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  • Impact of the integration of lupine (Lupinus albus) into crop rotation on the extent of soil compaction in the Westsik longterm field trial
    529-537
    Views:
    87

    In order to reduce or eliminate soil compaction, rational crop rotation and appropriate sequence of crops have an increasingly important role in addition to mechanical and tillage solutions. In this respect, introduction of greening in recent years has been a major step, which focuses on aspects of environmentally conscious, soil conserving farming and the improvement of biodiversity. The cornerstone of this strategy is the cultivation of crops that have a beneficial effect on soil properties, such as the use of nitrogen-fixing plants and green manure plants in the cultivation system that have a beneficial effect on soil structure. In our examinations, penetrometer measurements were carried out in the second longest crop rotation-based field experiment in Europe in order to quantify the effects of green crops and crop rotation strategies on soil resistance. Our aim was to evaluate and compare the impact of lupine (Lupinus albus) on the penetration resistance of soil on sour sandy soils. At the time of the penetration resistance measurement, different crop rotations had a significant effect on the development of the parameter in the examined soil layer. The most favourable penetration resistance values were found in the crop rotation, which included lupine as a green manure. The favourable effect is dominant below the cultivated layer (0–40 cm), which is statistically verified. The values of penetration resistance of the cultivated soil layer of lupine sown as primary green manure did not differ significantly from the values measured in the case of the fallowing-based crop rotation. Therefore, the use of lupine green manure instead of fallowing could be worth considering by practical application due to its favourable effects on soil penetration resistance. The use of lupine green manure after the production of rye cultivation resulted in penetration parameters similar to fallowing, irrespective of the green crop and the applied amount of nitrogen fertilizer, which justifies the cultivation of the crop as green manure. In the case of potato cultivating, recorded compaction within the cultivated layer is an obvious consequence of mechanical compaction during harvest; therefore, machinery operations are decisive for the development of penetration resistance values of the cultivated layer. In addition to the beneficial effect of lupine as a green manure crop on soil condition, its nitrogen-fixing ability is also important; it stresses the utilisation of the crop of sour sandy soils for the sake of proper soil management. 

  • The role of disease resistance in the registration of crop varieties in Hungary
    27-29
    Views:
    126

    Variety testing including disease resistance test of the major crops has been carrying out since the 1960’s in Hungary. Testing for resistance of the new candidate varieties is performed in the so-called VCU (Value for Cultivation and Use) trials under natural infection and in special small-plot or micro-plot trials using different disease provocative methods. Disease resistance, especially those of multiple and horizontal-type (race non-specific, partial or durable) resistances, has recently become a key limiting factor in the state variety registration. The role of disease resistance in the decision-making process of variety registration is demonstrated on the examples of winter wheat and sunflower as two major field crops in Hungary.

  • Selection of powdery mildew resistant and susceptible grapevine genotypes with molecular markers
    100-104
    Views:
    108

    Incorporation of competitive quality and resistance against the most important fungal diseases (powdery and downy mildew) in a cultivar is one of the most important aims of grapevine breeding. In the 20th century, the most advanced results in grapevine resistance breeding were achieved by French researchers. They used resistant cultivars in more than 30% of their growing areas. In these varieties, North American wild Vitis
    species were the resistance gene sources. The discovery of immunity-like resistance of Muscadinia rotundifolia opened new perspectives in resistance breeding. M. rotundifolia harbours a dominant powdery mildew gene, providing resistance in highquality cultivars after back-crosses with V. vinifera varieties. M. rotundifolia has been involved in the Hungarian grape breeding programs since 1996, thanks to a French-Hungarian variety exchange. In addition to traditional selection methods, application of MAS (Marker Assisted Selection) based on various types of
    molecular markers, can provide additional tools for these efforts. Run1 locus, responsible for powdery mildew resistance, was identified in Muscadinia rotundifolia. Molecular markers closely linked to this locus are very significant in screening progenies deriving from M. rotundifolia and V. vinifera crosses, making possible the discrimination between resistant and susceptible genotypes at DNA level. In our analyses BC5 progeny of {(M. rotundifola×V. vinifera) BC4}×Cardinal (V. vinifera) tested for powdery symptoms were analysed with PCR-RFLP (GLP1- 12P1P3) and microsatellite markers (VMC4f3.1, VMC8g9). Our results proved the applicability of the linked markers and reliability of marker assisted selection.

