关键词: 观赏海棠, CIELCH 色空间, 花色参数, 频率分布, 聚类分析

Abstract: With 97 ornamental crabapple cultivars as the research object，its flower color parameters
at big budding stage（S₁），blooming stage（S₂）and end flowering stage（S₃）were measured using X-Rite
chromatic meter，and the flower color relation among different cultivar series（or subseries）and dynamic
pattern of the flower color parameters distribution at different developing stages were studied
systematically. The research aimed to provide reference for tapping and establishment of special traits of
ornamental crabapples and for breeding and selection of special flower color. Also，the research aimed to
provide method reference for other flowering species study. Using Origin7.0 software，a set of dynamic
three-dimensional color parameters distribution diagrams of the 97 cultivars in the CIELCH color space at
the three flowering stages，were constructed. The results showed that，in the flowering process，color
parameter sites in the three dimension of L *，C * and h * presented a certain rule in spatial distribution and
moved regularly during the flowering process. In L * and C * dimensions，the L * values of all cultivars
increased continually whereas C * values decreased. As a result that the percentage of cultivars with higher
L * value and lower C * value increased significantly. In the h * dimension，h * value of most cultivars showed
a trend of increase during the flowering process and ratio of cultivars distributed in the red region（h * value =
0 to 20°）decreased from 85.6%（at S₁）to 52.6%（at S₃）whereas ratio of cultivars distributed in the yellow
region（h * value = 90° to 110°）increased from 2.1% up to 28.9%. Also，using software SAS 6.12，the tree
diagram of color clustering analysis was constructed according to flower color parameters in the CIELCH
color space at S₂ and S₃ flowering stages. The results as follows，in the genetic distances of 2.17 and 1.69，
the 97 crabapple cultivars could be divided into three color series and six color subseries，i.e red purple
series（including red purple，dark red purple and greyed red purple subseries），pink series（including pink
and white pink subsieries）and white series. Each color series or subseries had their own obvious colour
parameter characteristics. For the three color series，there existed significantly differences in color fading
degree and rhythm during flowering process. The white color series of cultivars faded fast and sharply
from red purplish（at S₁）to white（or slightly spotted with pink）（at S₂）and then to white（at S₃）. The
pink color series of cultivars faded greatly and at a constant speed from purplish（at S₁）to pink（at S₂）
and then to light pink（or close to white）. The red purple color series of cultivars faded greatly from
purplish red（at S₁）to purplish red（at S₂）and then to light purplish red（at S₃），but its total dilution degree
significantly was lower than that of pink series. In the six color subseries of cultivars，the dark red purplish
color subseries（A2）and red purplish color secondary subseries（A1-1）have stronger colour stability，
continually maintaining a high color chroma value，in contrast with the pink color subseries（B1）.

Key words: ornamental crabapple, CIELCH color space, flower color parameters, frequency
distribution, cluster analysis