Q. Show the value of embryology?
The value of embryology in solving taxonomic problems can be appreciated by studying some specific cases. Amongst the classical examples cited by embryologists is the taxonomic position of the genus Paeonia. In a majority of the classical systems of angiosperm classification, this genus is considered as a member of the family Ranunculaceae. However, several botanists have been recognising several characters of Paeonia which distinguish it from other members of the family Ranuncuiaccae. These include vascular and floral anatomy, basic chromosome number as well as-the size and morphology of the chromosomes. The most significant difference bitwee3 the genus Paeonia and other members of the family Ranunculaceae concerns several embryological characters and this study was carried out independently by Russian botanists Yakovlev and Yoffe as well as by the hdian botanist Prem Murgai. The most significant observation relates to' the embryogeny in Paeonia. Unlike other angiosperms, this genus exhibits a unique type of embryogeny.
According to the Russian botanists, the zygote nucleus undergoes repeated nuclear divisions forming a coenocytic structure. Later, the nuclei lodge themselves in a peripheral layer of the -cytoplasm, and this is followed by wall formation so that the peripheral region becomes cellular. Some of the peripheral cells then function as embryo initials but only one of these develops into an adult embryo. Murgai on the other hand observed a division of the zygote into a 2 celled proembryo and the basal cell of this proembryo develops into the coenocytic structure leading to the development of the adult embryo as described by the Russian botanists.