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The obtained results indicate that in analysed seed leaves of seedlings of spring triticale ‘Kargo’ cultivar exposed to low temperature occurs a statistically significant decrease in total protein content, comparing to the control. Similar results were showed by analysing the concentration of this protein fraction in propagation joints and roots of seedlings of spring triticale ‘Kargo’ (exception propagation joints after 24 h of exposition to low temperature). Simultaneously a statistically significant increase in soluble protein content in seed leaves was found (exception 12 h of exposition to low temperature) and propagation joints after 12 h of their exposition, comparing to the control plants. Moreover, statistical analysis showed a significant increase in concentration of this protein fraction in roots of seedlings exposed to coldness after 1 and 12 h, comparing to the control.
Tick-borne pathogens are common in the natural environment, but their occurrence has a focal character. They occur in the natural environment in the form of the enzootic sources of infection. The general components include the animal reservoir, amplifiers and the efficient vector. However, the particular role of components can differ depending on the pathogen, the host range and possible transmission routes. Animal reservoir of pathogen are vertebrate animals, being the hosts of pathogens. In Europe these are small or medium-sized mammals and sometimes birds that feed on the ground. The competence of an animal reservoir is determined by the ability to communicate the infection; long-term persistence of the pathogen in the host; long-duration of infectivity of the animal for ticks; a sufficient number of animals in the endemic region. Amplifiers for ticks are artiodactyls. They are hosts for nymphs and adult ticks, thereby making it possible for ticks to propagate and maintain the proper size of their population. Efficient vector for pathogen are ticks. The first characteristic feature of efficient vectors is feeding duration exceeding 24 hours; the high density of the tick population. The conditions necessary to consider ticks as efficient vectors are met in Central Europe by the Ixodes ricinus, Dermacentor reticulatus and D. marginatus ticks. There are the general differences in biology between Ixodes persulcatus complex ticks and Dermacentor ticks, affecting their different role and ability in pathogens spreading – the range of hosts; the ability to inhabiting of various environments and resistance to unfavourable conditions; the duration of larvae and nymphs activity. The combination of tick’s biology, pathogen ability to transmission, and mammal hosts’ competence, determines the particular role of larvae, nymphs and adults in pathogen circulation in the natural environment, as well as transmission to new hosts.
Host specialization plays a central role in physiological diversification of aphids and plant-insect co-evolution. Different morphs of the bird cherry-oat aphid (Rhopalosiphum padi L.) are specialized and locally adapted to both primary and secondary hosts. The abundance of bird cherry-oat aphid population was estimated using the technique of direct counting of aphid individuals infesting 50 randomly selected, fully expanded 1-year side shoots of bird cherry (approx. 40 cm long) grown in the Municipal Park „Aleksanria” in Siedlce (central-eastern Poland). Entomological observations were conducted during three consecutive vegetation seasons: 2001–2003. The impact of R. padi feeding on composition of free amino acids within leaves of its primary host (the bird cherry, Prunus padus L.), infested and uninfested by aphids were studied. Eight essential amino acids (Val, Thr, Phe, Ileu, Leu, Met, His and Lys) and seven non-essential amino acids (Asp, Glu, Pro, Ser, Ala, Gly and Tyr) were identified in the bird cherry-oat leaves with the use of highperformance liquid chromatography (HPLC) separation. There were quantitative differences in free amino acids content between the tested bird cherry-oat leaves (infested and uninfested by aphids). Levels of the free amino acids were decreased in leaves attacked by R. padi, and detailed analyses revealed about 20% decline in the content of studied components during maximal aphid abundance in comparison with non-infested leaves. Additionally, the feeding behavior of the bird cherry-oat aphid seasonal morphs (fundatrix, fundatrigeniae, alatae) on the primary host was investigated. Using the electrical penetration graph (EPG) we showed differences in feeding behavior of bird cherry-oat aphid morphs on primary host. The total probing time was greatest for fundatrigeniae among all studied morphs. These individuals spent more time during phloem sap ingestion then others. Adults of alatae were not active in the phloem sap ingestion on the bird cherry. Among the tested morphs xylem sap ingestion activity was greatest for alatae. It is hypothesized that rejection of primary host and subsequent the bird cherry-oat aphid migration onto secondary hosts may be stimulated by the decline in levels of free amino acids within primary host leaves caused by long-term R. padi feeding. Comparative analyses of the aphid probing behavior additionally proved that P. padus leaves possessed high nutritive value of food for non-winged morphs (early stages of aphid infestation), while not sufficient for winged alatae (terminal phase of infestation).
