Pollination biology of Amorphophallus albus (Araceae), an endemic plant in the dry-hot valley of Jinsha River

We performed a reproductive biology study on Amorphophallus albus P. Y. Liu et J. F. Chen (Araceae), an endemic species in the dry-hot valleys along the Jinsha River, within its natural habitat in Jinyang, Sichuan province and Yongshan, Yunnan province, China. Additionally, we compared hand pollination treatments of an introduced population of this species in Fuyuan, Yunnan province. The breeding system, floral odor, pollinators, and reproductive strategies of Amorphophallus albus were studied in detail. Results indicated that Amorphophallus albus was a protogynous plant species, and partly consumed by rove beetles belonging to the genera Atheta and Anotylus (Staphylinidae). Dimethyl disulphide and dimethyl trisulfide were identified as the main floral odor components by GC-MS (gas chromatography-mass spectrometry). Analyses by gas chromatography-electroantennogram detection (GC-EAD) led to a positive response by rove beetle antennas to dimethyl disulphide and dimethyl trisulfide. The artificial pollination treatments showed that artificial self-pollination and bagging did not set seed in the studied areas. These experiments indicate that Amorphophallus albus is a self-incompatible plant species, which attracts rove beetles as effective pollinators. Inflorescence odor may be an important olfactory signal for these pollinators. Based on our results, we provide basic information for the breeding of Amorphophallus albus and theoretical support for the co-evolution of plants and insects. This study aims to provide a scientific basis and theoretical guide for the effective conservation and utilization of this species.