Plant cell fusion technology — Prior to fusion, researchers prepare large numbers of which cell type to enable somatic hybridization and cybrid formation?

Introduction / Context:
Somatic hybridization allows fusion of plant cells from the same or different species to combine nuclear and cytoplasmic genomes, creating novel hybrids and cybrids. The prerequisite is removing rigid cell walls to permit membrane–membrane contact and fusion.

Given Data / Assumptions:

• Plant cell walls prevent direct plasma membrane fusion.
• Enzymes such as cellulase and pectinase digest walls to yield protoplasts.
• Large populations of viable protoplasts improve fusion efficiency and regeneration success.

Concept / Approach:
Protoplasts are naked plant cells bounded only by the plasma membrane. They can be fused chemically (e.g., polyethylene glycol, PEG) or by electrofusion (short electric pulses). After fusion, hybrid cells are cultured to regenerate cell walls and whole plants via tissue culture, enabling transfer of traits like cytoplasmic male sterility or disease resistance.

Step-by-Step Solution:

Verification / Alternative check:
Microscopy confirms wall removal (spherical morphology) and fusion events (heterokaryons). Regenerated plants can be genotyped to verify hybrid status.

Why Other Options Are Wrong:

• A single protoplast is insufficient for practical fusion work; large numbers are required.
• Intact-walled cells do not fuse efficiently.
• Different species can be fused, but only after wall removal.
• Bacterial spheroplasts are unrelated to plant somatic hybridization.

Common Pitfalls:
Neglecting the need for osmotic stabilization of protoplasts during handling; lysis is common without proper osmolarity control.

Final Answer:
Plant cells stripped of their cell wall (protoplasts)