The effect of inorganic and organic nitrogen sources and their combination on growth and metabolism of Vesicularia dubyana

Vesicularia dubyana (Bryophyta) was cultured with inorganic (nitrate, nitrite and ammonium), organic (glycine, methionine, serine, arginine and alanine) N sources (1, 10 and 30 mg/L) and their combination to study their effects on its growth and metabolism. Mosses grown in nitrate were short, had no branches and were robust, as evidenced by having the highest weight and dry weight: length ratio (0.11 ± 0.01–0.14 ± 0.01), whereas in ammonium they were long and thin (weight:length = 0.098 ± 0.01–0.104 ± 0.01) with the greatest length increase in 30 mg/L.; The plants grown in nitrate (10 mg/L) had the highest chlorophyll a, b and total chlorophyll content and at 10 and 30 mg/L had significantly higher protein content and chi a/b ratios than in any other inorganic treatments. Attached algae may have elevated the chlorophyll and protein concentrations of all samples.; Among the organic sources, dry weight was best in glycine and arginine (30 mg/L), with the best weight: length ratio in arginine. Chlorophyll a and total chlorophyll were significantly higher in 30 mg/L glycine and 10 and 30 mg/L serine, while all other amino acids inhibited chlorophyll b. The highest protein content occurred in 10 mg/L glycine.; Glycine (20 and 30 mg/L) was excellent for dry weight, length and weight: length ratio, but when combined with ammonium (20 and 30 mg/L) only length increased. Both ammonium (20 mg/L) and glycine (30 mg/L) resulted in significantly higher chi a and total chlorophyll than did other combinations. Ammonium and glycine alone or in combinations promoted the highest chi b content and the best chi a/b ratios. The highest protein content was obtained either in glycine or in glycine + ammonium. In ammonium nitrate, plants were thin, brown, and lacked branches. In glycine plants were healthy, green, long and some had branches, but in glycine + ammonium they were thinner. The most significant finding is the strong link between branching and organic N sources. Serine induced many long branches while glycine + ammonium, alanine and arginine stimulated even more but short branches. Glycine, ammonium and ammonium nitrate promoted few short branches, but methionine, nitrite and nitrate did not induce any.