Melilotus Alba Research Articles

Potential for the Accumulation of PTEs in the Biomass of Melilotus albus Med. Used for Biomethane Production

In this paper, a possible use of white sweet clover (Melilotus albus Med.) for phytoremediation was assessed. The plants were grown on soils with naturally occurring concentrations of potentially toxic elements (PTEs). First, the content of PTEs was determined in plant biomass and in soil samples using: (a) Optical emission spectrometry with inductively coupled plasma to determine Sb, As, Cd, Cu, Ni, Pb, and Se, and (b) thermal decomposition, amalgamation, and atomic absorption spectrometry to determine Hg. The effectiveness of Melilotus albus Med. (M. albus) for phytoremediation was evaluated using the bioconcentration factor (BCF). The phytoextraction potential of M. albus was determined using bioaccumulation factor (BAC) and translocation factor (TF) values. The highest concentration of PTEs in roots was detected for zinc (10.56 mg/kg of dry weight, DW) and copper (5.128 mg/kg of DW). Similarly, the highest concentration in above-ground parts of the plant was detected for zinc and copper (12.638 and 4.0 mg/kg of DW, respectively). Although the values were relatively high, the effectiveness of the absorption of these PTEs by plant biomass from the soil was relatively very low. BAC and BCF were always lower than 1. On the other hand, the results suggested that M. albus effectively transports PTEs (only for Zn, Pb and Hg) from roots to shoots, because TF was always higher than 1. However, the accumulation of PTEs from soils with a natural abundance of PTEs was not excessive in comparison to conventional maize silage. Therefore, there is no potential risk of biomethane production in biogas plants when biomass from M. albus is used.

Vertical Columns with Sustainable Green Cover: Meadow Plants in Urban Design.

Unique vertical column structures were constructed for the greening of a structure at the Botanical Garden of Vilnius University, in which a plant cover was formed using the turf rolls of semi-natural meadows that were wrapped on 197 columns, with each column consisting of three equal segments. By evaluating the species composition and the abundance of vegetation in the segments of the columns, we studied how this natural cover changes and what its survival potential is. During the five years of observation, 97 plant species were determined in total. Over time, the initial plant species of fertile soils were mostly replaced by ruderal, nitrophilous, and pioneer plants. Out of the 58 original species, 18 disappeared, while 39 new ones emerged. In the vegetation cover on the north exposition of the building, the original species composition declined faster. The most persistent species were ruderal short-lived Conyza canadensis, Melilotus albus, and Urtica dioica, and long-lived Elytrigia repens. As for vegetation classes, the initial plant communities of the Molinio-Arrhenatheretea elatioris vegetation class were partially replaced by the plant communities of the Koelerio-Corynephoretea canescentis and Artemisietea vulgaris classes; however, unformed plant communities finally became prevalent. All directions, including the north, east, south and west, were equally dominated by semi-shade- and semi-light-loving plant species, together with a less abundant representation of light-loving species. Meanwhile, an unexpected establishment of the light-loving annual Arabidopsis arenosa was observed on the least illuminated north exposition. Likewise, the perennial Festuca pratensis, which is particularly resistant to wintering, emerged and spread on all expositions. The vegetation in the vertical columns was dynamic, and the initial plant species significantly diminished in the five years; however, as new species took place, the columns remained sufficiently covered with a green carpet of plants. This study reveals the benefits of using semi-natural meadow turfs in vertical greening of buildings in the harsh climate of a 5b hardiness zone, which is accompanied by distressing climatic fluctuations during the vegetation season.

