Produção, qualidade e expressão isoenzimática de semente de trigo produzidas sob diferentes doses de boro

The use of novel technologies, like micronutrient fertilization, is necessary to achieve increased production of wheat grain. We aimed to evaluate the influence of boron fertilization on isozyme expression, germination, and yield of wheat seeds. The experiment was conducted at the seed analysis teaching laboratory and in a greenhouse, both at Capao do Leao municipality, Rio Grande do Sul state, Southern Brazil. We used wheat seeds from cultivar FUNDACEP Horizonte. The experimental design was completely randomized in a 2 x 6 factorial scheme, with two application times (sowing and tillering), six boron doses (0, 1, 2, 3, 4, and 5 kg ha-1), and four replicates. The boron source used was sodium tetraborate, which has 11.5% boron in its composition. The evaluated variables were: germination, first germination count, seed yield per plant, test weight, and thousand-seed weight. The studied isozyme patterns were: esterase (EST, EC 3.1.1.1), acid phosphatase (FAC, EC 3.1.3.2), glutamate oxaloacetate transaminase (GOT, EC 2.6.1.1), malate dehydrogenase (MDH, EC 1.1.1.37), and peroxidase (PO, EC 1.11.1.7). Boron application, at both sowing and tillering, reduces vigor and yield of wheat seeds from cultivar FUNDACEP Horizone. Isozyme electrophoretic variations are associated with boron uptake in wheat.