One hundred and eighteen varieties identified as resistant to brown planthopper and resistant to white-backed planthopper at the All-India Coordinated Rice Improvement Project, Hyderabad, were screened against three biotypes of brown planthopper and white-backed planthopper at International Rice Research Institute, Manila, Philippines. Fifty two entries were resistant to all the three biotypes of brown planthopper and of these 21 were also resistant to white-backed planthopper both at IRRI and AICRIP.
Among the 52 entries, 46 had red kernels. Further, a majority of the resistant entries were from Kerala.
The differential reaction of several of the entries to whitebacked planthopper at IRRI and AICRIP suggested the possible existence of biotypes in the whitebacked planthopper.
