Response of sorghum, millet and corn to different strains of sugarcane mosaic virus and strain A of maize dwarf mosaic virus

Abstract

A study was conducted to determine the response of sorghum, millet and corn to the strains A, B, D, H, and I of sugarcane mosaic virus (SCMV) and strain A of maize dwarf mosaic virus (MDMV) with respect to disease reactions and some agronomic characteristics. This study included two separate tests in the field besides one with sorghum in the greenhouse. Ten sorghum and three millet varieties made up one test. The other test involved ten different corns. A randomized split-plot design with three replications was used for both tests. Mass inoculation of the plants was accomplished through the use of the artist's air brush procedure. Screening of sorghum, millet and corn varieties to different strains of SCMV and strain A of MDMV resulted in a wide spectrum of reaction patterns. MDMV-A and SCMV-B were most severe on the sorghum genome in the field. MDMV-A and other strains of SCMV caused varying degrees of delayed maturity, stunting of the plants, smaller heads, lower threshing percentage, lowered test weight and reduction in yield. Little or no effect of the strains and viruses on number of seeds per 10-gram sample and seed size, except SCMV-I which stimulates seed production. Little increase in weight of 1000 seeds was found in inoculated varieties compared to non-inoculated ones. Increase in test weights of two inoculated varieties was also found. Most susceptible varieties, including NM-31 and Redlan, suffered greater economic losses. Martin and Wiley were consistently resistant to all the strains and were least affected. Three levels of resistant genotypes, Martin and Wiley, have been found. ...