Mikromicetai turi didelę reikšmę miglinių javų sėklos kokybei. Susidarius palankioms sąlygoms sėkla plintantys grybai gali sumažinti sėklos dygimo energiją ir daigumą, susilpninti augalo šaknų sistemą, sumažinti augalų žaliąj�� masę ir derlių. Kai kurie grybai sėklai gali padaryti netiesioginę žalą - pakeisti spalvą, kvapą, deformuoti jos paviršių. Gamindami ir išskirdami į aplinką mikotoksinus, mikroskopiniai grybai menkina javų grūdų kaip maisto, pašarų realizacinę vertę. Sėklos beicavimas cheminiais preparatais neleidžiamas ekologiniuose ūkiuose. Kaip alternatyva beicavimui, javų sėklai apdoroti naudojami įvairūs fiziniai metodai. Tačiau kai kurių metodų poveikiai sėkla plintantiems mikromicetams išaiškinti nepakankamai, nenustatytos šių poveikių optimalios ekspozicijos, atskirais atvejais po jų poveikių sumažėja sėklos daigumas, kuris yra labai svarbus grūdams, naudojamiems kaip sėklinė medžiaga. Be to, literatūroje yra mažai duomenų apie 100°C temperatūros drėgnojo vandens garo terminių impulsų panaudojimą siekiant mažinti sėkla plintančius mikromicetus. Lietuvoje literatūros apie atskirų fizinių procesų poveikių javų sėkla plintančių mikromicetų kontrolei tyrimus randama negausiai. Įvairios mikromicetų kontrolės priemonės tirtos skirtingu laiku, skirtingais parametrais, kai kurie iš parametrų tyrimų metu keitėsi, todėl tarpusavyje palyginti priemonių poveikių efektyvumus neįmanoma. Darbo naujumas. Vienalaikių tyrimų metu, esant vienodoms sąlygoms, naudojant įvairias... [toliau žr. visą tekstą] / Seed-borne fungi are highly important for the seed quality of Poaceae. Fungi under favourable conditions may reduce germination capacity and viability of seeds, weaken the root system of plants, decrease their yield and green mass. Some fungi may cause indirect damage to seeds, i.e. change the colour, deform seed coat. Producing and exuding mycotoxins, microscopic fungi degrade the realization value of grain crops. Fumigation of seeds using chemicals is prohibited in ecological farms. As an alternative to this, different physical methods are applied to treat the seed. However, the influence of some of the methods on seed-borne fungi has been ascertained insufficiently, optimal expositions of the influences have not been determined. In some cases their influence reduces seed viability, which is highly important for grains used as seed material. Besides, literature sources provide very few data on the use of 100°C damp steam thermal impulses to reduce the amount of seed-borne fungi. In Lithuania, literature on studies of the influence of different physical processes to control seed-borne fungi is rather scarce. Different measures to control pathogenic and saprophytic fungi were studied at different times, using different parameters, some of the parameters were changed during the studies, thus it is impossible to compare efficiency of the measures applied. Novelty. During simultaneous studies, under the same conditions, applying different electrophysical and thermophysical... [to full text]

Loose smut of barley, caused by fungal pathogen Ustilago nuda is one of the major concerns throughout the globe for barley producers. The infection takes place without exhibiting any obvious symptoms and an infected seed lot can only be identified at the heading stage when the fungal teliospores emerge at the place of crop. The percentage losses on yield are directly proportional to the occurrence of infection. Currently available detection methods include seed health testing protocols which are time-consuming and cumbersome. With the globalization of the international market and increased crop demand, development of rapid disease screening methodologies has become an essential focus in the field of plant pathology. The present study sought to develop a rapid probe-based detection method for screening of U. nuda with real-time qPCR. Two U. nuda specific primer pairs were compared using standard PCR alongside optimization of real-time qPCR assay. The advantage of high fidelity DNA polymerase for amplification of U. nuda genomic DNA was recorded. U. nuda genomic DNA was amplified and cloned into a vector which was further used for generation of a quantification curve with a specific probe. The qPCR assay developed in this study was successful in the detection of as little as 43 copies of U. nuda genomic DNA. With studies involving larger sample size and field samples, this assay can be improved for enhanced sensitivity and specificity which can help in monitoring infection from DNA extractions of barley seeds and further improving the current microscopic detection methods.