  • Increase of Wheat (Triticum aestivum L.) Resistance to Leaf Rust (Puccinia tritici) via Gene Transformation
    127-129
    Views:
    69

    Leaf rust is one of the most significant fungal disease of wheat not only in Hungary but also in other parts of the world. For improving leaf rust resistance of winter wheat variety (Hajdúság, 2003) produced by conventional breeding methods, verified by results of variety tests, showing outstanding results in the aspect of the most important economic values, integration of tissue culture technics, genetic engineering and traditional
    methods may provide facilities. Building the gene(s) responsible for resistance into the determined genome can improve the resistance in a way that changes other features of the plant slightly or not at all. In the course of genetical transformation of the variety Hajdúság we applied one of the wheat’s own effecient green-tissue specific insurer genetical regulator, the promoter of ribulose carboxylase 1-5 bisphosphate (RuBisCo) ‘s small
    subunit to control the expression of the gene cmg1.

  • Azoxystrobin resistance of Botrytis cinerea Pers.:Fr. isolates
    56-63
    Views:
    89

    Fungicide resistance is one of the most important problems endangering the effectivity of practical plant protection today. The frequent and subsequent usage of specific fungicides results the emergence of resistant fungal populations. This threatens is especially high in case of Botrytis cinerea Pers.:Fr. being an endemic pathogen with frequent infection. Nowadays the main method of protection as against Botrytis cinerea is the application of chemical fungicides chemicals. Therefore, a better knowledge of local populations is necessary for the planning of the protection procedures.
    Based on the results of our examinations we may establish that the growth of the examined samples showed a significant difference under in vitro circumstances, which shows a great deal of variability of the Botrytis cinerea populations in Hungary. Twenty-five Botrytis cinerea samples from different hosts were analyzed in this study. High resistance was found towards azoxistrobin in seven cases, and low resistance in eight cases.
    It was also proved, that the B. cinerea is able to bypass the inhibition site of the azoxistrobin via the alternative oxidase. The presence of this altermative mitocondrial electrotransport route considerably reduces the effectivity of the chemical. 

  • Q-PCR analysis of the resistance of Hungarian Botrytis cinerea isolates toward azoxystrobin
    41-44
    Views:
    76

    The genes being in the mitochondrial DNA primarily encode the enzymes of cellular respiration. Fungicides belonging to the family of quinol oxidase inhibitors (QoIs) play on important role in the protection against several plant diseases caused by fungi. These fungicides bind to the cytochrome bc1 complex so they block electron transport between cytochrome b and cytochrome c1. This way these fungicides inhibit the ATP synthesis consequently they inhibit the mitochondrial respiration. The QoI resistance has two mechanisms. One of them is the point mutation of the cytochrome b gene (CYTB), e.g. the substitution of a single glycine by alanine at position 143 results in high-resistance. The other is the cyanide-resistant alternative respiration sustained by the alternative oxidase.
    In a cell there are several mitochondria. The phenomenon when the genomes of all mitochondria in the cell are identical is called homoplazmy. If in the cell there is wild and mutant mitochondrial DNA this is called heteroplasmy. Whether the mutation in the mitochondria causes fenotypical diversity or does not depend on the dose, i.e. it depends on the percentage of the changed mitochondrials. During our work we investigated Botrytis cinerea single spore isolates which have been collected in 2008-2009 on different host plants. Our goal was to decide whether heteroplasmy influences the level of resistance. We managed to detect the change of the level of heteroplasmy, so the change the level of the resistance due to the treatment with fungicide.

