2.3 Design of common garden experiments
Common garden experiments were conducted in a rice field in Leizhou,
Guangdong Province of China (Figure S1) both in the early and late
rice-cultivation seasons, respectively. In the experiments, 60 WR
samples were included from each population and 10 well-developed seeds
from each sample were used to determine the ratios of seed germination.
Seeds were germinated in black boxes placed in the experimental rice
field (Figure S1b). Thirty-day old seedlings (<3 seedlings
from the same sample) were transplanted to the experimental rice field.
In the experiment, each plot containing 36 seedlings was arranged with a
6 × 6 grid (Figure S1c) and 30 cm between the hills and rows. Six plots
(replicates) were included for different treatments of each WR
population. All plots were arranged in the experimental field with a
complete randomized design with 60 cm spacing between the plots. About
80 days after seed germination, panicles were enclosed in mesh nylon
bags to avoid accidental shattering of seeds (Figure S1d).