Characterization and Gene Fine Mapping of a Rice Dominant Spotted-leaf Mutant Characterization and Gene Mapping of a Spotted-leaf Mutant spl21 in Rice (Oryza sativa L.) Characterization of a Novel Spotted Leaf Mutant spl32 and Mapping of Spl32(t) Gene in Rice (Oryza sativa) Physiological Characteristics and Genetic Analysis on a Spotted-Leaf Wheat Derived from Chemical Mutation