Comparison of Sorghum Seedling Reactions toSporisorium reilianumin Relation to Sorghum Head Smut Resistance Classes

Abstract

Seedlings of sorghum genotypes resistant and susceptible to Sporisorium reilianum were grown in peat pellets and inoculated by infesting vermiculite surrounding seedling epicotyls with 7- to 10-day-old teliospore cultures. Four days after inoculation, the seedlings were removed from the pellets, placed in test tubes containing water deep enough to completely submerge the first leaf, and incubated in darkness at 24 C for 5 days. After incubation, symptoms on the first leaf blade differentiated susceptible and resistant genotypes. Symptoms on the first leaf blades of susceptible genotypes were general chlorosis and brown spots (...)