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Chemical analysis of the pollen of plum varieties
Published May 24, 1999
25-26.

The chemical composition, amino acids and carbohydrates, of the pollen has been analysed in varieties grown in Hungary during the years 1993 at Kecskemet and 1995 at Cegléd and Pomáz. The distinction of 17 amino acids and 7 carbohydrates has been achieved. The aim of the study was to find criteria for the distinction of varieties.

The... total content of amino acids varied between 15.53 and 20.54 %. The highest ratios represented the asparagine and the glutamine acids. The relative content in other amino acids was between 2 and 7 % of the total. The less frequent were cysteine and valine.

 

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Rate of scab infection and quality parameters of apple fruit in organic and integrated production systems
Published August 23, 2000
63-67.

In this study, the rate of scab infection and quality parameters (content of vitamin-C, dry matter, sugar, total acids, specific weight, quality index and flesh firmness) of some apple cultivars are given, moreover, the relation between those characters was examined in two environmental systems (organic and integrated) in a rainy season. In the... organic fruit production, scab infection of leaves was significantly higher than in the integrated system, in case of the same cultivars, which means that the rate of decrease in leaf area was heavier in the organic production. Cultivars did not differ statistically in parameters of inner content when the integrated system was compared to the organic one. Results did not show statistical difference between loss of leaf area caused by apple scab and the parameters of inner content, which is attributed to the regeneration of leaf area due to favourable weather conditions. Data on apple scab and inner content of the fruit justify essentially the environmental systems of apple production.

 

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Studies on the alkaloid production of genetically transformed and non-transformed cultures of Lobelia inflata L.
Published June 6, 2001
65-71.

The investigations of the growth and alkaloid production of cell suspension-, callus-, organized- and hairy root cultures from Lobelia inflata L. proved that these cultures are able to synthesize the characteristic piperidine alkaloids of the intact plant. Alkaloid precursor amino acids (Phe, Lys) and plant growth regulators affect not... only the growth and differentiation of tissue cultures but also their secondary metabolism. The synthetic regulator Sz/I I combined with Phe increased the total alkaloid content considerably in callus- and organized cultures; regulator Sz/28 especially increased the lobeline content (in organized cultures in response to Lys, in callus tissues as a result of Phe application). With the aim of optimizing growth and alkaloid production of the genetically transformed hairy root cultures of Lobelia inflata L. we studied the effect of some growth regulators (NAA, IAA, kinetin) and precursor amino acids (Lys, Phe). The kinetin had inhibiting effect on the growth and lobeline production of the hairy roots. The IAA and NAA increased the biomass formation and lobeline production. The highest lobeline level was detected in tissues cultivated on hormone-free medium containing Phe.

 

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Antioxidant activity of medicinal plants used in phytotherapy
Published June 6, 2001
28-35.

Oxygen free radicals play an important role in the development of different disorders like inflammatory-immune injury, carcinogenesis, hepatic toxicity and artherosclerosis. The antioxydant role of a wide spectrum of natural products has been established. Flavonoids and other phenolic compounds (proanthocyanidins, rosmarinic acid, hydroxicinnam...ic derivatives, catechines, etc.) of plant origin have been reported as scavengers and inhibitors of lipid peroxidation.

We have studied the antioxidant activity as well as content and composition of natural phenolics in a series of medicinal plants with phytotherapeutical significance. Thus we determined the total phenol contents and studied the composition of flavonoids, polyphenols, phenolic acids of different vegetative and reproductive organs of medicinal plants: Anthriscus cerefolium (L.) Hoffm., Petroselinum crispum L., Cichorium intybus L., Helichrysum arenarium D.C.„cempervivum tectorum L., Taravacum officinale Web.

Characteristic constituents in the various crude drugs were determined by chromatographic (TLC, HPLC) and spectroscopic (UV, UV-VIS) methods. The non specific scavenger activities of the medicinal plant extracts were studied by the chemiluminometric technique. The changes of chemiluminescence intensity of the H,G,•0H-luminol system at increasing concentrations of the H702/ -OH were measured. Inhibitory effects of selected standardized fractions from plants were tested on ascorbic acid induced lipid peroxidation in rat liver and homogenates.

The best correlation were established with total phenolics in some medicinal plants (S. tectorum, T. officinale) while activities in other cases seem to be influenced by flavonoids (P. crispum, H. arenarium, A. cerefolium) and by hydroxicinnamic derivatives (C. intybus).

