Mechanisms and diversity of resistance to sorghum midge, Stenodiplosis sorghicola in Sorghum bicolor uri icon

abstract

  • Sorghum midge, Stenodiplosis sorghicola (Coquillett) is the most important pest of grain sorghum worldwide, and plant resistance is an important component for the control of this pest. To identify sorghum genotypes with diverse mechanisms of resistance to sorghum midge, we studied oviposition, larval survival, and midge damage in 27 sorghum midge-resistant genotypes, and a susceptible check under greenhouse conditions. Observations were also recorded on floral characteristics and compensation in grain mass. Of the 28 sorghum genotypes tested, 19 showed high levels of antixenosis to oviposition as a component of resistance, and had 80% midge damaged spikelets in QL 12 ? the susceptible check. Genotypes showing resistance to sorghum midge have smaller glumes than the susceptible check, QL 12. However, IS 7005, IS 18653, and ICSV 745 have relatively large sized glumes, but suffered 20% compensation in grain mass when the panicles were reduced to 250 spikelets and infested with 10 or 25 midges per panicle. There is considerable diversity in sorghum genotypes showing resistance to sorghum midge. Genotypes with diverse combination of characteristics associated with resistance to sorghum midge can be used in breeding programs to broaden the genetic base and increase the levels of resistance to this insect

publication date

  • 2002
  • 2002