农药胁迫对生菜叶片叶绿素荧光图像参数的影响

对生菜(Lactuca sativa)分别均匀喷洒浓度为70、140、280μg/L的杀虫剂氰戊菊酯,以清水为对照,以意大利全年耐抽薹生菜为试材,结果表明,随着农药浓度的增加,光系统Ⅱ的最大光化学效率、实际光化学效率、光化学淬灭系数和相对电子传递速率均下降,非光化学淬灭系数、非调节性能量耗散的量子产额和调节性能量耗散的量子产额上升,综合影响造成光系统Ⅱ的中心活性区域缩小、光合速率下降。另外生菜叶片自身的光化合保护机制能在一定程度上减轻农药的胁迫作用。与对照相比,光系统Ⅱ的实际光化学效率受农药影响最大,喷洒浓度为280μg/L的杀虫剂会对生菜光合作用过程产生持续性的、不可逆转的影响。     

Micropropagation of Prunus scoparia,a Suitable Rootstock for Almond under Drought Conditions

Prunus scoparia is a wild deciduous shrub, usually living on dry calcareous soils of the rocky mountains and has been used as a grafting rootstock for domesticated almonds to provide drought resistance. In the current study, micropropagation ability of P. scoparia was investigated using cytokinin and auxin. Uniform nodal shoot pieces (3–5 cm in length) of seedlings were used as explants. The explants were disinfected with 10% sodium hypochlorite solution. For adventitious shoot induction and proliferation, Murashige and Skoog (MS) media containing 7.00 g/l agar and 30.00 g/l sucrose containing five concentrations of benzyl adenine (BA) (0.00, 0.50, 1.00, 2.00, and 4.00 mg/1) and also containing six concentrations of Thidiazuron (TDZ) (0.00, 0.50, 1.00, 2.00, 5.00, and 7.00 mg/1) were compared. For rooting, in vitro shoots (2–3 cm) were transferred into ½ MS medium supplemented with 30 g/l sucrose, 7.50 g/l agar, and different concentrations of IBA (0.00, 0.25, 0.50, and 1.00 mg/l) and NAA (0.00, 0.25, 0.50, and 1.00 mg/l). Based on the results obtained for shoot proliferation, only 2.00 and 4.00 mg/l BA and 2.00 mg/l TDZ concentrations generated shoots, while other treatments did not show shoot proliferation. Among the three treatments that generated shoots, the best results for shoot number, leaf number, and leaf color quality were observed in media containing 2.00 mg/l TDZ. Based on the results obtained for rooting, the effect of IBA concentrations on the rooting percentage, root number, and root length was significant. Among IBA concentrations, only 0.50 mg/l IBA induced rooting, while there was no rooting in the media containing other IBA concentrations. None of the NAA concentrations showed rooting. In conclusion, MS culture medium supplemented with 2.00 mg/l TDZ and ½ MS culture medium supplemented with 0.50 mg/l IBA are suggested for in vitro shoot proliferation and rooting of P. scoparia, respectively. The results presented herein could be used for in vitro selection and micropropagation of P. scoparia.     

Municipal Waste and Poultry Manure Compost Affect Biomass Production,Nitrate Reductase Activity and Heavy Metals in Tomato Plants

Organic wastes can be usefully recovered to produce organic amendments, for example, compost, to be used for crop production, thus reducing impacts through efficient waste management. The aim of this work was to study the effects of compost obtained from municipal waste in combination with poultry manure on plant growth, nitrate reductase (NR) activity and absorption and distribution of heavy metals (HM) in plant tissues of tomatoes, grown in pots in greenhouses. Two compost types obtained from municipal waste mixed with poultry manure (C1?=?3:2 and C2?=?2:3) were used at two different ages (105 d and 173 d) and at two mix rates with soil (32.5?g pot^?1 and 65?g pot^?1); soil with no compost amendment was used as control. The experiment was conducted using tomato plants in pots and plant growth and nutrient plant uptake was determined after 65?days from plant transplanting. Results obtained indicated that compost type and compost rate affected biomass production. However, compost age did not influence the development of plants. Nutrient status of tomato plants was also investigated with reference to the N cycle. Nitrite accumulation in the leaves increased with the increase in compost doses. The accumulation of NO₂^? was associated with a significant increase in NR activity. HM content in leaves decreased with compost use. HM accumulated preferentially in roots and leaves and the soil to root metals transfer was in this order: Fe (1.08–2.14)> Co (0.53–4.10)>Cu (0.28–2.28) >Mn (0.3–1.34) >Zn (0.87–1.21)>Cr (0.12–1.64). The highest and lowest dynamic bioaccumulation factors (BAF_dyn) were observed in roots and stems, respectively. The root system acted as a barrier for Cd and Pb. It was concluded that compost use is beneficial for tomato plants, with particular reference to the compost obtained by using a higher amount of poultry manure (C2) in the mix.     