  • Examination of the physical state of the soil under conventional and reduced tillage systems
    183-186
    Views:
    149

    he effect of reduced and conventional tillage systems on soil compaction and moisture content in two years with extreme weather conditions is introduced in this paper. The investigations were carried out in a long-term soil cultivation experiment set on a heavy textured meadow chernozem soil at the Karcag Research Institute. In 2010 the amount of precipitation during the vegetation period of winter wheat was 623.3 mm, 2.2 times higher than the 50-year average, while in 2011 this value was 188.7 mm giving only 65% of the average. The examinations were made after harvest on stubbles on 4 test plots in 5 replications in the case of each tillage system. Soil compaction was characterised by penetration resistance values, while the actual soil moisture contents were determined by gravimetry. The values of penetration resistance and soil moisture content of the cultivated soil layer were better in the case of reduced tillage under extreme precipitation conditions. It could be established that regular application of deep soil loosening is essential due to the formation of the unfavourable compact soil layer under 30 cm. Conventional tillage resulted in enhanced compaction under the depth of ploughing, the penetration resistance can reach the value of 4 MPa under wet, while even 8 MPa under dry soil status.

  • Cytochrome b diversity of Hungarian Botrytis cinerea strains
    18-21
    Views:
    90

    In the mitochondrion of eukaryotes, cytochrome b is a component of respiratory chain complex III. Cytochrome b is encoded by the
    cytochrome b (CYTB) gene located in the mitochondrial genome. The fungicidal activity of QoIs relies on their ability to inhibit mitochondrial respiration by binding at the so-called Qo site (the outer quinol-oxidation site) of the complex III. Since their introduction, QoIs (like azoxystrobin) have become essential components of plant disease control programs because of their wide-ranging efficacy against many agriculturally important fungal diseases like grey mould on various crops. QoI resistance primarily arises from a target-site-based mechanism involving mutations in the mitochondrial CYTB. As the management of grey mould is often dependent on chemicals, the rational design of control programs requires the information about the diversity of genes connected with resistance in field populations of the pathogen.
    Monospore B. cinerea field isolates has been collected during 2008-2009 from different hosts in Hungary. PCR fragment length analysis
    indicated the high frequency presence of type large intron in the isolates while in a few strains G143A substitution could also be detected.
    These results indicated the heterogeneity of CYTB in the Hungarian B. cinerea populations, which possibly involve the heteroplasmy of this
    mitochondrial gene, moreover indicates the existence op azoxystrobin resistant populations in Hungary.
    This work was supported by NKFP-A2-2006/0017 grant. Erzsébet Fekete is a grantee of the János Bolyai Scholarship (BO/00519/09/8).

  • Use of extensigraph in the examination of wheat flours
    17-23
    Views:
    114

    The extensograph is widely used in quality control and research laboratories studying wheat flour quality. The most commonly used measurements include Rm, the maximum resistance (maximum height of the curve); R5 the resistance at a constant extension of 5 cm; E, extensibility (total curve length); Rm/E, the ratio of maximum resistance to extension; and A, the area under curve. The extensograph has proved useful in the classification and assessment of flours on the physical dough properties. Another important application is its use in wheat breeding programs. Furthermore, extensograph is an excellent tool to study the effects of a wide range of ingredients on dough properties of wheat flour (like oxidants, enzymes, salt and additives), and it can also be used measure the changes during the frozen storage. In the present study we provide a review of the scientific literature concerning the possible applications of the extensograph.

