RAPID SCREENING OF ALUMINUM TOLERANCE IN MAIZE USING HEMATOXYLIN STAINING

Abstract

Developing aluminum (Al³⁺)-tolerant maize genotypes is an important objective in breeding programs for acidic soils. Rapid and reliable screening methods are required to identify tolerant genotypes at the seedling stage. This study evaluated the response of ten maize lines to Al³⁺ stress using a nutrient solution containing 10 ppm Al³⁺ combined with hematoxylin staining. The experiment was conducted from March to May 2025 at the Plant Breeding and Seed Science Laboratory, Faculty of Agriculture, Hasanuddin University, Makassar, using a completely randomized design (CRD)  with three replications. Data were analyzed using analysis of variance, heritability, correlation, and cluster analysis. Hematoxylin staining classified the genotypes into four tolerance categories, consisting of 10% very tolerant, 30% tolerant, 60% comparatively tolerant, and no sensitive genotypes. Cluster analysis grouped the ten maize lines into three major clusters, indicating phenotypic variation in their responses to Al³⁺ stress. Among the evaluated lines, G1 exhibited the highest level of tolerance based on hematoxylin staining and cluster analysis. These findings indicate that hematoxylin staining provides a useful preliminary approach for distinguishing phenotypic responses among maize lines exposed to aluminum stress.