Cucumber Seeds Research Articles

Auxin production and plant growth promotion by Microbacterium albopurpureum sp. nov. from the rhizoplane of leafless Chiloschista parishii Seidenf. orchid.

The strains of the genus Microbacterium, with more than 150 species, inhabit diverse environments; plant-associated bacteria reveal their plant growth-promoting activities due to a number of beneficial characteristics. Through the performance of diverse techniques and methods, including isolation of a novel Microbacterium strain from the aerial roots of leafless epiphytic orchid, Chiloschista parishii Seidenf., its morphological and biochemical characterization, chemotaxonomy, phylogenetic and genome analysis, as well as bioassays and estimation of its auxin production capacity, a novel strain of ET2T is described. Despite that it shared 16S rRNA gene sequence similarity of 99.79% with Microbacterium kunmingense JXJ CY 27-2T, so they formed a monophyletic group on phylogenetic trees, the two strains showed clear divergence of their genome sequences. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values of ET2T differed greatly from phylogenetically close JXJ CY 27-2T. Based on the differences being below the threshold for species similarity, together with the unique chemotaxonomic characteristics, strain ET2T represents a novel species of the genus Microbacterium. Several genes, putatively involved in auxin biosynthesis were predicted. This strain revealed obvious plant growth-promoting activities, including diazotrophy and biosynthesis of tryptophan-dependent auxins (indole-3-acetic and indole-3-pyruvic acids). Microbial auxins directly stimulated the rhizogenesis, so that the ET2T-inoculated seeds of wheat, cucumber and garden cress showed evident promotion in their growth and development, both under optimal and under cold stress conditions. Based on phenotypic, chemotypic and genotypic evidences, the strain ET2T belongs to the genus Microbacterium, order Micrococcales, class Actinomycetes, and it represents a novel species, for which the name Microbacterium albopurpureum sp. nov. is proposed, with strain ET2T (VKPM Ac-2212, VKM Ас-2998) as the type strain.

Study of mechanical and technological properties of seed fruits of vegetable and melon crops

The analysis of literature sources shows that the production of seed material for vegetable and melon crops is one of the most important problems that exists in the field of agricultural processing. The production of cucumber and melon seeds is an urgent issue in view of the volume of their cultivation in Ukraine. To study the processes of fruit grinding and seed production in agriculture, the key parameters are the dynamic friction coefficient, the volume deformation coefficient and the static load coefficient, but existing methods and equipment are limited to determining the limit values of the indicators, not allowing a full study of the dynamics of changes in properties at different stages of the technological process. To solve this, it is proposed to develop new methods, in particular, the use of computer modelling, which will allow a more detailed study and optimisation of physical and mechanical properties and their changes. The aim of the article was to study the physical and mechanical properties of vegetable fruits, which have the greatest impact on the quality of the technological process of fruit seed grinding and preliminary seed extraction. The study was conducted in the problematic research laboratory of the Faculty of Engineering and Energy of Mykolaiv National Agrarian University. Experimental setups were used to determine the dynamic coefficient of friction of melon and cucumber seeds, a device for determining the initial density of seed fruits, and a device for determining the dependence of seed deformation on compressive load. Experimental data show that the most optimal values of the static coefficient of friction, depending on the type of surface, for cucumber and melon seeds are perforated sieves, the values of which are 0.75 and 0.85, respectively. Optimal values of dynamic friction coefficients for cucumber have a surface made of perforated sieve – 0.69 and for melon made of aluminium – 0.88. The dependence of the linear deformation of seed fruits on the specific pressure increases from 0.9 to 3.6. The values of fruit deformation from compressive load vary from 4.1 to 24.6. The research presented in the article is of practical importance and can be used in the field of agricultural production and in the development of new engineering solutions

The Effects of Exogenous 2,4-Epibrassinolide on the Germination of Cucumber Seeds under NaHCO3 Stress

The Effects of Exogenous 2,4-Epibrassinolide on the Germination of Cucumber Seeds under NaHCO3 Stress

Osmotic Adjustment and Antioxidant Activity of Cucumber Seeds Pre-treated with Stress Attenuators and Subjected to Drought Stress During Germination

Osmotic Adjustment and Antioxidant Activity of Cucumber Seeds Pre-treated with Stress Attenuators and Subjected to Drought Stress During Germination

Communication Strategies in the Fast Food Industry in Romania

The article analyzes the existing technologies and means of mechanization of melon and cucumber seeds, which showed that the imperfection of existing equipment is, first of all, the lack of necessary specialized machines and leads to unacceptable rates of loss and clogging of seeds. The research projects were carried out to study the mechanical and technological properties of placenta particles and seeds of melon and cucumber, the results of which were used to theoretically substantiate the process of obtaining seeds. Experimental studies of the technological process of obtaining seeds for these crops, as well as their analysis, made it possible to substantiate the boundaries of the main operating modes of the new complex of machines.