 

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Nutritional quality, fruit shape and relationships among exotic and local Capsicum pepper genotypes in Uganda
Published July 21, 2021
33-39.

Twenty-one hot pepper genotypes comprising of local (15) and exotic (6) types (C. annuum, C. frutescens and C. chinense) were characterized for selected fruit traits after propagation in a glasshouse at the Makerere University Agricultural Research Institute Kabanyolo in Central Uganda using a completely randomized design with... three replicates. Ripe fruits were harvested and analyzed; traits evaluated were all significantly different at P<0.05 with variations in quality attributes. The genotype OHA-B305-10 had the highest ascorbic acid content (128.86 mg/100 g) and is recommended for improvement of both local and exotic genotypes targeting the fresh market. Genotypes CAP0408-12 and UG2 WE0511-22, with highest total soluble solids (16.17 ºBrix) and dry matter content (28.59%), respectively should be used in improvements for industrial use or processing to products such as chilli powder or flakes. BRS-M205-04 with highest titratable acidity (1.04%) can be used in enhancing shelf life of genotypes with low titratable acids as well as for the fresh market. In spite of the intraspecific relationships among genotypes, significant differences were observed in their quantitative traits. These genotypes will, therefore, be useful in improving the quality of hot pepper fruit in Uganda.

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Stimulating effect of distilled water
Published June 24, 2003
47-49.

It is an early observation that plants in poor soil are developing roots quicker and more abundantly than on rich one. There is a similar correlation between the nutrient status of medium and adventitious root formation.

In order to throw more light on the background of this strange phenomenon we started a systematic experimental progra...m in which the biological effects of distilled water as model factor was investigated.

The experiments proved that the root formation of Pinto bean (Phaseolus vulgaris L.) cuttings with 3 cm long hypocotyls was promoted by distilled water.

The phenomenon above accompanied with slower decline and faster recovery of total and also water-soluble protein content, more intensive efflux of amino acids, greater amount of tryptophane and increased uptake of water compared to those in control hypocotyls. From other data obtained we may suspect that some additional active substance unknown for us also contributes to the stimulation of root initiation in distilled water.

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Carbohydrate utilization of Erwinia amylovora in vitro
Published May 10, 2004
31-34.

Nectar is a multi-component aqueous solution that promotes bacterial multiplication. The concentration of nectar in plant flowers is not stable since it is under the influence of environmental conditions, especially free moisture and relative humidity. Experiments were conducted with "artificial nectar" and directed along two lines: (1) determi...nation of the optimal concentrations of carbohydrates for the growth of E. amylovora development (2) consumption of different carbohydrates besides basic sugars.

Solutions of "artificial nectar" were prepared in different compositions by changing the dominance of basic sugars (fructose — glucose —sucrose) in proportions of 2:1:1, 1:2:1, 1:1:2 and between concentrations of 10-0.6% (diluted with Basal minimum broth) in order to determine optimal conditions for the development of E. amylovora.

At a basic sugar concentration of 10% bacterial multiplication started and continued until I log degree (from 106 to 107 cfu/ml). At concentrations of 5% and 2,5 % cells developed with nearly the same kinetics (from 106 to 8x107 cfu/ml and from 106 to 9x107 cfu/ml, respectively). Multiplication was more pronounced and nearly the same at concentrations of 1.2 % and 0.6 % (from106 to 2x108 cfu/ml). At a basic sugar concentration 30% total sugars bacterial multiplication did not occur, while at 20 % it was negligible, not measurable photometrically.

At minimal concentrations of F, G, S (between 1-0.1 %) bacterial cells were still able to multiply, producing organic acids from sugars.

Our study showed that E. amylovora requires only a small amount of sugars (0.1%) for multiplication (acid production) while high concentrations inhibit multiplication. There was a negative correlation between sugar content and cell density. The optimal range of sugar concentration was at about 1%.

Effect of "less frequent carbohydrates" to E. amylovora multiplication was also determined using the API 50 CH strip. We could provide information on utilization of 39 carbohydrates by the bacterium at different categories as follows: Not utilized-, Slowly and weakly utilized-, Slowly and completely utilized-, Quickly and completely utilized carbohydrates. We suppose that carbohydrates that belong to the latter two groups could play an important role as nectar components in promoting E. amylovora multiplication in the blossoms of pome fruit trees.

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