Castor is a plant that is commercially very important to the world. It is produced in about 30 countries lying in the tropical belt of the world. Due to high production and utilization of such crop, it gets essential to differentiate the varieties for benefit of mankind. Single species with 9 cultivars were subjected to RAPD analysis for differentiation from each other through unique banding pattern and combined profiles of 20 primers in the present study. The present study shows genetic relationship among cultivars of Ricinus communis using RAPD markers. Using the cluster pattern, genetic relationships can be obtained which may prove to be helpful to the breeders in identifying the diverse cultivars and construct the phylogenetic history of the species. This information can further help to distinguish modified castor varieties. The genetic similarity obtained from the analysis will be useful in selecting divergent parents for breeding and mapping purposes. RAPD analysis was proved to be a powerful technique for fingerprinting and relationship between and among the cultivars even from the same population.

Phytoplankton (microscopic algae) usually occurs as unicellular, colonial or filamentous forms and is mostly photosynthetic and is grazed upon by the zooplankton and other organisms occurring in the same environment. The phytoplanktons stand at the baseline of food webs in aquatic environments and are very sensitive to changes in the environmental conditions. Plankton, particularly phytoplankton, has long been used as indicators of water quality. They flourish both in highly eutrophic waters while a few others are very sensitive to organic and/or chemical wastes. Some species have also been associated with noxious blooms sometimes creating offensive tastes and odours or toxic conditions. Because of their short life cycles planktons respond quickly to environmental changes, and hence the standing crop and species composition indicate the quality of the water mass in which they are found.