The amounts of Fe, and Zn were measured in maize seedlings infected by smut gall tumour (Ustilago maydis Dc. Cda.) and in healthy seedlings five days after infection. The amount of elements was also measured under different stress intensities. Due to the infection, as a biotic stress, the amount and distribution of examined elements have been c...hanged. On the bases of the differences in the Fe distribution between the symptoms less and tumorial leaf parts, we have come to the conclusion that the infection also effects the mobilisation of Fe and Zn inside the plants. The Fe uptake was much higher in the infected plants and the tumour development also had an effect on the uptake and distribution of the examined elements. The experiments of infecting maize seedlings by monosporidial strain of crown gall tumour showed no tumour development. We found that the monosporidial strain also acts as a biotic stress and has an effect of iron and zinc distribution. We observed a slight difference in the iron and zinc contents in the roots of corn seedlings infected by different monosporidial sporidium concentrations, while the iron and zinc contents in the shoots were increased by the intensity of the infection. The roots do not form tumours. There is no difference between the roots of the infected and healthy corn seedlings. Since the Fe and Zn contents of the shoots of infected plants depend on the intensity of the infection, we have come to the conclusion that there must exist a „special” communication system regulating the transportation of the examined elements.
In the experiments with infected maize seedlings, it became necessary to get the iron chlorosis before the disease reaches the lethal phase. Although most of the iron reserves are located in the embryo, to accelerate the chlorosis, the endosperm was removed, and it was observed, that the iron chlorosis appears later in maize seedlings when the endosperm is removed. The relative chlorophyll content of the first and second leaves was measured in iron efficient and iron deficient maize seedlings at different times.
The higher IAA content of tumorial plant tissues is already known. The treatment with IAA decreases the iron concentration in the shoots and in the roots of +Fe precultured plants and increases at -Fe precultured ones. The TIBA retards the shoot-to-root transport of IAA. When the seedlings were treated simultaneously with IAA and TIBA, higher iron concentrations were observed in the shoots and in the roots of corn seedlings.
We found extremely high iron concentrations in the roots of infected seedlings and, in line with this, serious damage to the roots was observed that this can be caused by the high iron content generated free radicals. The results demonstrate that IAA has a role in the shoot to root communication.
More sensitive than Mimosa pudica and more beautiful than any adornment detached from nature by man, the azalea (Azaleea
indica) gathers through its shapes a real symphony of colours and enchanting hues, of elegant shapes, having no rival in the flower world.
The azalea can multiply through seeds and vegetatively: seedlings, grafting, lay
The widest reproduction method remains that through semilignified seedlings, a method that can be used throughout the year
avoiding the months less favourable for propagation by seedlings, with poor light: November and October. The best results are given by the
spring propagations by seedlings (February-March) and the summer propagations by seedlings (July-August). The rooting can last for 12-14
weeks until the seedlings can be transplanted in flower pots without risks.
A wide application in horticultural practice is the use of growth substances, that take part in the faster formation of roots and in a
higher percent for species of plants, that, normally, root with difficulty through seedlings. Under this aspect, many synthetical compounds
have proved to be very active (IAA, NAA, IBA, 2,4,5-T acid etc.) (3,4).
The environment is contaminated with heavy metals and other toxic compounds. One of the most important toxic element is the arsenic (As).
The objective of our study was to investigate the effect of As on fresh and dry weight of sunflower and maize in the early growth phases.
Seedlings were grown in climate room on nutrient solut...ion which were treated with 3, 10 and 30 mg kg-1 arsenic. The plants were treated separately with As(III) and As(V). After 14 day, changes in fresh and dry weight of maize shoots and roots were recorded. In the case of sunflower these parameters were measured after 21 day.
