Registration of Tift MR88 midge resistant sorghum germplasm.
Tift MR88, resistant to Contarinia sorghicola, was developed from a BC1 population of Redbine 60 × PI383856, the latter parent being the source of resistance. In trials at 3 Georgia sites during 1984-87, its damage rating (on a 0 = no damage to 9 = 90-100% damage scale) ranged from 0.5 to 2.0, vs. 3.2 to 8.5 for susceptible control BTx623; damage percentages in the 2 genotypes at College Station, Texas, were 8 and 94%, respectively. Tift MR88 reaches 2.1 m in height, flowers 2-3 days later than BTx623 × Tift MR88 hybrids and restores male fertility to A1Tx623 × Tift MR88 hybrids. Crosses of Tift MR88 with susceptible lines are midge-susceptible, indicating that its resistance is under recessive genetic control.