Nitrogen addition affects floral and vegetative traits, reproduction, and pollinator performance in Capsicum annuum L.

作者：Rui Gao, Baoshuang Hu, Yibin Yuan, Mengying He, Ruolan Wang, Yuanxin Lou, Junpeng Mu · 发表于：Annals of Botany · 年份：2023 · DOI：10.1093/aob/mcad121 · 被引用次数：12 · 研究领域：Plant and animal studies、Plant Reproductive Biology、Plant Physiology and Cultivation Studies

BACKGROUND AND AIMS: It has been demonstrated that nitrogen (N) addition alters flower morphology, floral rewards and pollinator performance. However, little is known about the effects of N addition on plant reproduction, including fruit set and seed set during selfing and outcrossing, floral and vegetative traits, and pollinator performance. We hypothesized that N addition would influence fruit set, seed set in selfed and outcrossed flowers, the relationship between vegetative and flower traits, and pollinator performance. METHODS: A 2-year pot experiment was conducted in which Capsicum annuum was exposed to three levels of relatively short-term N supply, i.e. 0 g m-2 (no N addition, as a control), 4 g m-2 (4N) and 16 g m-2 (16N), which are equivalent to about 0-, 1- and 4-fold of the peak local N deposition. We measured flower rewards, flower morphology, flowering phenology, as well as pollinator visitation rate, fruit set and seed set by self- and outcross-fertilization of C. annuum. RESULTS: The four levels of N addition increased plant biomass, biomass allocation to flowers, flower size, stigma-anther separation, nectar production and pollen production, resulting in an increase in pollinator visitation and fruit set. Nevertheless, the control and 16 levels of N addition reduced plant biomass, biomass allocation to flowers, flower size and stigma-anther separation, and nectar and pollen production, and consequently decreased pollinator visitation and fruit set. Exclusion ...