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DNA-based determination of suitable pollinating cultivars for the pear cultivar 'Carola' (Pyrus communis)
15-19.Views:142Pollen-limited fruit set has long been suspected in some relatively low-yielding orchards with the Swedish pear cultivar 'Carola'. Fruit was therefore harvested on 23 'Carola' trees in a commercial pear orchard. The seeds were germinated and five seedlings from each tree were sampled to determine which of the surrounding cultivars had been the most successful pollinators. Leaves of 'Carola', the 7 putative pollinating cultivars and the 115 seedlings were analysed with 6 RAPD primers. By comparison of the band patterns, paternity could be ascertained for 74 seedlings. The by far most successful pollinator was 'Clara Frijs' which had sired approx. half of the seedlings, followed by 'Herzogin Elsa', `Skanskt Sockerpiiron', 'Alexandre Lucas', 'Coloree de Juillet' and 'Doyenne du Cornice'. The latter is the maternal parent of 'Carola', and these two cultivars must therefore share one S-allele and hence can only be semi-compatible. In addition, 6% of the seedlings were in all likelihood derived from selling_ since they showed no bands that did not occur also in 'Carola'. Maximum distance between 'Carola' trees and suitable pollinators should not exceed 15-20 tn. Longer distances may produce a serious dearth of compatible pollen as evidenced by the large percentage of seedlings derived either from selling. (25%) or from long-distance (> 40 m) pollen transfer (25%) when 'Carola' trees were surrounded by non-preferred pollinators.
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Selection of the chance seedlings of `Mézes körte' (Pyrus communis L.) from the gene bank of Keszthely
21-27.Views:274We have concluded the selection tests of the `Mézes körte' seedlings planted in the spring of 2006, with special emphasis on the cotyledonary, foliage leaf and the height of plant. Out of the 75 seeds planted in rows, there were 40-45 pieces growing out, so during the first cotyledonary test we had to calculate with almost 40% decay. On 12th April 2006, we recorded some of the important characteristics of the seedlings in their cotyledonary stage which characteristics were important from the point of view of selection (cotyledonary form, cotyledonary length, cotyledonary thickness, cotyledonary colour, cotyledonary petiole length, cotyledonary petiole thickness, cotyledonary petiole colour). The above morphological characteristics are shown in Table No. 1-6. We have also tested the seedling in foliage leaf state, paying special attention on the development stage of the plants (colour of foliage leaf , height of plant). We have completed statistical calculations of the two above mentioned characteristics. The result of that is summarised in Table No. 8-9. The variation coefficient show smaller value in the case of the foliage leaf number (15-32%), while the wider range of spread of the data referring to the height of the plant is shown by the 33-61% CV values. On charts No 4-9. we present the relationship between the height of the plant and the number of foliage leaf, as well as the differences between the two graphs. Based on the above charts and graphs it can be defined that the 40% destruction of the developing seedlings during the period till the next measurement reached 70-80% level. In spite of this however some seedlings showed strong and balanced growth (A44, B42, C25, D16, E5, E39, F38), the further testing and selection of those is to be completed in the future.
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Effect of seedling quality on growth, yield and quality of tomato (Solanum lycopersicum L.)
64-72.Views:314A two trial greenhouse experiment was carried out at Rwanda-Israel Horticulture Centre of Excellence located at Mulindi Station to evaluate seedling quality on growth, yield and quality of tomato. The seedlings were grown in different growing media and produced seedlings with varying quality indices. The growing media of peat moss 100% (T2) and sand + goat manure + carbonized rice husks 50%: 10%: 40% (T8) were revealed in seedlings with the highest mean quality indices of 31 and 28 respectively, while sand 100% (T2) presented the lowest quality indices during both trials. The transplants were planted in polybags filled with 2:1 of topsoil and kitchen manure arranged in a randomized complete block design (RCBD) with four replications. Collected data were subjected to analysis of variance and means were separated using HSD test at a 5% level of significance. The results revealed that the seedlings grown in T1 (S1) and T8 (S8) consistently presented tomatoes with better growth performance and yield. S1 and S8 produced mean yield of 93.59 and 92.35 t/ha respectively while S2 had the lowest yield with 53.86 t/ha. The fruit produced from seedlings grown in T4 (S4) had the highest mean sugar acid ratio of 5.88 but not significantly different from 5.61 and 5.44 of S1 and S8 respectively. Hence, there was a positive relationship among seedling quality and growth and yield performance of tomato but not in fruit quality.