Studying Stimulant and Fungicidal Properties of Preparation “Argitos Agro” against Powdery Mildew in Greenhouse Conditions

“Argitos Agro” is a plant growth stimulant with fungicidal effect and when disinfecting cucumber seeds and applying during the growing season, it does not have a significant effect on the development of powdery mildew disease. The preparation, indeed, has a stimulating effect on the germination of cucumber seeds, the growth of seedlings and plants, accelerates flowering, increases the yield and improves its quality indicators.

Cucumber seed polypeptides regulate RANKL-induced osteoclastogenesis through OPG/RANKL/RANK and NF-κB

Postmenopausal osteoporosis (PMOP) is a common disease that endangers the health of elderly women. Cucumber seeds have shown excellent therapeutic effects on PMOP, but the mechanism of cucumber seed peptide (CSP) remains unclear. The expression levels of NF-κB and osteoclast-related genes were detected by RT-qPCR. The levels of apoptosis-related proteins were detected by Western blotting. Nuclear translocation of NF-κB p65 and osteoclast formation were detected by immunofluorescence and tartrate-resistant acid phosphatase (TRAP) staining, respectively. ELISA was used to detect the expression levels of OPG, M-CSF, and RANKL. Hematoxylin–eosin (H&E) and TRAP staining were used to observe the effects of CSP on bone formation. In RAW264.7 cells, CSP (0.4 mg/L, 4 mg/L, and 40 mg/L) effectively inhibited the expression of osteoclast-related genes (Cathepsin-K, MT1-MMP, MMP-9, and TRAP). TRAP-positive multinucleated giant cells gradually decreased. Furthermore, NF-κB pathway activation downstream of RANK was inhibited. In bone marrow stromal cells (BMSCs), the expression levels of M-CSF and RANKL gradually decreased, and OPG gradually increased with increasing CSP concentrations. Treatment of RAW264.7 cells with pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB) prevented the formation of osteoclasts. Treatment with different concentrations of CSP effectively decreased the levels of RANKL and M-CSF in rat serum and increased the expression of OPG in the oophorectomy (OVX) rat model. Furthermore, different concentrations of CSP could ameliorate the loss of bone structure and inhibit the formation of osteoclasts in rats. CSP inhibits osteoclastogenesis by regulating the OPG/RANKL/RANK pathway and inhibiting the NF-kB pathway.

Behavior, intestinal health, and growth of small sea cucumbers Apostichopus japonicus in different color morphs

Selecting high-quality seeds with long-term advantages in behavior, intestinal health, and growth are the key to improve production efficiency of sea cucumber aquaculture. It is proposed to distinguish the seed quality of sea cucumbers by color morphs. In the present study, we carried out a 6-week experiment to investigate behavior, intestinal health, and growth of small sea cucumbers Apostichopus japonicus in different color morphs. We found that dark-colored seeds of sea cucumber were significantly more adhesive than those with light-colored seeds. This indicates that the dark-colored seeds of A. japonicus are more adaptive in complex environments in stock enhancement. Food consumption and defecation outputs of dark-colored seeds were significantly higher than those of light-colored seeds. In addition, the feces of dark-colored seeds of sea cucumber had significantly lower crude protein content and better intestinal morphology, but there was no advantage in digestive enzyme activities. This suggests that there are potential digestive benefits in dark-colored seeds. Further, dark-colored seeds of A. japonicus showed significantly better intestinal microbiota composition and faster growth rate than that of light-colored seeds. In conclusion, the present results prove that dark-colored seeds of sea cucumber have long-term advantages in behavior, intestinal health and growth. Overall, this study provides important information for the early selection of seeds and the consequent production efficiency in sea cucumber aquaculture.

