Fig. 1From: Transcriptome profiles revealed molecular mechanisms of alternating temperatures in breaking the epicotyl morphophysiological dormancy of Polygonatum sibiricum seedsTemperature stratification treatments promote P. sibiricum seed germination and seedling establishment (A) and embryo development (B). A five main overall stages of P. sibiricum seeds during stratification: dormant mature seed before a warm stratification (Seed); seed germination with the embryo extruding from a hilum (Ger-S) and cormlet formation (Corm) at 25 °C stratification; the radicle and lateral roots form and the corm continues to grow at 4 °C stratification (Str_S); and seedling emergence with a leaf after transferring to 25 °C (Eme). B, four major stages of embryo development during the germination at 25 °C: i) undeveloped club-shaped embryo in a dormant seed at maturation; ii) immature embryo elongates and is extruded from the hilum, indicating the dormant P. sibiricum seed has germinated; iii) hypocotyl increases in size and a cormlet forms on the radicle; and iv) corm continues to grow and differentiate, which is accompanied by the emergence of a plumule. Em: embryo; Ra: radicle; Co: corm; Pl: plumuleBack to article page