Aphids were collected by Moericke yellow pan traps placed in the potato fields. The cumulative vector intensity is an index that describes the vector abundance and their propensity to transmit PVY (3). The vector intensity was obtained as the number of known PVY vector species caught and multiplied by their relative vector efficiency v...alue. Cumulative vector intensity for the season was calculated by accumulating species-specific vector intensity values at each trapping date. In those places where the number of PVY vectors caught by yellow pan traps were the highest (1194, 1495 and 663, 570, respectively), the cumulative vector intensity was also the highest (322 and 570, respectively). This high vector intensity resulted in high progeny tuber infection 21 and 31 %, respectively. In those years when the cumulative vector intensity did not reach the value of 10 until the end of June and the beginning of July the proportion of PVY infected progeny tubers met the requirements of the standard, it was less than 5 %. The cumulative vector intensity seems to be a reliable way to forecast virus threat to seed potato. Both seasonal variation and vector abundance is reflected in cumulative vector intensity, above all propensity of different vector species is included in the calculation. As the virus translocation from leaves to tubers takes 12-14 days. Therefore it is imperative that immediately after weekly trap catches cumulative vector intensity values are calculated, as when values reach around ten growers in seed potato growing region will have 12 days to execute killing leaves and stems of seed potatoes.
Potato is one of the most important plants in human nutrition, it is grown in about 140 countries. As a food, it can be prepared in many ways, it is easily digestable with proteins of high biological value, favourable dietetical-physiological characteristics, high starch content and good taste. An increase in its consumption would be favourable... from the dietetical point of view. In Hungary, the growing area of potato has decreased considerably for the last decades and we are lagging behind the Western-European countries regarding yield. The experiments were carried out at the Experimental Site of the University of Debrecen at Látókép between 2002 and 2004. In the large-plot experiment, the yields and the distribution of the tuber fractions were studied for 9 medium early cultivars. The experiment was set up on 50 m2 plots on calcareous chernozem soil. Among the studied cultivars, 3 were of Dutch (Desiree, Kondor, Kuroda) and 6 were of Hungarian breeding ('Góliát', 'Hópehely', 'Kankan', 'Lilla', 'Százszorszép', and 'White Lady'). The experiment was set up in 4 repetitions in a randomized design, two of the repetitions were irrigated while two were non-irrigated.
A five-year experiment was carried out in the Nyírség on its characteristic soil type, brown forest soil to investigate the impact of three types of potassium fertilizers (potassium chloride, potassium sulfate and Patentkali) in three different dosages (80, 160, 240 kg/ha K20), under non-irrigated conditions applying the same dosag...es of N, P in all treatments (the applied amount was different between years) in 10 treatments including the control on 50 m2-parcels with 3 or 4 replicates. The test plant was cultivar Desiree, Kondor, Agria and Pannonia in 1998 and 2000, 2001, 2002 and 2003, respectively. The obtained yields were analyzed by an analysis of variance. Based on the five-year results, the highest yields on the acidic sandy and sandy loam soils were obtained in the treatments with 530-800 kg/ha Patentkali containing 30% of K and 10% of magnesium active ingredients in addition to the same amounts of N and P applications. The dosage of 530 kg/ha Patentkali contains 160 kg/ha K+ 53 kg/ha Mg active ingredients, while the dosage of 800 kg/ha Patentkali contains 240 kg/ha K+ 80 kg/ha Mg active ingredients. It can be concluded that the potassium chloride fertilizer (KCI) was the least effective as regards yields and Patentkali proved to be the most effective fertilizer, it had higher yields than even those of potassium sulfate, the difference in the 160 kg/ha treatments was 17.7%, which was a significant difference. Based on the results of the multi-year experiment, we recommend to apply 530 kg/ha Patentkali fertilizer (160 kg/ha K+ 53 kg/ha Mg active ingredients) for the fertilization in potato under non-irrigated conditions on the acidic sandy and sandy loam forest soils of the Nyírség, which proved to be the most effective treatment and with which we could obtain 30 t/ha yield in the average of the years (with the simultaneous application of N and P).
The production facilities of large-sized microtubers in three potato varieties (cv. Desiree, BorO, Gfilbaba) and the effects of the applied tuberization conditions on the proportion of microtuber tissues, especially on the perimedullary region were investigated in present work. In vitro tuberization was induced on explants wit...h 2 or 5 nodes layered on MS medium supplemented with 8% sucrose. Induced cultures were exposed to short days (8 h) for 2 weeks, then to total darkness for further 11 weeks. For volume calculations of different tissue regions, the formula for ellipsoids (V=4/37c1/8/w2) was used. The number of large-size tubers (> 8 mm, up to 16 mm) reached 53%, 59% and 44% in cvs. Desiree, Giilbaba and Bore, respectively, which indicate that the size of microtubers could be increased by appropriate sucrose support and explant type. Microtubers produced on hormone-free medium have well-developed perimedullary region, and its volume rate seemed to be important in the final size of tubers. The increase in the rate of volume of the perimedulla was connected to the increase of tuber size until tubers reached 12 mm diameter. In microtubers larger than 12 mm in diameter, the volume rate of the pith was increased.