Effect of Mycorrhizae, Azotobacter and Vermicompost Tea on Nitrogen, Phosphorus, and Potassium (NPK) Concentrations in Soil and Cucumber Plants (Cucumis sativus)

An experiment was carried out inside a greenhouse (sandy loam soil) at the College of Agriculture / University of Anbar to investigate the effect of Vesicular-Arbuscular Mycorrhizaee, Azotobacterchroococcum and Vermicompost tea on the concentration of NPK macronutrients in soil and cucumber plants. A factorial experiment consisting of two factors was designed for this purpose: the first factor is a combination of mycorrhizae (M) with 35 g plant−1, azotobacter (A) bacteria 16 ml plant−1 with a microbial density of 2.2 x 109 cfu ml−1 and phosphate Rock (R) with 40 g plant−1, added with half of the mineral fertilizer recommendation each individually with its interactions, the second factor is the addition of three concentrations (0, 5, 10%) of vermicompost tea sprayed on the plant. The experiment was designed with a completely randomized block design (RCBD) with three replications. Cucumber seeds were planted on 15/9/2022 and service operations were conducted for the crop and the experiment continued until 15/12/2022. The result showed highest percentage of phosphorus in the leaves (PIL) (0.40%), the highest potassium in the leaves (KL) (1.95%), followed by the treatment of adding mycorrhizae with phosphate Rock and half the mineral recommendation (MR) with vermicompost tea at a concentration of 10%, then the treatment of adding mycorrhizae with azotobacter bacteria with half the mineral recommendation (AR) with 10% of vermicompost tea, then the treatment of mycorrhizae with phosphate Rock plus half the fertilizer recommendation (MR) with 10% of vermicompost tea, then the treatment of mycorrhizae with azotobacter plus half of the fertilizer recommendation (MA) with 10% of vermicombe tea.

Enhancing the salt stress resistance of seeds and seedlings via a brassinolide sustained release agent system

BackgroundThe growing escalation of soil salinization is tremendously threatening the global food security and the development of sustainable agriculture. To address the worldwide predicament caused by salt stress toward crops, combining nanotechnology with the merits of plant hormone may become an efficient and effective approach.ResultsIn this work, a sustained release agent system (BR@MSN) was developed by loading brassinolide (BR) to mesoporous silica nanoparticles (MSN) to enhance the salt stress resistance of cucumber seeds and seedlings. The obtained BR@MSN agent was about 120 nm. As an endogenous plant hormone, promotion in crop growth was found at low BR concentration. Due to the sustained release property, BR@MSN avoided excessive BR exposure to seeds and seedlings to cause inhibitory effects. After the soil application of BR@MSN, the promotion effect from BR combined with the regulation enhancement from MSN nanocarrier improved the seed germination rate by 11.76% under saline environment. Compared with the same BR concentration (2.0 mg/L), BR@MSN increased the seed germination rate even by 1324.29%. In addition, remarkable wettability on foliar surfaces was found, and the foliar application of BR@MSN significantly enhanced the salt stress resistance of cucumber seedlings by alleviating the accumulation of reactive oxygen species (ROS) and increasing the cell viability along with the improvement in superoxide dismutase (SOD) activity (234.11%), the decrease in malondialdehyde (MDA) content (61.30%), and the increase in chlorophyll content (110.88%).ConclusionsThe newly developed BR@MSN agents could effectively enhance the salt stress resistance of crop seeds and seedlings, and their applications significantly improved the seed germination rate and seedling growth. The remarkable efficacy makes this BR@MSN agent system potential in agricultural field for enhancing the salt stress resistance of crops and facilitating the development of sustainable agriculture.Graphical

Rapid Detection and Quantification of Viable Cells of Pectobacterium brasiliense Using Propidium Monoazide Combined with Real-Time PCR.

Pectobacterium brasiliense (Pbr) has caused significant economic losses in major vegetable production areas in Northern China by causing bacterial soft rot in cash crops such as potatoes and cucumbers. This study aimed to establish a PMA-qPCR detection method for Pbr by screening specific and sensitive primers based on the glu gene and the conserved region of the 23S rRNA gene. Based on the optimized PMA pretreatment conditions, a standard curve was designed and constructed for PMA-qPCR detection (y = -3.391x + 36.28; R2 = 0.99). The amplification efficiency reached 97%, and the lowest detection limit of viable cells was approximately 2 × 102 CFU·mL-1. The feasibility of the PMA-qPCR method was confirmed through a manually simulated viable/dead cell assay under various concentrations. The analysis of potato tubers and cucumber seeds revealed that nine naturally collected seed samples contained a range from 102 to 104 CFU·g-1 viable Pbr bacteria. Furthermore, the system effectively identified changes in the number of pathogenic bacteria in cucumber and potato leaves affected by soft rot throughout the disease period. Overall, the detection and prevention of bacterial soft rot caused by Pbr is crucial.

