Evaluation of wheat landraces of north-western Himalaya against rice weevil, Sitophilus oryzae L. vis-à-vis physical seed parameters.

The north-western Himalaya is one of the rich repositories of wheat genetic resources because of the preponderance of locally developed traditional crop varieties owing to high agro-climatic heterogeneity and local socio-cultural diversity. In the present study, 100 wheat landraces of this diversity rich region were evaluated for variability in physical parameters of seed to understand the basis of resistance against rice weevil, Sitophilus oryzae. The evaluation was based on the parameter of growth index (GI) of S. oryzae in different landraces. GI was correlated with different quantitative physical seed parameters, viz. hardness, length, width, length × width, test weight and qualitative parameter seed colour were studied to work out if these were related to resistance/susceptibility. Based on the parameter of GI, the six landraces viz. IC266831, IC266872, IC393109, IC392578, IC444217 and IC589276 were identified as resistant. Correlation coefficients between GI of S. oryzae and physical parameters of wheat landraces indicated that GI had significant positive relation with length × width (r = +0.573) and test weight (r = +0.549) indicated that small seeds confer resistance to S. oryzae. Also significant negative relation (r = −0.457) with GI of S. oryzae and seed hardness, indicated that hard seeds were relatively more resistant to S. oryzae. [ABSTRACT FROM AUTHOR]