Chromosome substitution lines for the analysis of heterosis in Arabidopsis thaliana

Heterosis is an important phenomenon used in agricultural crop improvement for several decades. The molecular basis of heterosis is still unclear despite the wide exploitation of heterosis for improving economically important traits of crops. The current experiment investigates the heterosis related to several morphological traits in Arabidopsis thaliana on an individual chromosome basis of cr. Whole chromosome substitution lines (CSLs) of chromosomes three, four and five of Arabidopsis, recurrent parent Columbia and the three relevant F, progenies were grown in a growth chamber in a completely randomised experimental design for the scoring of morphological traits. Data were analysed to detect the presence or absence of heterosis for each trait on per-chromosome basis. The traits rosette width at day 20, flowering time, height at flowering time, rosette and cauline leaf numbers at flowering displayed significant heterosis in different chromosomes. The findings revealed the presence of both positive and negative heterosis for rosette leaf number at flowering on different chromosomes. Genetic components of the means and the potence ratios indicated those parents having more dominant alleles in the cross in each chromosome. The results indicated the appropriateness of CSLs in studying heterosis in a micro scale rather than the whole genome level. The study demonstrates that breeding programmes can be designed to keep the desirable effects and remove the disadvantageous effects of heterosis caused by the genes present in different chromosomal parts in the genome.