Stimulative Effects of Lupinus sp. and Melilotus albus Underseed on the Photosynthetic Performance of Maize (Zea mays) in Two Intercropping Systems

In order to evaluate influential mechanisms for photosynthetic processes on the yields of an intercropping system composed of maize (Zea mays), Lupinus sp. and Melilotus albus, three treatments were designed and conducted in southern Moravia (Czech Republic) in the form of agronomy trials. The treatments included sole maize (SM), maize with Lupinus sp. (ML) and maize with field melilot (MM). The photosynthetic processes of Zea mays were monitored using several chlorophyll fluorescence techniques on the three treatments for 20 days in the late summer season. An analysis of fast chlorophyll fluorescence transients (OJIP) showed that the capacity of photochemical photosynthetic reactions in photosystem II (FV/FM), as well as the photosynthetic electron transport rate (ET0/RC), declined in response to a four-day episode of extremely warm days with full sunshine. Similarly, the performance index (PI), an indicator of general plant vitality, declined. The episode activated protective mechanisms in photosystem II (PSII), which resulted in an increase of thermal dissipation. For the majority of Z. mays photosynthetic parameters, their values decreased for particular treatments in the following order: MM, ML, SM. The MM and ML intercropping systems had a positive effect on the primary photosynthetic parameters in Z. mays.

PHOTOSYNTHETIC PRODUCTIVITY OF MELILOTUS ALBUS IN SINGLE-SPECIES AND COMBINED CROPS IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE OF UKRAINE

There is a significant shortage of high-protein feed in all regions of Ukraine. One of the ways to solve this problem and a powerful reserve for reducing the cost of livestock production is the cultivation of perennial leguminous grasses, among which Melilotus albus deserves special attention - a valuable fodder crop that, even under extreme hydrothermal conditions, forms stable and high yields of vegetative mass, each kilogram of which contains 34-44 g of digestible protein. Today, there is insufficient scientific information about the high fodder and agrotechnical value of Melilotus albus, regarding the peculiarities of its cultivation for fodder in mixed crops with cereal crops. Photosynthetic activity of crops belongs to the main factors of formation of productivity of fodder agrophytocenoses. The aim of the research was to establish the influence of technological factors of cultivation on the photosynthetic productivity of Melilotus albus in single-species and crops compatible with cereal components. The research was conducted during 2015-2018 at the experimental fields of the Department of Fodder Production, Land Reclamation and Meteorology in the conditions of the SS NULES of Ukraine "Agronomic Research Station" on typical low-humus chernozem. It was established that under the investigated rates of mineral fertilizers and grass mixture models, the most developed photosynthetic apparatus was formed by crops with a Melilotus albus seeding rate of 16 kg/ha. As it increased, the leaf surface of fodder agrophytocenoses decreased. Before the onset of harvest maturity, the largest leaf area in the experiment was formed by binary crops of Melilotus albus with Sorghum drummondii against the background of - N60P90K90 application - 52.5 thousand m2/ha. Sowings of the indicated variant of the experiment also provided the maximum photosynthetic potential - 1279.7 thousand m2×day/ha and the maximum productivity in the experiment in terms of dry matter yield – 7.94 t/ha.

"CHEMICAL COMPONENTS OF MELILOTUS OFFICINALIS AND MELILOTUS ALBUS, GROWING IN UZBEKISTAN"

"CHEMICAL COMPONENTS OF MELILOTUS OFFICINALIS AND MELILOTUS ALBUS, GROWING IN UZBEKISTAN"

Ecological plasticity and adaptive potential of annual form of white sweet clover (Melilotus albus Medik)

The ecological plasticity, stability, and adaptive potential of varieties and promising genetic lines of the annual form of white sweet clover were assessed. The studies were carried out in 2016-2020 in Volga Scientific Research Institute of Selection and Seed-Growing named after P.N. Konstantinov, Samara Federal Research Scientific Center, Russian Academy of Sciences. According to the parameters of ecological plasticity and stability, the studied varieties and genetic lines were differentiated into groups according to their response to the changes in environmental conditions. Most of studied varieties belonged to highly plastic genotypes; varieties Srednevolzhsky, Kinelsky, Zavolzhsky, and genetic line Hugh 0 were characterized by the highest stability under the conditions of the Samara Trans-Volga Region. Varieties Srednevolzhsky, Kinelsky, Zavolzhsky, and genetic lines Hugh 0, Hugh 40 and Indus 1 were highly resistant to unfavorable environmental factors. All the studied genetic lines and varieties are characterized by high selective value and thus may be used as a starting material for developing of new varieties of the annual form of white sweet clover.