Virus susceptibility of 11 varieties of vegetatively propagated petunia against 2 virus strains (TMV-C/U1 and PVYNTN) were examined. Neither resistant nor tolerant varieties of petunia were found. The virus infection of the Petunia genus was examined in Hungary. The most common pathogens were the Tobacco mosaic tobamovirus (TM...V) and the Tomato mosaic tobamovirus (ToMV), but the samples also contained Alfalfa mosaic alfamovirus (AMV), Cucumber mosaic ClIC11171014171S (CMV) and Potato Y potyvirus (PVY). Potato X potexvirus (PVX) was isolated in the varieties of trailing petunia for the first time.
In vitro tuberization was induced on explants with different number of nodes layered on a medium with high sucrose (8%) content: 30, 15, 10, 7 and 6 explants per jar were cultured containing 1, 2, 3, 4 or 5 nodes, respectively. Microtubers developed were graded by their smallest diameter, and the number of tubers per jar, thei...r size distribution, their fresh weight and the multiplication rate were recorded. The highest multiplication rate (1.98) was obtained for explants with 5 nodes. The size distribution of tubers was markedly affected by treatments. The majority of microtubers (49.4%) were 6-8 mm in the case of the smallest explants (with I node). When explants with 2 to 5 nodes were used, the most microtubers were 8-10 mm but with an increase of explant size, more and more microtubers were produced with larger diameter up to 16 mm and average fresh weight of tubers also increased with the increase of explant size. For the microtuber production of Desiree the use of explants with two nodes can be suggested because in this treatment the average fresh weight of microtubers was high enough (250 mg) and the number of large sized microtubers was very high (79% was larger than 6 mm and 53% was larger than 8 mm).
The objective of this study was to examine the reaction of 44 Capsicum genotypes to common strain of Tobacco mosaic virus (TMV-C/U1), Obuda pepper virus (ObPV), NTN strain of Potato virus Y (PVYNTN) and legume strain of Cucumber mosaic virus (CMVU/246). Reaction (extreme resistance, hype...rsensitive reaction, latent susceptibility, susceptibility) of the tested Capsicum species/hybrids and breeding lines seemed to be greatly depending on hosts and viruses. Out of the breeding materials 4/99 F2 and IX-8 in to CMV-U/246, while 32.Bogyisz. type, VI-57 ii. 57/83 and V-12=19/98 to TMV-C/Ui showed extreme resistance. Two lines (V-25 F1=32/98 F1 and V-27 in F4=35/98 F4) showed hypersensitive reaction to ObPV. Latent susceptibility to PVYNTN was observed in case of all eleven tested Capsicum genotypes and in case of several lines to TMV-C/U1, ObPV and CMV-U/246. Other breeding materials proved susceptible to the mentioned viruses. Pepper genotypes showing extreme resistance and hypersensitivity could be used for resistance breeding to viruses.
There is a very difficult equation for malnutrition and over-consumption. That means malnutrition even of vitamins and/or minerals (Ca, Cu, Fe, I, Mg, Se and Zn, vitamin A) affects more than two billion people worldwide, largely due to low concentrations or poor bioavailability of the nutrients in the diet. In some developed countries in contra...st, over-consumption, particularly of over-refined cerealbased foods, has contributed to the development of an epidemic of metabolic diseases. So, producing nutritious and safe foods sufficiently and sustainably is important target at the same time challenge of modern agriculture. In the past, great efforts have focused only on increasing crop yields, but enhancing the concentrations of mineral micronutrients has become an urgent task. The main daily food source is the staple crops specially in developing countries of the world, i.e., wheat, rice, cassava, beans, sweet potato or maize. These kind of plants are often deficient in some of mineral elements. Thus, the increasing of bioavailable concentration of micronutrients in edible crop tissues (via biofortification) has become a promising strategy in modern agriculture, providing more nutritious foods, to more people, with the use of fewer lands. Biofortification of these trace elements can be achieved application with agronomic process such as soil or foliar fertilization or crop breeding even conventional technic and/or genetic engineering. This review highlight progress to date and identify challenges faced in delivering biofortified vegetable crops as well as the agronomic approaches and tools to improve crop yield and micronutrient content of food crops.
The aim of our study was to examine susceptibility or resistance of 18 pepper varieties to four viruses [tobacco mosaic
tobamovirus (TMV), sowbane mosaic sobemovirus (SoMV), NTN strain of potato Y potyvirus (PVYNTN) and cucumber mosaic cucumovirus (CMV). Out of the 18 varieties, 13 were resistant to CMV infection. Thirteen varieti...es were susceptible to TMV, while five ones (Dabora Fl, Brill Fl, Feherozon Synthetic, Ciklon Fl, Cecil Fl) showed only local hypersensitive reaction. All of the tested pepper varieties showed resistance to SoMV. Eight varieties (Tuba, Fehérözön Synthetic, Boni, Alba Regia, Korona, Édesalma, Cecil Fl, Star) were found to be resistant to PVYNTN. Out of the examined varieties five (Boni, Alba Regia, Korona, Édesalma, Star) were resistant to three viruses (SoMV, CMV and PVYNTN). Only one (Cecil F1) displayed complex, extreme resistance to SoMV, PVYNTN, CMV and hypersensitive reaction to TMV, therefore this hybrid is very important in pepper breeding and growing for virus resistance.