Aditi Saha

Cytomixis—a unique phenomenon in animal and plant

Cytomixis is reported to be a uniform phenomenon in the context of fertilization during spermatogenesis of animals and in some lower groups of plants where oogamous reproduction prevails. However, the phenomenon is versatile in flowering taxa as it lacks uniformity in occurrences, causes, formation of intercellular bridges, involvement of number of cells in a cluster, evolutionary significance among others. A review on cytomixis is conducted with an objective that it may offer a scope to unravel some of the ambiguities associated with it and provide further information on cell, reproductive, structural and evolutionary biology.

B chromosomes in angiosperm—a review

A review article on B chromosomes (Bs) in angiosperms is documented considering occurrence, morphology, polymorphic B forms, divisional phase heterogeneity, chromatin organization and gene content, sequence composition, origin, evolutionary aspects and significant role on host with an objective to foresee the evolutionary perspectives as it still remains an enigma. Irrespective of the origin of Bs, it seems that they have attained the following modifications, namely, insertion of centromeric and telomeric sequences, structural reorganization and procuring mitotic and meiotic drives but shows genetic inertness and present in the host as selfish DNA. In the context, few questions are raised. Further, scientific quest may unravel the unexplored information about Bs to ascertain its evolutionary perspectives, if any.

Polyploidy in Angiosperms: Genetic Insight to the Phenomenon

Polyploidy in angiosperm is a well discussed phenomenon for last few decades but still the proper mechanism and its consequences remain to be an enigma. The present review revisited the phenomenon of polyploidy in angiosperms considering many aspects like genome merging and duplication, restructuring of genome, gene silencing, genome size dynamics, meiotic pairing behaviour of homologues, adaptive significance, relationship between C-value and DNA content among others and a few key questions are raised. It is rather difficult to understand whether all of these regulatory events under the ecological niche are unilateral forces or act as tools of a unified selection machinery of evolution, speciation and diversification. The present discussion may provide genetic insight on the phenomenon in an explicit dimension for proper understanding of evolutionary biology.

Assessment of Nanotoxicity (Cadmium Sulphide and Copper Oxide) Using Cytogenetical Parameters in Coriandrum sativum L. (Apiaceae)

Present investigation deals with cytogenetical consequences (using attributes namely, seed germination, seedling length, mitotic index, mitotic and meiotic abnormalities and pollen grain sterilities) of cadmium sulphide (CdS) and copper oxide (CuO) nanoparticles (NPs) treatment in Coriandrum sativum L. (Family: Apiaceae, spice of commerce). Ethyl methanesulphonate (EMS), a conventional mutagen is used as positive control. Results suggest that both CdS- and CuO-NPs can induce growth inhibition and cause cytological aberrations in both mitotic and meiotic cells in the studied species. EMS also responds similarly as that of NPs. Study highlights that rooted plant species can be effectively used as model for assessment of nanotoxicity considering cytogenetical parameters.