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Studies on the Tobamovirus resistance of the pepper (Capsicum annuum L.) cultivar Greygo
71-75.Views:143Resistance of the Hungarian pepper (Capsicum annuum L.) cultivar "Gre.ygo" to Tohamoviruses has been investigated. All plants of the population of Greygo proved to be resistant to tobacco mosaic and tomato mosaic viruses (TMV, ToMV), both represent the pepper pathotypes Po of Tohamoviruses. Individuals of Greygo, however, were found to be susceptible to pathotypes P12 and P123 of pepper mild mottle virus (PMMV). When inoculated with the XM isolate of dulcamara yellow fleck virus (DYFV, pathotype P1) the population of Greygo segregated in resistant and susceptible plants. These results as well as inoculations of the progenies of three TMV resistant plants clearly showed, that besides the resistance allele Li the cultivar Greygo possesses also an another allele. This allele, provisionally marked by L2g behaves like to the allele L2 characteristic to Capsicum frutescens cv. . Tabasco. Determination of the identity of the allele L2g to the allele L2 needs further genetic and pathological informations. Relations between the Tohamoviruses pathogenic to pepper and the alleles of the resistance gene L are outlined for the discussion.
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Xanthomonas resistance in Hungarian 4 spice pepper varieties
73-77.Views:145With a view to further enhance the reputation of Hungarian spice pepper it was necessary to improve resistance to the bacterium Xanthomonas campestris pv.vesicatoria, the most dangerous pathogen of pepper varieties. From among the familiar resistance genes in Hungary only the gene Bs-2 could provide sufficient protection against the aggressiveness spectrum of the bacterium species X.c.pv. vesicatoria. The first results of the resistance breeding are the spice pepper varieties Kaldom and Kalorez. In addition to the Bs-2 gene attempts are also being made at building in a gds gene into pepper, a gene creating a general defense system, a different strategy towards Xanthomonas campestris pv. vesicatoria.
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Real-case application of mycorrhizal inoculums on Capsicum annuum L. var. longum cv. Szegedi and Kalocsai
75-79.Views:175The aim of this study was to test the use of commercially available arbuscular mycorrhiza (AM) inoculant Symbivit, a mixture of six species of Glomus spp., in spice pepper field cultivation. The inoculants containing arbuscular mycorrhizal fungi (AMF) was able to establish a symbiosis in the rhizosphere of pepper plants and mycorrhizal inoculation increased fresh and dry weights of shoots of spice pepper cv. Szegedi and only fresh weight of Kalocsai type. There were no significant differences in the root weights due to treatment only in fresh weight of Kalocsai pepper type. Treated plants of both variants exhibited an increase in cumulative crop production compared with control non-treated plants and the growth response of pepper was higher for var. Szegedi than var. Kalocsai. Mycorrhizal inoculation had a great positive effect on external hyphal length of AMF also showing differences in that between Kalocsai and Szegedi variants. The root colonization showed seasonality by treated and non-treated plants. The lowest degree of colonization was observed in June in general and colonization percent increased during vegetative development and there was a slight decrease at harvesting. In conclusion, it can be stated that inoculation with Symbivit containing mycorrhizal fungi could be an integral part of spice pepper production.
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Some relationships between soil and nutrient requirements and nutrient supply of pepper (Capsicum annuum L.) with respect to types grown in Hungary
93-105.Views:158Exports and local marketability of both pepper protected cultivation and open field pepper production depend on whether we succeed in the near future achieving developments capable of bringing about significant improvement of yield and quality, as well as enhanced yield security. Results from experiments and surveys carried out on farms involved in production suggest that nutrient management is one of the factors whose development could considerably improve the marketability of pepper. Technological improvements in the field of nutrient supply are also urged by the more and more demanding environmental regulations, so it is inevitable to introduce a balanced system of nutrient supply system for pepper as well. The article is a collection and summary of the relevant results of 30-year experimental work in Hungary.
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Efficacy of ethrel (2-chloroethyl phosphonic acid) as a chemical hybridizing agent in red pepper (Capsicum annuum L. var. Pusa jwala)
41-44Views:162A field experiment was conducted during 2003-2004 and 2004-2005 to study the effect of foliar sprays of ethrel or ethephon (2- chloroethyl phosphonic acid) on pollen sterility and yield parameters in Capsicum annuum var. Pusa jwala. Effect of treatments was also studied in F1 hybrids raised from treated male sterile plants crossed with the control plants. Plants sprayed with 0.1, 0.2 and 0.3% (v/v) ethrel exhibited 93.1-100% pollen sterility. This was associated with significant reduction in yield parameters (number of flowers, fruits/plant, fruit size, number of seeds/fruit and total yield/plant). However, the plants sprayed only once with 0.1% ethrel at pre-meiotic stage showed 93.1% pollen sterility without any significant reduction in yield parameter. The F1 hybrids obtained by crossing the 100% male sterile treated plants with the pollen of untreated (control) plants exhibited only insignificant reduction in the number of flowers/ plant, fruits/plant, fruit size, number of seeds/fruit and total yield/plant. However, these parameters in F1 hybrids were significantly higher over the treated plants.
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Experiments on the Resistance or Pepper Cultivars to Macrophomina phaseolina
74-75.Views:121The ashy stern blight of pepper (Capsicum annuum) is often caused by Macrophomina phaseolina. Serious wilt disease occurred between 1994 and 1996 of pepper plants in Hungary. In 1996-98 screening experiments were made on many pepper cultivars. Culture (Knopp) solution experiments, pot experiments, greenhouse and field trials were carried out. We determined the incidence of disease by visual examinations, testing on PDA culture, and light microscope. There were significant differences in susceptibility of cultivars and breeding materials.