THE PHENOLIC PROFILE OF RAPESEED HONEY ENRICHED WITH MELILOTUS ALBUS FLOWERS AND ITS INHIBITORY EFFECT ON RAT PLATELET AGGREGATION

Background. The Melilotus plants are highly valued in herbal medicine, recommended for the prevention and treatment of thrombotic vein inflammation and varicose veins. Their health-promoting properties primarily result from the presence of coumarin and its derivatives. The aim of the study was to determine whether honey enriched with dried Melilotus albus flowers has the ability to inhibit platelet aggregation. The inhibitory activity of rapeseed honey (control sample), rapeseed honey enriched with 1 % w/w of M. albus dried flowers and pure coumarin were evaluated against ADP (5 µМ) and collagen (2 µg/ml) in duced aggregation of rat platelets. Platelet aggregation was measured by the turbidimetric method. Moreo ver, the quantitative polyphenolic profile determined using HPLC-PDA and volatile compounds profiles obtained by GC-MS methods for rapeseed and M. albus enriched honey were compared to identify the chemical factors that limit platelet aggregation. Results and conclusions. A beneficial, dose-dependent effect of enriched honey on the inhibition of the aggregation process was demonstrated, and for the highest concentration used (20 %), the inhibition of aggregation induced by ADP and collagen amounted to 75 % and 90%, respectively. A weaker inhibitory effect was found for pure rapeseed honey at 20 % concentration – 40 % and 55 % of inhibition, respective ly and pure coumarin (0.5 mg/ml) – 44 % and 20 %, respectively. The results obtained demonstrated that rapeseed honey enriched with M. albus flowers possesses antiplatelet activity resulting from the synergistic effect of coumarin and other bioactive compounds occurred in dried M. albus flowers, including phe nolic and volatile components.. However, the mechanism of this action needs further study.

Genome-Wide Analysis of the Rab Gene Family in Melilotus albus Reveals Their Role in Salt Tolerance

Melilotus albus is a high-quality forage, due to its high protein content, and aboveground biomass and salt tolerance. Rab (Ras-related protein in the brain) proteins are the largest GTPase family which play a key role in intracellular membrane transport, and many Rab genes have been identified in eukaryotes. The growth and distribution of M. albus are severely hampered by soil salinization. However, little is known about candidate genes for salt tolerance in M. albus. In this study, 27 Rab family genes were identified for the first time from M. albus, and divided into eight groups (Groups A-H). The number of introns in MaRabs ranged from one to seven, with most genes containing one intron. In addition, most MaRab proteins showed similarities in motif composition. Phylogenetic analysis and structural-domain comparison indicated that Rab family genes were highly conserved in M. albus. Members of the MaRab gene family were distributed across all eight chromosomes, with the largest distribution on chromosome 1. Prediction of the protein interaction network showed that 24 Rab proteins exhibited protein-protein interactions. Analysis of the promoter cis-acting elements showed that MaRab-gene family members are extensively involved in abiotic stress responses. RNA-seq data analysis of the MaRab-gene-expression patterns suggested that the Rab gene family possesses differentially expressed members in five organs and under salt stress, drought stress, and ABA (Abscisic Acid) treatment. Differentially expressed genes under drought stress, salt stress and ABA stress were validated by quantitative real-time PCR. Furthermore, heterologous expression in yeast was used to characterize the functions of MaRab1 and MaRab17, which were upregulated in reaction to salt stress. In summary, this study provided valuable information for further research into the molecular mechanism of the response of M. albus to saline stress, as well as the possibility of developing cultivars with high salt-resistance characteristics.

PHYTOEXTRACTION OF HEAVY METALS BY HERBAL PLANTS ON TECHNOGENIC SOILS

The purpose of the work is to study the specifics of the natural restoration of vegetation on highly toxic embryozems (on the example of the technogenic dump from the large chemical production «Usoliekhimprom», Irkutsk region). It was shown that organo-accumulative embryozem is the first stage of soil formation and the beginning of plant colonization. The level of technogenic soils pollution with heavy metals was assessed by a set of indicators, based on them, organo-accumulative embryozems were classified as soils with an extremely dangerous level of pollution. It was found that the first pioneers on these embryozems were 9 aboriginal species of herbaceous plants: Melilotus albus Medikus., Melilotus officinalis (L.) Pall., Trifolium hybridum L., Trifolium repens L., Trifolium pratense L., Vicia cracca L., Medicago sativa L., Sonchus arvensis L., Chamerion angustifolium (L.) Scop. A number of their unique features allow them to grow in conditions of very strong soil pollution – this is a high level heavy metals accumulation in phytomass, good adaptation of mineral nutrition to hard growing conditions, an increase in biomass during the growing season, and the absence of visual signs of damage. The obtained results give every reason to recommend these herbaceous plants for use as phytoextractors of heavy metals on technogenic dumps.

