The layer between seed coat and cotyledon probably includes the wall of the embryo sac.
Mutants of this class display shortened hypocotyls and small cotyledons after irradiation of seed.
They are present on the stems, leaves, cotyledons , rachises, pedicles, bracts and calyces.
Further development of cotyledonary embryo showing closed vascular system and characteristic cotyledonary notches.
In contrast, in seedlings grown in vitro, growth of the cotyledonary tissue, shoot and root was observed with growth in the root appearing later and proceeding more slowly than in the shoot.
The cotyledons are the ‘seed leaves’ produced by the embryo.
Seedlings at the vegetative cotyledonary stage, about 7-10 days old, were transplanted into plastic pots containing the same medium.
In the first attempts to achieve embryo-to-plantlet conversion, 16-week-old cotyledonary stage embryos (including 2 weeks pretreatment) were selected for use as experimental material.
However, protein biosynthesis in the axis organs and cotyledons of dicotyledonous seeds commences much earlier.
Three chlorophyll readings were made and averaged on the middle leaflet of the first trifoliate of soybean, the second true leaf of lettuce (counting up from the cotyledonary leaves) and the second leaf of wheat.