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Severely pollen-limited fruit set in a pear (Pyrus communis) orchard revealed by yield assessments and DNA-based paternity assignment of seedlings
67-74.Views:188In commercial fruit tree orchards, consistently high yields are necessary for a durable economy. The Swedish pear cultivar 'Carola' has been noted for low setting in some orchards, possibly due to insufficient pollination. In this study, fruit set was evaluated in a research orchard where `Carola' had been planted together with four potential pollinators. Total yield and number of fruits was noted during three and four years, respectively. In 2003, seeds were germinated from the harvested `Carola' fruits, and the paternity of three seedlings from 50 trees was determined with RAPD analysis. 'Clapp's Favourite' had sired 39.6% of the seedlings, closely followed by `Seigneur d'Esperen' (30.7%) and 'Clara Frijs' (26.7%) whereas 'Skanskt sockerparon' only sired 1.1% of the seedlings. The remaining 2.3% appeared to have been derived by selfing. Pollen-limited seed set was indicated at surprisingly short distances; accumulated number of fruits on the `Carola' trees was significantly higher when separated by only 2 m from one of the two most efficient pollinators, 'Clapp's Favourite' or 'Seigneur d'Esperen‘, compared to trees 4—l0 in away in the same row. Number of viable seeds per fruit was also higher in fruits from trees immediately adjacent to the pollinators, suggesting an effect of improved pollination success. The importance of very short inter-cultivar distances for efficient pollen transfer became even more clear when comparisons involved the true pollination distances as determined by RAPD; the accumulated yields decreased linearly from 55 kg at a 2 in distance to only 17 kg at 13 m.
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The inheritance and durability of scab resistance in apple progenies
39-46.Views:161In order to select the appropriate parent cultivars and maintain the durability of resistance, it is important to clarify the mechanisms of inheritance of scab resistance depending on the parents. It has been known that the progeny segregation ratios based on scab-resistance do not depend only on the genotype of the resistance locus but also on the genetical makeup of the donor and recipient parents as well as on the susceptible parent.
The aim of this study has been to demonstrate what factors in the Vf, Vr and VA scab-resistant cultivars — combined with susceptible and resistant parents — affect the inheritance and durability of resistance in seedlings in their first 4 year's growing four years' growth. After inoculating apple seedlings sown in 2001 with the suspension of Venturia inaequalis (Cke.) Wint. in the greenhouse, we studied the segregation ratios of the progenies into reaction classes. Seedlings showing resistance in the greenhouse were also evaluated for scab-resistance after they had been moved to the field and had naturally been infected with the pathogen in 2002 and 2004.
The majority of our results obtained in the greenhouse test, similarly to earlier experiences, have not justified monogenic inheritance at the phenotypic level. The effect of susceptible parent cultivars on the segregation ratio of progenies have become apparent again. The high infection rate of seedlings in the field trials, which had previously exhibited varying degrees of resistance in the greenhouse test, has raised concern. Our data has raised further doubts, concerning the durability of Vf resistance in Hungary. It is assumed that the composition of natural field populations of Venturia inaequalis in Szigetcsép has changed. The complexity of Vf resistance has been confirmed. The high infection rate in the progenies derived from Vf resistant cultivars draws the attention to the importance of utilizing additional sources of resistance.
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Impact of sodium-selenate on the growth of radish (Raphanus sativus L.) seedlings in vitro
113-115.Views:215Selenium (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 it is well known that some species among higher plants are able to accumulate selenium in their tissues, but others are not able to do so, and there is evidence that selenium is needed for the growth of algae, meanwhile the question of essentiality of Se in vascular plants is unresolved. We aimed to study the in vitro growing and to characterise some physiological properties in radish (Raphanus sativus L.) seedlings treated with 0 to 200 mg/1 sodium-selenate. The results showed that lower (2 mg/1) concentration sodium-selenate increased the biomass as well as the total antioxidant capacity of seedlings. The seedling's selenium content showed linear correlation with the sodium-selenate content of the medium.
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Top-dressing of paprika transplants in trays with fertilizers of phosphorus- and nitrogen surplus
47-49.Views:139By our experiments, we wished to answer the question: may top-dressing with nitrogen and phosphorus fertilizers, respectively, improve the quality of transplants grown in trays on a substrate enriched by 2 kg/m3 of retarded fertilizers?
