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Published in AgroLife Scientific Journal, Volume 5, Number 2
Written by Alexandra TRIF, Mihai GÎDEA, Aurelian PENESCU

The aim of this paper is to determine the benefit of modern methods of scanning and processing images of a rapeseed crop to determine affected areas at the end of winter. There are where the measurements took place is on the study grounds of “Belciugatele Research Station - Moara Domnească Farm”. Three methods were used, all based on the same image provided by a drone as a basemap, and RTK-GPS measurements. For the first method the affected areas were delimited using a RTK receiver, which required a person on the ground to manually provide the required data. The second method uses the same image, but digitizing was done at a later date by using GIS instruments. In the third method the digitizing was also done using software, by classifying the pixels. The result of the study showed that the third method was superior because of higher precision and lower processing time.

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Published in AgroLife Scientific Journal, Volume 5, Number 2
Written by Mihaela-Carmen EREMIA, Irina LUPESCU, Gabriela Valeria SAVOIU, Maria SPIRIDON

The trypsin inhibitor from common flax seeds (Linum usitatissimum trypsin inhibitor, abbreviate LUTI) is a member of the potato inhibitor I family. This was isolated and purified by ethanol fractionation, ion exchange chromatography and affinity chromatography. To determine the molecular mass of protease inhibitor we utilized gel electrophoresis in denatured conditions (SDS-PAGE). LUTI is the first serine protease-type inhibitor isolated from a plant of Linaceae family, and has a molecular mass 7000D.

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Published in AgroLife Scientific Journal, Volume 7, Number 1
Written by Victor Nicolae NITA, Magda-Ioana NENCIU, Violin St. RAYKOV, Carmen Georgeta NICOLAE

The most suitable sturgeon species for culture in artificial systems are freshwater and non-migratory species: sterlet - Acipenser ruthenus - and Siberian sturgeon - Acipenser baerii, recently introduced in Romania. The experiment aimed at establishing the age and salinity thresholds to be taken into account in attempting to rear (Siberian sturgeon - Acipenser baerii) in a recirculating system using Black Sea water. From the point of view of adaptability in general, in about a week the individuals adapted to the captive breeding conditions of NIMRD’s recirculating system. The specimens also easily adapted to manipulation during measurements, showing calm handling behavior. The food used was very easily accepted, the active feeding behavior being observed even in the presence of the staff. Throughout the experiment, the fish were active. The survival rate was 100%. However, adaptability to the brackish environment has posed problems. The experimental batch became more sedentary and ingested significantly less food compared to thecontrol group, when salinity exceeded 3‰. Upon reaching the 7‰ threshold, all individuals were already completely refusing food, which is why it was decided to stop sea water input. The return to freshwater caused the resumption of feeding behavior in just a week, calling for further research on the osmoregulatory mechanisms of A. baerii.

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Published in Scientific Papers. Series "AgroLife Journal", Vol. 4 ISSUE 1
Written by Huub LELIEVELD

Differences in regulations result in needless destruction of safe food and hamper food trade. The differences are not just the result of the history of food safety regulations, often developed in times before global cooperation, but are also built in new regulations. It may be responses to media hypes or for other reasons, but in most cases the differences cannot be justified scientifically. A major difficulty is that, due to the developments in analytical techniques the number of chemicals that are found in food is increasing rapidly and chemicals are always suspected to be a safety risk. By far most chemicals are of natural origin but could not be detected in the past because the methods available in the past were not sensitive enough. Demanding the absence of chemicals because the risk they present is unknown, however, would eventually make all food unacceptable. The general public should be shown that everything they eat is chemical, and all food components will be toxic if the amount is too high. It should also be shown that many of these chemicals will also cause illness and death if there is not enough of it as is the case with vitamins and minerals.

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Published in AgroLife Scientific Journal, Volume 6, Number 1
Written by Florin SALA, Olimpia IORDĂNESCU, Alin DOBREI

This study evaluated the possibility of characterization and discrimination of apple cultivars by fractal analysis of the shape of leaves. The geometry of the leaf lamina from five apple cultivars (Delicios de Voineşti, Florina, Generos, Jonathan and Pionier) was studied by fractal analysis, box-counting method, for obtaining fractal dimensions (D). Leaf lamina descriptor parameters (length - L, width – W, perimeter – P, and leaf area - LA) were determined for the comparative analysis with fractal dimensions in order to characterize the cultivars studied. Based on fractal dimensions (D) obtained from the analysis of the geometry of the leaf, the five apple cultivars studied were characterized and discriminated safely statistics (Cophenetic coefficient = 0.967). Regression analysis revealed the relationship of interdependence between leaf area and fractal dimensions (D) for each apple cultivar. From comparing the coefficient of variation of foliar parameters studied (L, W, P, LA), that the fractal dimensions (D) had the smallest variation within each apple cultivar, which shows that the fractal dimension (D) is a more stable parameter for characterization of the apple cultivars studied compared with other elements of the leaf lamina. According to the values of the correlation coefficient R2 and safety parameters (p and RMSE), the fractal dimensions (D) facilitated the prediction of leaf area certainly higher than in the classics descriptors parameters of the leaves L, W and P ( RD2 = 0.991 for Florina; RD2 = 0.985 for Generos and Pionier; RD2 = 0.982 for Delicios de Voinești and RD2 = 0.979 for Jonathan). Fractal analysis has proven to be a tool with great power for the analysis, characterization and discrimination of the five apple cultivars studied, and predicting of the leaf area based on fractal dimension (D), which recommends it as a tool in pomology studies.

