IDENTIFICATION OF DROUGHT RESISTANT SUNFLOWER GENOTYPES (HELIANTHUS ANNUUS L.)

The present study was conducted under water stress (WS) and stress-free (SF) conditions in randomized blocks design with 3 replications in 2012 and 2013 to determine drought resistance of normal-oleic (Sanbro and Tunca), medium-oleic (Saray and 10TR054) and high-oleic (P64H34 and Oleko) sunflower genotypes. In stress-free treatments, drip irrigations were performed as to bring the soil moisture level to field capacity when 50% of available moisture in effective root depth was depleted. A total of four irrigations were performed in WS treatments, but irrigations were not performed in SF treatments (except for the initial survival water). The differences between the genotypes with regard to investigated parameters were found to be significant (p<0.01). In the first year of experiments, the greatest yields in WS treatments were obtained from Saray and Tunca genotypes (3147-3109 kg ha(-1)) with the lowest crop water index (CWSI=0.29-0.31) and the greatest chlorophyll content (CC=46.6-47.7); the lowest yield (2370 kg hat) was obtained from Sanbro genotype with the greatest CWSI (0.70) and the lowest chlorophyll content (38.8). In SF treatments, the greatest yields (38183646 kgha(-1)) were observed in Tunca and Saray with the lowest CWSI (0.20-0.26) and the greatest CC (50.86 - 50.16); the lowest yield (3163 kgha(-1)) was seen in P64H34 with high CWSI (0.42) and low CC (41.88). In the second year of experiments, the greatest yields (3480-3394 kgha(-1)) in WS treatments were obtained from Tunca and Saray with the greatest CC (46.83 - 51.25) and the lowest CWSI (0.24-0.27); the lowest yield (2793 kgha(-1)) was obtained from P64H34 with the lowest CC (41.28) and high CWSI (0.53). In SF treatments, the greatest yields (4348-4217 kgha(-1)) were observed in Tunca and Saray with the lowest CWSI (0.12-0.17) and the greatest CC (51.66-45.65); the lowest yield (3848 kgha(-1)) was observed in Oleko with the greatest CWSI (0.46) and the lowest CC (40.13). Current findings revealed that the genotypes Tunca and Saray were prominent in both WS and SF conditions with regard to yield, CWSI and CC and they were able to use irrigation water optimally and identified as drought-tolerant genotypes. It was concluded that these genotypes could also be used in further drought-resistance studies. The genotypes Sanbro and 10TR054 with the lowest yield in WS treatments were identified as sensitive genotypes.