Short Communication: Variation of the genomic proportion of the recurrent parent in BC sub(1) and its relation to yield performance in sorghum (Sorghum bicolor) breeding for low-input conditions

In order to define the variation of the genomic proportion of the recurrent parent [G(RP)] and its relation to yield, G(RP) of individual BC sub(1) plants of two sorghum populations composed of a high-yielding cultivar as recurrent parent (RP) and a donor with superior drought resistance or grain quality, respectively, was estimated using AFLPs and SSRs. G(RP) in BC sub(1) ranged from 0.53 to 0.95 and averaged to 0.76 in the population (NP4453 x 'SV-2') x 'SV-2'. G(RP) varied between 0.60 and 0.86 and averaged to 0.74 in the BC sub(1) of (ICV-219 x 'SV-2') x 'SV-2'. Results show that plants with a G(RP) equivalent to BC sub(2) (0.875) or BC sub(3) (0.938), respectively, can be selected from BC sub(1). Yield performance of BC sub(1)S sub(1) families was tested in field trials carried out in South Africa. The correlation between yield and G(RP) in BC sub(1) was low. Selection according to G(RP) did not result in an effective preselection for yield.