The experiments started in spring and autumn 2002, in a large volume plastic house. The seedlings were grown in trays. Seed was sown directly into KITE trays of 187 cells (28 cm3 volume per cell, 779 seedlings per square meter). The trays were filled by "loose filling" (without packing) with the following soil mixture: 50% Baltic highmoor peat, 50% 'Nitrite lowmoor peat, 1,5 kg/m3 feed chalk, 2 kg/m3 slow acting chemical fertilizer of phosphorus overweight, 2 kg/m3 superphosphate. The test plant was the vegetable paprika variety `Tizenegyes'.
The trials were made in order to clear up if top-dressing done once or twice improves the quality of the seedlings. For this purpose, perfectly soluble fertilizers of phosphorus or nitrogen surplus were used. 3 I fertilizer solution of 0.2% concentration was given per square meter on every single occasion. The control plots received no top-dressing.
The following parameters were registered: stem diameter, plant height, fresh weight of the top, dry matter content of the top, fresh weight of the root system per plant, dry matter content of the roots.
The experimental results with top-dressing have clearly proved the insufficiency of mixing 2 kg/m3 of retarded fertilizer into the substrate, as usual in raising paprika seedlings in trays, because of the long period of transplant raising. According to our experiments the additional nitrogen fertilization influences positively the development of green parts of plants, while the multiple application of fertilizers with higher phosphorus-content helps to develop a strong root system. We suppose, that the more often applied additional fertilizers, maybe the combination of fertilizers with nitrogen and phosphorus amount could give use even better results.
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Influence of soaking periods and temperatures on germination and respiration of pea seeds
69-71.Views:269Samples of 50 wrinkled-seeded pea (Piston sativum cv. ‘Farida') were soaked for 0.5, 1, 4, 8, 24, 48 and 72 hours at temperature of 5, 10, 15 and 20 °C in distilled water before germination. Water absorption, percent of germination, vigorous seedlings and dry weight of normal seedlings were assessed after 8 days. Respiration of short and long seedlings were checked by IRGA, LI-COR 6200 photosynthesis system. Most plants had more or less respiration but some of them already had photosynthesis. Differences in the amount of water absorbed were evident after one hour, only. Water amount was increased by increasing soaking temperatures and times. The maximum was achieved after 24 hours. Normal germination percent was not improved at any soaking time and temperature combinations but it was significantly declined at 10 °C with soaking time combinations and at 20 °C for 72 hours. The seedling vigour values were not very different at the higher soaking temperatures, but the treatments at 20 °C temperature with 8 and 24 hour soaking periods are proved to be optimal for seedling vigour. At the low soaking temperature the increase of the soaking period influenced the seedling vigour. Reduction of dry weight percent was noticeable by any soaking time related to temperature and compared with the control.
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Using compost of grape manufacture and farm wastes as growing media in vegetable ad ornamental nurseries
45-50.Views:278This work was conducted at private nursery in Kafr El-Sheikh governorate during 2006 and 2007 seasons to investigate the possibility of using grape manufacture waste compost (GMWC) and farm wastes compost (FWC) in ornamental and vegetable nurseries as partially or totally replacement of coconut peat (CP) and vermiculite (V) in the growing medium and also to find out the optimum media of tomato (Lycopersicon esculentum, cv. Castle Rock) and Cockscomb (Celosia plumosa) as comparing to a mixture of CP and V (1:1 v/v). The authors used a ten mixtures as followed: 1- Control (CP+V at 1:1 v/v), 2-GMWC (100 %), 3- GMWC +CP (1:1 v/v), 4- GMWC + V(1:1 v/v),5- GMWC +CP + V (1:1:1 v/v/v), 6- FWC (100 %),7- FWC+ CP (1:1 v/v), 8- FWC+ V (1:1 v/v), 9- FWC+ CP+ V (1:1:1 v/v/v), 10- GMWC+FWC+CP+V (1:1:1:1 v/v/v/v). Data recorded as seedling height, No. of leaves, total pigments, shoot fresh and dry weights, root length and root fresh and dry weights in order to assess the quality of both transplants of tomato and cockscomb. Both seedlings grown in medium contain a mixture of GMWC+CP+V displayed quality traits similar or better as to those of recorded from the control treatment.
