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Micropropagation of Rudbeckia hirta L. from seedling explants
53-59Views:119We 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-strength solid Murashige and Skoog (1962) culture medium containing 10 mg/l of kinetin and 2 mg/l of kinetin + 0.1 mg/l 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/l of IAA. After four weeks of incubation, we obtained elongated shoots, which we separated and inoculated into a new culture medium and from which 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 respectt to breeding.
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Micropropagation of Leuce-poplar clones and its role in selection breeding
43-48Views:192Leuce-poplars (mostly white poplar and its natural hybrid grey poplar) are native tree species trough Hungary. They are covering more than 4.0 per cent of the Hungarian forested area (77 000 ha). The white (grey) poplars play a significant role in the forestation under sandy soil site conditions as well as they are of importance from nature conservation point of view as well.Long-term selection breeding work is going on at the National Agricultural Research and Innovation Centre Forest Research Institute (NARIC FRI), involving selection of fast-growing Leuce-poplar clones under dry site conditions.Micropropagation technology is relatively quickly spreading in forestry. In vitro multiplication of trees is applied mainly in fruit growing in Hungary, in case of forestry it is used mainly for selection breeding.This paper presents a short overview on the micropropagation trials with different Leuce-poplar clones and the early evaluation of the seedlings growing of the micropropagated clones/varieties. -
Cytokinin and auxin levels in micropropagating Red Fuji and McIntosh apple varieties
53-59Views:111Effects of media hormone content on in vitro shoot multiplication and rooting were examined in cv. Red Fuji and McIntosh apple scions. Multiplication responses of shoots to different concentrations (0.5 and 1.0 mg/l) of 6-benzylaminopurine and 6-benzylaminopurine riboside were tested at two levels (0.1 and 0.3 mg/l) of indole-3-butyric acid. The best proliferation rate was achieved on medium containing 1.0 mg/l 6-benzylaminopurine and 0.1 mg/l indole-3-butyric acid in cv. Red Fuji (5.3) and on medium containing 1.0 mg/l 6-benzylaminopurine and 0.3 mg/l
indole-3-butyric acid in cv McIntosh (10.3). The length of shoots on these media was enough for rooting (38.4 mm in cv. Red Fuji and 39.3 mm in cv McIntosh). Shoots developed on the best proliferation medium were used for rooting. Effects of different concentrations of auxin in the root induction media and presence of activated charcoal in the root elongation media were examined on rooting capacity. The best rooting rate (100% in cv. McIntosh and 83% in cv. Red Fuji) was achieved when the root induction medium contained 1.0 mg/l indole-3-butyric acid. In general, rooting was inhibited in the presence of activated charcoal. Because of high in vitro multiplication and rooting rate and high percent of survival during acclimatisation, the methods described here make effective micropropagation processes possible for cv. Red Fuji and McIntosh. -
Improvement of black locust (Robinia pseudoacacia L.) growing under marginal site conditions in Hungary: case studies
129-133Views:362In Hungary, black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species growing mostly under unfavourable ecological conditions for forest management. Due to climate change effects, its importance is increasing in many other countries, too. As a result of a selection programme, new black locust clones were tested in clone trials. Juvenile growth of 12 micropropagated black locust clones in two plots series established at different dates were evaluated in central Hungary under marginal site conditions. At age of 7 the clone R. p. ‘Bácska’ (‘KH 56A2/5’), at age of 10 the clones R.p. ‘Homoki’ (‘MB17D3/4’) and ‘PV201E2/4’ appeared to be especially promising for mass production. Based on the data obtained from the performed trials, it can also be concluded that tissue culture can be considered as a suitable tool for propagating superior individuals and offers new prospects for the rapid cloning of selected genotypes used for plantation forestry.
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Investigation of Potato (Solanum tuberosum L.) Salt Tolerance and Callus Induction in vitro
51-55Views:111Potato 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