Phenotypic plasticity in a soybean cultivar with indeterminate growth type

Abstract: The objective of this work was to evaluate how branch and stem variables contribute to grain yield in individual soybean (Glycine max) plants, cultivated at different planting densities, in a modern cultivar with indeterminate growth type. A field experiment was carried out during the 2013/2014 and 2014/2015 crop seasons, in a randomized complete block design with 12 replicates, using the cultivar NK7059 RR at four planting densities: 135, 235, 315, and 440 thousand plants per hectare. Grain yield per plant was evaluated and represented phenotypic plasticity, while the number of branches per plant, percentage of grain production in branches, and separate yield components from branches and stems were considered as the independent variables. The number of pods in branches per plant was found to be the most important variable for soybean plasticity. In addition, the number of pods per plant on stems, number of branches per plant, and the percentage of grain production in branches were also associated with plasticity. Contrastingly, the number of grains per pod and the mass of a thousand grains in the branches and stems contributed little to plasticity in 'NK7059 RR' soybean.

摘要：本研究旨在探究分枝与茎秆相关性状对不同种植密度下栽培的无限结荚习性现代大豆（Glycine max）单株籽粒产量的贡献作用。本研究于2013/2014及2014/2015两个作物季开展田间试验，供试品种为NK7059 RR，采用随机完全区组设计，设置12次重复，共设置4个种植密度处理：13.5万、23.5万、31.5万及44.0万株/公顷。本研究以单株籽粒产量作为表型可塑性（phenotypic plasticity）的表征指标，以单株分枝数、分枝籽粒产量占比、分枝与茎秆的产量构成要素作为自变量。研究结果表明，单株分枝荚数是影响大豆表型可塑性的最关键性状。此外，茎秆单株荚数、单株分枝数以及分枝籽粒产量占比同样与表型可塑性显著相关。与之相反，分枝与茎秆的每荚粒数及千粒重对‘NK7059 RR’大豆的表型可塑性贡献极小。