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Number of results: 8
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Abstract

The current research aimed to use non traditional methods to control some stored grain insects. The effects of 180 millitesla (mT) magnetic field (MF) for six different exposure periods (3 min, 30 min, 1 h, 12 h, 24 h and 48 h) on mortality (%) of two stored grain insects, Tribolium casteneum adults and Trogoderma granarium larvae, reduction in F1-progeny (%), seeds germination (%) and seed components (%) after 8 months storage period were studied under laboratory conditions. According to results, the mortality (%) of tested insects increased with increasing of MF time exposure. Trogoderma granarium was more resistant than T. casteneum in which mortality reached 56 and 75%, respectively 14 days after from exposure period. Without any negative effect on seeds germination (%) the MF was very effective in protecting stored wheat from insect infestation up to 8 months compared to non-magnetic seeds which became infested after 3 months of storage. Furthermore, the germination (%) was accelerated by 6 h compared to non-magnetic seeds. The MF level caused a slight increase in the percent of total carbohydrate, crude protein and ash while slightly decrease the percent of moisture, total fats and crude fiber.
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Abstract

The article presents an experimental-theoretical analysis of fluidised-bed drying of poppy seeds directed on minimisation of energy. The analysis was performed for a complete drying node incorporating a heat exchanger and a fan. Two complementary factors were used in the exergetic evaluation: exergy efficiency and unit consumption of exergy. An analysis of drying in stationary bed was carried out for comparison purposes. Results of the exergetic analysis can become a basis for innovative works focused on decreasing energy consumption of a technological node being analysed, e.g. by the use of recirculation of fluidising-drying medium.
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Abstract

An effective procedure for producing transformed Centaurium erythraea plants from synthetic seeds is described. Explants were encapsulated in 3% sodium alginate with 3% sucrose. Encapsulated hairy roots were cultured on half-strength Murashige and Skoog (1/2 MS) or Woody Plant (WPM) agar-solidified regeneration media supplemented with 6-benzylaminopurine (BAP) or without the cytokinin. The use of WPM with 0.5 mg/L of BAP gave the best shoot formation frequency (86%) and mean number of shoots (15) per root segment. Shoots rooted with 97% frequency on 1/2 MS without growth regulators. Encapsulated shoot buds were cultured on onethird- strength MS agar medium (1/3 MS) supplemented with indole-3-butyric acid (IBA) (0.05 mg/L). The plantlet conversion frequency was 32%. The encapsulated hairy roots and shoot buds were stored for 4, 6 or 14 weeks at 4°C. Synthetic seeds encapsulated with 3% sodium alginate with 3% sucrose stored at 4°C remained viable for 6 weeks but their developmental parameters significantly decreased. Adding nutrient medium and growth regulator to the alginate matrix increased plantlet recovery from both non-stored and stored synthetic seeds: synthetic seeds retained their viability and ability to form plantlets even after 14 weeks of storage. Regenerated transformed plantlets of C. erythraea were acclimatized in the greenhouse.
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Abstract

The aim of the studies was to evaluate the influence of sowing rate, foliar fertilization (Basfoliar fertilizer 6-12-6) and chemical composition on the mechanical properties of narrow- leaved lupine seeds of cultivars Bojar and Regent. Single seeds were burdened in the direction perpendicular to the parting plane of cotyledons with constant speed 10 mm∙min-1. The crop year and cultivar have significantly differentiated the value of all the analyzed strength parameters of narrow-leaved lupine seeds. The seeds of cultivar Bojar had significantly higher values of all the strength parameters. The designated strength parameters of lupine seeds were negatively correlated with ash content, fiber and protein except for the destructive force. They were also positively correlated with the fat content.
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Abstract

The embryology of three polar flowering plants of the family Caryophyllaceae was studied using the methods and techniques of the light, normal and fluorescence microscopes, and the electron microscopes, scanning and transmission. The analyzed species were Colobanthus quitensis of West Antarctic (King George Island, South Shetlands Islands) as well as Cerastium alpinum and Silene involucrata of the Arctic (Spitsbergen, Svalbard). In all evaluated species, flowering responses were adapted to the short Arctic and Australian summer, and adaptations to autogamy and anemogamy were also observed. The microsporangia of the analyzed plants produced small numbers of microspore mother cells that were differentiated into a dozen or dozens of trinucleate pollen grains. The majority of mature pollen grains remained inside microsporangia and germinated in the thecae. The monosporous Polygonum type (the most common type in angiosperms) of embryo sac development was observed in the studied species. The egg apparatus had an egg cell and two synergids with typical polarization. A well-developed filiform apparatus was differentiated in the micropylar end of the synergids. In mature diaspores of the analyzed plants of the family Caryophyllaceae, a large and peripherally located embryo was, in most part, adjacent to perisperm cells filled with reserve substances, whereas the radicle was surrounded by micropylar endosperm composed of a single layer of cells with thick, intensely stained cytoplasm, organelles and reserve substances. The testae of the analyzed plants were characterized by species-specific primary and secondary sculpture, and they contained large amounts of osmophilic material with varied density. Seeds of C. quitensis, C. alpinum and S. involucrata are very small, light and compact shaped.
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Abstract

We used germination tests to assess the frequency of polyembryony in 9 asparagus cultivars with a high propensity to produce double embryos with different ploidy levels: Alpha, Andreas, Boonlim, Cipres, Eposs, Helios, Limbras, Ravel and Sartaguda. Twin embryos inside a single seed were found in 3 cultivars: Eposs 2n, Ravel 2n and Sartaguda 2n, at 0.60% frequency (15 seeds with twin embryos out of 2500 seeds). Of 30 obtained seedlings, 14 were separated diploid-diploid twins, 6 were conjoined diploid pairs, 8 were separated diploid-haploid and 2 were diploid-haploid pairs conjoined in the hypocotyl region. Some embryos showed unilateral dominance of one embryo (size and shape). The haploid status of the smallest embryo was confirmed by chromosome number (n=x=10) and flow cytometry (nuclear C DNA amount 1.95 pg). The haploid obtained in this manner possessed enough vegetative vigor to undergo chromosome doubling.
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Abstract

Shoot tips excised from shoot culture of Salvia officinalis were encapsulated in 2% or 3% (w/v) sodium alginate and exposed to 50 mM calcium chloride for complexation. Immediately or after 6, 12 or 24 weeks of storage at 4°C, the synthetic seeds were cultured for 6 weeks on half-strength MS medium supplemented with indole-3-acetic acid (IAA) (0.1 mg/l) and solidified with 0.7% agar. The frequency of shoot and root emergence from encapsulated shoot tips was affected by the concentrations of sodium alginate and additives in the gel matrix (sucrose, gibberellic acid, MS nutrient medium) as well as duration of storage. The frequency of shoot and root induction of non-stored synthetic seeds was highest with shoot tips encapsulated with 2% sodium alginate containing 1.5% sucrose and 0.5 mg/l gibberellic acid (GA3). Shoot tips maintained their viability and ability to develop shoots even after 24 weeks of storage when they were encapsulated in 3% alginate with 1/3 MS medium, sucrose (1.5%) and GA3 (0.25 mg/l). Root formation tended to decrease with storage time. Overall, 90% of the plantlets derived from stored and non-stored synthetic seeds survived in the greenhouse and grew to phenotypically normal plants. This procedure can enable the use of synthetic seed technology for germplasm conservation of S. officinalis, a plant species of high medical and commercial value.
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