Search
Search Results
-
Inheritance of fruit colour and of shoot's pigmentation in the case of interspecific raspberry hybrids
33-36.Views:178In our research, fruit colour and the shoot's red pigmentation were evaluated in the hybrids of Rubus idaeus and Rubus parvifolius crossings. Y and Ys genes beside the T genes determine the fruit colour of interspecific hybrids, which is characteristic for raspberry. For the explanation of the significantly higher results of segregation then expected at the yellow fruit colour hybrids, we have supposed the presence of a second yellow gene (Y2). In the yellow colour, a lot of different shade colours can be identified from light yellow to the apricot colour. In the regulation of the production of yellow and red colour, several other genes can participate also. Identification of these genes would require more additional research. The C gene determines the shoot colour of raspberry and in the case of wild raspberries we have revealed the role of a dominant Pr gene. The Y and Pr genes are descended linked. The value of crossing over is approximately 15%. The anthocyanin production inhibitory effect of the Y gene extends only for fruit. At the shoots of yellow fruit plants, strong anthocyanin production was observed.
-
Study on the mushroom species Agaricus blazei (Murill)
45-48.Views:303Nowadays, Agaricus blazei is known all over the world as a mushroom species with unparalleled medicinal properties besides its culinary delights and therefore its regular consumption is recommended in the first place for the prevention of various cancers. For the past decade researchers have been active in the study of its therapeutic properties. Its production started only a decade ago and there are a number of questions yet to be answered. At the moment, the most widespread technique is to grow it using composts similar to those of the button mushroom. In contrast to the common button mushroom, its production differs markedly from that of the button mushroom in that it develops fruiting bodies only in light and requires that the compost temperature be high, around 25 °C, also in the fruiting period and has a much higher need for fresh air. It is also sold in fresh form but mainly as a dried product, in powdered form or as capsules or pills.
-
Stimulating effect of distilled water
47-49.Views:316It 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 program 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.
-
Sunburn assessment: A critical appraisal of methods and techniques for characterizing the damage to apple fruit
7-14.Views:691Many methods and techniques have been introduced for measuring alterations in the fruit and in its surrounding environment related to sunburn incidence. The research objectives, fruit materials and the environment to be evaluated dictate the methods to follow. These procedures are either non-destructive and involve techniques that allow us to track the course of sunburn development and related environmental parameters, or destructive and involve the removal of fruit from the tree for field/laboratory measurements. Techniques employed can be used for pre-symptomatic monitoring (before symptoms become visible) or characterizing the symptoms already present. The principles behind the measurements and their usefulness for sunburn assessments are discussed and critically evaluated in this review paper. Descriptions and evaluations of the methods and techniques were made in the following groups: 1. Thermal measurements; 2. Visual assessments; 3. Fruit quality measurements; 4. Measurements of physiological and biochemical alterations; and 5. Practical evaluation of sunburn damage. Thermal measurements involve methods tracking the ambient temperature and fruit surface temperature, and their relation to sunburn formation. Visual assessments cover all measuring techniques (skin color, chlorophyll fluorescence, radiation reflection, electron microscopy) that are able to detect changes on/in the fruit skin related to sunburn formation. Fruit quality measurements are used to point out differences in qualities (soluble solids, firmness, titratable acidity, and water content) between unaffected and sunburned areas of the fruit. The measurements of physiological and biochemical alterations (gas exchange, pigment analysis, enzyme activity, gene expression) give us a better insight to the mechanism of sunburn formation. Practical evaluations involve many procedures that are used by scientists to characterize the susceptibility of cultivars, evaluate protection technology, etc. For this purpose, the following methods are in use: expressing the percentage of the total fruit surface area affected by sunburn or the percentage of the total number of fruits damaged on the tree, or even a scale based on the severity of the symptoms occurred. All assessing methods and techniques described here have their pros and cons as well as their specific applicability, therefore any of these cannot be favored to use exclusively for assessing sunburn incidence. The combination of these techniques will be the best choice to meet a given research objective perfectly.
