Computation Of Differential Response Of Sunflower Genotypes For Achene Yield And Oil Quality Against Lead Toxicity

With increasing industrialization, soil contaminations with heavy metals especially lead (Pb) and its accumulation in edible crops is becoming a major concern. This research work was designed to find out differential response of sunflower genotypes against Pb toxicity and selection of Pb tolerant genotypes for utilization in future breeding program. Research trial was conducted in net house of Department of Plant Breeding and Genetics, University of Agriculture Faisalabad. Fifty sunflower genotypes were collected from international sources and evaluated for 100-achene weight, achene yield per plant, oil contents, fatty acid profile and Pb contents in roots, shoots leaves and achene under three levels of Pb viz., 0,150 and 300 mg Pb kg(-1) of soil. Sunflower genotypes, Pb levels and interaction among them had significant effect on most of the aforementioned traits of sunflower. Principal component analysis was used for selecting better sunflower genotypes for achene yield and oil quality under Pb stress environments. Results disclosed that the genotypes PI546356, CN42267 and CN36537 were Pb tolerant while PI650582, CN36721 and CN31766 were Pb sensitive genotypes. Increasing lead concentration in various parts; roots, leaves and shoots had enormous negative influence on plant growth in general and on achene yield per plant in particular. Oleic acid (omega-9) contents increases with the decrease in linoleic acid (omega-6) contents with increasing Pb stress. Moreover, sunflower genotypes accumulated more amount of Pb in roots and leaves as compare to achenes, a required part for oil extraction. In conclusion, divergent response of sunflower genotypes under Pb stress and more importantly different degree of its accumulation in vegetative and reproductive parts, less accumulation in achenes in particular, provided the sound basis for establishment of Pb tolerant genotypes of sunflower. (C) 2018 Friends Science Publishers