PRINCIPAL COMPONENT ANALYSIS
The cumulative percentages of PC1, PC2, PC3, and PC4 in all morphological variations were 42.9%. (PC1 = 15.0%, PC2 = 10.5%, PC3 = 9.1%, PC4 = 8.3%; Table 1)
PC1 showed positive and large values above 0.7 for internode length, intercluster length, distance from the ground to the first inflorescence, plant height at flowering, plant height at fruiting/number of inflorescences, plant height at fruiting and spike length/(number of inflorescences -1).
These results suggest that PC1 is an index of plant height.
PC2 showed large positive or negative values above 0.7 for flower color value of L*, a*, b*.
PC3 showed positive and large values (more than 0.7) for days to flowering, first flowering nodal position and corolla length.
PC4 showed large positive values above 0.7 for leaf color color value of L*, a*, b*..
The scatter plots of the scores of the principal components PC1 and PC3 scores for plant shape, days to flowering, and PC2 and PC4 scores for color showed differed among the regions (Fig. 2A, 2B).
In Fig. 1A, the Tsushima populations tended to show positive values for PC1 and negative values for PC3, indicating high plant height and early flowering.
On the other hand, the Nagasaki mainland populations tended to be negative values for PC2, indicating a low plant height characteristic.
The Goto Islands populations showed no tendency for PC1 and PC3.
The Koshikijima Islands populations tended to show a positive value for PC3, indicating late flowering.
Subsequently, Figure 1B showed that the Tsushima populations tended to show positive values for PC2 and negative values for PC4, indicating a characteristic of deep flower and leaf colors.
The populations in Nagasaki mainland and Goto Islands had the characteristics which the color of flowers was light because the value of PC2 tended to show negative in those populations.
The population of the Nagasaki mainland populations and the Goto Islands populations showed a tendency toward negative values of PC2, indicating a characteristic of light flower color.
The Koshikijima Islands population showed characteristics intermediate to those of other regions.