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  • Effects of tuberization conditions on the microtuber yield and on the proportion of microtuber tissues
    91-96.
    Views:
    111

    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 with 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.

  • The impact of irrigation on the yield and tuber fraction distribution of potato cultivars
    65-70.
    Views:
    122

    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.

  • Jerusalem artichoke (Helianthus tuberosus L.): A review of in vivo and in vitro propagation
    131-136.
    Views:
    490

    Jerusalem artichoke (Helianthus tuberosus L.) is an old tuber crop with a recently renewed interest in multipurpose improvement. It is a perennial tuberous plant rich in inulin and is a potential energy crop. During food shortages in times of war Jerusalem artichoke received more attention by scientists and farmers because of its multiple uses as a vegetable, medicinal plant, forage plant and source for biofuel. The energy crisis of the 1970s motivated research on Jerusalem artichoke for biofuel as the aboveground plant biomass and the tubers can be used for this purpose. There are different methods to propagate Jerusalem artichoke using tubers, rhizomes, slips (transplants derived from sprouted tubers), stem cuttings, seeds and tissue culture. So, this review was presented to highlight on propagation of Jerusalem artichoke via in vivo and in vitro techniques.

  • Cumulative vector intensity and seed potato virus infection in Hungary
    61-64.
    Views:
    108

    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 value. 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.

  • Dr. Ottó Orsós, the forgotten Hungarian pioneer in plant tissue culture
    9-13.
    Views:
    161

    The knowledge of tissue culture deserves attention in respect of understanding the development of universal biology. This study intends to contribute to the past of the plant tissue culture by such data of the history of science which have been unprocessed so far. It seems that the life-work of the Hungarian biologist, Dr. Ottó Orsós is a missing and essential link between those early plant hormone researchers and the representatives of the pioneers of tissue culture schools who have contributed substantially to the development of the modern in vitro plant morphogenesis and plant cell biology. Orsós cultured kohlrabi tuber cubes on White culture medium in a sterile manner. This way, he could efficiently direct the in vitro morphogenesis of the kohlrabi, the regeneration of its shoot and root, and the formation and steps to subculture of pure callus tissues in 1938. He supported the correctness of its statements by means of detailed anatomical examinations. Orsós successfully rooted and aclimatized complete regenerated plants. We may as well call the above system — in remembrance of the creators of the original concept — "Haberlandt-Orsós model". Between the publishing of his main paper in 1938 and 2003, a period of 65 years has lapsed. On the occasion of this anniversary, we bow before this forgotten pioneer.

  • How to produce large sized microtubers of potato cv. Desiree
    33-36.
    Views:
    143

    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, their 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).