Anatomical and Physiological Characteristics of Awn Development in Elymus nutans, an Important Forage Grass in Qinghai-Tibet Plateau

Awns are the important structures of inflorescence in many crops that belong to Poaceae family. In addition, they actively participate photosynthesis, transpiration, seed dispersal, and self-planting. The Elymus nutans Griseb. is an important, self-pollinated, allohexaploid (2n = 6x 42) perennial native forage grass Qinghai-Tibet Plateau shows variation awns length. However, changes anatomical structure, physiological traits, biochemical characteristics during awn development remain unclear E. nutans. Therefore, this study investigated structures, enzymatic activities, hormonal regulations at four developmental stages, i.e., booting, heading, flowering, maturity stages three accessions having different lengths. results showed cross-sections had acute triangular shape structural similarities wheat awns. growth long was recorded faster than short heading stage, but no significant differences lengths were found stages. sizes barbs stomata statistically non-significant; however, accession with more shorter all content cytokinin (CTK), abscisic acid (ABA), ethylene (ETH), activities superoxide dismutase (SOD) peroxidase (POD) significantly related awn. At flowering CTK, SOD POD higher accession. obtained provide a sound basis for future research on molecular mechanisms their potential role