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Antioxidant capacity, C-vitamin and anthocyanils content in the fruits of elderberry (Sambucus nigra L.) types
Published August 13, 2004

: Elderberry used to be a common medicinal plant since long. Its ripe fruit and inflorescence has been collected. Cultivation however, started in Hungary recently, with the early 90-es. Initially, has been planted, the 'Haschberg' cultivar. Our Department started first with the selection of favourable genotypes in the Hungarian spontan...eous populations of the species, we aimed to find clones, which are earlier ripening than 'Haschberg', moreover, superior in any of the agronomical or quality traits. Present study deals with 19 new selected clones by their content of vitamin-C, anthocyanins and their antioxidant capacity. Environmental stresses are inducing, increased, accumulation of free radicals in living organisms. To evoid the harmful effects of the free radicals, we need to consume antioxidant compounds (flavonoids, anthocyanins, vitamins, etc.) In the literature there are quite a few references related to the anthocyanins and antioxidants of the elderberry. Measurements prove that substantial differences exist among the population of the species as for the content and quality of those compounds. In anthocyanin content, the difference between the highest and lowest values was 3000 mg/I, whereas in antioxidant content this value was 6001.1M. Those types, which contained less anthocyanin (<5000 mg/I), produced lower antioxidant capacity, whereas the highest anthocyanin content was associated with the strongest antioxidant activity. C-vitamin content varied between 36.5 and 96.4 mg/100g. These values provide daily human requirements by their consumption. Summing up all parameters, examined the best type was Cinkota 1.

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Reactions of some cucumber (Cucumis sativus L.) lines and hybrids to zucchini yellow mosaic virus (ZYMV) and selection of tolerant breeding lines
Published September 13, 1999

In the past years zucchini yellow mosaic virus (ZYMV) has been appeared as a new pathogen of cucurbitaceous plants in Hungary. It caused severe disease outbreaks on the fields of pickling cucumber hybrids which are highly tolerant to cucumber mosaic virus (CMV). Preliminary inoculation tests have showed that all of the important pickling hybrids produced in Hungary were susceptible to ZYMV-P. However, a selection of Chinese Long and the breeding line I- KS 10C proved to be highly tolerant. The Fl plants of the crosses between the tolerant lines and the susceptible genotype H I were susceptible to ZYMV-P. F2 populations segregated for susceptible and tolerant individuals at a ratio of 3:1. The results strongly suggest that the resistance to ZYMV in our sources is controlled by a single recessive gene. Inoculations of the ZYMV and CMV susceptible cultivar Budai csemege and the CMV tolerant hybrid Perez Fl with the complex of ZYMV+CMV resulted extremely severe symptoms (strong mosaic and necrotic spotting of the leaves) on both cultivars. On the Chinese Long line, which is tolerant to ZYMV and CMV, respectively, the complex of the two viruses caused mild symptoms. The results show a synergistic pathological effect of ZYMV and CMV on differrent cucumber genotypes. More detailed studies on the interactions among the plant genotypes, viruses and virus strains are needed to develop cucumber hybrids that are highly resistant to the ZYMV+CMV complex.

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Some biological features of cherry leaf spot (Blumeriella jaapii) with special reference to cultivar susceptibility
Published March 25, 2009

In this review, some important features of biology are summarised for cherry leaf spot (Blumeriella jaapii). In the first part of the review, the geographical distribution of the pathogen and the causal organism are described. Disease symptoms and disease cycle of cherry leaf spot are also shown. Special attention is given to hosts and... then several cherry cultivars.are described in relation to their susceptibility to cherry leaf spot.

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Effect of dry and wet years on primary inoculum source, incubation period and conidial production of Venturia inaequalis
Published October 11, 2005

The present study focuses on the characteristics of epidemics caused by the selected model-pathogen, Venturia inaequalis in relation to weather elements, with special respect to the increasing or decreasing effects of the specific weather elements. First, those weather elements are discussed which have a role in the development of scab... epidemics. Subsequently, by accepting the thesis that climate change includes also weather extremes, an extremely hot and dry year (2003) and a colder year of higher than average precipitation (2004) were chosen as models. The presented examples verified that the variability of weather elements had had an undoubtable effect on the development of epidemics. The variability of weather elements manifests in the unusual behaviour of the pathogen, resulting in no or extreme disease epidemics. The extremities are well demonstrated by the fact, that in a year of drought an efficient protection can be achieved by considerably less applications than average, while in the next rainy year, the susceptible cultivar cannot be protected effectively even with such a high number of applications as is usual under humid Western-European climate conditions. It can also be noted, that the pathogen has a very good adaptability under unfavourable weather conditions. Consequently, more efficient management strategies should be developed for protection against the effects of extremities. However, it should be emphasized that it is very difficult to adapt to the variability and extremities of weather in the practice, because no long-term, accurate and reliable information is available about the variability of these elements.

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Effect of acidity on growth rate and stroma formation of Monilia fructigena and M. polystroma isolates
Published March 16, 2004

The effect of acidity (pH) ranges on the mycelial growth and stroma formation of Monilia fructigena Pers: Fr. and of M. polystroma van Leeuwen was determined on agar plates and apple fruits. Four isolates of each of the brown rot fungi and two apple cultivars, `James Grieve' and 'Cox's Orange Pippin', were used for th...e study. For the agar plate study, a range of the initial pH was prepared from 2.5 to 6.5. The dishes were inoculated with a 4 mm plug of each isolate and incubated at 23 °C in darkness. The mycelial growth was measured after 1.5, 4, 7, 10 and 20 days of incubation. After a 30-day incubation, stroma formation was determined by image analysis and weighing of mature stroma. In the fruit experiment, both cultivars were inoculated with one isolate of M. fructigena and of M. polystroma. The pH changes were determined after 7, 14, 28 and 35 days of incubation in both healthy and inoculated fruits. The fastest mycelial growth was at pH 4.5 for M. polystroma and at pH 3.5 for M. fructigena. After a 30-day incubation, M. polystroma isolates produced twice or three times more stroma compared to M. fructigena isolates. For both brown rot fungi, the amount of mature stroma increased from pH 3.5 to 5.5, and then decreased at pH 6.5. Results of the.fruit experiment showed that healthy fruits were quite acidic (pH < 3.5), but pH rapidly increased in the inoculated fruits for both cultivars, reaching pH 4.6-5.4 depending on cultivar and fungus isolate. On both cultivars, the stroma developed at a significantly higher pH for M. polystroma than for M. fructigena. Biological and practical implications of the results are discussed.

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