Vegetative Performance of Tropical Highland Maize (Zea mays L.) in the Field |
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| Authors: | A Stehli A Soldati P Stamp |
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| Institution: | Department of Plant Physiology, Faculty of Agriculture, Agricultural University of Kraków, Kraków, Poland |
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| Abstract: | An attempt has been made to work out a simple and reliable method of fast frost resistance evaluation of winter oilseed rape using in vitro cultures. In winter rape cv. Górczański, there was investigated cold acclimation ability of hypocotyle sections from 5-days old seedlings and also of callus tissue formed on these sections after subsequent 4 weeks growth on induction medium. It has been found that hypocotyle sections are unable to cold-acclimate. Winter rape calli acclimated well and optimum conditions for acclimation is fortnight's growth at +2°C. Exposure to light during hardening was not necessary for acquiring maximum resistance. On five winter rape cultivars freezing tests were performed using the best cold acclimation conditions. The differences in resistance between hypocotyle sections did not match the differences in field survival or frost resistance of whole plants. As distinct from hypocotyle sections callus tissue appeared to be suitable for evaluation of frost resistance. However, to ensure the objectiveness of assessment in this method is not so easy. The testing temperature must be chosen carefully, because the results can be reliable only at sufficiently low temperature. For correct estimation of the frost resistance level, it is possible to use both the decrease of triphenyltetrazolium chloride reduction rate during freezing and the increase of callus dry weight during 14 days after freezing.
(Abbreviations: BAP — 6-Benzylaminopurine; 2,4-D — 2,4-dichlorophenoxyacetic acid; LT50 — temperature at which 50 % of the plants (or plant material) has been frost killed; MS(0.5;2) — Moorashige and Skoog Basic Medium with addition of 0.5 mg 2.4-D and 2 mg BAP; PPFD — photosynthetic photon flux density; TTC — 2,3,5 triphenyltetrazolium chloride) |
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| Keywords: | Callus tissue cold acclimation frost resistance in vitro cultures winter rape |
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