Response of wheat (Triticum aestivum) landraces from north-western Himalaya to rice weevil (Sitophilus oryzae)

Wheat (Triticum aestivum L.) landraces (one hundred) from the north-western Himalayan region were evaluated for their response to rice weevil, Sitophilus oryzae L. under no-choice artificial infestation conditions in the laboratory. The differential reaction was based on the parameters, viz. number of adults emerged, development period, growth index (GI) and weight loss in seeds. On the basis of GI, these landraces were categorised as resistant (six landraces with GI from 0.33-0.49), moderately resistant (13 landraces, GI from 0.52-0.97), moderately susceptible (41 landraces, GI ranging from 1.01-1.50), and susceptible (41 with GI from 1.51-1.86). On the basis of seed weight loss, eight landraces were found resistant (8.3-18.5%), 32 as moderately resistant (20.1-39.5), 51 as moderately susceptible (40.3-59.9), and 10 landraces (61.4-68.8) were found susceptible. Four landraces, viz. IC393109, IC392578, IC444217 and IC589276 were found resistant both on the basis of GI and seed weight loss. These landraces can be used in breeding programme for development of wheat cultivars resistant to S. oryzae.