Přečtěte si více

161 cows from 4 farms were examined. The suspect animals were selected according to viscosity test, clinical symptoms and somatic cell count (SCC). The most frequently isolated was Ent. faecalis (n = 20), followed by S. aureus (n = 6) and St. uberis (n = 5). There was positive occurrence of bacteria genus Staphylococcus and Enterococcus at lower SCC (50 ths.ml-1) and at higher SCC (> 300 ths.ml-1) bacteria genus Streptococcus, Enterobacter and E. coli. Differences in SCC were significant (P 0.001) in negative samples xg 131 SCC versus 491 for positive, 611 for staphylococci and 464 ths.ml-1 for other positive. SCC discrimination limit for likelihood of pathogen occurrence estimation was calculated. This limit 174 ths.ml-1 could be recommended for practical use to apply preventive or curative measures.

Plant transformation may be defined as the sequence of delivery, integration and expression of foreign genes into the plant cells which will ultimately regenerate into a whole plant. This ability to introduce and express or inactivate specific genes in the plant genomes provides a new and powerful experimental tool for validating gene function, particularly in relation with various plant physiology mechanisms and processes that have not been resolved so far using other biochemical approaches. Another non-negligible application of this approach is that of obtaining and transferring genes that are not available to a given species due to sexual incompatibility from other plants, from microorganisms or even animals. The process involves choosing a trait, identifying and isolating the gene(s) encoding it. To be functional, such gene(s) must include the regulatory regions ensuring their correct expression in the plant. Then, a reliable protocol must be devised and followed for the transformation of genes into plants, and the DNA sequences introduced must subsequently be integrated, expressed and maintained in the genome throughout subsequent cell divisions and progenies. Finally, transformed cells must be competent for regeneration into whole plants. Gene delivery systems used to date can be divided into direct gene transfer (mediated by physical or chemical forces for delivery of the gene into plant protoplasts, cells and even tissues) and Agrobacterium-mediated gene transfer, where either A. tumefaciens or A. rhizogenes is used as vectors for introducing the foreign gene into the plant genome. In this context, recombinant DNA technology has revolutionised biotechnology in such a way that plant transgenesis is now a relatively mature approach, and plant biotechnology provides today not only novel genotypes which carry agronomically useful genes for biotic and abiotic stresses, but also others that improve plant nutrition or increase yield components.

The use of digital image analysis (DIA) for characterization of varieties is much quicker and easier than conventional morphometric methods. This non-destructive, highly effective technique employs an inexpensive imaging system, which allows image acquisition, image processing and feature extraction. In this study digital image analysis was used for the detection of assumed duplicates in the germplasm of a flax/linseed collection, based on petal measurements. A group of 131 different flax/linseed varieties was used in tests for defining key features. The aim of the investigation was to determine if petal size could be used to distinguish compared accessions (doubles, triples, quadruples). The linear regression model used for feature assessment enabled successful identification of the dissimilarity or similarity among tested accessions. The position and distance of accessions in groups of clusters were obtained by hierarchical cluster analysis. Duplicates in the germplasm of the flax collection were confirmed by non-significant statistical differences between tested accessions. Based on the passport descriptor ACCENAME analysis it was revealed that out of 97 evaluated couples 81(83.5%) showed a significant difference in petal size, resulting in the conclusion that they are not real duplicates. Only 10 couples (10.3%) showed non-significant differences in petal size and shape could be considered as real duplicates. Six couples (6.2%) remained undetermined, as it was not possible to make a clear distinction using the above mentioned methods, due to the influence of year or other external factors. Image analysis followed by hierarchical cluster analysis was recommended as one of the methods useful for the characterization and rationalization of a germplasm collection. (C) 2011 Elsevier B.V. All rights reserved.

