| I. Research Notes Studies on multilines in Wheat (Triticum aestivum L.). 10. Genetic analysis of inter-genotypic interactions amongst components of Kalyansona multilines for agronomic characters K.S. GILL, G.S. NANDA and G. SINGH Department of Plant Breeding, Punjab Agricultural University Ludhiana (Punjab), India In the breeding programme for the development of the component lines for multilines a breeder could follow one of the two approaches. First, a strict backcrossing may be adopted. In this procedure the final lines may recover the genotype of the recurrent parent most faithfully and these may not even be tested for the yield etc. The only difference which would occur among these isolines would arise from the genes conditioning the resistance to disease(s) the breeder is working for. In the second procedure (BORLAUG 1958) a limited back-crossing or even multiple crossing may be followed. The main idea behind this is that transgressive segregation may occur upon which selection may operate. Unlike the back-crossing, the multiple-crossing scheme may leave enough residual variability in addition to the one ascribable to re-genes, which may be having important bearing on the behaviour of the component lines. When grown in a mixture, the performance may vary depending upon the nicking ability of the component lines. There have been some studies earlier (HARPER 1964; JENSEN & FEDERER 1965; JAIN & MOSHA 1974 etc.) where efforts have been made to find-out the performance of lines grown in a mixture. But in these studies the lines were morphologically different and at the time of recording of the observation the components could be separated. However, in multilines the concern is more as to how the mixture as such behaves rather than what happens to each component as has been the case with the earlier studies. The present study was, therefore, planned to investigate the behaviour of some of the component lines of Kalyansona multilines when grown in a mixture. The result are presented in the present paper. Materials and Methods Ten lines were selected for establishing a mechanically mixture diallel from among a larger number of component lines developed for multilines in Kalyansona cultivar. The 45 mixtures (1:1 ratio on grain weight basis) together with ten parental lines were grown in a randomised block design with three replications at the Punjab Agricultural University, Ludhiana. The plot size of each entry was 0.72 m x 2.5 m. The row to row distance was 23 cm. The seed rate was used as recommended for commercial plantings. All the cultural practices as recommended for Kalyansona in this area were adopted. The data were recorded for days to 50 per cent flowering, plant height (cm), ear length (cm), number of tillers per meter row length, number of spikelets per spike, seed size (g) and grain yield (g) per plot. The statistical analysis was conducted as suggested by GRIFFING (1956) model 1, method 2. |
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