Efeitos do chumbo sobre a germinação de sementes e crescimento inicial de plântulas de trigo (Triticum spp var ORS Senna)

Abstract

The study of seed germination and seedling growth of wheat in soils contaminated with lead encompasses environmental, economic, and social factors, making it particularly relevant in regions where the presence of heavy metals compromises agricultural sustainability. In this context, the present work evaluates the effects of different lead concentrations on the germination of seeds and the development of wheat seedlings. The experiment was conducted in the Seed and Grain Laboratory at the Federal University of the Southern Frontier, Chapecó campus, using wheat seeds of the ORS Senna variety. A randomized experimental design was used with four repetitions. The seeds were divided into four batches with eight repetitions of 50 seeds each, and each repetition was sown on a germination paper substrate, previously moistened with distilled water in a volume equivalent to 2.5 times the weight of the paper. The water used for soaking the four batches was supplemented with different concentrations of lead acetate, resulting in final lead concentrations of 0.0, 200.0, 400.0, and 600.0 mg L -1 , generating four different treatments. The paper rolls were kept in germinators at a constant temperature of 25±2oC and a constant photoperiod of 24 hours. Growth assessment was conducted on the fourth and seventh days after sowing, counting normal, abnormal seedlings, and dead seeds. The primary root length and the shoot length were measured using a millimeter ruler. An analysis of variance (F-test at 5%) with quadratic regression (2nd degree) was employed to analyze the variables. Based on the obtained results, it is possible to conclude that lead reduced the viability of wheat seeds, affecting variables such as germination rate, hard and dead seeds, root length, and shoot length.