-
Preliminary results of renewal pruning an 18 years old sour cherry trees
41-42.Views:281Sour cherry is a light demanding fruit species. As most of the crop is developing from buds on one year old shoots and 2-yearold wood, the formation of bare wood can be seen apparently in a badly maintained canopy. The formation of „whip shoots” indicates the degree of bare wood. Unfortunately in many gardens and commercial orchards sour cherry trees resemble willow trees. Owners often decide to grub old orchards, although the useful cropping lifespan of the trees planted in a correct spacing can be 20-30 years on a move vigorous rootstock. Therefore renewal pruning can contribute to the full renewal of the orchard, but the length of its effect is depending on the growth characteristics and renewal capabilities of the cultivar. The growth characteristics of the cultivars are different. The regeneration capabilities of different aged wood are also different. These differences emphasize the need for cultivar specifi c pruning. Knowing the reactions to renewal pruning, we can ensure regular high crops with excellent quality by applying cultivar specifi c rotation pruning.
-
Aminoglycoside antibiotics affect the in vitro morphogenic response of chrysanthemum and tobacco
93-104.Views:192Broadly the success of genetic transformation of plants requires non-chimeric selection of transformed tissues and its subsequent regeneration. With rare exceptions, most plant transformation protocols still heavily utilize antibiotics for the selection of transgenic cells containing an antibiotic-degrading selectable marker gene. The morphogenic capacity of in vitro chrysanthemum and tobacco stem and leaf explants change with the addition of aminoglycoside antibiotics (AAs). Of 6 antibiotics tested, phytotoxicity occurred at 10-25 and 50-100 pgml-I in chrysanthemum and tobacco explants, respectively, depending on the size of the explant and the timing of application. The presence of light or darkness also had a significant effect. The use of transverse thin cell layers (tTCLs) in conjunction with high initial AA selection levels supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow cytometric analyses demonstrate that regeneration can be predicted in both species, depending on the ploidy level of the callus. Endoreduplication was not observed in chrysanthemum, even at high AA levels, but occurred (8C or more) in tobacco callus, even at low AA concentrations (5-10 pgml-1). The higher the AA level, the greater the DNA degradation and the lower the 2C and 4C values.
-
Studies on the effects of growing substrates and physical factors in sweet pepper forcing in context with the generation of calcium deficiency symptoms
61-65.Views:306In the publications available for us, exact levels of physical factors and those of the growing technology determining Ca2+ deficiency are rarely detailed. Although the influencing role of the various environmental factors (humidity, light, temperature) is known, we had only little information about their exact values which could be presented for the growing practice. Sweet pepper varieties of the same type grown in various substrates responded to the environmental factors in different ways. Our results revealed that increasing temperature of the root zone had the most significant effect on the incidence of Ca2+ -deficient fruits. Their amount, however, gave different results depending on the growing substrate. In forced sweet pepper grown in soil the proportion of Ca2+ - deficient fruits were significantly lower compared to the plants grown on rockwool. Fruits derived from forcing on perlite, in container were damaged the least by the blossom end rot deficiency symptoms. Our experimental results and technological suggestions are based on measurement results of three years.
-
The effect of nitrogen supply on specific yield and fruit quality of apple (Malus domestica Borkh.)
7-21.Views:663The aim of the present study was to determine the effect of nitrogen supply on yield and fruit quality of apple cultivars and to explore the relationships between canopy density and the different fruit quality parameters.
The experiments were carried out at Kálmánháza, in Eastern Hungary in a private orchard in 2003-2004. The response of four apple cultivars ('Elstar', 'Gala Prince', 'Granny Smith', 'Idared') to different nitrogen dosages was studied. The assessed and calculated indices were: yield, fruit diameter, fruit height, shape index, fruit mass, firmness, dry matter content and colouration. The results indicated that nitrogen fertilization has a significant effect on the yield and fruit quality of apple cultivars. The calculated specific yield values were reduced by the application of nitrogen via the increase in the volume of the canopy. An opposit trend was observed for fruit diameter, fruit height and fruit weight, which increased with increasing nitrogen supply. The reduced shape index caused flattening of fruits.
