Influence of types of sterile cytoplasm on the resistance to sorghum shoot fly (Atherigona soccata).

Abstract

Shoot fly Atherigona soccata (Rondani) is one of the most important insect pests affecting sorghum during early stages of crop growth. Commercial production of hybrid seed in sorghums relies on a single source of male sterility (A1) resulting in restricted nuclear genetic diversity of male-sterile (A) as well as restorer (R) lines. Alternative cytoplasms should be exploited to avoid insect pest outbreaks that might be related to the use of single source of cytoplasm. Therefore, this study was carried out to identify the non-milo cytoplasms that are less susceptible to shoot fly. Four isogenic lines in four male-sterile backgrounds, viz. A1, A2, A3 and A4, and their corresponding maintainer (B lines) lines were studied using a fishmeal technique across rainy and postrainy seasons of 2006–07. The A4 cytoplasm was found to be least susceptible to shoot fly as it was comparatively less preferred for oviposition and had lower deadheart formation across seasons than the other cytoplasms tested and thus can be exploited for developing shoot fly-resistant hybrids.