Biostimulants’ influence on tomato fruit characteristics at conventional and low-input NPK regime

ABSTRACT

Plant biostimulants are commercial products based on different chemical substances used to enhance plant growth and productivity. The effects of biostimulants, Megafol and Viva, with different dominant compositions (amino acids and humic acids) on two tomato cultivars (cv. Gravitet F1 and cv. Minaret F1) exposed to conventional and low-input macronutrient nutrition were investigated. Application of both biostimulants positively affected yield at conventional nutrition. In low-input nutrition variant, biostimulant application prevented yield loss only in cv. Minaret F1. Inter-cultivar differences were noticed in fruit characteristics (total phenol content, total flavonoids content and total antioxidative capacity) where application of biostimulants leads to opposite results in the examined cultivars. We considered the possibility of biostimulant usage as an effective nutritional addition for overcoming the problem of excessive fertilisation.     

Comparison of Growth and Chemical Profile of Diatom Skeletonema grevillei in Bioreactor and Incubation-Shaking Cabinet in Two Growth Phases

Marine microalgae, diatoms, are considered a source of a wide range of high-value compounds, and numerous studies indicate their biotechnological potential in the food and feed industry, cosmetic industry, nanotechnology, pharmaceutical industry, biodiesel production, fertilizers, and wastewater treatment. The aim of this study was to compare the growth, chemical profiles, and antioxidant activity of the diatom Skeletonema grevillei cultivated in a bioreactor and an incubation-shaking cabinet at different growth phases (after 192 and 312 h). Growth was monitored by evaluating cell density with the Sedgewick Rafter chamber, and the collected biomass was extracted with 70% ethanol assisted by ultrasound. Extracts were evaporated to dryness and compounds were identified in derivatized form by gas chromatography and mass spectrometry (GC-MS) analysis, while antioxidant capacity was evaluated by DPPH and ORAC. Significantly faster growth was observed in the bioreactor than in the incubation-shaking cabinet. Oleamide, palmitelaidic acid, glycerol monostearate, myristic acid, cholesterol, eicosapentaenoic acid, 1-monopalmitin, and 24-methylene cholesterol were identified as the major compounds in both systems. Among them, oleamide was the dominant compound in both systems. It is also shown that prolonging the cultivation period had a direct effect on increasing the extract yield. The highest DPPH inhibition (11.4 ± 1%) and ORAC values (93.3 ± 8.4 mM TE) were obtained for the S. grevillei extract recovered from the bioreactor after 312 h. The obtained results contribute to the possibility of using S. grevillei for various biotechnological applications in the future.     

Metabolism of some sterol inhibitors in fungi and higher plants,with special reference to the selectivity of fungicidal action

The metabolism of triforine, chloraniformethan, the α-(pyrimidin-5-yl)benzhydryl alcohols (fenarimol, nuarimol and triarimol), the trityl-azoles (fluotrimazole and clotrimazole), and the morpholine types of sterol inhibitors is reviewed; the metabolism of the azolyl-alkane derivatives (mainly triadimefon and triadimenol) is discussed in detail. Redox and hydrolytic reactions are of primary importance. Enzymic inactivation may be one factor influencing fungicide selectivity. Metabolism is the dominant factor of selectivity if it represents the activation process, as with triadimefon. Transformations in higher plants do not differ significantly from those occurring in fungi, except that factors such as the formation of conjugates with natural compounds of plant tissues also play a role, as with triforine and triadimenol. The selectivity of fungitoxic action may be influenced by metabolism both in the host plant and the pathogen.     

Platyzoma: a new look at an old link in ferns

Record of a chromosome number of 2n = 76, unusual for pteridophytes, in Platyzoma microphyllum R. Br. emphasizes other unique features of this monotypic Queensland fern and provides new evidence of its possible relationships. Other characteristics of this plant, which are not known among terrestrial ferns, are incipient heterospory-having two sizes of spores and a dioecious condition of the gametophytes. These and other morphological features show relationships of Platyzoma to members of the Schizaeaceae and Marsileaceae and relationships of these families to the Polypodiaceae, in which it is treated under the subfamily Platyzomatoideae.     

The assessment of feto-maternal hemorrhage in an artificial model using anti-D and anti-fetal hemoglobin antibody by flow cytometry

