AC. Sanchez and G.S. KWJSH

International Rice Research Institute, Manila, Philippines

We have selected a new mutant for extra glume character in rice. The mutant was isolated from an 1R43 protoplast-derived line developed at the International Rice Research Institute (IRRI). The spikelets of this mutant are characterized by the presence of an extra palea which is long and empty (Fig. 1). The gene, although completely penetrant, does not have 100% expressivity as not all spikelets in a panicle of a mutant plant has extra palea. A similar mutant, designated as eg was described by Iwata and Omura (1971). The extra palea in the new mutant looks like a single long empty glume. The spikelets of F, hybrids between eg and the new mutant are normal. The F2 population obtained from its cross with 1R36 (normal spikelets) segregated into 102 normal to 27 eg, respectively. Thus, the mutation is conditioned by a single recessive gene which is non-allelic with egi. We have designated the gene as eg2 (t).