Methods to improve frost resistance of winter wheat (Triticum aestivum L.) in conditions of Forest-steppe of Ukraine

Abstract

Aim. To carry through selections in artificial conditions by frost resistance among early generations of winter wheat hybrids (F₂ – F₄) and to verify their effectiveness in later generations (F₅ – F₆). Methods. As the material for research annually (2010–2014) more than 100 hybrid and hybrid-mutant populations F₂-F₄ through the use of improved methods of freezing seedlings by G.A. Samygin and modified at the Myronivka Institute of Wheat method of paper roll are used. The methods consists in hardening and freezing germinated to some extent seeds by definition viability percent at temperatures close to the critical and subsequent rearing survive seeds in the field. Control of frost resistance of selected from hybrid populations genotypes in F₅ – F₆ was determined using methods of freezing seedlings by methods according to V.Ya. Yuryev and M.I. Kucheryava. Results. Laboratory methods of evaluation of winter wheat frost resistance provide step-wise freezing germinated plant seeds followed by calculation of percentage and their viability compared with variety-classifier Myronivs’ka 808. The degree of frost resistance enables to differentiate detaily breeding material by level of frost resistance with identification three groups: low- − < 50 % survive plants; medium − 51–80 %; frost resistant – 81–100 %. Genotypes with winter-hardy varieties involved in their pedigrees had high level of frost resistance. Analysis of frost resistence has shown that new genotypes of winter wheat appreciably exceed standard classifier Myronivs’ka 808. For the sum of ranks genotypes: Volodarka / Dal’nyts’ka, (Podolianka / Etiud) / Yuvileina 100, Hospodynia / Lumai 13, Tsarivna / TAM 201 occupy top places. These winter wheat genotypes are remarkable for high levels of stability for 4 methods of freezing. Conclusions. The data obtained confirm expediency of freezing F₂ – F₄ hybrids of winter wheats to obtain predictive information concerning to availability of studied traits. In addition, based on selection of frost resistance forms subsequently genotypes with a set of economically valuable traits representing practical value for breeding are created.

Keywords: soft winter wheat, frost resistance, selection, freezing.