Moro Rosso Luiz Henrique, de Borja Reis André Froes, Ciampitti Ignacio Antonio
Department of Agronomy, Kansas State University, Manhattan, KS, United States.
Front Plant Sci. 2021 Sep 8;12:725767. doi: 10.3389/fpls.2021.725767. eCollection 2021.
Soybean [ (L.) Merr.] seeds are of global importance for human and animal nutrition due to their high protein and oil concentrations, and their complete amino acid (AA) and fatty acid (FA) profiles. However, a detailed description of seed composition at different canopy portions (i.e., main stem and branch nodes) is currently lacking in scientific literature. This study aims to (1) characterize seed yield and composition (protein, oil, AA, and FA) at the main stem (exploring a vertical canopy profile) and stem branches and (2) quantify the impact of canopy yield allocation on seed composition, focusing on branches as a potential contributor for higher yields. Four genotypes were field-grown during the 2018 and 2019 seasons, with seeds manually harvested from all the branches and three main stem segments (lower, middle, and upper). Seed samples were analyzed for seed yield (Mg/ha), seed size (mg/seed), protein and oil content (mg/seed) and their respective concentrations (g/kg), and AA and FA concentrations within protein and oil (g/100 g), herein called abundance. The upper main stem produced greater protein (25%) and oil (15%) content relative to the lower section; however, oil concentration increased from top to bottom while protein concentration followed opposite vertical gradient. Limiting AAs (lysine, cysteine, methionine, threonine, and tryptophan) were more abundant in the lower main stem, while the oleic/(linoleic + linolenic) ratio was greater in the upper segment. Overall, branches produced seeds with inferior nutritional quality than the main stem. However, the contribution of branches to yield (%) was positively related to limiting AA abundance and oil concentration across soybean genotypes. Future research studies should consider the morphological process of stem branching as a critical factor intimately involved with soybean seed composition across environments, genotypes, and management practices.
大豆[ (L.) Merr.]种子因其高蛋白和高油含量以及完整的氨基酸（AA）和脂肪酸（FA）谱，对人类和动物营养具有全球重要性。然而，目前科学文献中缺乏对不同冠层部位（即主茎和分枝节点）种子成分的详细描述。本研究旨在：（1）表征主茎（探索垂直冠层剖面）和茎枝上的种子产量和成分（蛋白质、油、氨基酸和脂肪酸）；（2）量化冠层产量分配对种子成分的影响，重点关注分枝作为更高产量潜在贡献者的作用。在2018年和2019年生长季将四个基因型种植于田间，从所有分枝和主茎的三个部分（下部、中部和上部）人工收获种子。对种子样品分析种子产量（Mg/公顷）、种子大小（mg/粒）、蛋白质和油含量（mg/粒）及其各自的浓度（g/kg），以及蛋白质和油中的氨基酸和脂肪酸浓度（g/100g），此处称为丰度。相对于下部，主茎上部产生的蛋白质（25%）和油（15%）含量更高；然而，油浓度从顶部到底部增加，而蛋白质浓度则呈相反的垂直梯度。限制性氨基酸（赖氨酸、半胱氨酸、蛋氨酸、苏氨酸和色氨酸）在主茎下部更为丰富，而油酸/（亚油酸+亚麻酸）比值在上部更高。总体而言，分枝产生的种子营养质量低于主茎。然而，分枝对产量的贡献（%）与大豆基因型中限制性氨基酸丰度和油浓度呈正相关。未来的研究应将茎分枝的形态过程视为一个关键因素，它与不同环境、基因型和管理措施下的大豆种子成分密切相关。
