Fine Mapping Of A Gene Responsible For Erect Panicle Trait In Rice (Oryza Sativa L)

To determine the chromosomal location of the Epl (t) gene rapidly, a largemapping population including 95 erect panicles and 608 normal bended onesderived from F₂ and TC₁F₁ populations were constructed.A linkage analysis using candidate SSR markers was performed in themapping population through bulked-segregant analysis (BSA) based onrecessive-class analysis (RCA). The result indicated that two markers RM107and RM566 on the chromosome 9 were linked to the gene responsible for erectpanicle trait in the respective populations above with 14.4cM and 11.5 cM ingenetic distance.After genome-wise scanning with microsatellite markers, this gene wasmapped in the long arm of chromosome 9 and 16 polymorphic markers, RM434,RM1189, RM7048, RM3600, RM410, RM242, RM278, RM201, RM24423,RM24427. CYZ-4, CYZ-5, CYZ-6, CYZ-10, CYZ-11 and CYZ-12 identified to link the gene. The result showed that the Epl(t) locus was mapped to a 0.14cM interval flanking CYZ-6 and CYZ-11, and one markers CYZ-12co-segregated with it.To physically map the Epl(t) locus, the linked markers were landed on thereference sequence of cv. Nipponbare through BIA. A contig map correspondingto the locus was constructed based on the reference sequence aligned by theEpl(t) markers. Consequently, the Epl(t) locus was defined to interval flankingmarkers CYZ-6 and CYZ-11, where only eight ORF in the region wereidentified to a DNA fragment of 43 kb in length by BIA.The fine mapping of the crucial gene responsible for erect panicle trait inrice is very valuable in developing of indica rice varieties with erectpanicles. The erect panicle rice is a new plant type in indica rice .The new ricehas some agronomic and economic functions different from the panicle bendedrice. So the close linkage markers identified in this study would be especiallyuseful for efficient marker-assistant selection in breeding program for paniclerice and map-based gene cloning in rice.