give reason why plumule comes out and grows Towards the sun
Answers
Answer:
Seeds of wheat have the embryo with a plumule (the embryonic shoot) and a radicle (primary root). The plumule includes the coleoptile, approximately four leaf primordia and the dome-shaped shoot apex that will be responsible for the development of more leaves first and reproductive organs later. Indeed, development of an individual includes leaf initiation started in the mother plant (Fig. 3.7) (Kirby and Appleyard, 1987; Hay and Kirby, 1991). Immediately after sowing, seed imbibition takes place and leaf primordia initiation is resumed. The initiation of new leaf primordia, as single ridges on opposite and alternating sides of the apex, follows an almost linear dynamic (Fig. 3.9a; Kirby et al., 1987; Delécolle et al., 1989; Kirby, 1990). The time between the initiations of two consecutive leaf primordia is called the leaf plastochron and can be estimated as the reciprocal of the rate of leaf initiation. Leaf initiation continues, still as single ridges, until the apex switches from initiating leaf primordia to initiate spikelet primordia at the time of floral initiation; this switch is paralleled by a morphological change of the apex from dome-shaped to a cylindrical, more elongated structure (but still differentiating single ridges). The number of initiated leaves is the final leaf number in the main shoot and depends on the duration from sowing to floral initiation and the leaf plastochron of each genotype in the specific conditions of growth. Indeed, final leaf number reflects variation in phenology with genotype (G), environment (E) and their interaction G × E.
Answer:
The plumule is the part of a seed embryo that develops into the shoot bearing the first true leaves of a plant. In most seeds, for example the sunflower, the plumule is a small conical structure without any leaf structure. Growth of the plumule does not occur until the cotyledons have grown above ground.