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Floral biology of tree fruit rootstocks
153-161.Views:174The modern nursery industry requires seed sources of a high quality and regular quantity year by year. Besides the seed sources of processed cultivars (Bartlett pear, Shipley, Elberta peach) special seed orchards are planted with selected seed trees producing high quality and genetically determined seed (hybrid seed or inbred lines). Seedlings are still the most common commercial source of rootstocks for stone fruits (almond, apricot, peach, plum, prune and walnut). Although clonal rootstocks are spreading, usage of seedlings is still predominant at stone fruits and nuts. For successful seed production and planning of seed orchard the knowledge on floral biology, flower fertility, pollination, blossom time of trees (selected clone or cultivars) used for seed production is essential. In this field very little systematic research was carried out most of the papers were published in the second half of the 20th century. Our mini review gives an overview on the importance of flower fertility in the mating systems applied in seed orchards, and the research results on floral biology of fruit tree rootstocks propagated by seed (Prunus avium, Prunus mahaleb, Prunus armeniaca, Prunus cerasifera, Prunus insititia, Prunus amygdalus, P persica, P amygdalopersica, Pyrus pyraster, Pyrus communis and Pyrus betulifolia) over the last decades.
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Salt tolerance of sweet pepper seedlings
62-66.Views:156Laboratory germination tests have been made with three white fruit pepper varieties and with one spice pepper in filter paper rolls wetted with KCl solutions of different concentration. Parallel tests have been conducted with the other species (lettuce, tomato, kohlrabi) to compare the salt tolerance of paprika with that of other vegetable crops.
In greenhouse, the action of KCl has been investigated with transplants raised in soil mixture, in rockwool and with seedlings transplanted from rockwool into soil mixture. Like the trials in the laboratory, the experiments in soil mixture have been made with other plant species, too.
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Rootstocks for Cherries from the Department of Fruit Science Budapest
63-66.Views:201Cherry rootstock breeding started at the Department of Fruit Science, SSU Budapest by the late 50-s and the activity can be divided into three main groups. In the first stage the activity was focused on collection of native mahaleb cherry (Prunus mahaleb L.) varieties lead by L. Sebők. After evaluation in the nursery and orchard tests there are four promising rootstock cultivars selected from this material: 'Korponay' used as self fertile seed tree, its seedlings are recommended for sour cherries. The mahaleb varieties 'Bogdány' (vigorous), 'Egervár' and 'Magyar' (medium vigour) are propagated by cuttings. The next project has started in 1979 with the aim to select self fertile mahaleb seed trees producing homogeneous seedling populations with reduced vigour. Inbred populations from isolated flowering self fertile trees were produced and planted out in 1980. The inbreeding of 'Korponay' self fertile P. mahaleb variety resulted in specimens with different fruit colour (yellow, red, black), fruit shape and size. From among them self fertile trees were selected with various growth characteristics. Seedlings of that self fertile mother trees (S2 population) were tested in seedbed, they showed homogeneous phenotype characteristics as liners in the nursery. As rootstock of 'Érdi bőtermő' sour cherry in the orchard most of the S2 lines proved to be less vigorous in comparison to SI popuplations. 'Érdi bőtermő' trees budded on certain S2 lines in the orchard are more productive than those on S1 ('Korponay' seedling). Characteristics of the S2 generation as seed tree were studied as well. We expect to get morphologically homogeneous seedling populations with different growth vigour and good productivity in the later inbred generations. In the last couple of decades the research activity concerning ground-cherry and its hybrids resulted in dwarfing rootstocks. Prunus fruticosa Pall. hybrids from the natural flora of Hungary were collected and artificial hybrids were created between P. fruticosa and mahaleb cherry. Most of them are in the initial tests, only one of them is before registration, named 'Prob', which is a dwarf rootstock for sweet cherry. By the screening of new hybrids medium vigorous or semi dwarfing and precocious rootstocks seem to be promising for the cherry industry.
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The impacts of different habitats on the development of Telekia speiosa (Schreb.) Baumg.