BACKGROUND: When fetal red cells enter the maternal circulation from placenta, an event would be happened that is described as feto-maternal hemorrhage (FMH). This life-threatening condition could be detected by using RBC antigens (surface antigens and intracellular antigens). Therefore, the measurement of fetal RBC in an artificial model would be useful to calculate FMH and consequently the dosage of Rhogam for prophylaxis. The aim of the present study was to evaluate FMH in an artificial mixture model. METHODS: A series of 40 artificial specimens were prepared consisting of Rh(D) negative adult blood (non-immunized) spiked with varying amounts of Rh(D) positive cord blood from mothers between 20-30 years old in Shahid Beheshti Hospital, Tehran, Iran. Monoclonal anti-D and anti-HbF (fetal hemoglobin) were used for detection of fetal RBC in artificial mixture sample modeling. RESULTS: This study showed that the percentage of fetal cells in artificial sample for anti-D antigen is in ranges of 0.28%-0.32% for a 0.25% dilution mixture, and 1.3%-2.05% for the mixture with dilution 2%. In addition, the ranges of data for anti-HbF staining was obtained 0.2%-0.34% for the 0.25% dilution sample, and the ranges of 1.04-1.8% for the 2% dilution. The regression analysis indicated that the correlation of anti-D assessment with expected standard method was r2 = 0.9672 and anti-HbF assessment was r2 = 0.8842. CONCLUSION: Although both molecule targets could be used for detection of fetal RBC, in this model, anti-D staining was more accurate than anti-HbF staining. However, since anti-D can not be utilized for low-density or weak phenotype and other incompatibility, the anti-HbF labeling could be used for all FMH.     

Assessment of the spatial genotypic and phenotypic diversity present in the various winter wheat breeding programs in Southeast Europe

The genetic diversity present in the breeding programs of southeast Europe was assessed in a set of 114 winter wheat (Triticum aestivum L.) cultivars using AFLP and SSR markers. The average genetic diversity characterised with the Jaccard’s distance coefficient was 0.605 with an interval of 0.053 and 0.889. The wheat cultivars originating from the four countries differed from each other in their clustering patterns, including the numbers of clusters and the most prevalent cluster, which was breeding program-specific. Hungarian and Romanian cultivars showed closer relationships, and Serbian and Macedonian cultivars grouped together more frequently. The phenotypic variability of the same cultivars was assessed under diverse ecological conditions of the four growing sites, measuring the disease resistance against two foliar diseases, and several agronomic traits. Of the phenotypic traits, powdery mildew and leaf rust responses showed significant associations with genetic diversity, whereas heading date, plant height and yield components did not. Through parallel assessment of genotypic and phenotypic diversity it was possible to separate winter wheat cultivars with similar genotype but diverse phenotype from those with similar phenotype but diverse genotype. This information will allow breeders to make informed decisions in selecting parents for new crosses.     

Segregation of axonal and somatic activity during fast network oscillations

In central neurons, information flows from the dendritic surface toward the axon terminals. We found that during in vitro gamma oscillations, ectopic action potentials are generated at high frequency in the distal axon of pyramidal cells (PCs) but do not invade the soma. At the same time, axo-axonic cells (AACs) discharged at a high rate and tonically inhibited the axon initial segment, which can be instrumental in preventing ectopic action potential back-propagation. We found that activation of a single AAC substantially lowered soma invasion by antidromic action potential in postsynaptic PCs. In contrast, activation of soma-inhibiting basket cells had no significant impact. These results demonstrate that AACs can separate axonal from somatic activity and maintain the functional polarization of cortical PCs during network oscillations.     

Dynamics of changes in the races and virulence of wheat powdery mildew in Hungary between 1971 and 1999

Important microevolutional processes have taken place in the wheatpowdery mildew population over the last thirty years. There has been aconsiderable change in the race composition of the pathogen populationand in the prevalent races. Of the 78 races identified, only eleven have`lived' for more than 15 years. Many races were only isolated in one ortwo years. The number of virulence genes rose from 2.03 in 1973 to 5.63in 1993. On the basis of race composition and virulence the wheatpowdery mildew population between 1971 and 1999 can be divided intofour distinct groups. A large proportion of the powdery mildew isolates arevirulent to most resistance genes. Complete resistance is provided byresistance genes Pm4a (Khapli) and partial resistance by Pm2 + Mld (Halle st. 13471), Pm4b+ (TP 315/2) and Pm1 + 2 + 9 (Normandie). The majority of cultivated varieties carry theresistance gene Pm8 due to the presence of the 1B/1R translocation.     

Plant availability of phosphorus sorbed to potential wastewater treatment materials

Ecologically engineered wastewater treatment facilities, such as constructed wetlands and infiltration plants, can be further improved in their P retention by using reactive media with a high P-retention capacity. In a sustainable system, the sorbed P should be recycled in agricultural production. The objective of the present study was to determine the plant availability of P sorbed to different P-retention media. The studied media were: crystalline and amorphous blast furnace slag, natural and burned opoka (a bedrock from Poland), limestone, burned lime, soil from a spodic B horizon, and light expanded clay aggregates (LECA). They were soaked in a P solution, rinsed and dried before incorporation into soil. An additional aim was to compare P taken up by barley with amounts chemically extracted for the estimation of plant-available soil P. P sorbed to the crystalline slag was delivered to the barley plants more efficiently than P added in K₂HPO₄ fertiliser. Soil extraction with acid ammonium lactate correlated well with P taken up by barley and indicated that P bound to Ca is more available to plants than P bound to Al and Fe. The Mg content of the used slag may replace Mg fertilisation in certain soils. It was concluded that among the investigated filter materials, crystalline slag was the most suitable sorbent from an agricultural point of view, since it possessed a large P-sorption capacity and the sorbed P was largely plant available. The heavy metal content of sorption materials must be examined carefully before their application to agricultural soils.