Nádorovitost kořenů brukvovitých (též boulovitost, hlenka, plasmodiofóra) je bezpochyby nejzávažnější chorobou brukvovitých rostlin a jednou z nejzávažnějších chorob rostlin vůbec. Přitom její význam narůstá, zejména proto, že je stále větším problémem dodržovat dostatečně dlouhé časové odstupy v zařazování brukvovitých rostlin do osevních postupů, řepka ozimá se seje dříve, její osevní plochy narůstají a stále častěji se používají brukvovité meziplodiny.

Fibre crops are world-wide distributed group of plant species belonging taxonomically to various plant families. The common denominator is their use of above-ground biomass for mainly industrial (non-food) or energy purposes. They include approximately 2,000 species—annual and perennial—belonging to monocotyledonous as well as dicotyledonous plants. About 20 species have got an economical (some of them local) importance. Majority of fibre species is grown in tropical and subtropical zones. Cellulose, a natural polymer with high strength and stiffness per weight, is the building material of long fibrous cells, which can be found in the stems, the leaves or the fruits/seeds of fibre plants. Thus, based on the fibrous cells localisation within the plant, we can recognise bast fibre species (e.g. flax, hemp, jute, kenaf, ramie and sida), leaf fibre species (sisal, banana and palm) and fruit/seed fibre species (cotton, coconut, kapok and luffa). During last 20 years, the fibre crops have been also considered as potential candidates for phytoremediation, particularly for phytoextraction of heavy metals from contaminated soils. Within fibre crops of temperate and subtropical zone, flax/linseed and hemp represent economically the most important species and also the majority of heavy metal-related experimental data were obtained and published in these two fibre crops. Here we bring information on biological potential of flax and hemp for heavy metal phytoextraction, the possibilities of agrotechnological treatments to affect/improve heavy metal uptake and, finally, the economical assessment of phytoremediation technology for flax and hemp growers and phytoremediation operators.

Metoda využití molekulárních markerů pro diagnostiku houbových chorob řepky byla optimalizována na izolátech hub Verticillium dahliae, Verticillium longisporum a Leptosphaeria maculans. Byly nalezeny markery umožňující spolehlivou identifikaci a odlišení těchto patogenů. Pomocí těchto markerů bylo otestováno 54 vzorků rostlin ozimé řepky s různě výraznými příznaky houbových chorob. U velké části vzorků bylo prokázáno napadení patogenem Leptosphaeria maculans, byly nalezeny různé rasy tohoto houbového patogena. Napadení patogenem Verticillium spp. bylo prokázáno pouze ve dvou případech.

Rozborem 60 rostlin napadených kořenovou hnilobou byl zjištěn výskyt 32 patogenních a saprotrofních druhů hub. Nejvíce se na kořenových a krčkových hnilobách podílely patogenní houby Rhizoctonia solani (66,6 %), Mycocentrospora acerina (55,0 %), Sclerotinia sclerotiorum (41,6 %) a Pythium ultimum (35 %). Devět druhů doprovodných saprotrofních hub nebylo dosud na kmínu z území ČR uváděno.

Metoda využití molekulárních markerů pro diagnostiku houbových chorob řepky byla optimalizována na izolátech hub Verticillium dahliae, Verticillium longisporum a Leptosphaeria maculans. Byly nalezeny markery umožňující spolehlivou identifikaci a odlišení těchto patogenů.

Significant differences among reactions of the pollen beetles originated from the fifteen compared localities to lambda-cyhalothrin applied in 100% rate (ANOVA for the counts after 5 hours : F = 4,450; df = 14, 28; Ftab = 2,726; P = 0,01). The differences in the lambda-cyhalothrin effectiveness expressed in according to Abbott exceeded 50 per cents among the several localities. On the contrary there were not found out any significant differences among the reactions of the pollen beetles originated from the five compared localities to the etofenprox applied in 100% rate (ANOVA for the counts after 5 hours : F = 0,748; df = 4, 8; Ftab = 3,838; P = 0,05). The differences in the etofenprox effectiveness expressed in according to Abbott (and in the pollen beetles mortalities) were minor on the compared localities. On the base of other analysis it is also possible to conclude that the localities where the beetles showed significantly different reactions to the lambda-cyhalothrin were not different in this aspect concerning the etofenprox.

