Physiological Character and Gene Fine Mapping of a Virescent Mutant v13(t) in Rice (Oryza sativa L.)

【Objective】On the basis of phenotypic characterizations of temperature sensitive virescent mutant v13(t),the gene virescent 13(t) was finely mapped.【Method】 One natural virescent mutant,named virescent 13(t),was identified from the indica rice cultivar 9311.The physiological basis of the phenotypic variation was observed by transmission electron microscope.And a map-based cloning strategy was employed to reveal the genetic basis of this variation.【Result】 At low temperature conditions(26℃),the initial three leaves of v13(t) showed white,with little green tips and sheath,and the seedling gradually died.At 28℃,only the leaf tips and edge appeared white,and then the leaves turned green.While at 30℃,a significant difference between it and wild-type was not observed.To uncover the genetic basis of this variation,an F2 segregating population,v13(t) mutant,was developed by crossing v13(t) and Wuyunjing 7.Genetic analysis indicated that this leaf color variation was controlled by one recessive nuclear gene.Gene V13(t) was initially mapped between the SSR markers RM3638 and RM459 on chromosome 5,with the genetic distance of 3.2 cM and 0.5 cM,respectively.Several new InDel markers around the V13(t) region were further developed for fine mapping.The target gene was finally delimited to a 98.9 kb region between markers InDel5-11 and InDel5-8 on BAC AC130729,and segregated with marker InDel5-2.【Conclusion】 One new temperature sensitive virescent mutant v13(t) was controlled by one recessive nuclear gene V13(t),and V13(t) was finally delimited to a 98.9 kb region on BAC AC130729.