Development of drought-tolerant bread wheat (Triticum aestivum L.) varieties through mutation breeding technique

One of the techniques used to develop drought-tolerant varieties in wheat is mutation breeding. The strong mutant genotypes that emerge in this way create specific responses that provide adaptation to drought. In this study covering the M1 and M2 generation periods, a small number of bread wheat (Triticum aestivum L.) mutant genotypes developed some adaptation mechanisms in response to stress. During M1 generation period, seedlings of Kınacı 97 and Doğu 88 varieties, whose seeds were treated with 0, 200, 300 and 400 Gy gamma rays, were exposed to drought (−1.03 MPa). As mutation dose applied to seeds in both varieties increased, amounts of chlorophyll and other parameters affecting yield of seedlings that developed from these seeds and were exposed to drought decreased, while amounts of proline increased. In terms of drought tolerance and yield, a small number of M1 mutant seeds obtained by 300 Gy mutation application to Kınacı 97 achieved the best performance. Thus, M2 generation period continued through seeds of 19 different mutant ears (mutant genotypes) developed from M1 mutant seeds. Seedlings developing from seeds of these 19 mutant ears were also exposed to the same level of drought. It was observed that proline amounts were lowest, TaMYB, TaMAPK, TaDHN, TaMIP, TaP5CS gene expressions and some yield criteria were highest in study groups 5, 16 and 19. Therefore, according to the data, it was determined that the most drought tolerant groups were 5, 16 and 19.