Isolated stem culture
Uniform stems of the invasive and native species were detached from
plants cultivated in a garden. The stems were washed with tap water and
cut into 10-cm-long segments. Five or 6 segments were placed into a 9 cm
petri dish that contained two pieces of filter paper and 8 mL of
distilled water and cultured in an RXZ growth chamber (Jiangnan
Equipment Factory, Ningbo, China). The cultures were maintained at
28°C/25°C (day/night) under a light/dark photoperiod of 14:10 h,
irradiation of ~40 μmol photon m–2s–1 and 70% relative humidity for 20 days. The
survival rate, root length and electron transport rate (ETR) of the
stems in the isolated cultures were then investigated.