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Published in AgroLife Scientific Journal, Volume 6, Number 1
Written by Aglaia BURLACU, Florentina ISRAEL-ROMING, Călina Petruța CORNEA

Xylanases have numerous applications in various fields, thus presenting an immense interest in studying. The sources for these enzymes include bacteria, fungi, yeast and others, the most important producers being fungi. The focus of this study was on enhancing the fungal strain ability to produce xylanase using random mutagenesis. Several mutants from Aspergillus brasiliensis and Penicillium digitatum were obtained through physical and chemical mutagenesis from strains previously selected as xylanase producers. The Petri plates with the fungal spores were exposed to UV light for physical mutagenesis at the distance of 10 cm and for 5-50 minutes. The chemical mutagenesis involved the use of Nmethyl-N′-nitro-N-nitrosoguanidine and ethyl methane sulfonate, by adding in the Petri plates with the fungal spores 150 μg/ml mutagen (N-methyl-N′-nitro-N-nitrosoguanidine or ethyl methane sulfonate). After both physical and chemical mutagenesis, several mutant strains were randomly selected and subjected to a qualitative and quantitative screening for their ability to produce xylanase. For the qualitative screening, the selected strains were cultivated on selective xylan agar medium with 0.8% oat spelt xylan as the only carbon source. The plates were analysed at every 24 h for the occurrence and evaluation of the hydrolysis area, using Congo red staining. Based on the measurements of the halo diameter, several strains were selected for a quantitative screening, using the DNS assay for reducing sugars to determine the xylanase activity. In order to determine the specific enzymatic activity, the protein assay was carried out. The comparison of the studied strains showed that there are differences concerning the production of xylanase between the mutant strains and the original ones.

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Published in AgroLife Scientific Journal, Volume 6, Number 1
Written by Georgiana DUŢĂ-CORNESCU, Camelia-Ecaterina PAVLUSENCO, Daniela Maria POJOGA, Marius Eduard NEGULICI, Nicoleta CONSTANTIN, Alexandra SIMON-GRUIŢA

Current cultivated roses varieties were obtained through intensive cross-breeding between a limited number of species of genus Rosa (about 8 to 20 from 200 wild species) and for many of them there are no accurate information about their genealogy. The present study aims to determine the genetic diversity of 10 rose varieties, from Botanical Garden of Bucharest collection, which are not included in the official list of rose varieties from Romania, according ISTIS. Choosing these cultivars started from the need to identify rose varieties resistant to the climate in SE Romania with extended summer drought and winter frost. A number of 86 individuals were genotyped using PCR-ISSR technique. From a total of 23 tested ISSR primers, 11 were selected due to their capacity to produce informative band patterns. These primers generated 292 ISSR markers, with a mean of 26.54 bands/primer and a polymorphism percentage of 96.025%. The average values of polymorphic information content (PIC), resolving power (Rp) and marker index (MI) proved the discriminatory power of ISSR markers (i.e PIC varied between 0.22 and 0.43 and Rp between 7.81 and 17.2). Genetic diversity as revealed by Shannon index (I=0.45±0.0734), genetic differentiation index (GST=0.027) and estimate of gene flow (Nm=16.982) is relatively high. The AMOVA analysis showed that 67.36% of the total genetic variation resides within cultivars, which is similar with other shrub species. The UPGMA dendrogram built on ISSR markers grouped the 10 cultivars in two major clusters according with their origin and some of their phenotype characteristics. ISSR fingerprinting proved to be appropriated for the quantification of the level of genetic variation in the selected cultivars.

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Published in AgroLife Scientific Journal, Volume 5, Number 1
Written by Gheorghe Valentin ROMAN, Lenuta Iuliana EPURE, Maria TOADER, Antonio-Romeo LOMBARDI

Grain legumes (pulses) are currently grown on 1.8% of the EU's arable land (compared to 4.7% in 1961) and as a result, Europe is dependent on protein imports totalling annually about 20 mil. tons of soybean meals and 12 mil. tons of soybean grains. Only about 2.5% of soybean meal consumed is produced in the EU. This imbalance between production and consumption creates economic and trade problems; in addition, imported soybean is mostly GM, which is not accepted by many European consumers. Since 2013, the Common Agricultural Policy included as a priority increasing the production of vegetal proteins by subsidies to grain legumes crops (including soybean non-GM), forage crops (alfalfa, clover) and oil crops (rapeseed, sunflower). In this framework encompasses the initiative Donau Soja (Danube Soya), which promotes the cultivation of conventional soybean in the Danube region and the development of yields processing and valorisation network. Romania falls well into these trends by traditions in cultivating soybean (over 500 thou ha before 1990), the favourability of natural conditions, the existence of biological material adapted to the specific natural conditions (varieties developed in ARDS Turda and NARDI Fundulea). Romanian farmers are interested in expanding soybean cultivation for ameliorating soil fertility and as a very good previous crop for winter cereals, but by providing an efficient weeds control, supplying water by irrigation and treating the seeds with bacterial preparations. Also, taking soybean harvest in the food networks involves a very rigorous quality control in terms of protein content and of avoiding contamination by GMOs. It is estimated that it can reach 700 thou ha with soybean, which can produce about 0.51 mil. tons proteins, which would add about 0.40 mil. tons of sunflower proteins (from 800 thou ha) and about 0.25 mil. tons of rapeseed proteins (from 500 thou ha).