The applied As(III) and As(V) decreased the fresh and dry mass of the shoots and roots of seedlings, especially at concentration 30 mg kg-1. We can draw the conclusion that the treatments of the maize and sunflower roots with arsenic had negative effects on the biomass accumulation. We found that the sunflower plants are more sensitive to arsenic toxicity than maize plants, and all data demonstrate that the As(III) is more toxic to these plants than the As(V).
Selenium (Se) is an essential trace element for animals, microorganisms and some other eukaryotes. It has become increasingly evident that Se plays a significant role in reducing the incidence of lung, colorectal and prostate cancer in humans. Although there is evidence that selenium is needed for the growth of algae, the question of essentiali...ty of Se in vascular plants is unresolved. Therefore Raphanus sativus (Se accumulator) and Capsicum annuum (non Se accumulator) were treated with 0-200 mg/l natrium-selenate. The results showed that lower (2 mg/l) concentration natrium-selenate increased the fitomass and total antioxodant capacity in seedlings.
In this study, maize (Zea mays L. cv. Norma SC) and sunflower (Helianthus annuus L. cv Arena PR) seedlings treated by molybdenum (Mo) that were cultivated in special plant growth boxes, known as rhizoboxes. During our research we tried to examine whether increasing molybdenum (Mo) concentration effects on the dry mass and absorption of some ele...ments (molybdenum, iron, sulphur) of shoots and roots of experimental plants.
In this experiment calcareous chernozem soil was used and Mo was supplemented into the soil as ammonium molybdate [(NH4)6Mo7O24.4H2O] in four different concentrations as follow: 0 (control), 30, 90 and 270 mg kg-1.
In this study we found that molybdenum in small amount (30 mg kg-1) affected positively on growth of maize and sunflower seedlings, however, further increase of Mo content reduced the dry weights of shoots and roots. In case of maize the highest Mo treatment (270 mg kg-1) and in case of sunflower 90 mg kg-1 treatment caused a significant reduction in plant growth.
In addition, we observed that molybdenum levels in seedling were significantly elevated with increasing the concentration of molybdenum treatment in comparison with control but the applied molybdenum treatments did not affect iron and sulphur concentration in all cases significantly.
Zinc (Zn) deficiency is a critical nutritional problem for plants and peoples all over the world. Almost half of the world’s cereal crops are deficient in Zn, leading to poor crop yield. In this study, the effect of different Fe/Zn ratio on some physiological parameters of maize seedlings were investigated on the dry matter of shoots and root...s and their ratio, SPAD index and the total length of shoots. The relative chlorophyll contents significantly decreased under increasing Fe given to the Zn deficient. The results showed that the different Fe/Zn supplies decreased the total length of shoots - ranging from 9% to 65% - by latent Zn deficiency. Corresponding to several scientific findings, it was observed that the non-optimal Fe/Zn ratio of tissues take part in the evolution of latent Zn deficiency in the case of high Fe concentration.
Etiology of pepper fruit melanotic ringspot (FMRS) disease (Salamon, 2009) was studied on fruit samples collected in forced pepper populations. It was noticed that in spite of heavy thrips (Frankliniella occidentalis) infestations and of TSWV epidemy detected in the forcing houses, FMRS occurred only in plants having healthy foliage. Symptomato...logical surveys strongly suggested that FMRS appeared exclusively in specific pepper genotypes. The size of melanotic ringspots has been observed to grow at room temperature during postripening of diseased fruits. A mechanically transmitted plant virus was isolated from symptomatic parts of 9 white pepper fruits affected by FMRS. On test plants each of the virus isolates caused systemic symptoms characteristic to TSWV. Using cDNA/PCR technique and TSWV N-gene specific primers a ca. 300 bp long DNA fragment has been amplified from total nucleic acid extracted from symptomatic tissues but never from asymptomatic parts of the fruits showing FMRS. Plant progenies grown from seeds of FMRS diseased fruits segregated in respect of resistance and/or susceptibility to TSWV infection. TSWV was also detected in and isolated from three fruits showed non-melanotic yellow rings (one of them was infected with a tobamovirus, too). Seedlings derived from these fruits proved to be susceptible to TSWV. Based on the above results we could conclude that the FMRS disease developed on fruits of “cecei” type white peppers that carry a TSWV resistance gene, most likely the Tsw gene in heterozygous form. These fruits were infected with thrips transmitted TSWV and FRMS appeared as a hypersentive reaction (HR) manifested in fruits.
