Fig. 1.

a Average of ten samples’ (pollen tubes) lengths for different concentrations of agarose in tobacco germination medium. Error bars correspond to 2σ. b Fixed reference system measurement method (a, b) versus co-moving reference system (a′, b′) of the same pollen tube apical region. L ₀₍₁₎ and T ₀₍₁₎ stand for longitudinal and transversal amplitudes; d ₀ = 6 μm is a constant assumed radius at which T is read off in the co-moving frame. Scale bar and the arrow pointing to the origin of the fixed reference system are indicated. Calculated spatial resolution ratio equals 0.226 ≈ 0.23 μm/px