In this study, a rice spikelet mutant, multi-floret spikelet 1 (mfs1), which was derived from ethylmethane sulfonate (EMS)- treated Jinhui 10 (Oryza sativa L. ssp. indica) exhibited pleiotropic defects in spikelet development. The mfs1 spikelet displayed degenerated the empty glume, elongated the rachilla, the extra lemma-like organ and degraded the palea. Additionally, mfs1 flowers produced varied numbers of inner floral organs. The genetic analysis revealed that the mutational trait was controlled by a single recessive gene. With 401 recessive individuals from the F2 segregation population, the MFS1 gene was finally mapped on chromosome 5, an approximate 350 kb region. The present study will be useful for cloning and functional analysis of MFS1, which would facilitate understanding of the molecular mechanism involved in spikelet development in rice.

Fertility restoration of cytoplasmic male-sterility in pepper (Capsicum annuum L.) is useful for commercial production ofhybrid seeds. However, the mechanism of fertility restoration has not been determined. We previously constructed acDNA library and identified some genes related to fertility restoration in pepper using suppression subtractive hybridizationtechnology. In this study, the expression patterns of 20 genes were investigated using semi-quantitative RT-PCR. Threegenes expressed only in restorer lines, but not in sterility lines. Four genes expressed only in anther, but not in otherorgans. Among these 7 genes, the clone TG31 was observed to specifically express in anther of restorer lines. The workdescribed here provides a comprehensive overview on the expression pattern of the genes that are induced by restoreralleles in pepper. It will also contribute to the current understanding of molecular networks for the regulation of fertilityrestoration.