Zinc (Zn) is an essential micronutrient needed not only for people, but also crops. Almost half of the world’s cereal crops are deficient in
Zn, leading to poor crop yields. In fact, one-third (33%) of the world's population is at risk of Zn deficiency in rates, ranging from 4% to
73% depending on the given country. Zn deficiency in agr
The Zn contents of soils in Hungary are medium or rather small. Generally, the rate of Zn deficiency is higher on sand, sandy loam or soil
types of large organic matter contents. High pH and calcium carbonate contents are the main reasons for the low availability of Zn for
plants (Karimian and Moafpouryan, 1999). It has been reported that the high-concentration application of phosphate fertilisers reduces Zn
availability (Khosgoftarmanesh et al., 2006). Areas with Zn deficiency are particularly extensive in Békés, Fejér and Tolna County in
Hungary, yet these areas feature topsoils of high organic matter contents. Usually, Zn is absorbed strongly in the upper part the soil, and it
has been observed that the uptakeable Zn contents of soil are lower than 1.4 mg kg-1.
Maize is one of the most important crops in Hungary, grown in the largest areas, and belongs to the most sensitive cultures to Zn
deficiency. Zn deficiency can causes serious damage in yield (as large as 80 %), especially in case of maize. On the other hand, Zn
deficiency can also cause serious reduction in the yields of dicots. One of the most important vegetables of canning industry is cucumber,
which is grown all over the world.
In this study, the effects of Zn deficiency have investigated on the growth of shoots and roots, relative and absolute chlorophyll contents,
fresh and dry matter accumulation, total root and shoot lengths, the leaf number and leaf area of test plants in laboratory. Experimental
plants used have been maize (Zea mays L. cv. Reseda sc.) and cucumber (Cucumis sativus L. cv. Delicatess). A monocot and dicot plant have
chosen a to investigate the effects of Zn deficiency, because they have different nutrient uptake mechanism.
It has been observed that the unfavourable effects of Zn deficiency have caused damage in some physiological parameters, and
significantly reduced the growth, chlorophyll contents of monocots and dicots alike.
Different bacteria and wood ash, as a possible micro-nutrient, and liming material, was examined in our experiment on the early growth of corn seedlings.
The development of renewing energy resources includes the use of energy grasses and energy forests. The intensive land use in forestry and in agriculture may cause the acidification of... soils due to the harvest, or leaching of cations. To maintain the sustainability of soils necessary to maintain it’s the buffer capacity, and pH. Beside the lime the wood ash can is one of the most effective sources to provide the sustainability of intensive land use. The soil born micro organisms play a significant role in the maintenance of soil quality. The bio fertilizer, that contains soil originated bacteria (Azotobacter, and Bacillus sp.), was used in the experiments. The plants release several organic acids by their roots lowering the soil pH, and make more available the sparingly soluble minerals. The amounts of released organic matter depend on stress intensity, as the high pH is. The soil life has a significant role to keep the soil conditions on sustainable level, since there are several similarities in nutrient uptake mechanism between the bacteria and higher plants. Advantageous effects of bio-fertilizer were observed in our experiments.
We came to the conclusion that the use of wood ash is recommended instead of lime for the improvement of acidic soils, on the evidence of its pH increasing effect. The wood ash contains several micronutrients in an optimum composition for forestry and agricultural plants. The solubility of heavy metals is very low; therefore there is no risk to use the wood ash in the agriculture and in the horticulture by our experiments. The retardation of growth at higher ash doses can be explained by the modification effect to the soil pH, as far as the original soil pH was pH 6.8, and when ash was given to the soil, the pH increases to 7.8 pH, that is unfavourable for the uptake of most nutrients.