We studied the effect of qualitative and quantitative variation of saponin content in foliar tissues of four European alfalfa (Medicago sativa L.) cultivars (Radius, Sapko, Sitel, Radius line 1) on pea aphid (Acyrthosiphon pisum Harris) development, and the effect of aphid infestation on alfalfa saponin content. Aphids (adult apterae, larvae, and adult alatae) were counted on 3-, 6- and 9-month-old plants (before the first, second and third cutting). Thin-layer chromatography was used to detect and estimate the quantity of the following saponins: 3GlcA, 28AraRhaXyl medicagenic acid; 3Glc, 23Ara, 28AraRhaXylApi zanhic acid (zanhic acid tridesmoside); and 3RhaGalGlcA soyasapogenol B (soyasaponin I). Radius, Sapko, and Sitel contained all three saponins but Radius line 1 did not contain zanhic acid tridesmoside or medicagenic acid glycoside. Saponin content was highest in Radius and lowest in Radius line 1. Regardless of the cultivar, saponin content was higher in aphid-infested than uninfested plants. For all sampling dates, aphid numbers were highest on Radius line 1 and lowest on Radius; that is, aphid numbers were inversely related to saponin content. Alfalfa has a herbivoreinduced defense. Saponin levels increase in the foliage of infested alfalfa. Attempts of plant breeders to reduce saponin content in order to increase alfalfa digestibility for livestock might make the plants more susceptible to aphids and other pests.
Qualitative and quantitative contents of free amino acids in the flag leaves and ears of winter tritica- le treated with herbicide Chwastox D 179 SL were determined, using ion-exchange chromatography. Fifteen protein amino acids were identified and determined. The obtained results showed that her­bicide treatment did not influence the qualitative composition of free amino acids in the tested win­ter triticale. The quantitative analysis proved a decrease of the studied compounds in plants treated with Chwastox D 179SL.
The molecular characteristics of partly purified sucrose synthase (NDP-glucose: D-fructose 2-α-D-glucosyltransferase, EC 2.4.1.13), extracted from the bird cherry (Prunus padus L.) leaves was elucidated. The sucrose synthase was successfully purified by using a four-step protocol including ammonium sulfate precipitation, dialysis, gel filtration on Sephadex G-150 and ion-exchange chromatography with the use of DEAE-cellulose. The analysed enzyme occurred in two isoforms (SuSyI and SuSyII). The relative molecular weight of native isoenzymes was estimated to be 200 and 180 kDa, respectively. Isoform SuSyI contained two different subunits of 57.5 and 52.8 kDa, whereas the structure of SuSyII was consisted of identical 63 kDa subunits. Experimental data indicated that the structure of both SuSy isoforms was composed of three subunits
The aim of the study was to determine the activity of ß-fructofuranosidase isolated from the bird cherry leaves collected in the period of spring development (April-May). The extracted enzyme was subjected to preliminary purification with ammonium sulphate and further purification with the use of column chromatography (Sephadex G-150). The obtained results proved that extracts purified by means of chromatography contained a more active enzyme and lower protein content in comparison with the crude ones. Furthermore, a statistically significant gradual decrease in invertase activity in the bird cherry leaves was noticed during the analysed period of vegetation.
Changes in activity of the grain aphid peroxidase (Px) and polyphenol oxidase (PPO) towards phenolics isolated from leaves of black currant, sour cherry and walnut were examined. Slight increase in activity of peroxidase was found within insect tissues after 24 h of walnut extract treatment, whereas black currant and sour cherry strongly inhibited activity of this enzyme. Later on, the walnut extract reduced activity of the enzyme, finally about 30%. The other extracts showed slight changes in Px activity. The grain aphid’s polyphenol oxidase was stimulated during the first 24 h of the experiment. Further treatment with the phenolics extracts reduced activity of the grain aphid polyphenol oxidase. Generally, phenolics isolated from the black currant and sour cherry were more effective in reducing activity of the aphid peroxidase, whereas phenolics from walnut reduced the polyphenol oxidase activity. Possible application of the phenolics isolated from the woody plants as modern biopesticides towards the grain aphid is discussed.
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