USDA/ARS Plant Genetics Research Unit, 110 Waters Hall, University of Missouri, Columbia, MO, 65211, USA.
Division of Plant Sciences, 110 Waters Hall, University of Missouri, Columbia, MO, 65211, USA.
BMC Plant Biol. 2020 Feb 7;20(1):65. doi: 10.1186/s12870-020-2276-y.
Soybean is native to the temperate zones of East Asia. Poor yields of soybean in West African countries may be partially attributed to inadequate adaptation of soybean to tropical environments. Adaptation will require knowledge of the effects of allelic combinations of major maturity genes (E1, E2, and E3) and stem architecture. The long juvenile trait (J) influences soybean flowering time in short, ~ 12 h days, which characterize tropical latitudes. Soybean plant architecture includes determinate or indeterminate stem phenotypes controlled by the Dt1 gene. Understanding the influence of these genetic components on plant development and adaptation is key to optimize phenology and improve soybean yield potential in tropical environments.
Soybean lines from five recombinant inbred populations were developed that varied in their combinations of targeted genes. The soybean lines were field tested in multiple environments and characterized for days to flowering (DTF), days to maturity (DTM), and plant height in locations throughout northern Ghana, and allelic combinations were determined for each line for associating genotype with phenotype. The results revealed significant differences based on genotype for DTF and DTM and allowed the comparison of different variant alleles of those genes. The mutant alleles of J and E1 had significant impact on DTF and DTM, and alleles of those genes interacted with each other for DTF but not DTM. The Dt1 gene significantly influenced plant height but not DTF or DTM.
This research identified major and minor effect alleles of soybean genes that can be combined to control DTF, DTM, and plant height in short day tropical environments in Ghana. These phenotypes contribute to adaptation to a low latitude environment that can be optimized in a soybean breeding program with targeted selection of desired allele combinations. The knowledge of the genetic control of these traits will enhance molecular breeding to produce optimally adapted soybean varieties targeted to tropical environments.
大豆原产于东亚温带地区。西非国家大豆产量低，部分原因可能是大豆对热带环境的适应性不足。适应需要了解主要成熟基因（E1、E2 和 E3）和茎结构的等位基因组合的影响。长幼期性状（J）影响大豆在热带短日照（~12 小时）条件下的开花时间。大豆植株结构包括由 Dt1 基因控制的定长或不定长茎表型。了解这些遗传成分对植物发育和适应的影响是优化物候并提高热带环境下大豆产量潜力的关键。
开发了来自五个重组自交系群体的大豆系，这些群体在目标基因的组合上存在差异。在加纳北部的多个地点进行了田间试验，以评估开花天数（DTF）、成熟天数（DTM）和植株高度，并确定了每个系的等位基因组合，以将基因型与表型相关联。结果表明，基于基因型，DFT 和 DTM 存在显著差异，允许比较这些基因的不同变体等位基因。J 和 E1 的突变等位基因对 DTF 和 DTM 有显著影响，这些基因的等位基因相互作用影响 DTF，但不影响 DTM。Dt1 基因显著影响株高，但不影响 DTF 或 DTM。
本研究鉴定了大豆基因的主效和微效等位基因，这些等位基因可以组合起来控制加纳短日照热带环境下的 DTF、DTM 和株高。这些表型有助于适应低纬度环境，在有针对性地选择所需等位基因组合的大豆育种计划中可以对其进行优化。这些性状的遗传控制知识将增强分子育种，以生产针对热带环境的最佳适应大豆品种。
