Genetic variability for aluminium tolerance in sunflower (Helianthus annuus L.)

Breeding for aluminium (Al) tolerance is a vital approach for enhancing the productivity of field crops in acidic soil regions where Al toxicity seems to be the most restraining factor for crop performance. Sunflower is generally considered extremely sensitive to Al toxicity; although no comprehensive information on the evaluation of sunflower genotypes for Al tolerance is available. In this study, 50 sunflower genotypes (set-I and set-II) were evaluated for Al tolerance at the seedling stage under hydroponic conditions. Substantial genetic variability in Al tolerance was observed among the studied genotypes. High estimates of heritability were obtained for both the total root length (TRL) and root regrowth (RRG), together with high estimates of genetic advance. A cluster analysis separated the genotypes into five different groups among the studied germplasm, the genotypes; NDLR-06 and EC-601861 were observed to be highly Al tolerant in terms of root regrowth under Al stress. In conclusion, the findings lreveal the complex mechanisms of Al tolerance in sunflower and may help to find new genetic resource for the improvement of Al tolerance in sunflower breeding.