PHENOTYPIC AND GENOTYPIC CHARACTERIZATION OF AN F2: F3 MAPPING POPULATION OF Sorghum bicolor FOR SEED DORMANCY

CANTORO R; FERNÁNDEZ L; RODRÍGUEZ MV; GIECO JO; PUEBLA A; PANIEGO N; HEINZ R; BENECH-ARNOLD RL

Costa do Sauipe

Congreso; 10th Conference of the International Society for Seed Science; 2011

ISSS (International Society for Seed Science)

Grain dormancy comprehension in cereals requires genetic studies that allow the identification of genomic regions related with the regulation of this process. This will make possible to confirm the roll for candidate genes that have been proposed for seed dormancy, and to identify new regulatory elements over dormancy expression. In this way, the aim of this work was to accomplish a phenotypic and genotypic characterization of a F2: F3 mapping population of Sorghum bicolor (L.) Moench, whose parental lines are IS 9530 (high dormancy) and Redland B2 (low dormancy) to detect QTL associated with seed dormancy. Genotyping is being held in 200 F2 plants, by microsatellites that resulted polymorphic between parental lines. By the moment, more than 50 SSRs have been evaluated by PCR and size determination was made with capillary electrophoresis in ABI 3130-Applied Biosystems. Phenotyping has been done over 200 F3 families (3 blocks and triplicates), in INTA Manfredi (Cba) experimental field, by calculating germination index (GI). GI obtained for the F3 families has shown a continuum variance within a rank of values between 0 and 100 (120 is the maximum value for GI). Once genotyping is complete, a genetic map will be constructed for this population and QTL analysis will be done. Identified QTL will provide the genetic proof necessary to reassert candidate genes rolls proposed for seed dormancy in grain sorghum and will open the possibility to identify new regulatory components in this system.