Registration of Tift MR9110, Tift MR9115, and Tift MR9120 midge resistant sorghum germplasm.
These 3 midge (Contarinia sorghicola)-resistant Sorghum bicolor lines (PI564512 to PI564514, respectively) were developed from a midge-resistant plant derived from the cross Redbine 60 × PI383856. Selection and successive selfing led to a F7 plant which was crossed with Tx2782. The F1 progeny of this cross contained 8 highly resistant plants and, after further selfing and selection, the 3 germplasm lines were obtained as F4-derived F8 selections. All 3 lines are midge resistant, have white seeds with a pigmented testa and maintain sterility of the A1 cytoplasm in crosses with ATx623. The lines are respectively 1.1 m tall with a semi-compact panicle, 1.4 m tall with compact panicle and 1.6 m tall with an open panicle. They flower in 58-65 days at Tifton, where BTx623 flowers in 56-60 days.