Blanchability of peanut (Arachis hypogaea L.) kernels: early generation selection and genotype stability over three environments

Abstract

Blanching is the removal of testa from peanut kernel by heating followed by abrasion. Blanchability is the capacity to recover kernels with all the testa removed. This study investigated the response to early generation selection for blanchability and the stability of 22 breeding lines over 3 environments.

F₂-derived families with 'good' and 'poor' blanchability were selected. BLUPs for F_4:5 lines from F₂ families were significantly correlated with the mean blanchability of F_2:3 rows. The within-family variance was mostly in 3 of the poor blanching families. In all other families, variance among lines within families was smaller than the error variance. Early generation selection was effective.

In the 22 lines × 3 site experiment, there was a high genetic correlation common to each pair of sites, suggesting that differences in blanchability are repeatable. The expression of genetic variation was much greater at Coominya, with a 5-fold greater genetic variance than at Walkamin. All 3 environments in this experiment were irrigated. Interaction may have been greater with the inclusion of rainfed environments.

Parent selection could make an important contribution to breeding for improved blanchability. Environment may not substantially affect the rank of genotypes but may affect the capacity to detect differences.