Genetic variation for salt tolerance in sunflower (Helianthus annuus L)

Genetic variation for salt tolerance in sunflower (Helianthus annuus L.) was estimated measuring individual plant performance at the vegetative growth stage. Thirty-one half-sib families of a salt-tolerant line, HO-1, and 32 of a salt-sensitive line, SMH-24, were chosen randomly. At anthesis each population was separately polycrossed. The progeny of each half-sib family within each population was separately polycrossed. The progeny of each half-sib family within each population was subjected to 0 (control) or 125 mol m(-3) NaCl in Full strength Hoagland nutrient solution. Shoot fresh and dry weight data were used to estimate narrow-sense heritabilities within each population. Salt tolerance was heritable, with narrow-sense heritabilities estimated at 0.46 to 0.72 in SMH-24, and 0.28 to 0.47 in HO-1. Differences in heritability estimates could be related to the differential salt tolerance of the two cultivars. These results suggest that a significant advance in salt tolerance in sunflower would be expected through further cycles of selection.