FRESH LOOK AT THE CYTOLOGY, GENETICS AND EVOLUTIONARY POTENTIAL OF AGAMOSPORY IN HOMOSPOROUS FERNS
SATISH CHANDER VERMA *
Department of Botany, Panjab University, Chandigarh-160014, India
*Author to whom correspondence should be addressed.
Obligate asexually reproducing ferns provide an important window into the evolution and maintenance of sexual reproduction cycle, and these are also challenging our concept of a species. Relatively speaking, there is high frequency of obligate apomictic/ agamosporous homosporous ferns when compared to the sister clade angiosperms, and more importantly its incidence is disparate amongst the ferns. Reasons for such a high frequency of apomictic taxa together with their unequal distribution in ferns are unclear. Agamospory adds to the enigmatic nature of homosporous ferns. Contemporary studies in ferns are focussing on several questions, and are providing valuable insights into the evolutionary dynamics of agamospory in ferns. A brief overview of the phenomenon, genetics, and evolutionary potential/ significance of agamospory in ferns is presented bringing into focus some recent revelations so as to impress upon the need to revisit the agamosporous mode of reproduction in agamic complexes and hybrids.
Keywords: Fern biology, agamospory, Döpp-Manton pathway in apogamy, sub-sexuality in agamospory, Novel meiosis in apogamous ferns, Autobivalents