Mapping and Inheritance analysis of a novel dominant rice male sterility mutant,OsDMS-1

We found a rice dominant genetic male sterile mutant OsDMS-1 from the tissue culture regenerated offspring of Zhonghua 11 ( japonica rice). Compared to wild Zhonghua 11, OsDMS-1 mutant anthers were thinner and whiter, and could not release any pollen although the glume opened normally; most of the mutant pollen was small and malformed, and could not be stained by iodine treatment; a paraffin section assay showed the degradation of OsDMS-1 mutant tapetum was delayed, with no accumulation of starch in the mutant pollen, ultimately leading to pollen abortion. Classical genetic analysis indicated that only one dominant gene was controlling the sterility in the OsDMS-1 mutant. However, molecular mapping suggested three loci simultaneously control male sterility in this mutant: OsDMS-1A, flanked by InDel markers C1D4 and C1D5 with a genetic distance of 0.15 and 0.30 cM, respectively; OsDMS-1B, flanked by InDel markers C2D3 and C2D10 with a genetic distance of 0.44 and 0.88 cM, respectively; OsDMS-1C, flanked by InDel markers 0315 and C3D3 with a genetic distance of 0.44 and 0.88 cM, respectively. Molecular mapping disagreed with classical genetic analysis about the number of controlling genes in the OsDMS-1 mutant, indicating a novel mechanism underlying sterility in OsDMS-1 . We present two hypotheses to explain this novel inheritance behavior: one is described as Parent-Originated Loci Tying Inheritance (POLTI); or the hypothesis is described as Loci Recombination Lethal (LRL). Key message Three loci, which were localized on the chromosomes 1, 2 and 3 respectively, simultaneously control a dominant rice male sterility in this mutant: OsDMS-1 .