31-32.Views:181Telekia speiosa (Schreb.) Baumg. is a 100-150 cm high bushy perennial, which has yellow flowers and smells good. According to the descriptions (Farkas, 1999), it can be detected in two smaller areas within Hungary, namely in the Bükk hills and on the Szatmár-Bereg Plain. By the time of writing this paper, the population around Tiszabecs has already got extinct. Therefore, it is a protected relict species. It is named in honour of Sámuel Teleki, chancellor of Transylvania.Within the frame of the experiment, the Telekia speciosa (Schreb.) Baumg. was planted to places differently illuminated (sunny, semi shadow, shade), then the morphological changes brought about the various light conditions were investigated. The experiment was launched with a stock sown in October 2008. The seedlings were planted to three beds with diverse light conditions. The area of each bed was 1 m2, and ten seedlings were planted per m2. The parameters investigated are as follows: the length of leaf blade, the width of leaf blade, the length of petiole, the number of leaves per plant, and the alterations of leaves. As a result of our research, we can state that semi shadow is the optimal habitat for the plant. Under such ecological conditions the highest leaf production was observed, the leaves were species specific, healthy and big. The mean number of leaves per plant was 6.6, the mean length of blade was 16.6 cm, the mean width of blade was 13 cm, while the mean length of petiole was 14.2 cm. In the shade the plants grew poorly and the size of leaves were smaller. The mean number of leaves per plant was 4.1, the mean length of blade was 8.6 cm, the mean width of blade was 7.1 cm, and the mean length of petiole was 9.4 cm. In the sunny habitat a similarly high leaf production was observed as in the semi shadow; however, the leaves had brownish spots, they shriveled, feel rough, so they revealed a reduced aesthetical value. The mean number of leaves per plant was 6.6, the mean length of blade was 17.8 cm, the mean width of blade was 11.3 cm, and the mean length of petiole was 13.1 cm.
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Inheritance of male sterility in apricot
12-14.Views:138Progenies (total of 1,114 seedlings) from crosses representing all possible genotypic combinations between 4 male-fertile and 1 male-sterile apricot parents were scored for the male sterility trait. Crosses between putative heterozygous normal cultivars yielded 25% of male-sterile seedlings, which supports a previous hypothesis that male sterility is controlled by a recessive allele of one nuclear locus. Crosses between those parents and putative homozygous normal cultivars did not produce any male-sterile tree. Finally, the proportion of male-sterile progeny in crosses between a male-sterile and two male-fertile cultivars depended on the genotype of the male parent. When it was heterozygous approximately 50% of the progeny was sterile, whereas when a homozygous fertile parent was used, no male-sterile progeny was obtained. These results confirm a previously proposed model, in which the male sterility trait in apricot is controlled by a single recessive gene.
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Susceptibility of European pear genotypes in a gene bank to pear psylla damage and possible exploitation of resistant varieties in organic farming
95-101.Views:287We evaluated 285 pear genotypes (commercial cultivars, ancient local varieties, unnamed local strains, seedlings, wild seedlings) in the largest gene bank of pear in Hungary from the point of view of psylla resistance to explore their possible exploitation in organic farming. We have found some 10 new resistant types (Bókoló körte, Bôtermô Kálmán, Füge alakú körte, Nagyasszony körte, Nyári Kálmán, Rozs nyári körte, Viki körte, Pb-242, Pb-299, 0-632) and 7 highly tolerant ones (Cure-6, Kései Kálmán, Kieffer, Kieffer Éd, Steiner, Téli Kálmán, II. B-3- 6/4, 96-16/5) (Table 1). These made up 3.5 + 2.8 per cent of the investigated genotypes, while 93.7 per cent of them were susceptible to pear psylla damage. Taking earlier and present results into account we can list more than 30 European pear cultivars being resistant or highly tolerant to pear psylla infestation and damage. In fact, the list of resistant and highly tolerant cultivars may serve as a basis selecting pear cultivars fitting to the specific requirements of the organic farming. By the end we can conclude that there is some real hope to exploit some resistant or highly tolerant ancient or local cultivars in organic farming but further investigations are needed to estimate their yield capacity and fruit quality.
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Allelopathic effect of the Cladonia verticillaris lichen extracts and fumarprotocetraric acid on the early growth of germinating seeds and seedlings in Allium cepa L.
31-35.Views:161The allelopathic activity of the different extracts of the lichen Cladonia verticillaris and fumarprotocetraric acid on the early growth of A cepa (IPA 6) seedlings depends on their chemical composition and concentration, respectively. It was observed that the length of the radicle was significantly stimulated by fumarprotocetraric acid at high concentrations and by the total extract of C. verticillaris thalli, which contained a high level of fumarprotocetraric, acid confirmed by HPLC-technique. In addition, it was found, that the phosphate buffer extract, which contained high level of methyl (3-orcinol carboxilate measured by HPLC, reduced the length of the hypocotyls significantly. Under our experimental conditions there was no influence of the different types of extract and fumarprotocetraric acid on the ratio of seed germination, in relation to the control. From the study of HPLC it was found that fumarprotocetraric acid and methyl 13-orcinol carboxilate were present in all extracts at different concentrations, depending on the method of extraction.