Further Molecular Diagnosis Determines Lack of Evidence for Real Seed Transmission of Tomato Leaf Curl New Delhi Virus in Cucurbits.

Begomoviruses (family Geminiviridae) cause serious diseases in many crop families. Since 2013, the Spanish isolate of tomato leaf curl New Delhi virus (ToLCNDV) has been a limiting factor for cucurbits production in the Mediterranean basin, forcing farmers to adapt new management and control techniques. Although it is well-known that begomoviruses are naturally transmitted by the whitefly Bemisia tabaci, the capacity of these viruses to be vertically transmitted through seeds remains controversial. Clarifying the potential ToLCNDV seed transmission is essential to understand the epidemiology of this threating-for-cucurbits virus and to design appropriate control strategies. We assessed ToLCNDV distribution in the leaves, flowers and seeds of the infected plants of susceptible Cucumis melo accessions and toleration to the infected genotypes of Cucurbita moschata by conventional and quantitative PCR. We analyzed whether the viral particle was transmitted to offspring. We also evaluated ToLCNDV presence in commercial seeds of cucurbits (zucchini (Cucurbita pepo), melon (C. melo), cucumber (Cucumis sativus) and watermelon (Citrullus lanatus)) and in their progenies. As the assayed seedlings remained symptomless, we increased the reliability and accuracy of detection in these samples by searching for replicative forms of ToLCNDV by combining Southern blot hybridization and rolling-circle amplification (RCA). However, integral genomic DNA was not identified in the plants of offspring. Although the seedborne nature of ToLCNDV was confirmed, our results do not support the transmission of this virus from contaminated seeds to progeny.

First Report of Diaporthe fruit rot and stem canker of hydroponic cucumber caused by Diaporthe sp. in the United States.

Multiple Diaporthe spp. cause root and fruit rots or stem lesions on Cucumis spp.: D. cucurbitae, D. melonis, D. longicolla (syn. D. eres), D. pterocarpi, D. sclerotioides, D. sojae, and D. ueckerae (Broge et al. 2020; Fukada et al. 2018; Udayanga et al. 2012, 2015). From May-August 2021, cucumbers (Cucumis sativus) 'Katrina' and 'Alcazar' were grown in a 24-plant, commercial Bato bucket system with rockwool blocks on a perlite substrate in a research greenhouse in Wooster, Ohio. At maturity, plants collapsed rapidly from stem lesions without foliar chlorosis (25% of 'Katrina' and 17% of 'Alcazar'). Lesions were 7.5 to 15 cm in length, tan to golden-brown with black pycnidia and located 5 to 15 cm above the crown. Stems shredded easily with vascular discoloration around the lesion. Two identical fungal strains were isolated on ½ acidified potato dextrose agar (APDA) following surface disinfestation with 0.6% sodium hypochlorite for 30 s and sterile water rinse. Fungal cultures were floccose, white to tan mycelia with pycnidia. Oblong, elliptical, biguttulate, aseptate alpha conidia were observed with mean dimensions: 8.0 µm (5.2-9.8 µm) by 3.1 µm (2.5-3.8 µm) on ½ APDA and 9.8 µm (6.6-12.4 µm) by 3.0 µm (1.9-5.3 µm) on petioles. On prune extract agar, beta conidia mean dimensions were: 19.7 µm (12.0-27.7 µm) by 1.2 µm (0.8-1.8 µm). Fungal DNA was amplified and sequenced bidirectionally with ITS (ITS4/ITS5), CAL (CAL228F/737R), HIS (CYLH3F/H3-1B), TEF1 (EF1-728f/EF1-986R), and TUB2 (Bt1a/Bt1b) primers (Carbone and Kohn 1999; Glass and Donaldson 1995) (GenBank: OP265712-13, OP288460-65, OQ418506-07). Based on a maximum likelihood phylogenetic tree of concatenated genes, this novel Diaporthe sp., most closely related to D. stewartii, has not been reported on Cucumis spp. Strains were deposited in the USDA-ARS Culture Collection (NRRL# 64461-62). Koch's postulates were conducted in a greenhouse with mean day temperature of 25°C and 12 hr supplemental lighting. One-month old cucumbers 'Katrina,' grown in rockwool cubes (5 plants per isolate) and potting mix (6 plants per isolate), were inoculated with a one-week-old culture of either strain. The second true leaf was cut and a pipette tip containing an inoculated plug of ½ APDA was placed on the remaining petiole (Mathew et al. 2018). Non-inoculated ½ APDA was used for controls. Plants were tarped for 24 hours to increase humidity and pipette tips removed after one week. After two weeks, petioles were shrunken, tan to golden brown with pycnidia. After 3-4 weeks, stem lesions matching those above were observed on inoculated plants, and plants collapsed. For fruit rot, three Beit Alpha cucumbers were rinsed with tap water, dried, a 5 mm plug was removed from the fruit and replaced with a 5 mm plug of one-week-old fungus on ½ APDA. After 3 days, fruits were water soaked and soft. For root rot, two plates of one-week-old cultures were macerated in 500 mL of sterile water and mixed with 1500 mL of vermiculite. Two seeds of cucumber 'Katrina' were planted into three reps of each isolate and control. All control seeds germinated, but all inoculated seeds experienced pre- or post-emergence damping off. No symptoms were ever observed on any controls. Fungi were isolated from all inoculated tissues as described above. Based on morphology, Diaporthe sp. was isolated from all inoculated plants but never from controls. This Diaporthe sp. may be a new constraint to hydroponic cucumber production, but incidence needs to be determined globally.

