GENETIC VARIABILITY AND TRAIT ASSOCIATIONS OF EARLY SEEDLING MORPHOLOGICAL CHARACTERISTICS IN SUNFLOWER (HELIANTHUS ANNUUS L.) ACCESSIONS FOR BREEDING SUPERIOR GENOTYPES

Abstract

Early seedling vigour is an important factor in crop establishment, resource efficiency, and final productivity in sunflower (Helianthus annuus L.). The current study examined the genetic variability and relationships among seedling morphological traits in ten sunflower accessions under controlled conditions in order to identify promising breeding material. Seedlings were grown in a completely randomized factorial design and harvested at three intervals (18, 26, and 32 days following sowing). Morphological traits such as shoot length, root length, leaf length, leaf breadth, number of leaves, number of secondary roots, fresh weight, and dry weight were measured.  There was significant variance among accessions, with G-61, A-9, G-1, G-30, and A-6 demonstrating higher performance for numerous growth parameters depending on harvest stage, but accession 017583 consistently shown poor seedling performance. Genotypic and phenotypic correlation analyses revealed considerable positive relationships between leaf characteristics, secondary root growth, biomass accumulation, and seedling vigour, implying that these traits can be increased concurrently via indirect selection. Positive correlations between fresh and dry biomass and leaf development and secondary root production emphasized their significance as dependable indicators of early growth potential. The study demonstrates that the evaluated sunflower accessions contain significant exploitable genetic variability and identifies key morphological traits that can be used as effective selection criteria for breeding vigorous, high-performing sunflower cultivars with improved establishment and productivity.