Assessment of Content of Fat and Tocopherols in Seeds of Amaranthus in Relation to Diversified Fertilization with Macroelements
This study is based on the field experiment carried out in the years 2007-2008, on an individual farmer's field in Bodaczow, near Zamosc. The aim of the experiment was to determine the influence of different dosages of NPK on the content of fat and homologous tocopherols in the seeds of two varieties of amaranth: Rawa and Aztek. The experiment was started on brown soil made from loess, with high content of P, K and Mg, and slightly acidic reaction (pH in l mol KCl·dm-3 - 5.8). The experiment was started with split-plot method in three repetitions, and involved: two varieties of amaranthus (Rawa and Aztek), and 4 variants of fertilization with macroelements NPK (kg · ha-1) (1 - object without any fertilization, 2 - 70 N, 50 P2O5, 50 K2O; 3 - 90 N, 60 P2O5, 60 K2O; 4 - 130 N, 70 P2O5, 70 K2O). The content of fat was marked in the seed with Soxhlet's method, and α-, β-, γ- and Δ-tocopherol with high performance liquid chromatography (HPLC). The study reveals that the amount of accumulated fat in the seeds of amaranthus largely depended on the variety of the plant and variant of fertilization with macroelements. Significantly high content of fat in the seeds was found at the fourth (the highest) level of fertilization with NPK. Higher content of fat in the seeds was determined in Aztec variety than Rawa. The varieties of amaranthus varied considerably in the content of: α-, β-tocopherol and their total amount. Higher content of α-tocopherol and its higher total amount was found in the seeds of Aztek variety, rather than Rawa. The seeds of Rawa variety had significantly more β-tocopherol than Aztek variety. Fertilization with growing dosages of NPK had a significant, positive influence only on the amount of α-tocopherol and its total amount.
A study was carried out on the effect of varied NPK fertilization on catalase activity per gram fresh weight of the leaves of two varieties of amaranth, Rawa and Aztek, at different developmental stages (seedling, five-leaf, flowering and mature seed), as well as in the seeds. Amaranth was grown in a field experiment in southeast Poland, at wide-row spacing on good wheat complex soil. The following combinations of macronutrient levels were applied: I - 50 kg N ・ ha-1, 40 kg P ・ ha-1, 40 kg K ・ ha-1, II - 70 kg N ・ ha-1, 50 kg P ・ ha-1, 50 kg K ・ ha-1, III - 90 kg N ・ ha-1, 60 kg P ・ ha-1, 60 kg K ・ ha-1 and IV - 130 kg N ・ ha-1, 70 kg P ・ ha-1, 70 kg K ・ ha-1. The study showed that catalase activity exhibited a downward trend during the vegetation period of amaranth. The highest catalase activity was noted in the leaves during the first stage, ie the seedling stage. Increasing levels of NPK led to an increase in catalase activity. Leaves of the Rawa variety had higher catalase activity than those of the Aztek variety at every stage of development. The level of catalase activity in the amaranth seeds was also significantly affected by fertilization and the variety of amaranth. Higher levels of the fertilizers caused an increase in catalase activity in the seeds.