Nutrients,Free Amino Acids,and Sugar Contents in Narcissus Roots Affected by N,P, K Deficiency during Winter

Non-rooted bulbs of Narcissus L. cv. “Garden Giant” were planted on October 25, 1993 and cultivated under N, P, or K deficiency or in complete medium (control). The roots emerged on November 5 and were sampled on March 7, 1994. The X-ray microanalyzer images showed the distribution of N, P, K, Ca, Mg, S, and Cl in a control root. The distribution of Cl was similar to that of K and also a similar distribution was found between Ca and S. There were significant differences in the concentration of N, P, K, Ca, Mg among treatments. Interaction among nutrient levels was observed. Control roots accumulated a large amount of nitrogen (84 mg g DW^-1) which was partitioned almost equally between the 80% ethanol soluble and insoluble fractions. N-deficient roots in the -N treatment, on the other hand, accumulated only about 12 mg g DW^-1 nitrogen, mostly in the insoluble fraction (83% of total N). Total amino acid contents responded to N, P, or K deficiency. Glutamine was a major free amino acid in control roots (17 mg N g DW^-1) and K-deficient roots (29 mg N g DW^-1), while arginine seemed to be the predominant amide in P-deficient roots. Content of total soluble sugars in the control, -P and -K treatments that was 49, 46, and 49 mg g DW^-1, respectively, was lower than in the -N treatment (137 mg g DW^-1). Mono- and disaccharides; fructose, glucose, and sucrose, were found in narcissus roots.