Phenotyping of Sorghum Lines for Resistance to African Stem Borer (Sesamia Calamistis)

Abstract

Stem borer (Sesamia calamistis) is a serious insect pest of sorghum (Sorghum bicolor) resulting in grain yield losses ranging between 15-80%.  However, genotypes showing complete resistance to these borers have not been identified in Nigeria. Utilization of resistant varieties in combination with other methods of control would offer a sustainable strategy for S. calamistis management in sorghum production. The objective of this study was to validate the acclaimed resistance in the materials received from Kenya and India in Nigerian environment and to screen and ascertain the status of some Nigerian Sorghum to Sesamia calamistis. Eighty-eight sorghum lines were artificially infested with the eggs of the stem borers at two different environment (Field and Screen House) using alpha-lattice design, consisting of 11 plots in eight blocks, replicated twice. Data were collected on leaf feeding, number of dead-hearts, cumulative stem tunnel length, number of exit holes, and selected agronomic traits.  There were significant (p<0.01) differences among the test genotypes for all the traits measured. Based on the selection index, 15% of genotypes were categorized as resistant, 42%  as moderately resistant,33 as moderately susceptible and 10% as susceptible.13 genotypes showed resistance across the environments (field and screen house): ICSB464, ICSL71086, SSV20041-2YELLOW, ICSL71018, ICSR94032, ICSV700, ICSL71193, ICSR94030, ICSL71253, ICSL71268, ICSL71023, ICSL71061 and ICSL71137 were resistant with selection index ranging from 0.0 to 0.5. These sorghum lines with various resistance to S. calamistis could be used as source of resistance and as parents in sorghum improvement programme in breeding for resistance to stem borer.

Keywords: Genotypes, novel source of resistance, Sesamia calamistis, Sorghum bicolor

DOI: 10.7176/JBAH/11-18-04

Publication date:September 30^th 2021