关键词: 观赏海棠, 品种群, 色素组分, 动态特征, 色系

Abstract: With 58 ornamental crabapple cultivars as the research object，their pigment components in flower petals at big budding stage（S₁），blooming stage（S₂）and end flowering stage（S₃）were measured. Meanwhile，the differences of pigment component among different cultivar series（or subseries）and their dynamic patterns at different developing stages were studied systematically. The research aimed to provide references for excavating and utilizing special pigment traits of ornamental crabapples，which had high content and stability of anthocyanin，and for improving flower color and oriented breeding. Based on the reflection spectrum index（RSI）obtained by Unispec-SC spectrum analyzer and the actual content of pigments by UV-2450 ultraviolet-visible spectrophotometer，the coupling functions between them for anthocyanins（Anth），carotenoid（Car）and chlorophyll（Chl）were built respectively：y_Anth = 0.014x + 0.0012（R² = 0.9974），y_Car = 0.0038x^0.3772（R² = 0.9902），y_Chl =–0.1007x² + 0.3221x–0.2169（R² = 0.8179）. Using Origin7.0 software，a set of dynamic three-dimensional diagrams of pigment component content and proportion of the 58 cultivars at the three flowering stages were constructed. The results showed that Anth was the major pigment in crabapple petals，and Car and Chl were both secondary pigments. In flowering process，Anth，Car and Chl content generally presented a tendency toward lower level，whereas the proportion of each pigment component maintained relatively stable despite the fact that the proportion of Anth declined slightly，while that of Car and Chl both rised slightly. Also，the tree diagrams of pigment component clustering analysis were constructed according to Anth content and proportion at S₂ and S₃. The results were as follows：In the genetic distances of 1.15，the 58 crabapple cultivars could be divided into five color series，i.e. white series（A），pink series（B），light reddish-purple series（C），reddish-purple series（D）and dark reddish-purple series（E），in which C，D and E series constituted a pan-reddish-purple series. Each color series or subseries had their own obvious pigment component dynamic characteristics. For instance，the pink color subseries B₂ had a higher Anth content[（0.090 ± 0.038）mg · g^-1] at S₁，but its stability was so lower（Anth content at S₂ and S₃ decreases by 83.2% and 93.3% respectively）that its valuable ornamental period was only limited before the full bloom stage（S₂）. By contrast，the pink subseries B₁ had a higher Anth content and stability than the pink subseries B₂（Anth content of B₁ was respectively 1.7 times，3.3 times and 3.2 times of B₂ at S₁，S₂ and S₃），which improved the ornamental values of B₁ subseries in a certain degree. Compared with the pink series，the pan-reddish-purple series had such much higher Anth content and stability that they maintained red or purple at the whole flowering stage，which significantly prolonged their valuable ornamental periods. For example，at S₁，S₂ and S₃，the Anth contents of D and E series were 1.8–2.0 times，3.9–6.5 times and 8.1–10 times of pink series respectively. It was worth mentioning that the Anth contents of D and E series at S₃ still reached the same level with that of B series at S₁. As for C series，it was inferior to D and E series but significantly superior to B series in Anth content and stability. Even the Anth content of the C series at S₃ reached 43.2% and 152.5% of B series at S₁ and S₂ respectively.

Key words: ornamental crabapple, cultivar groups, pigment component, dynamic characteristic, color series