Selection of sorghum plants and construction of stem-derived small RNA libraries for deep sequencing. (a) Grain sorghum BTx623 with low Brix and early flowering phenotype, was crossed with sweet sorghum Rio with high Brix and late flowering phenotype and an F2 population was created. A total of 553 F2 plants were phenotyped for flowering time (measured as the total number of leaves at flowering) and Brix degree. Using a bulked segregant analysis (BSA) approach, we selected an equal number of F2 plants with low Brix and early flowering (LB/EF) and with high Brix and late flowering (HB/LF) phenotype, respectively. (b) A flow chart describing the procedure for small RNA library construction and sequencing. (c) Histograms displaying the Brix degree and flowering time data obtained from plants grown in the field. We selected 11 LB/EF F2s displaying Brix degree ≤ 5 and number of leaves ≤ 9, whereas the 11 HB/LF F2s selected displayed a Brix degree ≥ 13 and number of leaves ≥ 14.
Calviño et al. BMC Genomics 2011 12:356 doi:10.1186/1471-2164-12-356