Figure 1.

Agar-containing petri dishes wrapped with low-porosity film generate ethylene. Ethylene concentrations (microliters per liter) measured using flame-ionization detector gas chromatography in the headspace of 1.5% (w/v) Bacto-agar containing petri plates, tilted at 45° over 7 d. Treatments were: Murashige and Skoog nutrients and 3% (w/v) Suc (solid lines) or zero nutrients, zero Suc (dashed lines). White symbols denote plates without seedlings and closed symbols plates with seedlings. All plates were wrapped with Nescofilm (sealed plates) except for data points represented by a black circle corresponding to samples from aerated plates (wrapped with porous surgical tape). Sealed plates containing KMnO₄ crystals (0.1 or 0.01 g) are represented by (▵) and (⋄), respectively. Day 1 corresponds to the day of germination. Error bars are se (n = 12).