Correlation between C-reactive protein level,immunology, and hematology of a <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis> infected with <Emphasis Type="Italic">Lactococcus garvieae</Emphasis>

The aim of this experiment was to evaluate the symptoms, variation, and correlation of hematological factors and some parameters of the innate immune response of the infected rainbow trout (Oncorhynchus mykiss) fish with Lactococcus garvieae bacteria. A total of 270 fish were divided into three groups including infected fish with a high and low concentration of L. garvieae and a control group without infection. The blood and tissue (brain, head, kidney, and spleen) samples were collected from each group (n?=?6 fish) at 0, 3, 14, and 21 days after treatment. The most observed symptoms during infection were lethargy, exophthalmia, and ascites. The mortality rates for the high and low dose-infected fish were defined as 60 and 25%, respectively. The infected groups had significantly (p?<?0.05) higher activity of serum lysozyme, myeloperoxidase, classical and alternative pathways of complement, serum bactericidal effects, and the specific antibody titer. Also, a significant (p?<?0.05) lower hematocrit and hemoglobin levels and higher white blood cell numbers were observed in the infected groups. A significant correlation was observed between the CRP levels and some of the hematological and immunological indices as bactericidal effects, classical complement pathways, lysozyme activity myeloperoxidase activity, white blood cell numbers, and hematocrit levels. The clinical symptoms, immune responses, and hematological indices variation among L. garvieae-infected fish are dependent on the duration and bacterial dose of the infection.     

Characterisation of a novel ilarvirus causing grapevine angular mosaic disease

Unusual symptoms were observed on ‘Baresana’ x ‘Baresana’ Vitis vinifera hybrid vines in the Grapevine Variety Collection of the Grapevine Institute, Athens. The affected vines showed sharp angular mosaic on leaves, along the veins and in vein angles, malformations, abortive flowers or very few berries with smaller, wrinkled and non-germinating seeds, as well as gradual decline, severe stunting and death of the vine. Serological tests on diseased vines for the presence of 13 known grapevine viruses gave negative results. An infectious agent was transmitted mechanically to several herbaceous indicator plants. Koch’s Postulates were fulfilled, and the agent, proven to be a virus, was named Grapevine angular mosaic virus (GAMV). Serological tests have been developed for the virus. The most conserved polymerase region showed significant similarity of GAMV with members of subgroup 1 of the Ilarvirus genus; however ML phylogenetic analysis could not support its clustering within this subgroup. GAMV differs serologically and in particle morphology from Grapevine line pattern virus (GLPV) a putative member of the Ilarvirus genus that infects grapevine. It is proposed that GAMV is a novel member of the Ilarvirus genus.     

Function of sodium and potassium in growth of sodium-loving Amaranthaceae species

We observed that the growth of three Amaranthaceae species was promoted by sodium (Na), in the order dwarf glasswort (Salicornia bigelovii Torr.) >> Swiss chard (Beta Burgaris L. spp. cicla cv. Seiyou Shirokuki) > table beet (Beta vulgaris L. spp. vulgaris cv. Detroit Dark Red). In the present study, these Na-loving plants were grown in solutions containing 4 mol m^?3 nitrate nitrogen (NO₃-N) and 100 mol m^?3 sodium chloride (NaCl) and potassium chloride (KCl) under six Na to potassium (K) ratios, 0:100, 20:80, 40:60, 60:40, 80:20 and 100:0, to elucidate the function of Na and K on specific characteristics of Na-loving plants. The growth of dwarf glasswort increased with increasing Na concentration of the shoot, and the shoot dry weight of plants grown in 100:0 Na:K was 214% that of plants grown at 0:100. In Swiss chard and table beet, growth was unchanged by the external ratio of Na to K. The water content was not changed in Swiss chard or table beet by the external Na to K ratio. These observations indicate that both Na and K have a function in osmotic regulation. However, dwarf glasswort could not maintain succulence at 0:100; therefore, Na has a specific function in dwarf glasswort for osmotic regulation to maintain a favorable water status, and the contribution of K to osmotic regulation is low. NO₃-N uptake was promoted by Na uptake in dwarf glasswort and Swiss chard. NO₃-N uptake and transport to shoots was optimal at 100:0 in dwarf glasswort and at 80:20 in Swiss chard. These functions are very important for the Na-loving mechanism, and the contribution of K was lower in dwarf glasswort than in Swiss chard.     

Modulatory function of NMDA glutamate receptor on MC<Subscript>3</Subscript>/MC<Subscript>4</Subscript> receptors agonist-induced hypophagia in neonatal meat-type chicken