  • Movement of Particles in the Air
    22-26
    Views:
    99

    The physical characteristics of particles (seeds and fertilisers) can strongly influence their movements both in seeding and spreading machines and in the air. It is therefore essential to study these particles when constructing such machines. In this respect the size, shape, coefficient of friction and aerodynamic resistance of particles are of great importance.
    Due to their irregular shape, determining the size of particles is a troublesome process. A precise description of particles has to include several sizes and can be obtained from their screen size. Many physical properties of particles are relevant during movement in the air, but the aerodynamic resistance coefficient is the most important (Hofstee et al., 1990). Two types of wheat and four types of fertiliser particles were investigated (supported by the National Scientific Foundation OTKA, T-026482). An elutriator was designed and constructed (Csizmazia et al., 2000), in which an airflow is supplied by a centrifugal fan. Air velocity was measured with a thermal sensor. Particle sizes, mass and terminal air velocity were measured. The influence of the aerodynamic resistance coefficient on the particles’ motion is also discussed.

  • Fruit melanotic ringspot (FMRS) – a disease of resistant Capsicum genotypes infected with Tomato spotted wilt virus (TSWV) on the fruits
    64-69
    Views:
    64

    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. Symptomatological 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.

  • Examination of resistance against Aeromonas hydrophila infection on genetically different common carp variants (preliminary results)
    7-11
    Views:
    75

    Septicemia disease caused by the bacterium Aeromonas hydrophila is a major problem for fish farmers around the world. In our experiment resistance to the disease was investigated on carp variants with diferent genetical backgrounds. 96 different genetic variants(„families”) were created by crossing various individuals of 4 carp strains (2 wild and 2 cultured ones). Families were reared until reaching the size of 10 gramms and 100 fish of each families were marked with an individual electronic identifier. Marked fish were divided into 5 groups. Fish from one group were infected with A. hydrophila and mortality were registered during 2 weeks. Based on mortality data, the most resistant and most susceptible families will be selected using population genetics methods.

  • Testing disease resistance in autumn wheat genotypes by means of field experiments
    30-40
    Views:
    80

    According to our scientific results we can state that we have to use integrated pesticides management in crop protection against the diseases of winter wheat. One of the most important elements of IPM is to select a genotype characterised by good resistance to diseases (and by high yield ability and excellent baking quality). It is especially important that the wheat variety have tolerance against not only to one or two leaf and spike (grain) diseases, but „complex” tolerance. It is not necessary to give up the growing of a variety which has susceptibility to different diseases because we can protect it using appropriate chemical management. In the intensive growing stage of wheat (BBCH 32-37) we can use a noncompulsary fungicide-treatment (depending on e. g. the infection, ecological conditions) and, at the beginning of the flowering stage
    (BBCH 59-65), we have to use a compulsary fungicide-treatment (in spite of e. g. special weather conditions, resistance genotype)to ensure high yield and good quality.

  • Comparative analysis of Staphylococcus aureus strains by molecular microbiology methods
    34-39
    Views:
    107

    Staphylococcus aureus is a very important pathogen for dairy farms and milk processing plants. Subclinical mastitis is often caused by this species, and it can contaminate bulk tank milk when milking cows are suffering from mastitis. Additionally, thermostable enterotoxins (SE) produced by some types of this bacterium can cause food poisoning.
    The aim of our research was to examine the number of S. aureus in bulk tank milk in two dairy farms and the enterotoxin-producing ability, genetic relation (pulsotype) and antibiotic resistance of S. aureus strains from different sources (bulk tank milk, udder quarter milk and environment).
    The results show that the mean number of S. aureus of bulk tank milk of two farms significantly differed (P<0.05). Fourteen isolates were selected for further molecular genetic studies (five isolates were from bulk tank milk and nine isolates were from udder quarter milk). S. aureus was not recovered from the environmental samples. Three of the fourteen isolates (21.4%) tested by multiplex PCR were positive for SE genes. Two isolates carried one gene (seb) and one isolate carried two genes (seg and sei). The fourteen strains were classified into three pulsotypes and two subtypes at 86% similarity level. Isolates from bulk tank milk (n=5), were divided into 2 pulsotypes (A, C) and one subtype (C1). The isolates from udder quarter milk (n=9) belonged to three different pulsotypes (A, B, C) and two subtypes (A1, C1). The distribution of pulsotypes in the present study revealed genetic relationship between S. aureus isolated from udder quarter milk and bulk tank milk. This could be explained by the fact that in farms with a high number of infected cows, these cows could represent the main source of contamination. The results of the antibiotic resistance investigations show, that all strains were susceptible to methicillin, cefoxitin, lincomycin, tetracycline, erythromycin and sulfamethoxazole/trimethoprim. Thirteen out of fourteen strains were resistant to penicillin (A and C pulsotypes, A1 and C1 subtypes) and just one isolate was susceptible (B pulsotype) to all antibiotics tested.

