Genotype-by-environment interaction affects the essential mineral composition of peanut (Arachis hypogaea L.) kernels

The concentrations of 15 essential minerals (B, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Se, and Zn) in kernels of nine diverse peanut genotypes, which were cultivated in five distinct growing environments, were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and -mass spectrometry (ICP-MS). The effects of genotype, environment, and genotype-by-environment (G × E) interactions were significant (P < 0.05) for all elements excluding Cr. Genetic control of mineral composition was demonstrated by large (P < 0.05) genotypic differences in Ca, Mo, K, Na, and P contents, and clustering of some genotypes in environment-centered principal components analysis (PCA) along axes comprising both macro (Ca, Mg, P, and K)- and microelements (Co, Cu, Fe, Mn, and Zn). Mo and Na concentrations were strongly influenced (P < 0.05) by the growing environment, with very high levels measured in samples from Bundaberg. The results confirm that that there is breeding potential for several important minerals in peanuts, although significant G × E interactions will complicate the response to selection. From a practical viewpoint, combining genetic improvement with agronomic management may be a useful strategy to consistently achieve desirable mineral concentrations in peanut kernels.