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• Investigation of Potato (Solanum tuberosum L.) Salt Tolerance and Callus Induction in vitro

  51-55

  Pál Pepó

  Szilárd Tóth

  Views:

  90

  Potato 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

• Increase of Wheat (Triticum aestivum L.) Resistance to Leaf Rust (Puccinia tritici) via Gene Transformation

  127-129

  Gabriella Tikász

  Views:

  69

  Leaf rust is one of the most significant fungal disease of wheat not only in Hungary but also in other parts of the world. For improving leaf rust resistance of winter wheat variety (Hajdúság, 2003) produced by conventional breeding methods, verified by results of variety tests, showing outstanding results in the aspect of the most important economic values, integration of tissue culture technics, genetic engineering and traditional
  methods may provide facilities. Building the gene(s) responsible for resistance into the determined genome can improve the resistance in a way that changes other features of the plant slightly or not at all. In the course of genetical transformation of the variety Hajdúság we applied one of the wheat’s own effecient green-tissue specific insurer genetical regulator, the promoter of ribulose carboxylase 1-5 bisphosphate (RuBisCo) ‘s small
  subunit to control the expression of the gene cmg1.

• Development of a New Maize (Zea mays L.) Breeding Program

  25-30

  Pál Pepó

  Szilárd Tóth

  Views:

  91

  Genetic manipulation may not replace any conventional method in crop breeding programs, but it can be an important adjunct to them. Plant regeneration via tissue culture is becoming increasingly more common in monocots such as corn (Zea mays L.). In vitro culturability and regeneration ability of corn decreased as homozigosity increased, which suggested that these two attributes were controlled primarily by dominant gene action. Pollen (gametophytic) selection for resistance to aflatoxin in corn can greatly facilitate recurrent selection and screening of germplasm for resistance at a much less cost and shorter time than field testing. Integration of in vivo and in vitro techniques in maize breeding program has been developed to obtain desirable agronomic attributes, speed up the breeding process and enhance the genes responsible for them. The efficiency of anther and tissue cultures in most cereals such as maize and wheat have reached the stage where it can be used in breeding programs to some extent and many new cultivars produced by genetic manipulation have now reached the market.