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Investigation on the transmission of some Tobamoviruses by pollen and seed in pepper (Capsicum annuum L.)
127-131.Views:227Five pepper cultivars were mechanically inoculated with isolates of three Tobamovirus species, viz. the "Gelb" strain of tobacco mosaic virus (TMV-G), the XM-isolate of dulcamara yellow fleck virus (DYFV-XM) and the Nov/H isolate of pepper mild mottle virus (PMMV-Nov/H), respectively. Symptoms caused by the viruses were characterised. The viruses were sucessfully re-isolated from different organs (roots, leaves, fruit parts) of susceptible peppers to test plants. It was estabilished, that the pollen of diseased peppers carried infective virions at least on their surface. Washes of seeds were highly infective, but no infectivity was found after treatment of the seeds with 2% NaOH or 10% Na3PO4. No infectivity of inocula prepared from seed-coats of alkaline treated seeds was established. Infection of young seedlings grown from untreated seeds was demonstrated, while the seedlings came from alkaline treated seeds remained free of infective virus. The possible role of pollen and seed in the epidemiology of Tobamoviruses pathogenic to pepper as well as the importance of seed treatment is discussed.
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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:181In 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.
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Nutritional quality, fruit shape and relationships among exotic and local Capsicum pepper genotypes in Uganda
33-39.Views:328Twenty-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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Macronutrient accumulation in green pepper (Capsicum annuum L.) as affected by different production technologies
13-19.Views:215Based on the experiments, an assessment was made to determine for green pepper the amount of nutrients extracted by unit weight of fruit and plant parts not meant to be consumed (foliage, stem, root), i.e. the specific nutrient requirements of pepper. A further objective was to find out to what extent nutrient accumulation in individual plant organs was influenced by differences in production technology and soil conditions.
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Effect of black plastic mulch and raised bed on soil temperature and yield of sweet pepper
107-110.Views:153A field study was conducted in Central Hungary in 2001 and 2002 in order to evaluate the effects of black plastic mulch and raised bed on soil temperature and on yield and fruit quality of sweet pepper (Capsicum annuum L. cv. `Kárpia'). The experiment was a complete block design with four replicates. Four different technologies were used as treatments: raised bed with black PE mulch, raised bed without mulch, level ground with black PE mulch and level ground without mulch. In both years soil temperature was the highest in the covered raised bed treatment, about 2 °C higher than in the uncovered raised bed. Optimum soil temperature requirement of sweet pepper roots was met to the highest degree in case of the covered raised bed, 26-28% of the total growing period. The more favourable soil temperature conditions resulted in better yield, compared to the uncovered level ground treatment the covered raised bed treatment produced 19% and 14% higher yield in 2001 and 2002, respectively.
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Comparative investigations on protoplast culture of some Brazilian and Hungarian sweet pepper cultivars and hybrids
39-45.Views:177Cotyledon protoplasts were isolated from 16-18-day-old in vitro grown seedlings of 9 Brazilian and 3 Hungarian pepper varieties and hybrids. Large numbers (average 9.59 X 106 protoplasts g 14 fresh weight) of highly viable (average 87.0%) protoplasts were released using a pectocellulolytic enzyme mixture. Protoplasts were cultured in K8p mediuni using an alginate disc embedding method. The osmotic pressure of the medium surrounding the alginate-embedded protoplasts was reduced by replenishing the liquid medium at K8p:K8 ratios of 1:0. 2:1, 1:1 in the first. second, and third week, respectively. Initial plating efficiency (IPE) average was 38.5% and after 21 days protoplasts reached microcolonies (15-20 cells) stages. Microcolonies were transferred after 3-4 weeks to a MS-based medium supplemented with 1.0 mg I-1 zeatin, 3.0% (w/v) sucrose, 0.24% (w/v) phytagel and pH 5.8, whereupon they formed callus. Final plating efficiency (FPE) average was 0.29% at a plating density of 1.0 x 105 protoplasts Protoplast-derived calli were cultured on a range of MS-based media supplemented with either BAP, IAA, TDZ; and zeatin. No morphogenic response was observed in any genotype investigated.
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Detergent induced pollen sterility in some vegetable crops
85-88.Views:133Efficacy of a popular synthetic detergent, Surf excel in some important vegetable crops viz. Okra or lady finger (Abelmoschus esculentus L.), chilli or red pepper (Capsicum annuum L.) and tomato (Lycopersicon esculentum Mill) was evaluated for inducing male sterility and hybrid seed production. Foliar sprays with aqueous solutions of Surf excel (1.0 and 1.5% w/v) in these crops induced complete pollen sterility. The treated plants showed a delay in flowering, a reduction in the number of flowers and fruits/plant, number of seeds/fruit resulting in a reduction in yield/plant. However, the male sterility thus induced was successfully exploited for hybrid seed production.
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Pedological and agrochemical investigations on media using in vegetable forcing
119-122.Views:111In spite of the several good properties of peat, recently, some experiments were carried out with the aim of finding natural materials which can substitute for peat. According to the results, several inorganic and organic materials were proved to be suitable for this purpose. This study examines the effect of different organic materials (example: pine bark, composts, peats) on the growth and yield of green pepper (Capsicum annuum L., variety Danubia). We found that the most developed plants were grown in peat-mixtures and pine bark. The average fruit weight was the highest at those plants which were planted also in these media. The plants which were grown in composts fell short of our expectations in development and in yield, too.