Abstract
Rice flowers are composed of one lemma, one palea, two lodicules, six stamens and one carpel. Nagasawa et al. (1996) previously identified the floral organ number1 (fon1) mutant of rice, which showed a specific increase in floral meristem size and consequent increase in the number of lodicules, stamens and carpels. Recently, the FON1 gene was identified as the rice ortholog of the CLAVATA1 gene of Arabidopsis (Suzaki et al., 2003).
Here we report the identification of a new allele of fon1, fon1-5, which have a stronger phenotype than the previously reported fon1-1 allele. fon1-5 plants not only show a higher increase in inner floral organs, but also the formation of extra lemma/palea-like structures as well as fasciations of inflorescence branches, features that are not observed for fon1-1. fon1-5 contains a frameshift mutation upstream to the extracellular LRR domain, indicating that it might represent a null allele.
