Abstract

                                Histopathological studies on Rotylenchulus reniformis infected three Bt hybrids viz., Bunny Bt, Rasi Bt, and Jagannath fusion Bt in comparison with their respective non Bt (Refugia) were carried out. R. reniformis caused heavy damage to cortical, endodermis, pericycle, phloem cells in addition to extensive hypertrophy, dissolution and breakdown of cell wall in non Bt cotton. Whereas in Bt the cell damage caused due to was not severe compared to non Bt cotton. The compact arrangement of cortical and phloem cells and reduced area of phloem vessels in Bt cotton might have reduced severity of R. reniformis damage in Bt cotton.

Key words : Bt hybrid, Cotton, roots, reniform nematode damage, compact cell arrangement