Assessment of digestates prepared from maize, legumes, and their mixed culture as soil amendments: Effects on plant biomass and soil properties.

Digestate prepared from anaerobic digestion can be used as a fertilizer, as it contains ample amounts of plant nutrients, mainly nitrogen, phosphorous, and potassium. In this regard, digestates produced from mixed intercropped cereal and legume biomass have the potential to enrich soil and plants with nutrients more efficiently than monoculture-based digestates. The objective of this study was to determine the impact of different types of digestates applied at a rate of 40 t·ha-1 of fresh matter on soil properties and crop yield in a pot experiment with lettuce (Lactuca sativa) as a test crop. Anaerobic digestion of silages was prepared from the following monocultures and mixed cultures: broad bean, maize, maize and broad bean, maize and white sweet clover, and white sweet clover. Anaerobic digestion was performed in an automatic custom-made system and applied to the soil. Results revealed that fresh and dry aboveground biomass as well as the amount of nitrogen in plants significantly increased in all digestate-amended variants in comparison to control. The highest content of soil total nitrogen (+11% compared to the control) and urease (+3% compared to control) were observed for maize digestate amendment. Broad bean digestate mediated the highest oxidizable carbon (+48%), basal respiration (+46%), and N-acetyl-β-D-glucosamine-, L-alanine-, and L-lysine-induced respiration (+22%, +35%, +22%) compared to control. Moreover, maize and broad bean digestate resulted in the highest values of N-acetyl-β-D-glucosaminidase and β -glucosidase (+35% and +39%), and maize and white sweet clover digestate revealed the highest value of arylsulfatase (+32%). The observed differences in results suggest different effects of applied digestates. We thus concluded that legume-containing digestates possibly stimulate microbial activity (as found in increased respiration rates), and might lead to increased nitrogen losses if the more quickly mineralized nitrogen is not taken up by the plants.

Influence of Bacteria of the Genus Pseudomonas on Leguminous Plants and Their Joint Application for Bioremediation of Oil Contaminated Soils

The modern approach to the creation of biological products to stimulate plant growth is based on the study of specific inter-bacterial interactions. This study describes the impact that the introduction of strains of the genus Pseudomonas has on annual and perennial leguminous plants and the ecosystem of the leguminous plant-the indigenous microbial community. The objects of research under the conditions of vegetation experiments were plants of field peas (Pisum sativum L.), white lupine (Lupinus albus L.), chickpea (Cicer arietinum L.), alfalfa (Medicago sativa subsp. varia (Martyn) Arcang.), and white sweet clover (Melilotus albus Medik.). For the treatment of plant seeds, a liquid culture of strains of growth-stimulating bacteria Pseudomonas koreensis IB-4, and P. laurentiana ANT 17 was used. The positive effect of the studied strains on the germination, growth and development of plants was established. There was no inhibitory effect of inoculants on rhizobia; on the contrary, an increase in nodule formation was observed. The possibility of recultivation of oil-contaminated soil using chickpea and alfalfa as phytomeliorants and growth-stimulating strains P. koreensis IB-4, P. laurentiana ANT 17 as inoculants was evaluated. It is proved that seed treatment improved the morphological parameters of plants, as well as the efficiency of oil destruction.

Genome-Wide Identification and Expression Profiling of the SRS Gene Family in Melilotus albus Reveals Functions in Various Stress Conditions.

