EVALUATION OF THE SALT TOLERANCE OF SUNFLOWER (Helianthus annuus L.) ACCESSIONS USING STRESS TOLERANCE INDICES

Abstract Salinity poses a significant abiotic stress challenge that affects plant growth and development, ultimately reducing crop productivity. Owing to the genetic variability present in crop plants, they display a range of responses when faced with salinity stress. This diversity has allowed plant scientists to identify salt-tolerant crop varieties. As a key selection criterion, Plant breeders have been improved the salinity tolerance in different plants through prioritizing seed yield or plant vigor. The evaluation process become feasible and advantageous when crops show clear signs of the salinity tolerance at the cellular level, entire plant, or tissue levels. Salinity varies in the field; therefore, testing plants in a controlled environment with consistent saline conditions is reliable and effective. The hydroponic culture (soilless culture) method is frequently used to study how salinity affects crop plants, allowing researchers to observe the impacts of nutrient deficiencies and toxicities. In this study, 80 sunflower accessions were evaluated in a hydroponic culture for salinity tolerance. Statistical data were collected for the seedling parameters root and shoot lengths, fresh root and shoot weights, dry root and shoot weight, dry root and shoot weight, sodium potassium ratio stress indices. The 10 tolerant (A-18, A-37, A-78, A-35, A-13, A-10, A-30, A-58, A-6, A-64) and four sensitive accessions (A-28, A-80, A-73 and A-29) were carefully chosen based on computed indices from principal component analysis (PCA). In a controlled experimental assay, this study could be useful for comparing salinity indices and identifying salinity-tolerant sunflower accessions for future breeding initiatives.