  • Effect of fish feeds with high vegetable oil and low fish oil content on the growth performance and innate immune system of common carp (preliminary results)
    7-12
    Views:
    76

    Fish meal and fish oil are very important components of fish feeds used by aquaculture. They contain poly-unsaturated fatty acids, which are essential nutrients both for fish and human nutrition. However, sources of fish meal and fish oil are limited, there is a need for new feed components to supply the increasing fish production and the increasing demand for fish feed. The aim of AQUAMAX project, supported by the European Union is to replace the fish meal and fish oil with vegetable oils. As a participant of this project, group of immunology in Research
    Institute for Fisheries, Aquaculture and Irrigation (HAKI) examined the effect of three different fish feeds on the growth performance, innate immune response and resistance against Aeromonas hydrophila infection of common carp in an in vivo experiment. Fish feed supplemented with Camelina oil, but still containing fish oil significantly increased growth performance of experimental fish and their resistance against the infection. Fish feed containing linseed oil only did not enhance the growth performance, and it had a negative effect on resistance against infection. Based on the experimental results it can be concluded that fish oil used in fish feeds cannot be replaced effectively with vegetable oils, but can be supplemented with them. 

  • Examination of resistance to Sclerotinia stalk and head rot in sunflower (Helianthus annuus L.) hybrids
    34-37
    Views:
    135

    Nowadays, phytopathogenic fungi cause the most serious yield loss in open field cultures, and sunflower (Helianthus annuus) is no exception to this phenomenon. Sclerotinia stalk and head rot (Sclerotinia sclerotiorum) is present in the whole area of Hungary, and can cause serious financial loss. In our experiment, sunflower hybrids were tested for resistance to Sclerotinia sclerotiorum infection. 16 sunflower hybrids were examined at the Experimental Breeding Site in Jászboldogháza. Pesticide treatment and also nutrient replacement were applied on the sunflower fields.

  • The Effect of the Mineral Content of the Leg-Horn and the Age of Sheep on the Mechanical Parameters of the Horn
    42-45
    Views:
    71

    Species and individual animals with hard leg-horn have higher resistance against foot diseases. The reason for this is the fact, that bacteria can penetrate the hard leg-horn with more difficulty than the soft leg-horn, and in this way it is also more difficult for them to cause an illness. From among the mechanical parameters of the leg-horn the P = 0.1% negative linear correlation between the hardness and the water contents of the horn is significant. There is a positive linear correlation between the shock resistance and the water contents of the leg-horn. In the case of air-dry horn (with less than 8% water contents) there is a positive linear correlation between the Ca- and Zn contents as well as the Ca:P ratio and the hardness of the horn. The results suggest that the wider the Ca:P ratio of the horn, the harder the horn is, while the water content is the same. The leg-horn of the Hungarian Merino ewes have larger Ca contents and wider Ca:P ratio than juvenile animals have. This is why the juvenile animals with a softer leg-horn can be more susceptive to foot diseases than the older animals.

