Fig. 7.

Shoot apical meristem, epicotyl, plumule and cotyledon development in Viburnum betulifolium seeds collected in 2007. Scanning electron microscope (SEM) photograph of the shoot apical meristem in a fresh mature seed where the apical meristem will appear (arrow, A) and in an embryo at the time the seed coat splits at 20/10 °C, when the apical meristem began to grow (B). SEM photograph of developing first true leaves after radicle emergence to 1 mm in length (C). Dissecting microscope photograph of cotyledons and plumule (first true leaves) inside radicle-emerged seed incubated at 20/10 °C for 24 weeks (D) and at 5 °C for 20 weeks (E). Abbreviations: C, cotyledon; L, first true leaves; M, shoot apical meristem; P, plumule.