Anatomy of root, Completion to Root Atlas vol. 1+5

In comparison with the shoot, the roots of plants have been investigated to a lesser extent so far. Therefore, several questions concerning the relationship between shoot and root as well as the relationship between root and environment have not been dealt with in a satisfactory or correct way in the literature. Among these are the first and initially most important function of the root and the root cap, according to their anatomical structure. Further functions of the root are added in complementing the function of the shoot which are shown in the anatomical structure of both organs too. Therefore, apart from investigations of the different structures of the roots of the species, some basic questions of the root growth need to be clarified. The investigations were carried out on more than 150 species based on earlier investigations on more than 500 species. The first function of the root is the uptake of the temporary overproduction of assimilates produced by the shoot. According to literature, the foremost function of the root is the uptake of water. But one of the most important preconditions for this is the high content of sugar in the outer layers of the young root. So the uptake of water can only take place as second step. The root cap is of great importance for the intensive growth of the young root. Its function is to protect the cells of the root body from premature entry of water from outside. In this way only, the high energy content and the ability of dividing the cells of the root body are preserved. Unfortunately, the textbooks demonstrate the mechanical protection of the root body as the first function of the root cap. The fact that water roots have the biggest root caps stands in great contrast to this, a fact which has already been pointed out by H. Guttenberg. By preventing the entry of water the root cap also prevents the entry of poisonous substances. The entry of poisonous substances is only possible when passing the middle part and not the flanks of the root cap. If the latter is the case the root will die, because the body of the root lacks a core in its centre. Only the shoot has a core, although we can often find the definition "the core of the root" in the literature. The missing of the core in the root is, among other things, helpful for the building up of the root pressure. The root pressure is one of the most important preconditions for the rise up growth of the plants. This is shown by the fact that plants have grown higher than 50 cm not before the phylogenetic development of roots and finally that, with the increasing develop-ment of the roots, trees can grow higher than 100 m. Essential for the water transport is, as we know, the development of water conducting elements, such as tracheid and trachee. Both are to be regarded as a reservoir for water, i.e. the water is accumulated inside. The transport of water takes place mainly in the cell wall. In contrast to this, textbooks have made us believe for about one hundred years that the water transport takes place inside the conducting elements in form of a continuous thread of water. If the water ring is interrupted the ability of water transport is lost. Considering the importance of the water transport, this erroneous explanation was not helpful for the understanding of the plant growth. It is the definition of the water conducting elements as water reservoirs that gives us a satisfying understanding of the survival of plants during dry periods as well as of the growth of plants in desert areas in general. The different taxa vary the structure of their tissues in order to fulfil the fundamental functions of the roots. Due to these variations the species are able to settle and survive in different areas or biotopes. Therefore, the research work presented has extended our knowledge of the importance of the vegetation on arable land, green- and woodland regarding the improvement of the soil fertility and land use. This understanding enables us to meet the requirements of both the economy and the conservation of nature by a better selection and cultivation of the species according to their habitat.