Intogression of barley drought tolerance qtl using marker-assisted selection

One of the most convenient ways to make a sustainable production under drought stress is to develop and use cultivars that can adapt to these conditions. In this study, three QTL in chromosomes 1, 2 and 6, which provide tolerance to drought, were transferred to Baronesse cultivar in order to improve drought tolerance in barley via marker assisted selection in 2015-2018 years. DNA markers were employed to monitor both transferred QTLs and barley genomic background. Lines and parent cultivars were examined in two greenhouse and four field trials. The lines developed by transferring the QTL1 region had 4.7-7.7% higher leaf relative water content than the cultivar Baronesse in greenhouse trials. The QTL1 region have resulted in small changes in heading time, spike length, maturation time and 1000-grain weight, and increased the number of grains per spike by 1.4 and harvest index by 4.7%. The QTL2 region increased relative water content of leaf by 4.4-13.1% in the greenhouse and by 2.1% field trials. In field trials, QTL2 shortened heading time by 2.8 days, plant height by 4.2 cm, maturity time by 2.4 days, increased spike number per square meter by 134 and harvest index by 4.5%. QTL2 region increased the grain yield of Baronesse cultivar by 15% in Tokat rain sheltered field trial where terminal drought conditions were established. QTL6 region provided the highest increase of leaf relative water content by 7.1-15.9% in greenhouse and by 2.4% in field trials. The QTL6 region delayed heading time by 2.0 days and increased SPAD index by 1.6. Although the QTL6 lines had 2.3 g less 1000-grain weight than cultivar Baronesse, they did not differ from cultivar Baronesse for other traits. As a result, it was concluded that three QTL regions were associated with drought tolerance. Developed lines constitute valuable resources for studying QTL interactions through combining them in the same genotype and for map-based cloning of these QTL. Besides, QTL2 lines are promising cultivar candidates with improved drought tolerance.