The plant-specific SHI-related sequence (SRS) family of transcription factors plays a vital role in growth regulation, plant development, phytohormone biosynthesis, and stress response. However, the genome-wide identification and role in the abiotic stress-related functions of the SRS gene family were not reported in white sweet clover (Melilotus albus). In this study, nine M. albus SRS genes (named MaSRS01-MaSRS09) were identified via a genome-wide search method. All nine genes were located on six out of eight chromosomes in the genome of M. albus and duplication analysis indicated eight segmentally duplicated genes in the MaSRS family. These MaSRS genes were classified into six groups based on their phylogenetic relationships. The gene structure and motif composition results indicated that MaSRS members in the same group contained analogous intron/exon and motif organizations. Further, promoter region analysis of MaSRS genes uncovered various growth, development, and stress-responsive cis-acting elements. Protein interaction networks showed that each gene has both functions of interacting with other genes and members within the family. Moreover, real-time quantitative PCR was also performed to verify the expression patterns of nine MaSRS genes in the leaves of M. albus. The results showed that nine MaSRSs were up- and down-regulated at different time points after various stress treatments, such as salinity, low-temperature, salicylic acid (SA), and methyl jasmonate (MeJA). This is the first systematic study of the M. albus SRS gene family, and it can serve as a strong foundation for further elucidation of the stress response and physiological improvement of the growth functions in M. albus.

THE FIRST EXPERIENCE IN THE DEVELOPMENT OF THE RICHES OF THE VASYUGAN SWAMP

Introduction to Siberia of bees of different breeds such as Italian Apis mellifera ligustica Spin., Apis mellifera carnica Pollm., Kuban (yellow Caucasian) Apis mellifera remipes Gerst., Far Eastern Apis mellifera acervorum, grey mountain Caucasian Apis mellifera caucasica Gorb. led to the fact that crossbreeds of an unknown generation predominate in the Novosibirsk region. These bees are rich in swarms, do not winter well, and the egg-laying of the queens is low. Currently, the importation of packet bees has stopped due to sharp increases in fuel prices (fuels and lubricants) and air and rail transport. But the importation of fetal queen bees is still ongoing. The authors studied the method of reproduction of bee colonies to preserve the beekeeping industry in Western Siberia. In one of the promising regions of Western Siberia, in the Vasyugan swamps, nectariferous plants grow for breeding bees. In that place, plants grow such as Rubus idaeus L. (common raspberry), Angelica sylvestris L. (wood angelica), Archangelica decurrens L. (Siberian angelica), Ribus nigrum L. (black currant), Sonchus arvensis L. (field sow thistle), Melilotus officinalis L. (yellow sweet clover), Melilotus albus Medik. (White sweet clover), Centaurea scabiosa L. (rough cornflower), Salix L. (willow), Taraxacum Wigg. (dandelion), Dracocephalum nutans L. (Siberian snakehead), Glechoma bederaceae L. (ivy-shaped budra), Prunella vulgaris L. (common blackhead). These plants are an excellent forage base for beekeeping. For two years of research, the authors found that the collection of honey per bee colony was in the group where the bees were propagated by natural swarming, 51.8 ± 5.1 kg, individual layering - 49.9 ± 4.3, prefabricated layering - 55, 6±3.1 kg. The strength of the families that went into the winter was 8.47±0.30; 8.77±0.20 and 9.06±0.40 bee space, respectively. Reproduction of bee colonies for two years showed that it is possible to increase the number of bee colonies from 4 to 16 (403%) by natural swarming, by individual layers - up to 19 (572%), and teams - up to 17 (422%).

