Q.The two protoplasts are fused with a fusogen called :

Matching gives Sterilization of culture room-Ethanol, Fusion of protoplast-PEG, Solidifying agent-Agar, Isolation of protoplast-Macerozyme, which is option (a).

Working

Each List-I item is matched to its correct List-II reagent based on its standard use in plant tissue culture:

1. Sterilization of the culture room: the walls, floor and working surfaces of the culture room/laminar air-flow cabinet are routinely wiped down with Ethanol (commonly 70% ethanol) as a quick, effective surface disinfectant -- matches (ii).
2. Fusion of protoplast: two isolated protoplasts (from the same or different species) are chemically induced to fuse together using Polyethylene Glycol (PEG), which destabilises their cell membranes enough to allow fusion (used in somatic hybridisation) -- matches (iv). …

Polyethylene glycol (PEG) is the chemical fusogen commonly used to fuse plant protoplasts.

Somatic hybridisation in plant tissue culture begins with the enzymatic removal of the cell wall (using cellulase and pectinase) to obtain naked protoplasts from the two parental sources. To bring about fusion of their plasma membranes, a fusion-inducing agent (fusogen) is required. Polyethylene glycol (PEG), typically used at high molecular weight and concentration in the presence of calcium ions at high pH, causes localised destabilisation and agglutination of the protoplast membranes, allowing adjacent protoplasts to fuse and form a heterokaryon that can then develop into a hybrid cell. (Electrofusion, using an electric …