We conducted experiments for developing an in vitro micropropagation protocol starting from meristems of Rudbeckia hirta L seedlings. We pre-soaked the seeds in sterile ion-exchanged water for 17 hours, and then achieved surface disinfection in two separate steps. First, we used concentrated household sodium-hypochloride solution for 20 minutes... and, also for 20 minutes, we applied hydrogen peroxide of 10%, which was followed by washing with sterile ion-exchanged water three times. For the propagation of seedling meristems, the combination of half-strength solid Murashige and Skoog (1962) culture medium containing 10 mg/l of kinetin and 2 mg/l of kinetin + 0.1 mg/l of 2iP proved to be the most suitable. The average number of shoot-buds developed from the seedling axillary meristem in the best culture media varied between 5 and 17. Without separating them, we inoculated the shoot-bud clusters on MS culture medium containing 2 mg/l of IAA. After four weeks of incubation, we obtained elongated shoots, which we separated and inoculated into a new culture medium and from which we obtained elongated roots. The rooted plants were gradually acclimatised in the cultivation room, potted and carried to a greenhouse, and then planted in open field for subsequent observation. By adopting this method, our laboratory started the micropropagation of the superior and/or elite genotypes of the Rudbeckia hirta L. being of special value in respectt to breeding.
Bio-fertilizers promote the nutrition uptake, firstly enhance the baring and mobility of nutrients, on the other hand biofertilizers elevate nutrient uptake in direct way. Although there are a lot of questions about their application in polluted soils. The cadmium ion is easily collectable and also transportable inside plants. Thus the Cd... can get into the food-chain causing public health problems. The cadmium treatment decreases the dry matter accumulation, and the intensity of photosynthesis at the experimental plants, while the treatments with bio-fertilizer increased these parameters. The cadmium accumulated in the roots, the transport to the shoots was low. We came to the conclusion, that –because of the different nutrient-uptake systemthe sunflower took up more cadmium. Using bacterium containing bio-fertilizer the toxic effect of cadmium was moderated. By our experimental results the use of Phylazonit is offered under contaminated conditions.
In Hungary, the woolly cupgrass (Eriochloa villosa [Thunb.] Kunth) endanger row crops (i.e. corn, sunflower). Its fast spreading based on some reason viz. long-lasting emergence, reduced sensitivity to many kinds of herbicides, vigorous competitional ability and fast initial growth. Allelopathy, ability of many plant species to produce one or m...ore biochemicals wgich is used tocompete with each others. In this experiment we examined, whether the woolly cupgrass possesses allelopathy, and if so, how influences on the development of cultured crops like maize, sunflower and lettuce.
Various abiotic stresses including high salinity strongly affect seed germination. Three Hungarian wheat landraces Gamási, Fóti and Kartali have been tested for seed germination, seedling growth and chemicals parameters when seeds were soaked in gibberellic acid (GA3) at the concentrations of 0, 75 and 150 ppm and at four levels of salinity s...tress 0, 5, 10 and 15 dSm-1. A laboratory experiment took place at Research Institute of Nyíregyháza. Factorial Experiment based on Randomized Complete Block Design (RCBD) in four replications has been conducted. Seed soaking in GA3 before sowing significantly affected germination characteristics, seedling properties and the results of chemical analysis. The highest germination as well as K+ content of seeds were observed at seed soaking into 150 ppm GA3. However, Na+ and proline contents in seedling were decreased. The behavior of the tested Hungarian wheat varieties was genotype-dependent. Increasing salinity stress up to 15 dSm-1 significantly affected germination characteristics, seedlings parameters and chemical analysis. Fóti variety turned out to be the best at 150 ppm GA3 compared to the other two varieties. Moreover, it had the lowest Na+ and proline contents and highest K+ content.