Current status of host plant resistance in sorghum in India

Host plant resistance in itself is an excellent pest-suppressing method and when integrated with other methods of insect control offers a sound approach to deal with insect pests. Insect resistant varieties provide pest control at essentially no cost to farmers. This approach holds great potential for sorghum, which is known to be poor man's crop. Progress in several aspects of host plant resistance in sorghum in India has been quite encouraging. Well-developed mass rearing techniques are available in case of shootfly (Atherigona soccata Rond.) and stem borer (Chilo partellus (Swinhoe)). Many promising sources of resistance viz., IS 1054, IS 5359, IS 5470, IS 2123, IS 1055, IS 18333, IS 18366, IS 17645, IS 17610, PS 14913, PS 13827, PB-8104-1, CSV-5, CSV-6 CSV-7, SPY 102, P 311, SPY 1015, E 601, E 501, E 201, TAM 2566, SGRL-MR-1, AF 28 etc. to key pests have been identified both under natural and artificial infestation conditions. It is evident that resistance to individual pest is available in sorghum. But it is not enough as sorghum is attacked by a series of key insect pests at different growth stages. Thus developing different cultivars for resistance to different insect pests may not be practicable. A programme has been initiated under AICSIP at different locations to develop cultivars possessing resistance to shoot fly Atherigona soccata Rondani, stem borer, Chilo partellus (Swinhoe), midge Stenodiplosis sorghicola Coquillett and mirid head bug, Calocoris angustatus Leth. Incorporation of insect resistance genes into high yielding sorghum varieties or hybrids should be the major objective of sorghum breeding programmes. The major strategy for future will be identification of multiple resistance sources and transferring the resistance into high yielding varieties and hybrids. Development of new germplasm like PFGS-97, PFGS-98 and PFGS-I00 with multiple resistance is a new step in this direction.