Hidden reserves of the Vasyugan swamps for the production of beekeeping products

In recent years, the demand for organic products has increased on the world market, including environmentally friendly and healthy beekeeping bioproducts. Organic beekeeping currently exists in 60 countries around the world. In our country, there are vast territories for creating apiaries of a new topical direction. These territories are located north of the Trans-Siberian Railway from the right bank of the Irtysh to the left bank of the Ob - these are the Vasyugan swamps. Administratively, Vasyuganye unites the Omsk, Tomsk, and Novosibirsk regions. This territory is located in the wind rose, where the air masses of cities with industrial gases bypass it. Therefore, bee products collected by bees do not contain harmful elements. At present almost no one lives here and does not engage in agriculture. As a result of a survey of the natural forage base of the Vasyugan swamps, the authors discovered the most important honey plants and perganos. These are common coltsfoot, soft fluffy lungwort, marsh marigold, medicinal dandelion, late dandelion, Asian bathing suit, willows, warty birch, fluffy birch, ivy-like budra, bird cherry, white clover, black currant, yellow acacia, Siberian snakehead, chistets swamp, forest kupyr, mouse peas, thin-leaved peas, meadow geranium, forest geranium, forest raspberry, dissected cow parsnip, forest angelica, common goutweed, wild parsnip, common serpukha, field bodyak. Thus, this area is a rich pasture for bees. The authors recommend sowing wastelands with yellow sweet clover (Melilotus officinalis L.) and white sweet clover (Melilotus albus Medik.) if it is expedient to organize apiaries in Vasyuganye. This area will always be well visited by bees and provide honey collection from 5 to 10 kg per day for several years.

Genome-Wide Identification of ERF Transcription Factor Family and Functional Analysis of the Drought Stress-Responsive Genes in Melilotus albus.

As an important forage legume with high values in feed and medicine, Melilotus albus has been widely cultivated. The AP2/ERF transcription factor has been shown to play an important regulatory role in plant drought resistance, but it has not been reported in the legume forage crop M. albus. To digger the genes of M. albus in response to drought stress, we identified and analyzed the ERF gene family of M. albus at the genome-wide level. A total of 100 MaERF genes containing a single AP2 domain sequence were identified in this study, named MaERF001 to MaERF100, and bioinformatics analysis was performed. Collinearity analysis indicated that segmental duplication may play a key role in the expansion of the M. albus ERF gene family. Cis-acting element predictions suggest that MaERF genes are involved in various hormonal responses and abiotic stresses. The expression patterns indicated that MaERFs responded to drought stress to varying degrees. Furthermore, four up-regulated ERFs (MaERF008, MaERF037, MaERF054 and MaERF058) under drought stress were overexpressed in yeast and indicated their biological functions to confer the tolerance to drought. This work will advance the understanding of the molecular mechanisms underlying the drought response in M. albus. Further study of the promising potential candidate genes identified in this study will provide a valuable resource as the next step in functional genomics studies and improve the possibility of improving drought tolerance in M. albus by transgenic approaches.

PHYTOSANITARY STATE OF THE AGROECOSYSTEM OF WINTER WHEAT DEPENDING ON THE PREDECESSORS OF PERENNIAL LEGUMINOUS GRASSES

The article deals with the issues of increasing the resistance of winter wheat crops to the effects of the most common diseases, weeds and pests for growing after the predecessors of six types of perennial leguminous grasses without using pesticides. The damage caused to the leaf surface of winter wheat by septoria and powdery mildew diseases has been shown. The number of cockchafer larvae has been analysed. Determining the predominant types of weeds in the context of predecessors the level of weed infestation of winter wheat crops has been researched. The level of winter wheat yield depending on its predecessors has been assessed and correlation-regression dependences between it and the spread of pests, diseases and weeds in their crops have been identified. A close correlation between winter wheat yield and the damage caused to the leaf surface by powdery mildew has been proved. It has been shown that the highest level of winter wheat yield is observed after meadow clover. The slightest damage to the leaf surface of winter wheat caused by powdery mildew has been found after the predecessor of meadow clover. After the predecessor of white sweet clover the damage caused to the winter wheat’s leaf surface by the septoria disease was minimal. During the sowing season of winter wheat, no cockchafer larvae were found in the arable layer of soil after the predecessors of alfalfa, white sweet clover and fodder galega. The smallest number of weeds during the spring growth of winter wheat was found after the predecessor of white sweet clover. Meadow clover provides the highest productivity level of the winter wheat yield in case of cultivation after six types of perennial leguminous grasses without additional use of mineral fertilisers – 5,8 t/ha. The minimal damage to the leaf surface of winter wheat plants caused by powdery mildew Erysiphe graminis DC has been found after the meadow clover predecessor – 6%, without using fungicides. The damage to the leaf surface of winter wheat from Septoria tritici Mg disease without fungicides was the smallest after white sweet clover – 5%. During the sowing season of winter wheat no cockchafer larvae Melolontha melolontha L. has been disclosed in the arable layer of the soil after alfalfa, white sweet clover and fodder galega predecessors. The smallest number of weeds in the period of spring growth of winter wheat has been observed after white sweet clover predecessor – 12 pcs/m2.

