CHARACTERISTIC ASSOCIATION AND PATH COEFFICIENT ANALYSIS OF DIFFERENT MORPHOLOGICAL TRAITS IN SUNFLOWER (HELIANTHUS ANNUUS L.)

Abstract

Genetic diversity for early seedling growth is a critical precondition for developing superior sunflower (Helianthus annuus L.) genotypes with improved establishment and biomass yield. The current study compared genetic variation among ten sunflower accessions (G-61, A-2, G-16, G-1, A-12, G-13, A-9, A-6, G-30, and 017583) at three seedling harvest stages: 18, 26, and 32 days after sowing (DAS). Seedling shoot length, root length, leaf length, leaf breadth, number of leaves, number of secondary roots, fresh seedling weight, and dried seedling weight were all documented. Analysis of variance indicated significant variation among accessions, harvest stages, and their interaction for various seedling parameters, demonstrating high genetic diversity and developmental-stage-dependent expression of these attributes. Accession A-9 had superior shoot growth at the first and third harvests, while G-61 had the longest shoot length at 26 DAS. G-16 had the highest fresh seedling weight, but A-6 consistently generated the highest dry seedling weight throughout the harvest phases. According to regression analysis, G-1 outperformed 017583 in terms of shoot length, root length, and leaf area, as well as G-13 in terms of secondary root development. Correlation analysis revealed that connections between morphological features changed with seedling age, emphasizing the dynamic nature of trait relationships throughout early development. Path coefficient analysis revealed that fresh seedling weight had a consistent positive direct effect on dried seedling weight across all harvest stages, whereas the direct contributions of shoot length, root length, leaf characteristics, and secondary roots varied depending on developmental stage. The results show that the studied sunflower accessions have significant genetic variety, with G-1, G-13, G-16, and A-6 emerging as attractive sources for specific seedling vigour and biomass-related parameters. These accessions could be useful genetic resources for selection and hybridization in sunflower breeding programs that aim to improve early seedling establishment and biomass buildup.