  • Susceptibility of maize hybrids to corn smut diseas
    39-42
    Views:
    142

    Corn smut disease is one of the most common maize diseases. In the previous years the disease lost from its importance, however nowadays it is becoming more and more important and widespread. The protection against it encounters great difficulties, therefore it is important to emphasize prevention and resistance based protection. The aim of the research was to investigate under laboratory circumstances the resistance of Hungary’s most commonly cultivated maize hybrids to corn smut disease. Twelve species were investigated. We distinguished two susceptibility groups within the hybrids based on the investigated parameters. The results are intended to assist the protection against corn smut disease and to make a suggestion for the farmers so that they could apply more environmental friendly and economical production.

  • Population genetic results of Hungarian Botrytis cinerea isolates establishing new technologies with decreased chemical usage against grey mould
    259-261
    Views:
    103

    Botrytis cinerea causes gray mold on a high number of crop plants. Information about the populations of plant pathogen fungi may help to develop new strategies for the effective and economic crop protection with reduced fungicide usage. Hungarian B. cinerea populations were characterized with using different molecular genetic parameters. B. cinerea group I strains, characterized with high rate of fenhexamid resistance, could be detected only in restricted number. The Hungarian B. cinerea populations were characterized with high genetic diversity, and the regular occurrence of sexual reproduction. These results highlight the importance of rotating different type of fungicide in the plant protection technology against grey mould.

  • Stress Response of four Common Carp (Cyprinus carpio L.) Varieties with Different Genetic Background
    26-29
    Views:
    68

    Four different carp varieties were tested for stress reaction, with the help of 10 °C cooling and 100 g/l crowding. The selected varieties represented a broad genetic spectrum of carp species. The stress was monitored by measuring plasma cortisol, glucose and lysozim levels. In each test different varieties showed significantly different reaction to stress. This means that they differ in the trait of general resistance. Thus, this trait can be used in selection programmes and the acquired information helps to understand fish-environment interaction and specific resistance. These traits should be used in selection to improve the breeding of new more tolerant species for intensive farming or for organic production.

  • Tenability of ram semen
    63-66
    Views:
    106

    It could be stated that the diluted semen of Awassi rams taken in the breeding season preserved its fertilizing abilityat different temperatures for different periods of time. The motility of spermatozoa kept at 23 vs. 8oC was checked daily. The largest spread of data was observed 24 hours after taking the semen, then the motility rate of cells showed a linear decrease. Motility results of fresh and frozen-thawed samples were compared also after heat resistance test and significant differences were found between these groups. Significant individual differences were observedin the sperm motility after heat resistance test.

  • Research on rheological characteristics of winter wheat varieties
    266-272
    Views:
    113

    The gluten examination test is dominant in Hungary, comparing it to the qualification system of other countries. The determination of alveographic parameters is a basic criterion of winter wheat specifications in some western and southern European countries.
    In the Hungarian and foreign winter wheat qualification systems, in the standards, there is no limit for extensographical parameters. Customers dictate the limits and make their claims as to the specifications.
    We analyzed the alveographic and extensographical parameters of 19 winter wheat varieties grown by the Cereal Research Non-Profit Company in Hungary, and we made a comparison between the results in the challenges of the European Union expectations.
    Examining the information of alveographic and extensographical values, we found that the experimental varieties provide high base to flour types suitable for baking bread and baker’s ware. The GK Élet, GK Petur, GK Memento, GK Csillag, GK Kapos and GK Marcel varieties can meet the market of paste flour needs, too.
    In the variety series, the GK Kalász represents the highest values and the GK Garaboly shows the lowest parameters regarding the alveographic W and the resistance to extension.
    On the basis of relation, we can establish that we can estimate the following little known and used quality indexes: the extensographical resistance to extension with extensographical energy and the alveographic W value, the extensographical energy with the alveographic W value and the alveographic P and L values with the other alveographic parameters.