Characterization of B-box family genes and their expression profiles under abiotic stresses in the Melilotus albus.

B-box (BBX) proteins are one of the zinc-finger transcription factor that plays a critical role in plant development, growth, and multiple stress responses. Although BBX genes have been reported in many model organisms, no comprehensive study has yet been conducted on the BBX genes in Melilotus albus, and the biological functions of this family remain unknown. In this study, a total of 20 BBX (MaBBX) genes were identified in M. albus and were phylogenetically divided into five clades. BBX members within the same clade showed similar conserved domain, suggesting similarity of potential biological function. Analysis of MaBBX conserved motifs showed that every subfamily contained two common motifs. Distribution mapping shows that BBX proteins are nonrandomly localized in eight chromosomes. The synteny showed that most homologous gene pairs of the MaBBX gene family were amplified by segmental replication, which meant segmental replication was the main way for the MaBBX gene family to evolve. Additionally, the cis-element analysis predicted light-responsive, various hormone and stress-related elements in the promoter regions of MaBBXs. Furthermore, the expression levels of all 20 MaBBX genes were detected by qRT-PCR under salt, cold, and dark stresses in M. albus. Moreover, it was observed that 16 genes had higher expression levels after 3 h of salt treatment, 10 genes were significantly upregulated after 3 h of cold treatment, and all genes were up regulated after 3 h of dark treatment, and then appeared to decline. In addition, it was also noticed that MaBBX13 may be an important candidate for improving tolerance to abiotic stress. The prediction of protein tertiary structure showed that the tertiary structures of members of the same subfamily of MaBBX proteins were highly similar. The hypothesis exhibited that most of the MaBBX proteins were predicted to be localized to the nucleus and cytoplasm and was validated by transient expression assays of MaBBX15 in tobacco leaf epidermal cells. This study provides useful information for further investigating and researching the regulatory mechanisms of BBX family genes in response to abiotic stresses in M. albus.

Pollen assemblage variability of Apis mellifera honeys (Diamante, Entre Ríos, Argentina)

The pollen assemblage of 27 honey samples produced by Apis mellifera from three apiaries in the Diamante department, Entre Ríos (Argentina) were analysed. The study area is highly anthropised with cereal, oilseed and forage crops. The samples were obtained sequentially over four apicultural seasons (1999–2000; 2000–2001; 2001–2002; 2002–2003). In each season, one to three honey extractions, corresponding to the initial (I), middle (II) and final (III) productive periods, were made. Pollen assemblage of the honey reflected the study area vegetation. Monofloral honey were exclusively from exotic species, mainly of the dominant crops. Monofloral honey of Lotus corniculatus, Melilotus albus, Medicago sativa, Ammi, Glycine max and ‘clovers’ were obtained. The monofloral honey corresponded to 87.5%, 50% and 66%, respectively, to the honeys obtained in each productive period over the four apicultural seasons. The intra-annual variation of the samples responded to the phenology of the plant species. The inter-annual variations were associated with differential foraging, and the amount of precipitation during the apicultural period. Significant variations were observed when each apiary is compared to itself in different apicultural seasons, and in identical productive periods. Apis mellifera used a fraction of the available flora as nectar resources. The number of plant species visited remained relatively constant throughout the productive periods although it was higher during the apicultural seasons with lower rainfall.

