Physico-chemical characteristics of rice (Oryza Sativa L.) grain imparting resistance and their association with development of rice weevil, Sitophilus oryzae (L.) (Coleoptera:Curculionidae)

Abstract

Association between rice grain characteristics and Sitophilus oryzae development were deciphered through laboratory experiments. Among the different physical characteristics evaluated, significant and negative correlation of 100 seed weight was observed with weevil emergence (r = − 0.53) and susceptibility index (r = − 0.51). Hence, 100 seed weight was found out to be important characteristics of grain. Similarly, hardness of the grain delayed weevil emergence (r = − 0.41) and reduced the grain weight loss (r = − 0.245). Biochemical characteristic of grain, like protein was found positively associated with weevil emergence (r = 0.741) and negatively associated with median developmental period (r = − 0.537). Amylose being an important component of grain had negative relation with weevil emergence (r = − 0.007); median development period (r = − 0.093). Among different varieties tested, Cross-12 was found to be moderately resistant compared to others. It was the only variety having long broad grain and recorded highest 100 seed weight indicating size of the substrate could hinder the development of weevils. The aim of the current study is to decipher the association of development of S. oryzae and physico-chemical characteristics of grain governing it.