title: Root-mediated sex recognition in a dioecious tree.
abstract: Recent studies have demonstrated that plants can determine the identity of neighbouring roots (e.g., self and non-self, kin and non-kin), but whether they can discriminate by sex remains an open question. Here, we predict that dioecious plants can modulate their root performance in response to local root conditions related to sex. Female and male Populus cathayana cuttings were planted in a greenhouse in root-owner (one individual without a root neighbour) or root-sharer pairs (two individuals with roots neighbouring each other) with equal amounts of nutrients and space per plant in three combinations (females-females, males-males or females-males); root morphology, biomass and allocation were investigated. P. cathayana root-sharers altered their root growth in same-sex but not in different-sex combinations. Females enhanced root growth and allocation but decreased root proliferation (greater diameter with reduced branching and specific root length) in the presence of a female root neighbour, while males reduced root growth but increased root morphological proliferation in contact with another male. Therefore, the effect of a neighbour of the same sex differed from that of a neighbour of the opposite sex, which suggests that these plants can recognize the sexual identity of their neighbours.
authors.affiliation: Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, and College of Life Sciences, China West Normal University, Nanchong, Sichuan, 637009, China.
authors.forename: Tingfa
authors.initials: T
authors.lastname: Dong
authors.affiliation: Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, and College of Life Sciences, China West Normal University, Nanchong, Sichuan, 637009, China.|School of Urban-rural Planning and Landscape Architecture, Xuchang University, Xuchang, 461000, China.
authors.forename: Junyu
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, and College of Life Sciences, China West Normal University, Nanchong, Sichuan, 637009, China.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Liao
authors.affiliation: College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China.
authors.forename: Bin J W
authors.initials: BJW
authors.lastname: Chen
authors.affiliation: Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, and College of Life Sciences, China West Normal University, Nanchong, Sichuan, 637009, China. xuxiao_cwnu@163.com.
authors.forename: Xiao
authors.initials: X
authors.lastname: Xu
mesh_terms: D018533:Biomass; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000254:growth & development*; D032107:Populus / Q000502:physiology; D019655:Quantitative Trait, Heritable; D014197:Trees / Q000502:physiology*