Expression of resistance to Atherigona soccata in F1 hybrids involving shoot fly-resistant and susceptible cytoplasmic male-sterile and restorer lines of sorghum

In recent years, cytoplasmic male-sterility (CMS) has been recognized as a potential danger to the stability of crop production and resistance to insect pests in sorghum. Therefore, the influence of CMS on the expression of resistance to sorghum shoot fly was studied at the ICRISAT, Patancheru, India using the interlard fishmeal technique. The experimental material consisted of 12 restorer, 12 CMS and the maintainer lines, and their 144 F-1 hybrids. Shoot fly-resistant CMS lines were preferred for oviposition and had more damage because of deadhearts than the corresponding maintainer lines. The hybrids based on shoot fly-resistant CMS x resistant restorer lines were significantly less preferred for oviposition than the hybrids based on other cross combinations and exhibited the highest frequency (69.1%) of shoot fly-resistant hybrids. The hybrids based on glossy and trichomed parents had the highest frequency (> 90%) of hybrids with glossy and trichome traits, emphasizing the need to transfer these traits into both parents for better expression in the F-1 hybrids. The expression pattern of trichome density, leaf glossiness and leaf sheath pigmentation in the F-1 hybrids and their parents suggested that the interactions between cytoplasmic and nuclear genes possibly control the expression of traits associated with resistance to sorghum shoot fly in the F-1 hybrids.