- Initially, there are two root systems which support a grass seedling
1) the seminal root which arises from the root itself and
2) the adventitious or secondary roots which arise from the crown node located at the base of the coleoptile. Seminal roots are called primary roots because they develop first.
The seminal roots function until adventitious roots become established. There are no roots on the mesocotyl. The mesocotyl is an underground stem segment often called the subcrown internode or real stem. It elongates in a manner that helps push the coleoptile upward through the soil crust. This is important because the leaf enclosed within the coleoptile might unfurl beneath the soil surface and thus fail to emerge. The first results of germination are the enlargement of the coleoptile and coleorhiza, a sheath that protects the primary root. This is followed by elongation of the primary root and the mesocotyl. Within days, additional mesocotyl roots develop. Roots developing in the crown area are called adventitious roots. Adventitious roots are the roots of the mature grass plant. The seminal roots will disappear. The roots anchor the plant to the ground, absorb nutrients and water from the soil, and function as carbohydrate storage tanks (Fig. 6, root diagram).