  • Studies on the Fusarium stalk rot infection of the maize genotypes using the Findex percentage and a computerised image analysis program
    45-51
    Views:
    83

    In a continental climate, the pathogens causing the most serious problems are species belonging to the Fusarium genus. When the pathogen attacks the stalk, the plant dies earlier, reducing grain filling and resulting in small, light ears. In addition, the stalks break or lodge, resulting in further yield losses from ears that cannot be harvested. During the three years of the experiment, 14 inbred lines were examined. The genotypes were sown in a two-factor split-plot design with four replications, with the genotypes in the main plots and four treatments in the subplots: two Fusarium graminearum isolates (1. FG36, 2. FGH4), 3. sterile kernels, 4. untreated control. The results experiments showed significant differences between the genotypes for resistance to fusarium stalk rot. Among the inbred lines the best resistance to fusarium stalk rot was exhibited by P06 and P07, both of which were related to ISSS. The precision and sensitivity of disease evaluations carried out visually and using image analysis software were compared in the experiment, and with two exceptions the CV values were lower for the image analysis. As the CV for measurements can be considered as a relative error, it can be stated that image analysis is the more precise of the two methods, so this technique gives a more accurate picture of the extent of stalk rot. The extent of stalk rot developing in response to natural infection is extremely environment-dependent, so the use of artificial inoculation is recommended for selection trials. 

  • Investigation of Potato (Solanum tuberosum L.) Salt Tolerance and Callus Induction in vitro
    51-55
    Views:
    90

    Potato production plays an important role in Hungary and the other countries of Europe. Consumption of potato products has increased to a large extent during the past several years. We can satisfy market demands with high quality and virus-free varieties.
    Results of potato production depend on tolerance/resistance to abiotic stresses. In many cases, increased concentration of NaCl causes yield loss. Selection of salt tolerant varieties proved to be a difficult problem. Nowadays, the salt tolerance of potato varieties can be determined by cell/tissue/ protoplast techniques. Somaclonal variation provides a great potential for selection of lines resistant to salt stress. In vitro shoots and callus, derived plantlets selected for salt tolerance/resistance provide material for micropropagation.
    In vitro shoot development of potato (Solanum tuberosum L. cv. Kuroda) was investigated under salt stress (40 mM, 80 mM, 120 mM NaCl) conditions. Shoot heights of plantlets cultured under salt conditions were lower than the control through the investigation. However, the shoot development of plantlets originated from in vitro meristems was almost at the same level as the control under 40 mM NaCl concentration.
    There was no significant difference in the in vitro biomass production between control and treatment with 40 mM NaCl concentration. We measured a significant decrease in dry-matter mass under 120 mM NaCl concentration. There is a need for more investigation of different genotypes and for a conclusion as to whether in vitro tolerance could occur under in vivo circumstances in plants originated from somaclones as well.
    Under in vitro conditions, we investigated shoot and leaf callus initiation using different culture media with different 2,4-D concentrations. Under dark conditions, callus induction of shoot/leaf decreased as the 2,4-D concentrations increased.
    In light conditions, there was a little callus induction, while callus initiation from the shoot from 5 μM to 12 μM 2,4-D concentration showed a significant increase

  • Development of a New Maize (Zea mays L.) Breeding Program
    25-30
    Views:
    91

    Genetic manipulation may not replace any conventional method in crop breeding programs, but it can be an important adjunct to them. Plant regeneration via tissue culture is becoming increasingly more common in monocots such as corn (Zea mays L.). In vitro culturability and regeneration ability of corn decreased as homozigosity increased, which suggested that these two attributes were controlled primarily by dominant gene action. Pollen (gametophytic) selection for resistance to aflatoxin in corn can greatly facilitate recurrent selection and screening of germplasm for resistance at a much less cost and shorter time than field testing. Integration of in vivo and in vitro techniques in maize breeding program has been developed to obtain desirable agronomic attributes, speed up the breeding process and enhance the genes responsible for them. The efficiency of anther and tissue cultures in most cereals such as maize and wheat have reached the stage where it can be used in breeding programs to some extent and many new cultivars produced by genetic manipulation have now reached the market.