Contribute to Know the Enzymes that Secreted by Trichoderma viride and its Spores Loaded by Alginic Acid on Cucumber Seeds

Trichoderma species are utilized as a biological fungicide in agriculture due to their great antagonistic ability. Additionally, they can increase nutrient uptake, fertility, stress resistance, and plant development. They are also opportunistic and symbiotic infections, which may cause plant defense systems to become active. There is a need to reveal the molecular underpinnings of the disease resistance that Trichoderma induces despite research documenting its biocontrol effectiveness against fungal diseases. Therefore, the objective of the current investigation was to identify the fungus-secreted enzymes and its spores loaded by alginic acid on cucumber seeds

Effect of Mycorrhizae, Azotobacter and Vermicompost tea on Nitrogen, Phosphorus, and Potassium (NPK) Concentrations in Soil and Cucumber Plants (Cucumis sativus)

An experiment was carried out inside a greenhouse (sandy loam soil) at the College of Agriculture / University of Anbar to investigate the effect of Vesicular-Arbuscular Mycorrhizaee, Azotobacterchroococcum and Vermicompost tea on the concentration of NPK macronutrients in soil and cucumber plants. A factorial experiment consisting of two factors was designed for this purpose: the first factor is a combination of mycorrhizae (M) with 35 g plant-1, azotobacter (A) bacteria 16 ml plant-1 with a microbial density of 2.2 x 109 cfu ml-1 and phosphate Rock (R) with 40 g plant-1, added with half of the mineral fertilizer recommendation each individually with its interactions, The second factor is the addition of three concentrations (0, 5, 10%) of vermicompost tea sprayed on the plant. The experiment was designed with a completely randomized block design (RCBD) with three replications. Cucumber seeds were planted on 15/9/2022 and service operations were conducted for the crop and the experiment continued until 15/12/2022. Concentrations of nutrients were measured in the soil after harvesting the crop as well as in the leaves of the plant. The results of the research proved that the use of mycorrhizae, azotobacter bacteria and phosphate Rock with half the mineral recommendation (MAR) and spraying vermicompost tea at a concentration of 10% are the best in increasing the concentration of nutrients in the soil and plant and revealed significant differences compared to mycorrhizae or azotobacter or vermicompost tea individually, so this treatment gave the highest concentration of available nitrogen (AN) (56.37 mg kg-1 soil), the highest available phosphorus (AP) (16.34 mg kg-1 soil), the highest available potassium (230.3 mg kg-1 soil), and gave the highest percentage of nitrogen in the leaves (NIL) (2.80%), The highest percentage of phosphorus in the leaves (PIL) (0.40%), the highest potassium in the leaves (KL) (1.95%), followed by the treatment of adding mycorrhizae with phosphate Rock and half the mineral recommendation (MR) with vermicompost tea at a concentration of 10%, then the treatment of adding mycorrhizae with azotobacter bacteria with half the mineral recommendation (AR) with 10% of vermicompost tea, then the treatment of mycorrhizae with phosphate Rock plus half the fertilizer recommendation (MR) with 10% of vermicompost tea, then the treatment of mycorrhizae with azotobacter plus half of the fertilizer recommendation (MA) with 10% of vermicombe tea. Then the two treatments of mycorrhizae (M) and azotobacter (A) separately, while finally came the treatment of chemical fertilization (S), which gave the lowest values to the mentioned properties in the soil and plants.

