Faculty of Agricultural MechanisationBook 1.1 · Agricultural Engineering. Agricultural Science and Medicine. Repair and Reliability. Industrial Design. Thermotechnics, Hydro- and Pneumotechnics. Ecology and Environment Protection

FRI-8.303b-1-AMT&ASVM-02

INVESTIGATION OF THE EXPRESSION OF HETEROSIS AND DEGREES OF DOMINANCE IN TEST CROSSES OF F1 MAIZE FOR THE TRAITS: GRAIN LENGTH, LENGTH AND WIDTH ON THE EAR LEAF

Assist. Prof. Lyubomir Ivanov, PhD

Institute of Agriculture and Seed Science “Obraztsov chiflik” - Ruse Agricultural Academy - Sofia

E-mail: nslivanov@abv.bg

Abstract

Heterosis represents a major biological mechanism in increasing the productive potential of maize, having a significant impact on economically important traits such as grain yield and its related components. Extensive studies on heterosis have played a critical role in breeding programs by advancing the understanding of trait inheritance patterns in modern maize hybrids. The present study aimed to evaluate the heterosis and degree of dominance in F1 hybrids for key morphological traits, particularly grain length and pinnate leaf dimensions. Experimental trials were conducted from 2020 to 2022 using a randomized block design under non-irrigated conditions. The results showed significant phenotypic variability due to agro-climatic factors during the study period. Positive heterosis was mostly observed for leaf traits in most hybrids, while grain length showed a tendency towards negative heterosis. The findings highlight the need for continued research into genotype-environment interactions, which are vital for optimizing breeding strategies. Among the hybrids tested, AML 70 x 26 A and ABL 120 x 26 A were identified as the most promising for leaf length, while ACL 124 x 26 A and BGL 144 x 26 A showed good results for leaf width. Line 26 A demonstrated high stability in terms of the grain length trait, highlighting its potential as a parental line for future hybrid development.

Keywords

maize test crosses, inbred lines, degrees of dominance, BPH (best parent heterosis)

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