Genetic analysis of sodium content and Na/K ratio in relation to salinity tolerance in pearl millet Pennisetum glaucum (L.) R. Br.

Genetic analysis of sodium and sodium/potassium (Na/K) ratios in leaf and stem was carried out through diallel analysis involving two tolerant, one moderately tolerant, and two sensitive genotypes as parents. Three-week-old seedlings were subjected to a critical level of salinization (17 decisiemens per meter of electrical conductivity). Leaf and stem sampling (from 5 parents and 20 hybrids arranged in a randomized block design with three replications of 10 each) was done 30 days after salinization when susceptible parents were severely effected. Predominance of non-additive gene action for stem sodium and dominance component for leaf Na/K were noticed while both additive and non-additive components played a significant role for stem Na/K. A single group of genes seems to be operative for these characters. Hybrids produced by crossing the two sensitive parents were tolerant suggesting genetic complementation and involvement of different loci in the two parents for salinity tolerance. The overall dominant nature of tolerance and the additive gene action for these salinity related characters suggested the possibility of breeding pearl millet lines through hybridization and selection to pyramid the favorable genes.