Populations were developed from crosses between a low Na~+ durum landrace (line 149) and high Na~+ accumulation genotypes, Tamaroi and durum landrace, line 141. Parental and progeny lines were grown in 150 mM NaCl and the 3rd leaf assayed for Na+ uptake. Sodium concentrations were smaller in line 149 compared to Tamaroi (5-fold greater Na~+ accumulation) and 141 (7-fold greater Na~+). Progeny in the F_2 generation of both populations segregated for Na accumulation in a 15 (low Na ): 1 (high Na~+) ratio (square~2_(l5:l) = 0.27 and 0.46, P -0.50ns for 149/Tamaroi and 149/141, respectively) indicating duplicate dominance epistasis arising from segregation of two interacting dominant genes. Realised heritabilities were high (h~2_r = 0.43 to 0.90) indicating good response to selection for low Na~+ accumulation. High heritability and simple genetic control of Na' accumulation suggests relative ease of selection of durum lines with low Na~+ accumulation.
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