2.6 Statistical analyses of data
To estimate the effects of population (the corresponding early- and late-season WR populations), population pair (CD, DC and HJ from different collecting sites) and transplant season (the EARLY and LATE rice-cultivation season) on plant growth and development during the common garden experiments, two-way ANOVA (analysis of variance) was used to determine the factors affecting the plant growth and development significantly. Four groups of ANOVAs conducted: (1) estimation of the effects of population and population pair in the EARLY rice-cultivation season (Table 1), (2) estimation of the effects of population and population pair in the LATE rice-cultivation season (Table S4), (3) estimation of the effect of transplant season and population pair in the early-season weedy rice populations (Table S5), and (4) estimation of the effect of transplant season and population pair in the late-season weedy rice populations (Table S6). The first two groups of ANOVAs aimed to estimate the differences in growth and development traits, which were measured in common garden experiments, between the early- and late-season WR populations in the early and late rice-cultivation environments, respectively. The later two groups of ANOVAs aimed to estimate the differences in growth and development of the same population in different rice-cultivation seasons.
In addition, differences included in this study were tested based on the student t test (Blalock, 1972), and the method of two-tails and equal variance test of two samples were adopted. Two-way ANOVAs and t test were both performed using the software IBM SPSS Statistics ver. 22.0 for Windows (SPSS Inc., IBM Company Chicago, IL, USA, 2010).