Protoclonal variation in the seed progeny of plants regenerated from rice protoplasts

Abstract

Plants have been regenerated from Oryza sativa (var. Taipei 309) protoplasts isolated from cell suspension cultures. Seed progeny (R1) from these protoplast-derived plants were grown at IRRI in a Randomized Complete Block Design during the 1987 Dry Season. A total of 13 phenotypic characters were evaluated for variation studies. Protoclones (R1) had delayed flowering and reduced flag leaf length. In general there was an increase in flag leaf width and the flag leaf length/width ratio was significantly reduced. Overall there was a unidirectional positive shift in the means of protoclones for days to flower, flag leaf width, primary and secondary branches per panicle and spikelets per panicle and a unidirectional negative shift in flag leaf length, flag leaf L/W ratio and panicle length. It appears that like quantitative mutations, protoclone variation shifts means away from the direction of the previous selection history of the variety, and the variability generated can be exploited for crop improvement.