Genetic analysis and molecular tagging on a novel excessive tillering mutant in rice.

A rice (Oryza sativa L.) mutant with an excessive tiller number, designated ext-M1B, was found in the F2 progenies generated from the cross between M1B and GMS-1 (a genetic male sterile), whose number of tillers was 121. The excessive tillering mutant also resulted in significant changes in plant height, flag leaf, stem, filled grains per panicle, and productive panicles per plant.