Melanocortin 3 and 4 receptors (MC₃R and MC₄R) are known as the main receptors for melanocortin-induced hypophagia in mammalian and poultry. Also, central glutamatergic system has mediatory role on function of the melanocortin system in some brain areas. So, the aim of the current study was to determine the role of MC₃/MC₄ receptors agonist on food intake and its interaction with glutamatergic in 3-h food-deprived (FD₃) neonatal broilers. In experiment 1, chickens were intracerebroventricular (ICV) injected with control solution, MTII (MC₃/MC₄ receptors agonist; 2.45, 4.8 and 9.8 pmol). In experiment 2, control solution, SHU9119 (MC₃/MC₄ receptors antagonist; 0.5, 1 and 2 nmol) were ICV injected. In experiment 3, birds ICV injected with control solution, SHU9119 (0.5 nmol), MTII (9.8 pmol) and co-injection of the SHU9119 + MTII. Experiments 4–8 were similar to experiment 3, except birds injected with MK-801 (NMDA glutamate receptors antagonist, 15 nmol), CNQX (AMPA glutamate receptors antagonist; 390 nmol), AIDA (mGLUR₁ glutamate receptors antagonist; 2 nmol), LY341495 (mGLUR₂ glutamate receptors antagonist; 150 nmol) and UBP1112 (mGLUR₃ glutamate receptors antagonist; 2 nmol) instead of SHU9119. Then, cumulative food intake was recorded until 120 min after injection. According to the results, dose dependent hypophagia observed after ICV injection of the MTII (p < 0.05). ICV injection of SHU9119 significantly increased food intake in birds (p < 0.05). Co-injection of SHU9119 + MTII significantly inhibited MTII- induced hypophagia in neonatal chicks (p < 0.05). In addition, hypophagia- induced by MTII was significantly attenuated with co-injection of MTII + MK-801(p < 0.05). These results suggested MC₃ and MC₄ receptors have inhibitory role on food intake and this effect is probably mediated by NMDA glutamate receptors in neonatal chickens.     

Assignment of the CD Cotton Effect to the Chiral Center in Pseurotins,and the Stereochemical Revision of Pseurotin A2

Pseurotins A₁ (1) and A₂ (2) were isolated from a culture broth of the fungal strain Aspergillus fumigatus WFZ-25 as stereoisomers of pseurotin A (3) in 2011. We also isolated 1 and 2 together with 3 from A. fumigatus OUPS-T106B-5 separated from the marine fish Mugil cephalus. In this study, we re-examined the stereochemistry of 1 and 2 using chemical transformation and the CD spectra, and found the relationship between the CD Cotton effect and the absolute configurations of 1 and 2, which led us to revise the stereostructure of pseurotin A₂.     

Physico‐chemical characterization of humic‐metal‐phosphate complexes and their potential application to the manufacture of new types of phosphate‐based fertilizers

The aim of this review is to describe the main physicochemical characteristics of diverse types of humic‐metal‐phosphate acid complexes. The effects of these complexes on phosphorus (P) fixation in soils with different pH values and physicochemical features and on plant phosphorus uptake are also discussed. Humic‐metal‐phosphate complexes have apparent stability constants in the same range as those of metal‐humic complexes, in solutions with diverse pH and ionic‐strength values. Likewise, the molecular‐size distribution of humic‐metal‐phosphate complexes as a function of pH is similar to that of potassium or sodium humates and metal‐humic complexes. Humic‐metal‐phosphate complexes are able to decrease phosphate fixation in soils and increase plant growth and phosphate uptake. Phosphorus fertilizers containing humic‐metal‐phosphate complexes proved to be efficient to improve plant growth and P uptake with respect to conventional fertilizers such as single superphosphate. The values of parameters related to plant phosphorus‐utilization efficiency (PUt E) suggest that the regulation of root acquisition of phosphate from these complexes could involve the interregulation of a system for the optimization of metabolic P utilization in the shoot and another system involving stress responses of roots under phosphorus deficiency.     

Evaluation of immobilizing agents as soil quality conditioners in addition to their metal(loid) immobilizing effect

In trace metal (TM)-contaminated agricultural soils,management of TM availability is important for safe crop production.In addition,maintenance or improvement of soil quality is vital for sustainable crop cultivation.Decreased TM phytoavailability and increased soil quality can be achieved by the application of various immobilizing agents to soil,which can supply both macronutrients and organic matter.This study investigated the long-term influences of four common immobilizing agents on soil biogeochemical properties and the phytoavailability of TMs in mixed metal-contaminated soil from a cultivated upland near an abandoned mining site.Lime (L),gypsum (G),fly ash (F),and animal manure-based compost (C) were applied to pots containing contaminated soil,either individually or in combination.After incubation for three years under sequential cultivation of two crops and fallow,soil biogeochemical properties were determined,and Brassica rapa plant bioassay was performed.The phytoavailability of all TMs (both cationic metals and anionic metalloids) remained significantly lower in soils treated with immobilizing agents even after three years,when compared with the no-agent control (CK) soil.In addition,the soil quality was significantly improved by treatment with immobilizing agents.For instance,the C and L+C treatments were the most effective in improving soil physical (bulk density,porosity,and water-resistant aggregate stability),chemical (pH,organic matter,total nitrogen,cation exchange capacity,and plant-available phosphorus,magnesium,and potassium),and biological (microbial biomass carbon and dehydrogenase activity) properties.The improvement of soil properties and lowering of TM bioavailability were also consistent with the most significant increase in B.rapa biomass production observed in the C treatment,followed by the L+C,G+F,L,G,F,and L+G treatments,as compared with that in CK.These results indicate that the function of the TM-immobilizing agent as a soil quality conditioner,in addition to its TM immobilizing effect,should be considered when selecting such agents for agricultural or ecological applications.