Valorization of Posidonia oceanica biomass: Role on germination of cucumber and tomato seeds

Biostimulants are organic compounds from plant sources such as botanical extracts and bioactive substances that promote plant growth, enhance photosynthesis and increase crop quality. The accumulation of detached Posidonia oceanica leaves on coasts of the Mediterranean Sea results in economic problems, due to the rejection of the tourists who frequent the beaches in the summer months. However, it is a plant with high content of secondary metabolites that can be used in sustainable agriculture. In this study we investigated the physicochemical characterization of Posidonia oceanica extracts with three different solutions and their application in tomato and cucumber seeds germination. The results showed that the aqueous extract of Posidonia oceanica had a high concentration of macro and micronutrients, as well as secondary metabolites with bioactive activity. The aqueous extract had a beneficial effect on both leaf and root growth on tomato seeds, specifically, an increase of 76% for the relative root growth and 73% for the germination index was obtained with respect to the control using the sample with the intermediate dilution (POe0.5). In addition, the extracts did not show toxicity to either germination or growth of the tomato plant. As for cucumber seed germination, the improvement was less significant and did result in a phytotoxic effect on both germination and plant growth. The most diluted extract had better results on seed germination. Therefore, the application of aqueous extracts of Posidonia oceanica were suitable to be appropriate for tomato germination and in turn contribute to eliminate the lots of Posidonia oceanica remains recovered in summer months in Mediterranean beaches.

In vitro assay of neutral electrolyzed water against Fusarium oxysporum and its application as germination pretreatment on tomato (Lycopersicon esculentum), lettuce (Lactuca sativa L.) and cucumber (Cucumis sativus) seeds.

Seed germination is critical for seedling procedures, and new technologies are required to increase crop yields. Some substances are considered elicitors or stimulating agents because they promote seed germination as well as plant growth (like root and plumule length, and germination rate among others). Some of these, could be applied during plant growth, or in earlier phases before germination as seeds pretreatment. Neutral electrolyzed water (NEW) is a solution of oxidizing agents mainly studied for its antimicrobial power mainly applied to food pathogens, and in less reports to phytopathogens. The objective of this work is to evaluate the effect of NEW on germination and morphological parameters of tomato (Lycopersicon esculentum), cucumber (Cucumis sativus) and lettuce (Lactuca sativa L.) seeds as well as to evaluate the in vitro activity of NEW against F. oxysporum. Two experiments were carried out to determine the in vitro and in vivo effects of NEW in seed pretreatment and another in vitro experiment was also carried out to determine antifungal effect against F. oxysporum. NEW in vitro treatments at 50 mg/L decreased spore concentration greater than 4 log spores/mL. Germination parameters and morphological variables were analyzed after NEW pretreatments. For in vitro germination, NEW pretreatments up to 75 mg/L did not show effect on germination parameters however highest dose was slightly adverse (4 % against water control). For in vivo germination, NEW pretreatment of 100 mg/L had a stimulating effect on the germination rate in cucumber seeds (100 % FGP against 83 % FGP for water control). For tomato seeds germination neither stimulate nor adverse effect was observed (same percentage as water control). For lettuce seeds germination an inhibitory effect for 12 and 24 h of exposure time was achieved (73 % NEW treatment against 90 % of water control). For tomato and lettuce seeds, the NEW pretreatment of 50 mg/L during 12 h increased its germination capacity.

