18个木芙蓉品种与2个近缘种的数量分类和主成分分析

Quantitative classification and principal component analysis of 18 Hibiscus mutabilis cultivars and 2 related species

【目的】选取18个性状指标对18个木芙蓉品种和2个近缘种进行主成分分析和聚类分析,并进行初步分类,以期为木芙蓉在分类性状选取、亲缘关系梳理以及新品种培育等方面提供参考依据。【方法】以18个木芙蓉品种和2个近缘种为材料,首先对选取的18个性状指标进行系统的观测,并对观测数据进行R型聚类分析和主成分分析,然后对18个木芙蓉品种和2个近缘种进行Q型聚类分析。【结果】R型聚类分析的结果显示:除花径与内轮花瓣数、花瓣长与花瓣宽、苞片长与苞片宽以及柱头颜色与叶片质地的相关性较高外,其余指标均相对独立,各个性状的选取较为合理。主成分分析的结果显示:18个性状指标可综合为6个主成分,其累计贡献率达86.872%,其中以苞片大小的特征值最大,贡献率最高。Q型聚类分析的结果显示:18个木芙蓉品种和2个近缘种在不同的等级结合线处可被分为2大类、4大类或10大类,以划分为4大类最为合理,其中第1大类的共同特征为苞片平均宽度>4.3 mm且均结实,包括1个品种和2个近缘种;第2大类的共同特征为苞片平均宽度为3.0~3.8 mm且均不结实,包括3个品种;第3大类的共同特征为苞片平均宽度<2.7 mm且均结实,包括6个品种;第4大类的共同特征为苞片平均宽度<2.7 mm,不结实或少量结实,包括8个品种。【结论】苞片宽、是否结实、花径、初开花瓣主色、花瓣是否变色、花瓣指数、内轮花瓣数、花期早晚、叶色以及叶缘锯齿等性状对木芙蓉品种分类具有实际应用价值,且以苞片宽和是否结实的重要性较高,表明数量分类可作为木芙蓉品种分类的一种有效方法。

【Objective】In this research,18 Hibiscus mutabilis cultivars and 2 related species were studied.18 traits were selected for principal component analysis and preliminary classification,in order to provide a reference basis for the selection of categorical traits,phylogeny clarification and breeding.【Method】The selected 18 traits were firstly systematically observed,and the observation data was analyzed by R-type cluster and principal component analysis,and then further Q-type cluster analysis based on the initial analysis results was performed.【Result】R-type cluster analysis results proved that except for the obvious correlation between flower diameter and inner petal number,petal length and petal width,bract length and bract width,stigma color and leaf texture,other indexes were relatively independent,and the selection of each trait was reasonable.The principal component analysis results showed that the 18 traits can be integrated into 6 principal components and their accumulative contribution rate reached 86.872%.Among them,the characteristic value of bract size was the largest and the contribution rate was the highest.Q-type clustering results showed that the 18 Hibiscus mutabilis cultivars and 2 related species can be divided into 2,4 and 10 categories at different grade junction lines,and it is most reasonable to divide into 4 categories.The first category included 1 cultivar and 2 related species,which bract width was above 4.3 mm and can all fructify.The second category shared the common feature that the average width of bracts was 3.0-3.8 mm and was not fruitful,consisting of 3 cultivars.The common feature of the third category was that the average width of bracts was less than 2.7 mm and can all fructify,including 6 cultivars.The average width of bracts of the fourth category was less than 2.7 mm,and all 8 cultivars of this category produced no or little fruit.【Conclusion】In summary,the characteristics of bract width,whether it is fruitful or not,flower diameter,primary color of the petals,whether the petals change color,petal index,number of inner petals,flowering period,leaf index and jagged leaf margin have practical applications for the classification of Hibiscus mutabilis cultivars.The importance of bract width and whether it is fruitful indicates that the quantitative classification can be used as an effective method for the classification of Hibiscus mutabilis cultivars.