Resistance in sorghum to Sitophilus oryzae (L.) and its association with grain parameters

Abstract

Sorghum is the fifth most important cereal and suffers heavy damage from rice weevil Sitophilus oryzae, reducing their quality and quantity. Studies were conducted to identify the association of grain characteristics and their relationship with resistance to the rice weevil. The paper discusses the associations between sorghum seed parameters, insect oviposition, development data and grain weight loss. The important grain characteristics, viz., 100 seed weight was significantly positively correlated with grain hardness (0.55**) and median development period (0.47**) and significantly negatively correlated with grain weight loss (- 0.43*). However, the grain hardness was significantly negatively correlated with oviposition (- 0.49**), adult emergence (- 0.75**) and grain weight loss (- 0.82**) and was significantly positively correlated with median development period (0.85**). The pest parameter, viz., oviposition was significantly positively correlated with adult emergence (0.43*) and grain weight loss (0.55**). Two principal components (PCs) were extracted explaining cumulative variation of 76.2 %. Seed weight, grain hardness, oviposition, adult emergence, median development period and grain weight loss were the reliable variables for characterization of resistance to S. oryzae. The sorghum lines EC 24, EC 22, PEC 8, PEC 7, EP 78, EP 57, AKR 354 were classified as resistant to S. oryzae and these could be used in future breeding program as resistant sources.