Bryophytes (Mosses, Liverworts, and Hornworts) are among the main categories of green plants. Mosses are small plants, non-vascular, and without flowers. Neckera complanata is one of the most prominent species in the Hircanian wetland that has smooth Leaves, not transversely undulate, lingulate or spatulate, with a short or sometimes elongated point; margin plane, dentate in the upper part of the leaf. Seta tall; capsule longly exserted; stomata small and few at the base of the capsule. Spores about 24- protein-based work has been done on this moss in Iran yet. The purpose of this study is to investigate the differences and similarities among N. complannata moss populations by using isoenzymes biochemical markers (peroxidase). Isoenzymes are enzymes that differ in the composition of amino acids but accelerate the same chemical reaction, therefore, identification and isolation of these isoenzymes have a diagnostic value. For this purpose, two populations are collected from Golestan province (Loveh and Kourdkoy) and two populations from Mazandaran province (Hezrajarib and Dodangeh) in the same altitude in 2017 autumn. According to the results, the number of isoenzymic bands in populations of Dodangeh and Loveh are more than the isoenzymic bands of the Kourdkoy and Hezarjarib populations. The results showed that this enzymic system has polymorphism in different populations.
