Germinação após alagamento, fenologia, morfologia e bioquímica de sementes de Campsiandra angustifolia Spruce Ex Beth

Abstract

Periodic flooding, a characteristic of Amazonian riparian forests, plays a central role in the ecological dynamics of these environments, but also poses challenges for plant species. The study involved the manual collection of Campsiandra angustifolia Spruce ex Beth fruits from 10 mother trees located on the banks of the Xingu River in Altamira. After the fruits had naturally opened, the seeds were evaluated for their characteristics, including measurements of length, width, thickness and weight. The water content of the seeds was also determined and biochemical analyses were performed, such as the quantification of proteins, amino acids and soluble carbohydrates. Two experiments were conducted to evaluate seed germination under flooding conditions, the floating time and post-flooding germination, with different flooding periods. The seeds were characterized as large, flat, dark brown in color and smooth in texture. In terms of size, they are on average 45.16 mm long, 52.02 mm wide, 7.70 mm thick and weigh 6.82 g. The seeds present an average of 17.6164 mg PRT/gDM for total soluble proteins. Among the protein fractions, glutelins presented the highest concentration, followed by prolamins, albumins and globulins. Total soluble amino acids presented a concentration of 65.5260 mg AA/gDM. As for sugars, the values of total soluble sugars (AST) and reducing sugars (RS) were 66.0156 mg AST/gDM and 61.9131 mg RS/gDM, respectively. Although all the seeds initially floated and later sank in the water, the environment did not provide the necessary conditions for germination. However, the results indicated that C. angustifolia seeds have a high germination capacity after short periods of flooding (15, 30 and 45 days). However, in longer periods of flooding (60, 75 and 90 days), germination was progressively reduced. The absence of significant effects of flooding on seedling growth variables indicated that, once germinated, they can develop relatively uniformly under different initial flooding conditions.