The aim of our work was to characterize linseed (Linum usitatissimum L.) genotypes divided into groups with high and low content of alpha-linolenic acid (ALA). Out of 32 linseed genotypes, 68.75 % represented high alpha-linolenic genotypes and 31.25 % were genotypes with low ALA content. Proportional representation of fatty acids was realized according to the norm (Czech O ce for Standards, Metrology and Testing, 1994). Oil content was analyzed according to the internal methodology of Agritec Ltd., based on the norm (Czech O ce for Standards, Metrology and Testing, 2011). The content of total fat ranged from 36.22 % to 46.35 %, that of ALA from 1.10 % to 65.20 %, and that of linoleic acid (LA) from 11.10 % to 75.00 % in the analyzed seed samples within all groups. The genotypes were divided also according to the seed color and a linear correlation between all three parameters within these groups was observed. Negative linear dependence was con rmed between parameters; ALA and LA content in the groups: high ALA brown seed (p 0.0001; correlation coe cient (r) = –0.70), and high ALA yellow seed (p 0.001; r = –0.36). Also, positive linear dependence between the total fat and the LA content in the groups: low ALA brown seed (p 0.001; r = 0.34); low ALA yellow seed (p 0.0001; r = 0.62), was found.

The mycoparasitic efficiency of 28 strains/isolates of Clonostachys rosea f. rosea and Clonostachys rosea f. catenulata against the pathogenic fungus Bipolaris sorokiniana was determined in dual cultures on Czapek-Dox nutrient agar. Strains with low and medium efficiency were antagonistically inhibited by B. sorokiniana, and inhibitory zones were formed between the colonies of both fungi. The mycelium of Clonostachys strains with high efficiency overgrew and degraded B. sorokiniana colonies without formation of an inhibitory zone. In dual cultures, Trichoderma sp. and the most effective Clonostachys strains degraded B. sorokiniana colonies within 3 to 5 and 12 to 15 days, respectively. When rye seeds were treated with a mixture of C. rosea f. rosea, Trichoderma sp. and B. sorokiniana, development of B. sorokiniana on both seeds and seedlings was reduced when compared with a B. sorokiniana treatment. The treatment of rye seeds with Clonostachys and Trichoderma had a positive effect on seed germination and seedling length.

V pěstitelských systémech zvyšuje len olejný biodiverzitu zemědělské výroby a nezatěžuje další rostlinnou produkci. Jedním z požadavků pro řádně založené porosty je kvalitní a zdravé osivo, kterému předchází úspěšná semenářská produkce. Z8kladem efektivní produkce je dodržení základních pěstitelských parametrů a potřeb olejného lnu.d.

In an attempt to enhance the phytoextraction capacity of L. usitatissimum through overproduction of an efficient heterologous Cd-binding peptide, we engineered linseed breeding line AGT 917 to constitutively express genetic fusion of α-domain of mammalian metallothionein 1a (αMT1a) and β-glucuronidase gus gene under the control of CaMV 35S promoter. An improved transformation protocol was developed. When tested in soils amended with Cd at 20 and 360 mg kg-1, the mature αMT1a::gus plants accumulated more Cd than parental AGT 917: the stem Cd concentrations in the best performing αMT1/2 line were 3.3- and 1.9-fold higher, respectively. Moreover, hypocotyl explants of αMT1/2 line showed 1.7-fold higher biomass than those of AGT 917 on media containing 15 mg Cd l-1, indicating that αMT1a::gus did confer higher Cd tolerance to engineered plant. Overproduction of metal-binding peptides thus appears to be a viable strategy for the production of L. usitatissimum with improved phytoremediation capacity

