Evaluation of Genetic Variations in Iranian Confectionery Sunflower Landraces (Helianthus annuus L.) under Various Water Treatment Conditions

In order to evaluate morpho-physiological traits of confectionery sunflower under different irrigation regimes, an experiment was carried out under field conditions in Agricultural Research Center of West-Azerbaijan province, Urmia, Iran in 2012. Fifty six confectionery sunflower landraces were arranged in 7 × 8 rectangular lattice design with two replications in each one of well-watered, moderate and severe stress conditions with 50%, 70% and 90% depletion of available water, respectively. Combined analyses of variance revealed significant effect of genotype, irrigation regime and their interaction on studied traits including grain yield, chlorophyll content, grain and kernel weight, grain length and width and kernel/grain ratio. ʹUrmia-Anghane 4ʹ, ʹ Urmia-Gharagoz 1ʹ and ʹSalmas-Sadaghianʹ produced the highest grain yield (6310.31), (3778.83) and (2217.95 kg/h), under well-watered, moderate and sever stresses, respectively. In contrast ʹMashhadʹ, ʹPiranshahr-Andizehʹ and ‘‘Mashhad’’ presented the lowest values. Severe drought stress caused 49% reduction in grain yield compared to well-watered condition. ʹShabestar-Kouzeh Kanan 2ʹ (46.05) and ʹUrmia-Heydarlou 1ʹ (19.47) showed the highest and lowest chlorophyll content under well-watered and severe drought stress conditions, respectively. The high grain length was seen in ʹMarand-Dizaj-Ghalamiʹ landrace (29.59 mm). Under the well-watered, moderate and severe stress conditions, grain yield had significantly positive correlations with kernel and grain weight and grain width and length. Based on cluster analysis, the studied landraces were grouped in three clusters both in well-watered and severe stress conditions. But under moderate stress conditions, the studied landraces were grouped in five clusters. Considering all studied traits, the landraces 1, 2, 3, 4, 5, 11, 12, 13, 49, 55, 56 were superior genotypes under well-watered conditions. In moderate and severe stress conditions, the best landraces were (12, 35, 26, 31, 32, 56) and (2, 3, 5, 7, 9, 11, 12, 14, 15, 18, 22, 25, 27, 30, 31, 42, 43 46, 47, 55), respectively.