2.3 Harvest and measurement
The plant materials were harvested on May 7th, 2014
after 106 days of growth when the plant vegetative parts entered the
decaying process. First, the fruit sets were collected. Second, all
turions in each mesocosm were collected. The number of fruits and
turions were counted. The scale leaf number of each turion was recorded.
Then, the biomass of fruits and turions was determined after ovendry at
70 ℃ for 48 h. Since the scale leaf number of turion ranged from 1 to 8
in the present experiment, the turions were divided into two groups
based on the scale leaf number – the oligophyllous turion
(the turion with scale leaf number
≤ 4) and the pleiophyllous turion (the turion with scale leaf number
> 4). This classification method for turion has been
certified to be effective in discriminating its fitness since scale leaf
number has a direct correlation with the turion sprouting potential
(Jian et al., 2003; Qian et al., 2014). The percentage for each group
was calculated.