Inheritance of some spike related polygenic traits in spring wheat (Triticum aestivum L)

ive quantitative spike related traits were studied in wheat genotypes by analyzing F1 data derived from a 5 × 5 diallel cross to assess the magnitude of gene action. The experiment was conducted at experimental area of Plant Breeding and Genetics, University of Agriculture, Faisalabad. Analysis of variance proved to be significant for all characters and absence of epistasis for all traits which in turn attested fitness of the data for additive dominance model for genetic analysis. Number of grains spike-1 and grain yield plant-1 were found to be advocated by over-dominance type of gene action while preponderance of additive with partial dominance was observed for spike length, number of spikelets spike-1and spike density. It was observed that varieties Pasban-90, line 9267, Pak-81 and Chakwal-86 possessed most of the dominant genes for spike length, number of spikelets spike-1, number of grains spike-1, grain yield plant-1 and spike density. The operation of additive type of gene action with partial dominance for spike length, number of spikelets spike-1 and spike density entails pedigree method of breeding for significant genetic improvement of   these traits while heterosis can be exploited  for  number  of  grains  spike-1  and  grain  yield plant-1.   Key words: Wheat, gene action, inheritance, genetic parameters, spike characters.