Wyniki wyszukiwania - Biblioteka Nauki

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Chitosan biostimulant controls infection of cucumber by Phytophthora capsici through suppression of asexual reproduction of the pathogen

100%

Zohara F. , Surovy M. Z. , Khatun A. , Prince F. R. K. , Ankada A. M. , Rahman M. , Islam T.

Acta Agrobotanica

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2019

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tom 72

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nr 1

EN

The biopolymer chitosan is a derivative of chitin, which can promote plant growth and protect plants from phytopathogens. This study aimed to evaluate the efficacy of chitosan as a biostimulant and a biorational agent to protect cucumber plants from damping-off disease caused by Phytophthora capsici. Cucumber seeds were treated with a range of chitosan concentrations, viz. 0, 125, 250, and 500 ppm, to evaluate effect on seed germination and fresh root and shoot weight of the seedlings. Chitosan significantly (p ≤ 0.05) enhanced seed germination and root and shoot growth of cucumber in a dose-dependent manner up to 500 ppm. Application of in vitro chitosan suspension onto P. capsici mycelial plug suppressed growth of mycelia, formation of sporangia, and release of P. capsici zoospores at 125–500 ppm concentrations. Cucumber seedlings from chitosan-treated seeds showed enhanced resistance to damping-off disease caused by P. capsici compared to untreated control. Cucumber seedlings from 500 ppm chitosan seed treatment showed 100% disease resistance against damping off caused by P. capsici. These results suggest that chitosan could be used as a natural and environmentally safe alternative to a synthetic growth promoter and pesticide for sustainable production of cucumber.

PL

Biopolimer chitozan jest pochodną chityny, może on stymulować wzrost roślin i chronić je przed fitopatogenami. Celem badań była ocena skuteczności chitozanu jako biostymulatora i „bioracjo-nalnego” środka ochrony ogórka przed zgorzelą wywołaną przez Phytophthora capsici. Nasiona ogórka poddano działaniu różnych stężeń chitozanu tj. 0, 125, 250 i 500 ppm w celu oceny ich wpływu na kiełkowanie nasion oraz świeżą masę korzeni i pędów siewek. Chitozan istotnie (p ≤ 0,05) stymulował kiełkowanie nasion oraz wzrost korzeni i pędów ogórka w sposób zależny od dawki do 500 ppm. Zastosowanie zawiesiny chitozanu w zakresie stężeń 125–500 ppm w warunkach in vitro hamowało wzrost grzybni P. capsici, tworzenie sporangiów i uwalnianie zoospor P. capsici. Siewki roślin uzyskanych z nasion traktowanych chitozanem charakteryzowały się zwiększoną odpornością na zgorzel wywołaną przez P. capsici w porównaniu z nietraktowanych chitozanem. Siewki ogórków z nasion traktowanych 500 ppm chitozanu wykazywały 100% odporność na zgorzel powodowaną przez P. capsici. Wyniki te sugerują, że chitozan może być stosowany jako naturalna i bezpieczna dla środowiska alternatywa dla syntetycznych stymulatorów wzrostu oraz pestycydów w zrównoważonej produkcji ogórka.

2

Patterns of genetic diversity in populations of Filipendula ulmaria (L.) at different stages of succession on a meadow abandoned for 30 years

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Falinska K. , Lembicz M. , Jarmolowski A. , Borkowska L.

Polish Journal of Ecology

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2010

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tom 58

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nr 1

EN

Genetic diversity and spatial variation of two populations of Filipendula ulmaria (L.) were analysed at the initial stage (macroforbs) and the late succession stage (forest community) during a 30-year succession on the abandoned meadows in Białowieża National Park. The study demonstrated a high level of genetic diversity in both populations (D = 0.86 and D = 0.79 in the population at the initial and late succession stage, respectively). Significant genetic differentiation was observed at the cross-population level (FST = 0.008, P <0.001). Among 303 ramets in the population at the initial stage 261 genotypes were detected, of which 24 were clonal, and the remaining (237) were unique (91%). In the population at the late succession stage 92 genotypes were detected among 116 ramets of which 10 were clonal, and 82 unique (89%). The results did not confirm a hypothesis that the low level of the population’s genetic diversity should be expected at the late succession stage. Additionally, the study demonstrates that the prolonged clonal spreading does not always result in genetic monotony of a population. It has been demonstrated that the high level of genetic diversity in the population of clonal species F. ulmaria could be the result of temporal changes in life history traits of long-lived genets. The formation of gaps caused by the disintegration of senile genets and the permanent recruitment of seedlings over 30 years of population development reinforce the appearance of new genets. This process was reflected in both populations by the domination of unique genets and spatial pattern of genotypic diversity.

3

Binary fission, telotroch formation and conjugation in Mantoscyphidia Jankowski, 1980 [Ciliophora: Peritrichia]

100%

Peters H. , Van As L. L. , Basson L.

Acta Protozoologica

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2010

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tom 49

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nr 1

61-74

4

Krzyżówki drożdży browarniczych. Cz.4. Przemysłowo użyteczne fenotypy krzyżówek międzygatunkowych

75%

Harasym J. , Podeszwa T. , Bogacz-Radomska L.

Przemysł Fermentacyjny i Owocowo-Warzywny

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2018

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tom 62

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nr 04

EN

Genomes and their function in newly created brewery yeast hybrids are still an area of intensive and pioneering research. The stability of the resulting hybridization genom is a key element for their further functioning. This feature depends not only on de novo hybrids creation technology, but also on environmental conditions in which they grow and develop.

PL

Genomy i ich funkcjonowanie w nowo utworzonych krzyżówkach drożdży browarniczych stanowią wciąż obszar intensywnych i pionierskich badań. Stabilność utworzonego w efekcie hybrydyzacji genomu jest kluczowym elementem dla dalszego funkcjonowania krzyżówek drożdży. Cecha ta zależna jest nie tylko od techniki pozyskiwania krzyżówek de novo, ale również od warunków środowiska, w jakich następuje ich dalszy wzrost i rozwój.