However, the improvement of fruit quality via increasing nitrogen dosage is only virtual, since these dosages increase the fruit size, but firmness, dry matter content and colouration are diminished, which decreases the value of the fruits on the market.
The authors also studied the relationships between canopy density responsible for assimilation and light supply of the fruits and the different fruit quality parameters. The closest linear inversely proportional relationship was found in the case of colouration. There was a negative linear relationship between canopy density and firmness or dry matter content. The relationship between canopy density and fruit mass could be described by a quadratic polinomial function.
-
Luminescence variations in cucumber (Cucumis sativus L.) leaves derived from different regeneration systems
50-52.Views:241Plants obtained from in vitro culture can show increased susceptibility to environmental stress conditions. In the process of their adaptation to natural conditions it requires monitoring of their physiological state. The methods used to check this phenomenon should estimate quickly and exactly the tolerance to suboptimal environmental factors. Such requirements are satisfied by the methods of measuring chlorophyll luminescence in vivo, e.g. fluorescence induction and delayed luminescence. The objects of our studies were cucumber plants regenerated from cultures of callus and embryogenic cell suspension, as well as the plants obtained from seeds. The plants derived from in vitro cultures displayed a poor physiological condition at the early phase of adaptation characterised by higher susceptibility both to stress caused by increased density of the light flux and low temperature (4 °C) in comparison with the plants obtained from seeds.
-
Development in intensive orchard systems of cherries in Hungary
76-86.Views:576High density central leader systems, the so called "spindle trees" are spreading in intensive stone fruit orchards established for hand picking in Hungary. Results of Brunner (1972, 1990) and Zahn (1967, 1996) inspired the researchers to implement their theories into practice under our climate and special soil conditions. For sweet cherry it is essential to apply an orchard system appropriate for hand picking because of the European market requirements. In intensive sweet cherry orchards two new training and orchard systems are developed and adapted to environmental conditions in Hungary based on previous inventions. The first step of the development is represented by modified Brunner-spindle, which applies the delayed heading of the central leader and the sectorial-double-pruning system from Brunner (1972), resulting intensive orchard of 600-800 trees/ha density, planted on standard vigour rootstocks. Modified Brunner-spindle trees are developed with a central leader and wide-angled branches on it. Light bearing wood is positioned on the central leader and wide-angled branches. During training, shoots for branches are bent or a sectorial double pruning is used. The growth of central leader is reduced by delayed heading, and the strong upright shoots are pinched in summer. Based upon tree size spacing of 5 m between row and 2.5-3 m between trees is recommended, tree height is around 3.5-4 m. This training system is useful for hand-picking; 60-70% of the crop can be harvested from ground. Modified Brunner-spindle is suitable for either standard or moderate vigorous rootstocks. The cherry spindle is an intensive orchard planted with 1250-2300 trees per hectare and it is recommended for sweet and sour cherries on semi dwarf to vigorous rootstocks, depending on soil fertility and quality. Trees are 2.5-3.5 m high, 75-80% of the crop can be harvested from the ground. Permanent basal scaffolds are developed on the basis of the canopy to counteract the stronger terminal growth. The tree is headed only once, after planting, from the following year the central leader grows from the terminal bud. The central leader developed from the terminal bud results moderated growth in the upper parts of the tree head. The strong upright shoots that may develop below the terminal bud are pinched to 3-4 leaves in the summer or removed entirely. The weaker, almost horizontal shoots growing from the central leader form fruiting twigs in the following year if their terminal bud is not removed. Brunner's double pruning is used only once or twice on the permanent basal branches because of its good branching effect. Trials on various rootstocks are running to find optimum spacing and fruiting wood management. The training and pruning guidelines are discussed in the paper. The average crop of bearing years is around 20-30 t/ha depending on site and cultivars. This new system is spreading in Hungary, around 70 ha sweet and sour cherry orchards are trained according to our guidelines.
