2026/06/23 by Hassan Noorinezhad, Khalil Alami-Saeid, Shahab Sadat · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Crop Yield and Soil Fertility #Genetic Mapping and Diversity in Plants and Animals #Genetics and Plant Breeding
paper · pdf · doi:10.31285/agro.30.1838
openalex publication_date 2026/06/23 · openalex created_date 2026/06/24 · openalex updated_date 2026/06/28
Khuzestan province lacks improved cultivars of maize adapted to its extreme heat and drought. The present study aimed to evaluate the genetic parameters and general combining ability of the promising lines of maize produced in Khuzestan using the top cross method. To identify traits influencing grain yield and improve local maize lines, 289 Khuzestan-bred lines were crossed with SC704 and evaluated over two cropping seasons (summer 2016 and spring 2017) at Dezful Agricultural Research Center. The experiment employed a 17×17 simple lattice design with two replications. Traits measured included plant height, ear length, ear diameter, grain depth, number of rows per ear, number of grains per row, 100-grain weight, grain yield, biological yield, and harvest index. Genetic parameters were estimated using ANOVA and general combining ability (GCA) analysis. Findings showed significant genetic diversity among maize lines for most traits except ear length, number of rows per ear, and grains per row. Combined analysis confirmed significant genotype effects for all traits (P<0.01), with significant genotype × season interactions, indicating differential responses between seasons. Broad-sense heritability ranged from 12.1% (ear diameter) to 97.7% (biological yield). The largest genetic advances were recorded for plant height (40.0 cm) in summer and biological yield (8,239.4 kg ha⁻¹) in spring, demonstrating ample additive genetic variation. Different lines were superior across seasons, confirming strong seasonal differentiation in trait expression and adaptive potential. Lines combining high yield and 100-grain weight with reduced plant height are promising parental candidates for developing stress-tolerant, high-yielding maize cultivars.