No-choice Cage Technique to Screen for Resistance to Sorghum Midge (Diptera: Cecidomyiidae) uri icon

abstract

  • A cage technique to screen sorghum cultivars for resistance to Contarinia sorghicola under no-choice conditions is described. Forty adults, collected from flowering sorghum panicles in Andhra Pradesh, India, and introduced to the cage at the top- to half-anthesis stage for 2 consecutive days, resulted in maximum damage in the susceptible cultivar CSH 1. Use of a wire-framed cage covered with a blue bag resulted in the greatest damage in CSH 1. This technique was useful for verification of resistance under field conditions. The resistance of 21 cultivars to C. sorghicola was compared under no-choice cage and natural conditions for 4 seasons. Of 15 cultivars reported to be resistant under natural conditions, only 3 (DJ 6514, TAM 2566, and IS 12666C) showed repeatable levels of resistance under no-choice conditions. TAM 2566 and IS 12666C were less attractive to adults (<4 adults/5 panicles) than the susceptible hybrid CSH 1 (19 adults/5 panicles) under field conditions. Fourteen cultivars which were either less attractive to adults or had <12% florets with larvae under natural conditions, showed a susceptible reaction under no-choice testing in the cage. Cultivar reactions were stable over 4 seasons (except IS 2328). TAM 2566 and DJ 6514 were the most resistant cultivars. Sources of resistance placed in groups could be used to increase levels of resistance by hybridization among cultivars belonging to different groups

publication date

  • 1988
  • 1988