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Published in AgroLife Scientific Journal, Volume 6, Number 2
Written by Irina CALCIU, Olga VIZITIU, Cătălin SIMOTA

Use of renewable energy resources is regulated by EU Directive 2009/28/CE from April 23rd 2009. The reduction of the greenhouse gas emissions coming from the biofuels and bioliquids use is calculated according to the Article 19 of the Directive and is based on typical and default values. In this study the coefficients for sunflower crop (typical emissions of greenhouse gas -g CO2 ech MJ-1) were evaluated at NUTS3 level (county) taking into account the pedoclimatic and technological conditions of Romania. The evaluation of greenhouse gas emissions and of energy consumptions within the whole production chain of biofuels and biodiesel was done by using Carbon Calculator – version 1.1 designed by E4Tech for Renewable Fuels Agency from UK. This program was used for different crop production levels: multiannual national average for the period of 1991-2014 provided by National Institute of Statistics; the lower level of crop production defined as difference between multiannual average and standard deviation of crop production years; the upper level of the crop production defined as sum between multiannual average and standard deviation of crop production years; crop production for which the default values of crop coefficients are given in Annex V/part D. The aggregation of information on greenhouse gas emissions (g CO2 ech MJ-1) at NUTS3 level corresponding to the fourth levels of crop production was done as an average of emissions from each soil-terrain unit under arable land use. The E4Tech model was then used for evaluation of spatial distribution of emissions. It was used the dependence between typical greenhouse gas emissions specific to sunflower crop and crop yield (optimum technology: multiannual average, multiannual average ± standard deviation; actual technology: multiannual average). The aggregation of these results at NUTS3 level showed that the default values for typical emissions included in the Directive are not reached even in case of optimum technology applied in favorable years for sunflower cultivation (average production + standard deviation). The greenhouse gas emissions had the lowest values in Braila, Ialomita and Calarasi counties. The reduction of greenhouse gas emissions within the whole chain of biofuels and biodiesel production from sunflower cultivation, which were evaluated based on multiannual national average for the period of 1991-2014 (actual technology) were 35% in favorable years and 11% in unfavorable years. These values are lower than the typical and default values from Annex V/part D from EU Directive.

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Published in AgroLife Scientific Journal, Volume 5, Number 2
Written by Silvia-Simona GROSU-TUDOR, Iulia-Roxana ȘTEFAN, Medana ZAMFIR

Lactic acid bacteria (LAB) used as starter cultures in food industry must survive under several stress conditions, including low pH, low water activity, high and low temperatures, oxidative stress, starvation and competition with other species. Also, a high resistance to low pH values and in the presence of bile salts is necessary for probiotic strains, in order to survive in the stomach and intestine, or even to compete with other bacterial groups in this environment and to colonize the gastrointestinal tract (GIT) of the host. The purpose of the present work was to evaluate the growth/survival of 19 LAB strains with biotechnological applications (production of bacteriocins, exopolysaccharides, S-layer proteins) under different stress conditions. The strains were investigated for tolerance to acidity (pH 2.0, 3.5, 4.5 and 5.5), bile salts (0.05%, 0.1%, 0.2%, 0.3% and 0.5%), different temperatures (15°C, 20°C, 28°C, 37°C, 42°C, 47°C, and 50°C), and different concentrations of NaCl (1%, 3%, 5%, and 7%). All 19 tested strains grew well at 28°C and 37°C, with a viability between 1010-1014 CFU/ml. Three strains grew well at 50°C reaching a viability of 108-109 CFU/ml. Four strains were resistant to pH 3.5 and 4.5, after 24 h of incubation reaching a viability of 1010 CFU/ml and 1014 CFU/ml, respectively. After 3 h of exposure to pH 2.0, two strains, namely Lb. brevis FV403 and Lb. brevis FV530, maintained a viability of 102-103 CFU/ml. Concerning the bile salt resistance, all tested strains showed a high resistance to a concentration of 0.3% (w/v), reaching a cell viability of 107-109 CFU/ml after 24 h of incubation. After 3 h of exposure to 0.5% (w/v) of bile salts, the viability of Lb. brevis FV530 was about 1010 CFU/ml. Six of the selected strains had a high resistance to NaCl (up to 7%) reaching a viability of 109 CFU/ml after 48 h of incubation.

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