Anther cones increase pollen release in buzz-pollinated Solanum flowers

To measure the velocity of the vibrations applied and measured, we used a Doppler laser vibrometer (PDV-100, Polytec Ltd, Coventry, UK) set to 500mm/s maximum velocity and a Low Pass Filter at 22kHz. . The force applied by the shaker was simultaneously measured using the miniature force sensor. The signals of both the laser vibrometer and the force sensor were simultaneously acquired using a two-channel NI9250 Sound and Vibration module (NI Corporation (UK) Ltd, Newbury, UK) and a USB-powered data acquisition module (cDAQ-9171, NI). For each recorded vibration, we estimated the dominant frequency (Hz) and the RMS amplitude for both the velocity (mm/s) measured in the distal anther, and the force (mN) measured in the proximate anther. To estimate the number of pollen grains released after experimental buzzes, we used a particle counter (Multisizer 4e Coulter Counter, Indianapolis, USA).