Mandayam Osuri Parthasarathy Iyengar(1886-1963) was a prominent Indian botanist and phycologist who researched the structure, cytology, reproduction and taxonomy of Algae. He is known as the "father of Indian phycology" or "father of algology in India".
Professor M.O.P Iyengar served a major part of his life teaching at the Presidency College, Madras, and the last dozen years as Professor at the new established University Research Laboratory at Madras. Iyengar aimed to obtain a comprehensive knowledge of India’s algal wealth, its diversity and ecology.
Iyengar’s earlier studies began with the Volvocales and these provided the material for his publications, both from Madras and from Professor Fritsch’s laboratory in London. At the University research department, as a Professor and Director, many in-depth studies of the colonial Volvocales were made. Their work revealed the occurrence of singular patterns of inversion both in the vegetative and reproductive stages of development among the spherical or globular genera. The fertilization stages were also recorded.
A pseudo-filamentous alga, Ecballocystopsis Iyengar, led him to conceive of a new way of developing a filamentous condition, a step in the development of a multicellular condition. The two sibling cells do not separate from each other as in unicellular Volvocales though each gets enveloped in a complete cell wall. They remain enclosed in the remnants of the parental envelope partially or totally. With further divisions, parental envelopes of different generations begin to get ruptured but the daughter cells are kept together by fragments of parental envelopes of the immediate previous generation. The upshot is a linear, end to end association of daughter cells of many generations but without protoplasmic connections between neighbouring cells. Instead of producing a mass of cells, a multicellular condition is arrived, a pseudofilamentous condition. The objective was to understand the morphological steps representing the probable evolutionary steps to achieve a multicellular organism and ultimately the structural framework to achieve a land habit,
Iyengar described another interesting alga from India, Fritschiella which show a heterotrichous habit, one part of the body being subterranean and one part, aerial. In one of the interesting genus, named Gilbertsmithia Iyengar, the eight daughter cells formed from each parent cell take on the shape of a rosary. The eight are attached to each other by eight fragments of the parent cell. In the next generation a compound of the eight rosaries is formed. Iyengar waited many years to see the complete life cycle of his favourite organism, sometimes in vain. Many years later Prof. Smith visited India and saw it. These species constitute the floral components of an unusual habitat, and are called muddy water algae. Thus a palmelloid association is made up of partial remnants of parent walls and mucilage derived by gelatinization of portions of the parent wall.
An active teacher all his life, Iyengar had acquired a reputation for the credibility for his observations and it was hazardous to contradict him. No wonder, because he was reticent to publish in a hurry. He would wait, often endlessly, to study rare algae with their peculiar and important characteristics before publishing.