,对永兴县发展冰糖橙产业的土地适宜性进行了评价。结果表明:永兴县共有冰糖橙种植高度适宜性土地1 426.85hm2,适宜性土地28 858.43hm2,勉强适宜性土地406.57hm2,不适宜性土地4 639.71hm2,适宜性土地面积占土地总面积的85.72%,整体隶属度值为0.84,位于二级水平。基于土地评价结果,形成了永兴县冰糖橙适宜性评价体系,并提出了永兴县冰糖橙产业发展的建议。  相似文献   

14.
Due to high nitrogen deposition in central Europe, the C : N ratio of litter and the forest floor has narrowed in the past. This may cause changes in the chemical composition of the soil organic matter. Here we investigate the composition of organic matter in Oh and A horizons of 15 Norway spruce soils with a wide range of C : N ratios. Samples are analyzed with solid‐state 13C nuclear magnetic resonance (NMR) spectroscopy, along with chemolytic analyses of lignin, polysaccharides, and amino acid‐N. The data are investigated for functional relationships between C, N contents and C : N ratios by structural analysis. With increasing N content, the concentration of lignin decreases in the Oh horizons, but increases in the A horizons. A negative effect of N on lignin degradation is observed in the mineral soil, but not in the humus layer. In the A horizons non‐phenolic aromatic C compounds accumulate, especially at low N values. At high N levels, N is preferentially incorporated into the amino acid fraction and only to a smaller extent into the non‐hydrolyzable N fraction. High total N concentrations are associated with a higher relative contribution of organic matter of microbial origin.  相似文献   

15.
This study was initiated to evaluate the effect of locally isolated Rhizobium on nodulation and yield of faba bean at Haramaya, Ethiopia for three consecutive years. Ten treatments comprising of eight effective isolates of rhizobia, uninoculated, and N-fertilized (20 kg N ha?1) were laid out in a randomized complete block design with three replications. The result of the experiment indicated that all inoculation treatments increased nodule number and dry weight over the control check in all cropping seasons. The result, however, showed the non-significant effect of Rhizobium inoculation on shoot length, number of tiller per plant and 100 seed weight in all cropping season. Inoculating Haramaya University Faba Bean Rhizobium (HUFBR)-15 in 2011 and National Soil Faba Bean Rhizobium (NSFBR)-30 in 2012 and 2013 gave the highest grain yields (4330, 5267 and 4608 kg ha?1), respectively. These records were 75%, 48%, and 5% over the uninoculated treatment of respective years. Over the season, NSCBR-30 inoculation resulted in the highest nodulation and grain yield production as compared to the other treatments. In general, isolates from central Ethiopia were better than those isolated from eastern Ethiopia and Tropical Agricultural Legume (TAL)-1035 in enhancing faba bean production at Haramaya site. Therefore, NSFBR-30 is recommended as a candidate isolate for faba bean biofertilizer production in eastern Ethiopia soils.  相似文献   

16.
The partial sterilization of soil eliminates useful microorganisms, resulting in the reduced growth of mycorrhizae-dependent citrus plants, which are often unresponsive to the application of fertilizer. Research was conducted to test the hypothesis that indigenous mycorrhizae (IM) inoculation is as efficient as selected mycorrhizal inoculation under sterile and non-sterile soil conditions. Rhizophagus clarus and indigenous mycorrhiza spores, isolated from citrus orchards, were used as arbuscular mycorrhizae fungi under greenhouse conditions with sterile and non-sterile Çanakçi series (Typic xerofluvent) soils with low phosphorus (P) fertility. Different P (0 and 100 mg kg?1) and zinc (Zn) (0, 5 and 10 mg kg?1) concentrations were used at the start of the experiments. The shoot, root dry weight (RDW), root colonization, and P, Zn, iron (Fe), copper (Cu) and manganese (Mn) concentrations of the shoot were determined; mycorrhizae dependency (MD) was also calculated.

The results indicate that R. clarus and indigenous mycorrhiza in sterile and non-sterile soil conditions considerably increased the growth of citrus plants. Owing to existing beneficial indigenous rhizosphere microorganisms, citrus plant growth without inoculation was better in non-sterile soils than in the sterile soils. In non-sterilized soil, the plant growth parameters of R. clarus-inoculated soils were higher than those of indigenous mycorrhiza-inoculated soils. Mycorrhizae infection increased certain citrus plant growth parameters, such as root infection, biomass and nutrient uptake (P, Zn, Fe, Mn and Cu). In sterile soil, the addition of up to 5 mg kg?1 soil Zn and the inoculation of R. clarus significantly increased plant growth; inoculation with indigenous mycorrhiza produced more dry weight upon the addition of up to 100 mg kg?1 phosphorus pentoxide (P2O5). Under sterile soil conditions, without considering fertilizer addition, MD was found to be higher than that of non-sterile soils. In general, the contribution of the indigenous soil spores is significant. However, indigenous soil mycorrhizae may need to be managed for better efficiency in increasing plant growth and nutrient uptake. The major finding was that the inoculation of citrus seedlings with mycorrhiza is necessary under both sterilized and non-sterilized soil conditions.  相似文献   

