Data from: Interspecific hybridization transfers a previously unknown glyphosate resistance mechanism in Amaranthus species

A previously unknown glyphosate resistance mechanism, amplification of the 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) gene, was recently reported in Amaranthus palmeri. This evolved mechanism could introgress to other weedy Amaranthus species through interspecific hybridization, representing an avenue for acquisition of a novel adaptive trait. The objective of this study was to evaluate the potential for this glyphosate resistance trait to transfer via pollen from A. palmeri to five other weedy Amaranthus species (A. hybridus, A. powellii, A. retroflexus, A. spinosus, and A. tuberculatus). Field and greenhouse crosses were conducted using glyphosate-resistant male A. palmeri as pollen donors and the other Amaranthus species as pollen recipients. Hybridization between A. palmeri and A. spinosus occurred with frequencies in the field studies ranging from <0.01% to 0.4%, and 1.4% in greenhouse crosses. A majority of the A. spinosus x A. palmeri hybrids grown to flowering were monoecious and produced viable seed. Hybridization occurred in the field study between A. palmeri and A. tuberculatus (<0.2%), and between A. palmeri and A. hybridus (<0.01%). This is the first documentation of hybridization between A. palmeri and both A. spinosus and A. hybridus.

近日在帕尔默苋（Amaranthus palmeri）中首次报道了一种此前未知的草甘膦抗性机制——5-烯醇式丙酮酰莽草酸-3-磷酸合酶（EPSPS）基因扩增。该进化而来的抗性机制可通过种间杂交渐渗至其他杂草苋属物种，为其获取全新适应性性状开辟了途径。本研究旨在评估该草甘膦抗性性状通过花粉从帕尔默苋向另外5种杂草苋属物种（杂交苋A. hybridus、鲍威尔苋A. powellii、反枝苋A. retroflexus、刺苋A. spinosus、块茎苋A. tuberculatus）转移的潜力。研究以抗草甘膦的雄性帕尔默苋作为花粉供体，以其余苋属物种作为花粉受体，开展了田间与温室杂交实验。田间试验中，帕尔默苋与刺苋的杂交频率介于<0.01%至0.4%之间；温室杂交实验的杂交频率则为1.4%。多数发育至开花阶段的刺苋×帕尔默苋杂交后代为雌雄同株，且可产生有活力的种子。田间试验中还观测到帕尔默苋与块茎苋（杂交频率<0.2%）、帕尔默苋与杂交苋（杂交频率<0.01%）之间的杂交事件。本研究首次证实了帕尔默苋分别与刺苋、杂交苋之间的杂交现象。