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Diversity of sooty blotch fungi in Poland

63%
Sooty blotch is one of the most common disease of apples in organic orchards in many countries. Results of molecular studies performed in USA indicated approximately 30 different fungi species associated with this disease. Fungi species causing sooty blotch in Northern, Central and Eastern Poland were identified on the basis of morphology and nucleotide sequence of the rDNA internal transcribed spacer region (ITS). A total 245 isolates were collected in spring and early summer in the years 2006–2009 from fruits with visible symptoms of the disease. Isolates were grown on PDA medium and identified on the basis of morphological characters. DNA was extracted from representative isolates and used as matrices for PCR amplification with ITS1F and ITS4 primers. Fragments of amplified rDNA ITS were sequenced. It was found that 66.53% of all isolates causing sooty blotch were species from genera Microcyclosporella, followed by Aureobasidium pullulans – 22.86%, Microcyclospora sp. – 6.12%, Phialophora sessilis – 3.67%, Peltaster sp. and P. fructicola – 0.41%.
The response of Polish winter wheat genotypes to M. graminicola (preliminary experiments and cu1tivar collections) was observed in different regions of Poland. : Observations were carried out in 1995-1999. The winter wheat genotypes showed a broad spectrum of reaction to this pathogen. Between 1997 and 1999 the highest degree of infection on winter wheat breeding lines was noted in Kończewice. During this tirne no genotypes free from infection were observed (preliminary breeding experiments). Cultivars with no symptoms of Septoria tritici blotch (Leszczyńska Wczesna and Żelazna) were found among old genotypes in Słupia Wielka only in earlier experiments (1995-1996). In the years 1997-1999 the winter wheat cultivars were classified into groups on the basis of their response to the pathogen. The degree of infection for the .majority cultivars was quite high.
The biotechnical preparations: Biosept Active (based on a grapefruit extract) and BioZell (based on thyme oil) as well as Hypericum perforatum extract, streptomycin solution and fungicide Champion 50WP (active ingredient substance – e.i. 50% copper hydroxide) were investigated for antimicrobial effects against plant pathogenic bacteria: Agrobacterium tumefaciens, Pseudomonas syringae pv. syringae and Xanthomonas arboricola pv. corylina. The screening was carried out in vitro on three media: Nutrient Agar (NA Difco), Pseudomonas Agar F (Merck) – analogue of King B and 523. In the experiments, the agar plate method was applied. There were no statistically significant differences in the effect of streptomycin and Champion 50WP on the growth inhibition of three bacteria strains for medium 523 and Nutrient Agar and of P. syringae pv. syringae and X. arboricola pv. corylina for medium King B. It was determined that the antibacterial activity of Biosept Active and BioZell biopreparations and H. perforatum extract against Agrobacterium tumefaciens (strain C58), Pseudomonas syringae pv. syringae (strain 760) and Xanthomonas arboricola pv. corylina (strain RIPF-x13) were dependent on the strain of pathogen as well as the growth medium used. According to the research results obtained, the Biosept Active preparation and H. perforatum extract demonstrated high bacteriostatic activity against three bacterial strains grown on the Nutrient Agar medium.
The aim of the work was to study an occurrence and intensity of septoria tritici blotch on wheat in different regions of Poland as well as reaction of winter wheat cultivars and breeding lines to infection by Mycosphaerella graminicola (Fuckel) Schroeter (an. Septoria tritici (Rob. ex Desm.) under field conditions. Observation conducted during 1994-1996 indicated on occurrence of septoria tritici blotch each year and on important infection degree of winter wheat by Mycosphaerella graminicola in some regions of the country. The highest infection was noted in 1995 and the lowest in 1994. Infection degree for majority of cultivars was quite high. Some cultivars and lines were characterized by very high infection. Among them were the old (Kujawianka Więcławska and Wysokolitewka Sztywnosloma) and the newest (Tercja) cultivars. On some old cultivars (Leszczyńska Wczesna and Żelazna) even no traces of infection were observed although favourable weather condition existance and the presence of neighbourhood diseased plants. Field observation of cultivars and breeding lines showed different reaction of tested wheat genotypes to Mycosphaerella graminicola infection.
Valdensia heterodoxa as a parasitic fungus was observed on Ericaceae family plants i.e. blueberry (Vaccinium corymbosum L.), bilberry (V. myrtillus L.) and lingonberry (V. vitis-idaea L.). Isolates of this polyphagous were obtained from the infected leaves of different cultivars of highbush blueberry collected from commercial plantation in Mazovia province and from bilberry collected from forests in Pomerania province. PCR amplification of selected rDNA fragments (ITS1, 5.8S, ITS2) was done with ITS1F and ITS4A primers. Bioinformatic analysis revealed similarity 99–100% between selected nucleotide sequences of V. heterodoxa isolates from bilberry and highbush blueberry. The sequences of bilberry isolates were obtained and described for the first time in Poland. Their reference sequence was deposited in GenBank (KT121733). In laboratory experiments conidia of selected bilberry isolates on OA medium were 278 ±6 × 140 ±4 μm. Conidia from highbush blueberry, bilberry, and lingonberry were measured. Depending on the host plant conidia were different in the length of the arms and width of the head. The growth of the fungal isolates on PDA (potato dextrose agar), OA (oatmeal agar), WOA (weak oatmeal agar), SNA (salt nutrient agar) media was examined. The cultures were divided into two groups based on their morphology on PDA medium.
Sooty blotch is a disease of apple and pear caused by a complex of fungi that blemish the fruit surface. Results of molecular studies indicated approximately 30 different fungi species associated with this disease. Apples and pears with symptoms of sooty blotch were collected in summer and early autumn 2006–2010 from trees grown in fungicide non-treated orchards and small gardens located in various regions of Poland. Fungi causing sooty blotch were isolated from fruits and the isolates were divided into six groups, according to their morphological characters. Growth of the fungi colonies were tested on different agar media (PDA, CMA, MEA and Czapek). The ITS region of rDNA from 16 isolates from the first group was amplified by PCR technique and one representative sequence of this isolates was used to alignment in Gene Bank. This isolate was identified as Aureobasidium pullulans and isolates from this group were compared with it on the base of morphological features.
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