17.
Abstract

A field experiment was conducted on an alkaline calcareous soil of Agronomy farm of the College of Agriculture, University of Udaipur to study the effect of sulphur on crop yield, leaf elemental composition, chlorophyll synthesis and activities of haematin enzymes. Application of elemental sulphur 21 days before planting with and without 0.1 per cent foliar sprays of H2SO4. increased crop yield by 137 to 197 per cent. Application of all these treatnents had no effect on nitrogen, phosphorus and potassium content of leaves but sulphur content was signficantly increased. Iron content of green leaves was decreased significantly 4 to 5 times together with an increase in the activity of catalase and peroxidase enzymes. Chlorosis in these soils appears to be on account of a reduced physiological availability of iron after absorption.  相似文献   

18.
Limited information is available on reduced cowpea (Vigna unguiculata L. Walp.) and green gram (Vigna radiata L.Wilczek.) yields in Kenya. Declining soil fertility and absence or presence of ineffective indigenous rhizobia in soils are assumptions that have been formulated but still require to be demonstrated. In this study, soils were collected from legume growing areas of Western (Bungoma), Nyanza (Bondo), Eastern (Isiolo), Central (Meru) and Coast (Kilifi) provinces in Kenya to assess indigenous rhizobia in soils nodulating cowpea and green gram under greenhouse conditions. Our results showed that highest nodule fresh weights of 4.63 and 3.32?g plant?1 for cowpea and green gram were observed in one soil from Isiolo and another from Kilifi, respectively, suggesting the presence of significant infective indigenous strains in both soils. On the other hand, the lowest nodule fresh weights of 2.17 and 0.72?g plant?1 were observed in one soil from Bungoma for cowpea and green gram, respectively. Symbiotic nitrogen (N) fixation by cowpea and green gram was highest in Kilifi soil with values of 98% and 97%, respectively. A second greenhouse experiment was undertaken to evaluate the performance of commercial rhizobial inoculants with both legumes in Chonyi soil (also from Coast province) containing significant indigenous rhizobia [>13.5?×?103 Colony Forming Units (CFU) g?1]. Rhizobial inoculation did not significantly (P?相似文献   

19.
Fertilization is required for optimum plant growth, particularly in unfertile soils, while optimizing nutrient use efficiency is an alternative to reduce inorganic fertilizer needs and reduce environmental problems caused by nutrient leaching. This study investigated soil properties and cowpea yield responses to biochars (BCs) made from different feedstocks, baby corn peel biochar (BC1), branches of mango tree biochar (BC2), and rice husk biochar (BC3), applied in combination with nitrogen-phosphorus-potassium (NPK) fertilizers. The experiment was conducted in a greenhouse, using an acid sandy soil (Arenosol) that was submitted for 70 d to the following eight treatments:i) control; ii) full dose of NPK (a commercial compound fertilizer (12-24-12 of N-P2O5-K2O) + urea (46% N)); iii) BC1 + half dose of NPK; iv) BC1 + full dose of NPK; v) BC2 + half dose of NPK; vi) BC2 + full dose of NPK; vii) BC3 + half dose of NPK; and viii) BC3 + full dose of NPK. All biochars were applied at a rate of 0.9% (weight/weight), and each type of biochar was combined with half and full doses of NPK fertilizers. Soil pH increased significantly (P < 0.05) in treatments with BC1 and BC2, while cation exchange capacity (CEC) and available P were higher in the treatments with BC1; BC1 and BC2 also induced higher activity of enzymes related to the P cycle and higher cowpea yield. Similar soil properties and cowpea yield parameters were obtained with the full and half doses of NPK fertilizers for each type of biochar used. In conclusion, biochars in the combination with NPK fertilizers improved soil chemistry and enzymatic activities, allowing reduced fertilizer application and food production costs in the acid soil studied.  相似文献   

20.
The effects of soil amendments [i.e., control, gypsum, farmyard manure (FYM), and gypsum?+?FYM] and seed priming (i.e., unprimed, seed soaked in water for 10?hr prior to sowing, and seed soaked in 0.4% gypsum solution for 10?hr prior to sowing) were assessed on growth and yield of wheat (Triticum aestivum L.) crop in alkali soil in northwestern Pakistan. A split plot design was used, keeping priming methods in main plots and soil amendments in sub-plots. The results showed that the effects of soil amendments and seed priming on grain yield, straw yield, harvest index and number of spikes were significant but their interactive effect was non-significant. The highest crop yields and yield index were obtained with gypsum?+?FYM amendments, and seed priming with gypsum solution. The effect on seed emergence, plant height and number of grains per spike was, however, not significant. Grain yield increased by 104% in gypsum?+?FYM treatment over control and by 16.8% with seed primed in water, followed by 8.5% with priming in gypsum solution, as compared to non-priming. The weight of 1000 grains was significantly increased by 35% in gypsum?+?FYM treatment and by 15.8% in gypsum priming. The phosphorus (P) and potassium (K) content increased with soil amendments. Soil pH and gypsum requirement reduced significantly with soil amendments. The blend of gypsum and FYM has improved the properties of salt-affected soil and enhanced fertility for optimum production of wheat in addition to the beneficial effect of seed priming in gypsum solution on crop yield. Using these amendments could be ameliorative in removing the adverse effect of the salt-affected soils, rendering the soil a good medium for plant growth.  相似文献   

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