A modified pedigree method of selection.
A dismal 81% failure of newly bulked lines against checks was observed in Indian wheat material evolved by the pedigree method. This is considered to be the consequence of selection in space planting in early generations followed by yield tests in a competitive environment which did not allow any scope of selection for competitive ability. Thus, most of the homozygous lines, which were until now raised and carried forward under space planting, failed to compete with the checks for yield in close planting. It is, therefore, necessary to modify the method to combine both the competitive ability and identity of selected plants. The proposed modified procedure involves raising the population under spaced planting as well as under drilling from F2 onwards. Evaluation for tiller index marks an important step. On the basis of tiller index, single plants are isolated from spaced populations. Steps of the modified procedure are outlined in detail. The modified method, which economises on breeders' workload and other physical inputs, besides having other advantages, can also be used for certain other grain crops. Preliminary results based on the modified method during the past two seasons have indicated its utility.
Genetics Division, Indian Agricultural Research Institute, New Delhi, India.
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Kulshrestha