The root system

• The function of the root system is twofold: first, it enables the intake of water and nutrients from the soil; and second, it serves to anchor the plant.
• Two kinds of roots will develop from a planted seed piece.
• The set roots, which arise from the root band, are thin and highly branched; the shoot roots, originating from the lower root bands of the shoots, are thick, fleshy and less branched.                          
• Before shoots form, the germinating seed piece must depend entirely on the set roots for water and nutrients.
• The set roots, however, are only temporary and their function will eventually be taken over by the shoot roots as they develop.
• The life of the shoot root is also limited.
• Each new tiller (shoot) will develop its own roots that eventually take over the function of the original shoot roots.
• This rejuvenation, governed by the periodicity of tillering, is important because it allows the plant to adjust to changing environmental conditions.
• A longitudinal section of a root tip consists mainly of four parts:

1. the root cap:The root cap protects the tender tissues of the growing point as the root pushes through the soil
2. the growing point: The growing point consists mainly of an apical meristem, where cell division takes place
3. the region of elongation: In the region of elongation, the cells increase in size and diameter until they reach their ultimate size
4. and the region of root hairs: The region of root hairs is characterized by epidermal cells forming outgrowths (hairs) which dramatically increase the root absorbing surface