Biophysical and structural mechanisms of resistance against pod borer complex in pgeonpea - A review

Abstract

Host plant resistance is an important tool for minimizing the losses in pigeonpea due to pod borer, Helicoverpa armigera (Hubner), spotted pod borer, Maruca vitrata (Geyer) and pod fly, Melanagromyza obtusa (Malloch) which are the most  threatening hidden pests of pigeonpea crop. Resistant cultivars has a remarkable potential for use in integrated pest management programme. The biophysical, morphological and structural attributes of plants plays an important role in plant defense mechanisms. The glandular (type A and type B) and non-glandular (type A) trichomes on pods of top and middle canopy of the plant and pod wall thickness were associated with resistance to H. armigera, M. vitrata and M. obtusa whereas, the non-glandular lengthy (type C) trichomes and pod length were associated with susceptibility to the said insects. The expression of resistance to H. armigera, M. vitrata, and M. obtusa was associated with the high amount of fat, phenol and tannin content. Whereas, the higher amount of crude protein and total soluble sugar content were responsible for higher pod infestation.