Abstract: In order to evaluate the difference of fruit quality of different varieties (lines) of avocado, Fuerte, Guiyan 10, GYL-1, GYL-2 and GYL-3 were used as test materials to determine 12 quality indexes, including single fruit weight, fruit width, fruit length, edible rate, water content, soluble solid content, titratable acid content, soluble protein content, vitamin C content and crude fat content. Principal component analysis and cluster analysis were used to objectively and accurately analyze the differences of avocado fruit quality. The results showed that: ① the quality characteristics of different varieties (lines)  were significantly different, the coefficients of variation were 4.39%~4068%, the variation of crude fat content was the largest, and the variation of water content was the smallest. ② The quality of avocado was GYL-2 > Fuerte > Guiyan 10 > GYL-1 > GYL-4 by membership function value analysis; ③ The principal component analysis showed that the first four main components were extracted and the cumulative contribution rate was 100%. The first principal component was determined by titratable acid content, water content, soluble protein content and soluble solid content. The second principal component was determined by crude fat content, vitamin C content, solid acid ratio and edible rate. The third principal component was determined by fruit shape index and fruit width. And the fourth principal component was determined by vitamin C content. According to the results of cluster analysis, five varieties (lines) of avocado were divided into three groups, among which the fruit quality of group one including GYL-2, Fuerte and Guiyan 10 was better than that of GYL-1 and GYL-4 groups. To sum up, the results of membership function, principal component analysis and cluster analysis were basically the same, that is, the quality of GYL-2 was the best, that of Fuerte was the second, and that of GYL-4 was the worst. The present research revealed the differences of fruit quality among five varieties (lines) of avocado, and established a set of suitable  methods for evaluation of avocado fruit quality, which laid a theoretical foundation for sustainable development of Guizhou avocado industry.

Key words: avocado, quality trait, principal component analysis, difference analysis

摘要： 为评价不同品种（系）油梨果实品质差异，以富尔特、桂研10号、GYL-1、GYL-2、GYL-3为试验材料，测定其单果重、果实横径、果实纵径、果形指数、可食率、含水量、可溶性固形物含量、可滴定酸含量、可溶性蛋白含量、固酸比、维生素C含量和粗脂肪含量共12个品质指标，利用模糊数学隶属函数、相关性分析、主成分分析和聚类分析，客观、准确地分析油梨果实品质的差异。结果表明:①不同品种（系）油梨果实品质性状差异明显，变异系数在4.39%～40.68%之间，以粗脂肪含量的变异程度最大，含水量变异程度最小。②通过隶属函数值分析，不同油梨品种果实品质优劣依次表现为GYL-2＞富尔特＞桂研10号＞GYL-1＞GYL-4。③主成分分析表明，前4个主成分的累积贡献率达到100%，决定第1主成分的主要为可滴定酸含量、含水量、可溶性蛋白含量和可溶性固形物含量；决定第2主成分的主要为粗脂肪含量、维生素C含量、固酸比和可食率；果形指数和果实纵径对第3主成分的贡献率最大；第4主成分主要反映指标维生素C含量；根据主成分分析的综合分值，不同品种（系）排名为GYL-2＞富尔特＞桂研10号＞GYL-1＞GYL-4。④聚类分析结果显示，5个油梨品种（系）被分成3类，其中GYL-2、富尔特、桂研10号的果实品质优于GYL-1和GYL-4。综上，隶属函数法、主成分分析和聚类分析结果基本一致，即品种GYL-2果实品质最好，富尔特次之，GYL-4最差。研究结果揭示了5个油梨品种（系）果实品质的差异，建立了一套适合油梨果实品质评价的方法，为贵州油梨产业可持续发展奠定理论基础。

关键词: 油梨, 品质性状, 主成分分析, 差异分析