Effect of multiple nonthermal plasma treatments of filamentous fungi on cellular phenotypic changes and phytopathogenicity

The effect of multiple sublethal doses of non-thermal plasma treatments on fungal cells phenotypical changes and the reduction in phytopathogenicity of Fusarium oxysporum, Botrytis cinerea, and Alternaria alternata was examined. The intensity of these changes depended on the species of fungus and the number of exposures of the mycelia to the DBD plasma. Microscopic observations showed that the plasma damaged the surface of the hyphae, increased their thickness and decreased overall dry biomass of the organisms. A decrease in pectinolytic activity was found in F. oxysporum and A. alternata, in contrast to B. cinerea, where an increase in pectinolytic activity was observed after the fifth plasma treatment. Changes in specific xylanase activity varied and were dependent on the species of fungus. The percentage of cucumber seeds germinated artificially infected with mycelium after multiple plasma treatments increased compared to those that were mycelium infected prior to plasma exposure. Plants that developed from seeds after plasma exposure were characterized by a higher biomass and longer roots and stems. Multiple treatments of the studied fungi with plasma, followed by seed infection, increased the SWVI and SWVI indexes of cucumber seedlings, but they did not reach the characteristic value of the control seeds (not infected with fungi). The reduced phytopathogenicity of the tested fungi was confirmed by artificial infestation of tomato fruits.

Dormancy Behaviour and Effectiveness of Dormancy Breaking Methods in Cucumber Seeds (Cucumis Sativus)

This study aimed to examine the dormancy behaviour and effectiveness of various dormancy breaking treatments on cucumber seeds. Freshly harvested cucumber seeds of varieties CU-1047 and CU-1051 were extracted, dried and stored for eight weeks at ambient temperature. The stored seed lots were tested for seed germination once a week and hormone analysis (ABA, GA, zeatin and kinetin) every two weeks. In a second experiment, dormancy breaking methods using dry heat treatment (DHT) at 36, 50 or 80°C for various lengths of time. Chemical treatments were also tested, with a 24-hour soaking time using GA3, KNO3 or ultra-fine bubble (UFB) water. The results showed that the dormancy persistence in both varieties was three weeks after the seeds were harvested, by which time germination reached more than 85%. The decrease in ABA content during the storage period correlated with an increase in seed germination. The most effective methods of breaking dormancy were dry heat at 80°C for 24 hours (highest germination: 62%) and a DHT chamber (59%) compared with control (1%). An alternative method was soaking the seeds in 1% KNO3 followed by drying to the initial moisture content (55% germination). UFB water was not effective in breaking the dormancy of cucumber seeds.

Seed Science and Technology. Volume 51 Issue 2 (2023)

Seed-enhancement treatments as a theme run through many of the papers in the second issue of volume 51 of Seed Science and Technology: the uses of priming are explored in two papers, one of which compares agents with the potential to improve chilling tolerance of tobacco seed during germination, and the other suggests Pseudomonas fluorescens and Bacillus amyloliquefaciens as forms of biocontrol against Bacterial Fruit Blotch when priming melon seeds. Dormancy-breaking is essential for many species, and two papers proffer suggestions that can be applied to seeds of cucumber (dry heat) and to kala zeera (chilling, phytohormones). A lesser- utilised seed enhancement, that of plasma pre-treatments, is explored in terms of promoting seedling growth and development when applied to seeds of a popular horticultural species, Platycodon grandiflorus. Cautionary notes when following approved seed testing methods are sounded in a finding that the impact of variety complicates the interpretation of results when using the radicle emergence test to evaluate seed quality of wheat, and in a report of the results of a capacity-building exercise, where the correlation between skill levels and successful propagation of Melia volkensii seeds was evident. Useful SSR markers for assessing genetic similarity and degree of purity of wheat cultivars grown in Romania are suggested, as too is an approach to using germination and/or viability data in order to allow seed banks to make data-informed management decisions that would ensure time and resources are effectively allocated. An invited review gives a thorough and comprehensive review of all matters relating to the determination and control of seed moisture, and includes discussions on water activity and working with seed that needs to be at high moisture contents. A book review of ”Plant Regeneration from Seeds: A Global Warming Perspective ”strikes a positive note, concluding that it will leave readers with ”a deep appreciation for the complex interplay of factors that influence plant regeneration and the potential consequences for ecosystems around the world ”.