Evaluasi Karakter Fisiologis dan Hasil Tanaman Padi (Oryza Sativa L.) F2 Hasil Persilangan Tetua Toleran Merkuri

Abstract

Mercury (Hg) contamination in agricultural land is a major constraint in rice cultivation as it negatively affects plant physiological performance and yield. This study aimed to evaluate the physiological characteristics and yield of F2 rice (Oryza sativa L.) derived from crosses of mercury-tolerant parental lines. The research was conducted at the Experimental Field of the Faculty of Agriculture, Universitas Sumatera Utara, Medan, in April 2025. The plant materials consisted of ten F2 genotypes along with their reciprocal crosses derived from five rice varieties, namely IF-16, IR-64, Inpari-32, Cakrabuana, and Siganteng. The planting medium was topsoil treated with 15 ppm mercury to simulate heavy metal stress conditions. Observed parameters included chlorophyll content, stomatal density, leaf area, fresh and dry weight of shoots and roots, and yield per plant. The results showed significant differences among several genotypes and their reciprocals in most physiological and yield parameters under mercury stress. Certain cross combinations exhibited better physiological performance and higher yield, indicating the inheritance of mercury tolerance traits from the parental lines. Therefore, F2 rice genotypes derived from mercury-tolerant parents have potential as selection materials in breeding programs aimed at developing mercury-tolerant rice varieties.