GENOTYPE × ENVIRONMENT INTERACTION FOR PHOSPHORUS USE EFFICIENCY IN MAIZE NATIVE TO THE P’URHEPECHA PLATEAU

Abstract

Phosphorus (P) deficiency reduces agricultural productivity. The identification and selection of stable cultivars with greater P use efficiency may represent a more sustainable solution than the one that depends only on the application of phosphate fertilizers. The genotype by environment interactions (GEI) and the stability of the P use efficiency (PUE), P acquisition efficiency (PAE) and P use efficiency (PUsE) were assessed on 25 native maize landraces and two controls. All samples were grown in five localities of the P'urhépecha Plateau of Michoacán, in soils with P deficiency simulated with reduced (25 kg P₂O₅ ha^-1) (RP) and high (50 kg P₂O₅ ha^-1) (HP) fertilization doses. The results for PUE, PAE and PUsE were analyzed by using the additive main effects and multiplicative interactions model (AMMI). Pooled analysis of variance for PUE, PAE, and PUsE showed that the effects of environments, genotypes and the GEI were significant, which indicates that the genotypes responded differentially to the changes of the environments or that the tested environments differentially discriminated the genotypes, or both. Under conditions of limited availability of P in acid soil, both PAE and PUsE were factors that explained the variation in PUE. A higher efficiency of P was associated with a better distribution of biomass of the plant and a higher rate of accumulation of P in the seed. The genotypes with higher PUE and stable in environments of reduced availability of P (RP) were Santa Clara [115], DP × Tromba [127], Macho-I-04 [234] and a regional landrace [242]. The environments of Erongarícuaro and Charahuén showed the lowest GEI, and those could be the best locations to discriminate genotypes with higher PUE. Maize germplasm from the P'urhépecha Plateau has genotypic variation and phenotypic stability for PUE in acidic soils.