Zaplevelování porostů olejného lnu způsobuje nejen přímé kvantitativní škody spočívající ve sníženém výnosu semene, ale zároveň přispívá k rozvoji chorob lnu, zhoršuje podmínky pro mechanizovanou sklizeň, zhoršuje kvalitu semene a také může snižovat, pro případné další využití, kvalitu krátkého vlákna a koudele. V průběhu řešení problematiky herbicidní ochrany olejného lnu byly založeny maloparcelní polní pokusy, na kterých byly aplikovány preemergentně i postemergentně vybrané herbicidy proti běžně se vyskytujícím dvouděložným plevelům. Důležitou součástí herbicidních pokusů bylo sledování a hodnocení nejen herbicidní účinnosti zvolených herbicidů, ale především selektivita vůči rostlinám lnu. Na základě výsledků získaných v průběhu řešení projektu lze potvrdit pozitivní vliv aplikace herbicidů na cílové plevele, při zachování požadované selektivity vůči rostlinám olejného lnu.

There were cheeses produced from raw cow’s milk and from mixed milk compared. Mixed milk contained small ruminants’ milk (goat’s and ewe’s milk) and cow’s milk in diff erent proportions. There were technological, physical and health parameters, mineral composition, microbiological indicators and sensory quality evaluated. Cow’s milk, compared to mixed milk, contained markedly lower amounts of fat, protein, casein, total solids, solids non fat, urea and acetone and higher values of lactose, citric acid and free fatty acids and showed signifi cantly lower values of somatic cell count. Mixed milk showed lower (better) results for freezing point depression, markedly higher titration acidity and higher values for Ca, Mg, K, P, Cu, Mn and Zn. The results of microbiological analyses confi rmed good hygienic quality in terms of total count of mesophlic, psychrotrophic and thermoresistant bacteria and coliforms. Negative incidence of L. monocytogenes and mostly negative incidence of S. aureus are important results and confi rmed high quality of raw material for cheese production. None of S. aureus strains were confi rmed as MRSA. The results of sensory evaluation showed no signifi cant diff erences between cheeses originated from cow’s milk and cheeses from mixed milk.

Ve vegetační sezóně 2013/2014 probíhal na Šumpersku a Opavsku opět monitoring fomového černání stonku řepky a bílé hniloby řepky. Na 3 lokalitách Rapotín, Kujavy a Opava byly založeny maloparcelkové polní pokusy v řepce odrůdy Orion s plošnou polní inokulací patogeny L. maculans a S. sclerotiorum. Navýšení napadení řepky olejky po inokulaci bylo u L. maculans, L. biglobosa až 16 % a u S. sclerotiorum až 6,75 % oproti přirozenému infekčnímu tlaku patogenů. Na fungicidně ošetřených parcelách bylo napadení potlačeno a byl pozitivně ovlivněn výnos. Na 48 lokalitách v obou regionech byl vyhodnocen výskyt bílé hniloby řepky a stanoven poměr primární a sekundární infekce původcem choroby. Dle získaných výsledků letos převažoval primární typ infekce nad sekundárním. Ve 13 porostech na Opavsku nebyla infekce zaznamenána vůbec.

Cílem metodiky jsou informace o možnostech biologické ochrany rostlin s využitím hub rodu Clonostachys proti půdním fytopatogenním houbám a využití této metody pro pěstitelskou praxi. Směsný přípravek se vyznačuje vyšší a rychlejší mykoparazitickou účinností proti širšímu spektru fytopatogenních hub. Degraduje půdní fytopatogenní houby Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium cepivorum, Botrytis cinerea, Fusarium solani, Fusarium oxysporum, Bipolaris sorokiniana, Mycocentrospora acerina, Colletotrichum spp., Alternaria spp. aj. Přípravek aplikovaný na osivo, sadbu nebo do půdy pozitivně ovlivňuje zdravotní stav a výnos rostlin. Snižuje četnost výskytu fytopatogenní mykoflory na osemení a v rhizosféře rostlin.

Jsou popsány dvě strategie infekce ozimé řepky hlízenkou - infekce askosporami přes květní plátky a přímá infekce báze rostliny myceliem ze sklerocií a důsledky obou těchto možností pro pěstitele. Dále je uveden přehled možností ochrany řepky proti tomuto patogenu.