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Micropropagation of Rudbeckia hirta L. from seedling explants
105-108Views:198We 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-strenght solid Murashige and Skoog (1962) culture medium containing 10 mg/1 of kinetin or 2 mg/I of kinetin + 0.1 mg/1 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/1 of IAA. After four weeks of incubation we obtained elongated shoots which we separated and inoculated into a new culture medium and 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 respect of breeding.
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Estimating of water consumption of cherry trees
15-17.Views:216Despite of its importance there is no exact information on water use of new scion/rootstock composite trees, which would be needed to optimized irrigation. Our research purpose is to define exact water-demand of different rootstock/scion composite trees, calculating seasonal weather changes and by using the results decrease irrigation costs. The investigations are carried out in Soroksár, at the Experimental Farm of Corvinus University of Budapest in May 2008. From among the investigated trees two are budded onto Prunus mahuleb `Érdi V' seedlings, two on "Korponay' seedlings. The sapflow measurements are carried out using Dynamax Flow 32 equipment with Dynagage trunk sensors. The first daily maximum of sapflow was around 10:00 a.m. (2.5 kghour I), the second maximum was always between 14:00-15:00 p.m. (2 kgday- I). Comparing to the very intensive morning water uptake by 20:00 p.m. the water flow slowly reached the minimal level. Significant differences can be seen on rootstocks: trees on `Korponay' rootstock always showed more intensive sapflow and a higher morning peak than trees on `Árdi V'. But later during the day they have the same run.Based on our results the water quantity transpired only by the trees reached in May 86-104 mm, while the precipitation was only 42.4 mm. This means a 40-60 mm deficit in the orchard, which should have been supplied by irrigation despite of the satisfying horticultural performance of the orchard. In the first half of the month beside the steady vapor pressure deficit the shoot and leaf surface growth could cause the increased sapflow.
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Investigation on the transmission of some Tobamoviruses by pollen and seed in pepper (Capsicum annuum L.)
127-131.Views:255Five 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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Inhibition and recovery of germination and growing ability of seedlings under and after osmotic stress induced by polyethylene glycol in 8 pea genotypes
53-59.Views:138Germination and early seedling growth of eight pea genotypes were examined under and soon after different (5%, 10%, 15%, and 20%) PEG treatments. Seeds were germinated on PEG solution for 3 or 6 days and then further germinated and cultured on filter paper moistened by water for 3 and 6 days. The length and fresh weight of shoots and roots of seedlings were measured and used for evaluation of genotypes. Roots were less inhibited by osmotic stress than shoots similarly to other plant species. The variability among the genotypes was the greatest in the case of shoot growth at 5% PEG treatment and in the case of root growth at 15% PEG treatment. Results suggest that growing responses of genotypes after cessation of stress are more suitable for the evaluation of their osmotic tolerance, than their responses expressed during in vitro stress conditions. Genotypes with relatively high or low osmotic stress tolerance, respectively, could be distinguished with 6 days after recovery from 3-day-long 15% PEG treatment concerning the rate of shoot weight to root weight.
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Long term investigations of flowers and leaves on mainly non-domestica plums
73-79.Views:193The author dealt with plum species representing different eco-geographic areas by their genetic adaptation and their hybrids, as European (P. domestica, P. italica, P. cerasifera), Asian (P. salicina, P. simonii, P. ussuriensis), American (P. americana, P. besseyi, P. munsoniana, P. tomentosa). The rootstocks of the trees examined were seedlings of C. 679 myrobalan with the exception of Laroda and Santa Rosa II, which were grown on three different stocks: seedlings of C. 174 myrobalan, C. 449 bitter almond and C. 471 sweet almond. The size of peduncle, length of pistil, stamen number per flower, relative stamen number (SN/PL) have been suitable for description and distinction of varieties. Similarly shape of leaves, length of petiole, length and width of blade helped the identification.