ЕКОЛОГО-ЕКОНОМІЧНА ТА БІОЕНЕРГЕТИЧНА ОЦІНКА ТЕХНОЛОГІЙ ВИРОЩУВАННЯ ПШЕНИЦІ ОЗИМОЇ ПІСЛЯ БОБОВИХ БАГАТОРІЧНИХ ТРАВ

Topicality. The economic crisis requires modern winter wheat cultivation technologies based on the principles of financial feasibility, energy saving and environmental safety. Issues. Changes in animal husbandry have led to the differentiation of fodder crops, which are used as predecessors of winter wheat. Now, other types of perennial legume grasses are grown along with its traditional predecessor meadow clover. However, it is necessary to carry out research and calculations due to the lack of results of the ecological, economic and bioenergy feasibility of non-traditional perennial legume grasses as predecessors of winter wheat. Aim. To investigate the indicators of ecological, economic and bioenergy efficiency of winter wheat cultivation after six species of perennial legume grasses as predecessors, such as meadow clover, alfalfa, sand esparcet, white sweet clover, bird's-foot-trefoil, eastern galega, and also after the maize for silage (control). Methods. Field studies with subsequent calculation of economic efficiency of winter wheat cultivation based on technological charts and costs, as well as the energy efficiency of the technologies under study according to the methods of O.K. Medvedovskyi, P.I. Ivanenko and VASKHNIL were conducted. Results. The highest grain yield was 6.52 t/ha when winter wheat was cultivated after maize for silage with high rates of mineral fertilizers and pesticides. When winter wheat was cultivated after perennial legume grasses, the rates of mineral fertilizers and pesticides were significantly lower. Accordingly, the grain yield of winter wheat grown after perennial legume grasses was by 11.1–38.2 % lower than after silage maize, and it was 4.03–5.80 t/ha. The highest grain yield was observed after meadow clover, and the lowest – after bird's-foot-trefoil. The highest level of profitability (90.7 %) is provided by the cultivation of winter wheat after the predecessor meadow clover. When winter wheat was grown after such predecessors as meadow clover, white sweet clover, sand esparcet and eastern galega with limited rates of pesticides and mineral fertilizers, the level of profitability was 5.7–46.8 % higher than indicator for winter wheat after silage maize with high rates of mineral fertilizers and pesticides At the same time, winter wheat profitability after bird's-foot-trefoil and alfalfa equaled to the indicator for silage maize. Conclusions. The technology of winter wheat cultivation after meadow clover, which provided the highest energy coefficient 4.96, is the most profitable and the least energy-intensive. Key words: economic assessment, bioenergy assessment, cultivation technology, winter wheat, predecessors.

Viability of Wildflower Seeds After Mesophilic Anaerobic Digestion in Lab-Scale Biogas Reactors.

The use of wildflower species as biogas feedstock carries the risk that their seeds survive anaerobic digestion (AD) and cause weed problems if spread with the digestate. Risk factors for seed survival in AD include low temperature, short exposure and hardseededness (HS). However, it is not possible to predict how AD will affect seed viability of previously unstudied species. In laboratory-scale reactors, we exposed seeds of eight species from a mixture of flowering wild plants intended as biogas feedstock and three reference species to AD at two mesophilic temperatures. Half of the species were HS, the other was non-HS (NHS). Viability was determined using a combination of tetrazolium and germination tests. Viability and germinability were modeled as functions of exposure time using a dose-response approach. Responses to AD varied considerably among species, and none of the considered influencing factors (time, temperature, HS) had a consistent effect. Seed lots of a species differed in inactivation times and seed-killing efficacy. The HS species Melilotus officinalis, Melilotus albus, and Malva sylvestris were particularly AD-resistant. They were the only ones that exhibited biphasic viability curves and tended to survive and germinate more at 42°C than at 35°C. Viability of the remaining species declined in a sigmoidal curve. Most NHS species were inactivated within a few days (Cichorium intybus, Daucus carota, Echium vulgare, and Verbascum thapsus), while HS species survived longer (Malva alcea). AD stimulated germination in the HS species A. theophrasti and its AD-resistance overlapped with that of the most resistant NHS species, C. album and tomato. In all seed lots, germinability was lost faster than viability, implying that mainly dormant seeds survived. After the maximum exposure time of 36 days, seeds of HS species and Chenopodium album were still viable. We concluded that viability responses to mesophilic AD were determined by the interplay of AD-conditions and species- and seed-lot-specific traits, of which HS was an important but only one factor. For the use of wildflowers as biogas feedstock, we recommended long retention times and special care with regard to HS species.