广州地区19个引进龙眼品种果实品质的评价与分类

对广州地区引进的19个龙眼(Dimocarps longan)品种的果实品质进行了评价与分类研究。结果表明：在表观性状方面，除品种间肉质、果形差异较大外，其它性状差异不大，部分性状之间具有一定的关联性；小果或薄皮的品种一般可溶性固形物含量较高，薄皮、厚肉或横扁的品种一般可食率较高。运用分层聚类的方法，依据各品质指标将品种划分为3类; 运用基于主成分分析的因子分析法，将8个品质指标用3个主成分来表示(累计贡献率达88.27%)；确定简化后的品质评价指标为单果质量、果形指数、可食率和肉厚率，并依据因子得分和简化指标对19个品种进行聚类，两种聚类结果基本一致。

Evaluation and Classification on Fruit Quality of 19 Varieties of Longan Introduced to Guangzhou

Longan fruits of 19 varieties introduced to Guangzhou were compared and evaluated in the characteristics of fruit quality. The results showed that there were no significant differences in most of the apparent characteristics among the varieties except for the fruit shape and flesh texture, and there were also some correlations between some of the characteristics. There were significant negative correlations between fruit size and total soluble solids (TSS) content, as well as between skin thickness and TSS. The fruits with thin skin, thick pulp or with the shape of oblate spheroid in transverse were positively correlated to the high edible rate. The 19 varieties were classified into 3 clusters using a hierarchical clustering method and evaluated according to the 8 quality indices. By performing a factor analysis based on the principal component, the 8 quality indices were represented with 3 principal components (their cumulative contribution reached 88.27%). It was concluded that the simplified evaluation indices included mass per fruit, fruit shape index, edible and pulp thickness rate. Further more, the clustering results of 19 varieties according to the factor scores and the simplified indices were coincident with each other.