The ratio of the dimensions of leaves, length of petiole and of leaf blade, also contributed to the distinction of European, Asian and American plum species, notwithstanding their relations with ecological conditions as well as historical, technical properties, pomological features, etc. Computed indicators (relative stamen number and shape-index of leaves) also have been useful data.
Significant correlations have been found between colour of nectaries and mean values of variety-groups. The potential values of non-European varieties for purposes of commercial production could be forecasted from the point of view of quality, ecological, pomological as well as market value. It is important, however, to know the effect of the rootstock and growing site as well as their interaction, on the one hand, whereas the resistance or tolerance of the varieties as limiting factors, at least to the sharka (Plum pox) virus, Xanthomonas pruni, on the other hand (cf. Surányi & Erdős, 2004a and 2004b).
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Anatomical relations of root formation in strawberry
71-75.Views:215Anatomical 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.
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Self-incompatibility alleles in Esatern European and Asian almond (Prunus dulcis) genotypes: a preliminary study
23-26.Views:212Almond [Prunus dulcis (Mill.) D. A. Webb.] as one of the oldest domesticated plants is thought to have originated in central Asia. Gametophytic self-incompatibility of almond is controlled by the highly polymorphic S-locus. The S-locus encodes for an S-ribonuclease (S-RNase) protein in the pistils, which degrades RNA in self-pollen tubes and hence stops their growing. This study was carried out to detect S-RNase allelic variants in Hungarian and Eastern European almond cultivars and Turkish wild growing seedlings, and characterize their S-allele pool. Five new alleles were identifi ed, S31H, S36-S39 in Eastern European local cultivars. The village Bademli and Akdamar island are two distinct places of almond natural occurrence in Turkey. Trees growing wild around Bademli city showed greater genetic diversity than those originated on Akdamar island. Many of the previously described 45 S-RNase alleles have been also detected in these regions. Homology searches revealed that Turkish almonds carried some P. webbii alleles indicating hybridization between the two cultivars and massive introgression events. Our results supply long-awaited information on almond S-allele diversity from regions between the main cultivation centres and the centre of origin of this species; and are discussed from the aspect of methodological developments and evolution of the cultivated almond.
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Effect of hydroponic and peat-free media in transplant production of Rudbeckia hirta varieties under different photoperiodic lighting and their photosynthetic parameters
110-117Views:405The purpose of this research was to determine the effects of varieties, different light conditions (short day, long day, natural short day with light pollution), and different growing media (perlite, peat-free, peat-based, aeroponics system) on Rudbeckia hirta plant production under controlled conditions (greenhouse). The morphological effects of each treatment (photoperiodic lightings and media) on different Rudbeckia varieties determined at 11 weeks-old ’Napfény’, ’Toto Gold’, ’Autumn Colors’, ’Prairie Sun’ and 16 weeks-old ’Napfény’. Plantlets received 12 hours daylight did not initiate flowers, remained stage of the leaf rosette in case of all varieties. The 14 hours light treatment in the aeroponics system and the same treatment in perlite and control (natural short day with 14 hours light pollution) plantlets had developed inflorescences or flower buds. The inflorescence axis of ‘Napfény’ was appeared at 13 weeks under long-day conditions, with 1.7 (perlite) - 2.7 (aeroponics) flower buds in 16 weeks. ’Toto Gold’, ’Autumn Colors’, ’Prairie Sun’ varieties developed inflorescences at 8 weeks, 14 hours aeroponics system resulted in the most of flower buds (’Toto Gold’: 6.5, ’Autumn Colors’: 3.25,’Prairie Sun’: 4.8 flower buds) at 11 weeks. Long daylight manipulation could be minimized crop times and achieved flowering potted plants at 11 weeks. The peat-based and peat-free media effect was observed on ‘Autumn Colors’. The number of leaves of peat-free ‘Autumn Colors’ transplants (16.8-20.3) was significantly higher than peat-based media (13.5-15.5). Other morphological parameters were not affected by the media treatments.
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The use of rootstocks for European (Prunus domestica) and for Japanese (Prunus salicina) plums (review)
7-13.Views:491The worldwide tendency to increase the intensity of fruit growing technologies prefers generally for every fruit species rootstocks with week or mediocre vigour. From this viewpoint, the use of rootstocks for plums are rather unilateral in Hungary, where 95–99% of plum plantations are grafted on mirobalan seedlings (P. cerasifera v. mirobalana). The score of plum rootstocks abroad is much more diversified. The present study summarises the respective knowledge referring to the literature available.