*3.1. Analysis of Significantly Different Architectural Traits of Spray Cut Chrysanthemum between EN2019 and EN2020*

To explore the effects of different years on architectural traits, nine architectural traits in EN2019 and EN2020 were compared, and their significance was assessed (paired-sample t tests). As shown in Figure 1, there were significant differences in plant height, total number of lateral buds, number of upper primary branches, stem diameter, primary branch diameter and primary branch length between EN2019 and EN2020, while there were no significant differences in number of leaf nodes, number of lateral flower buds or primary branch angle. Among these traits, the median plant height, stem diameter, primary branch diameter and primary branch length in EN2019 were larger than those in EN2020. The median total number of lateral buds in EN2019 was similar to that in EN2020, while the median number of upper primary branches in EN2019 was smaller than that in EN2020.

**Figure 1.** Violin plots indicating variation in architectural traits of 195 spray cut chrysanthemum varieties in EN2019 and EN2020. (**a**) Plant height; (**b**) Number of leaf nodes; (**c**) Total number of lateral buds; (**d**) Number of upper primary branches; (**e**) Number of lateral flower buds; (**f**) Stem diameter; (**g**) Primary branch diameter; (**h**) Primary branch angle; (**i**) Primary branch length. Note: \*\*\*, \*\* and \* indicate significant differences at the 0.001, 0.01 and 0.05 probability levels, respectively.

## *3.2. Descriptive Statistics of the Architectural Characteristics of Spray Cut Chrysanthemum in EN2019 and EN2020*

The basic statistical analysis results of the data of the nine phenotypic traits of the 195 spray cut chrysanthemum species in EN2019 and EN2020 are shown in Table 1. Although there were different coefficients of variation (CVs) for all the traits, the same traits

in both years showed a significant positive correlation. In EN2019, the CV varied from 12.67% to 85.84%, among which the CV of stem diameter was the smallest and the CV of number of lateral flower buds was the largest. In EN2020, the CV varied from 13.30% to 73.81%, and traits with extreme values were the same as those in EN2019. These results showed that stem diameter trait was rather stable, while number of lateral flower buds varied among the different spray cut chrysanthemum varieties. In addition, compared with the other traits, primary branch length and number of upper primary branches also was associated with larger CVs, which were more than 30%.

**Table 1.** Phenotypic characteristics of the architectural traits of 195 spray cut chrysanthemum varieties.


Note: *r* refers to the Pearson correlation coefficient between the two environments (EN2019 and EN2020). \*\* indicates a significant difference at the 0.01 probability level.