-
In vitro regeneration from cotyledons of watermelon
96-98.Views:265Cotyledonary segments of five different genotypes of watermelon were used to induce organogenesis. Five different hormone combinations were applied to enhance the induction of shoot formation on the surface of the segments. The phases of organogenesis were followed with light and scanning electron microscope. Shoots were obtained after four weeks, then the shoots were transferred to hormone free medium for root induction.
This method of regeneration can be applied in transformation experiments. GUS histochemical assay was made to check the expected success of using Agrobacterium for the transformation.
-
Anatomical relations of root formation in strawberry
71-75.Views:434Anatomical relations of root formation are traced throughout the life cycle of the strawberry plant from the germinating seed up to the runners of the adult plant. Histological picture of the root changes a lot during the development of the plant. First the radicle of the germ grows to a main root, which makes branches into side roots and later adventitious roots are formed on the growing rootstock or rhizome. The anatomy of the different types of roots is also conspicuously different. First tiny branches appear relatively early after germination on the seedling's radicle, but soon the hypocotyl of the seedling thickens and develops side roots, which are already somewhat stronger. During this interval, the first true leaves are formed. The 4th or 5th of them being already tripartite, and the initiation of new roots extends into the epicotylar region of the shoot. The second years growth starts with the development of reproductive structures, inflorescences and runners starting from the axils of the new leaves. Near the tips of the runners below the small bunch of leaves, new root primordia are initiated. The tiny radicle of the germ develops a cortical region of 5-6 cell layers. Cells of the central cylinder are even smaller than the cortical parenchyma and include 3-4 xylem and 3-4 phloem elements as representatives of the conductive tissue. Roots originating from the shoot region are much more developed; their cortical zone contains 17-20 cell layers, whereas the central cylinder is about half as large. In the next year, new roots are formed at the base of the older leaves. These roots differ hardly from those of the last season in size and volume, however, they are recognised by colour and their position on the rhizome. The roots of the last year are dark, greyish-black, and grow on the lower third length of the rhizome, on the contrary, the new ones, on the upper region, are light brown. Roots starting from the shoot or rhizome are, independently from their age or sequence, mainly rather similar in size and diameter, thus being members of a homogenous root (homorhizous) system, i.e. without a main root. Plants developed and attained the reproductive phase develop in the axils of the leaves runners being plagiotropic, i.e. growing horizontally on the surface of the soil. The runners elongate intensely, become 150-200 mm, where some long internodes bear a bunch of small leaves and root primordia on short internodes and a growing tip. Runners do not stop growing, generally, further sections of 15-25 cm length are developed according to the same pattern, with small leaves on the tip. The growing tip of the runners is obliquely oriented, and small, conical root primordia are ready to start growing as soon as they touch the soil. The roots penetrate the soil, quickly, and pull, by contraction, the axis of the runner downwards, vertically, developing a new rhizome. The short internodes elongate a little and start developing adventitious roots. At the end of the growing season, the plantlets arisen on the rooted nods of runners are already similar to the original plants with homogenous root system. On the side of the adventitious roots, new branches (side-roots) are formed. The root-branches are thinner but their capillary zone is more developed being more active in uptake of water and nutrients. The usual thickening ensues later.
-
Comparative anatomical study of leaf tissues of scab resistant and susceptible apple cultivars
43-45.Views:296According to previous studies some anatomical features seem to be connected with resistance or susceptibility to scab caused by Venturia ineaqulis (Cke./Wint.) in case of a given cultivar. Study of leaf anatomy of three scab resistant (‘Prima’, ‘Florina’, MR–12) and two susceptible (‘Watson Jonathan’, ‘Golden Delicious Reinders’) apple cultivars have been made. Preserved preparations made of leaves has been studied by light microscope. Studied parameters were: thickness of leaf blade, thickness of palisade and spongy parenchyma, thickness of epidermal cells, thickness of the cuticle. By measuring leaf thickness and epidermal cell thickness visible differences appeared in certain cultivars, while most conspicuous difference has been shown in thickness of the cuticle.
