Effects of phosphorus and seed priming on seed vigor, fatty acids composition and heterotrophic seedling growth of black seed (Nigella sativa L.) grown in a calcareous soil

Abstract

In order to investigate the effects of increasing soluble phosphorus (P) on seed vigor, fatty acids composition and heterotrophic seedling growth of black seed (Nigella sativa L.) in a calcareous soil, a two-year field experiment was conducted at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013 and 2014. The fertilizer resources (vermicimpost (V)+Tiobacilus thiooxidans (T), Sulfur (S)+T, V+S+T and control) and three levels of P (0, 30 and 60kgha−1) were the first and second experimental factors, respectively. In the second experiment, selection treatments (which showed emergence below 60% in the previous experiment) and seed priming (no-priming, water-priming and three levels of P-priming of 100, 300 and 500mM KH2Po4) were the first and second experimental treatments, respectively. The resources of soil amendment (V+T, S+T and V+S+T) significantly decreased the P concentration in seed coat and mean germination time. However, 1000 seed weight, seed vigor, P concentration in embryo and intact seed were significantly increased. The soluble P had significant decreasing effects on linolenic acid. There was the highest significant relationship between linolenic acid and seed vigor (R2=0.74**). In addition, seed reserve depletion percentage, seed reserve utilization efficiency and emergence percentage significantly increased by P-priming treatments. There was a positive correlation between weight of mobilized seed P and emergence percentage of black seeds (R2=0.90**).