Identification and Genetic Mapping of a Lesion Mimic Mutant in Rice

A lesion mimic stripe mutant, designated as lms1 (lesion mimic stripe 1), was obtained from the M-2 progeny of a Co-60 gamma-radiation treated japonica rice variety Jiahua 1. The lms1 mutant displayed propagation type lesions across the whole growth and developmental stages. Physiology and histochemistry analysis showed that the mutant exhibited a phenotype of white stripe when grown under high temperature (30 degrees C), and the lesion mimic caused by programmed cell death under low temperature (20 degrees C). The genetic analysis indicated that this lesion-mimic phenotype is controlled by a single locus recessive nuclear gene. Furthermore, by using simple sequence repeat markers and an F-2 segregating population derived from two crosses of lms1 x 93-11 and lms1 x Pei'ai 64S, the lms1 gene was mapped between markers Indel1 and MM0112-4 with a physical distance of 400 kb on chromosome 6 in rice.