不同南瓜品种的综合评价

  目的   建立一套适合南瓜Cucurbita moschata资源的评价方法。  方法   以10个南瓜品种为试材，测定植株生长、果实、质地、种子、品质等相关的30个指标，并利用主成分分析法对南瓜进行综合评价。  结果   不同南瓜品种间各性状存在显著差异。‘玩偶’‘Doll’的雌首花节位最高，‘红栗’‘Red Chestnut’和‘蜜本’‘NGMB’分枝性较强，‘日本黑’‘Black Japan’的叶柄直径、叶片显著大于其他9个品种，叶绿素SPAD值则最低，‘旭日’‘Rising Sun’和‘锦栗’‘Jin Li’的叶绿素SPAD值显著高于其他品种。‘锦栗’的可溶性糖和淀粉质量分数均最高。‘红栗’果肉色度值最高，色度角最低，周长最大，单果质量最大。奶油系列和‘黄狼’‘Yellow Wolf’果肉较硬，‘奶油NL1’‘Cream NL1’‘奶油Y’‘Cream Y’和‘黄狼’的果皮韧性差异显著。‘旭日’种子数最多，‘奶油’南瓜系列种子数较少；‘红栗’种子质量最大，且其种子的纵径和厚度显著大于其他品种。主成分分析共提取了5个主成分，累积贡献率达87.240%。  结论   以5个主成分及单个主成分所对应的特征值占提取主成分特征值和的比例作为权重，构建了南瓜综合评价模型，综合得分最好的品种为‘红栗’，‘奶油NL1’最差。

Comprehensive evaluation of pumpkin cultivars based on a principal component analysis

  Objective   The aim is to quickly perform the difference among pumpkin cultivars, a suitable evaluation system was established for pumpkin.  Method   10 pumpkin cultivars were used to determine 30 indicators relevant to plant growth, fruit, texture, seed, as well as quality characteristics. Biological characteristics were obtained by ruler etc and analysis of nutritional quality were performed according to the methods from references. Each sample was analyzed five times and each experiment was conducted in five repetition (n=5). The results were expressed as means ±SE. Statistical comparisons were made by one-way analysis of variance (ANOVA) followed by Duncan's multiple range test (P=0.05). A principal component analysis was used for a comprehensive evaluation of the pumpkin cultivars and was constructed by taking the eigenvalues corresponding to the principal components and the ratio of a single principal component to the extracted principal components.  Result   There are strong differences among pumpkin cultivars. The first pistillate flower node of 'Doll' was earlier than that of others. Also, the branchiness of 'Red Chestnut' and 'NGMB' were strong. Although the chlorophyll content of 'Black Japan' was lowest, petiole diameter and leaf size of 'Black Japan' were higher than those of the other nine cultivars. Chlorophyll content of 'Rising Sun' and 'Jin Li' was highest. As for soluble sugar and starch content, 'Jin Li' was the best among all pumpkin cultivars. The highest chroma value and lowest chroma angle were found in 'Red Chestnut' which had the largest circumference and the most important single fruit. The flesh of the Cream series and 'Yellow Wolf' was relatively hard, and the toughness was very different for 'Cream NL1', 'Cream Y', and 'Yellow Wolf'. The seed number in 'Rising Sun' was highest, but in the cream pumpkin series the seed number was small. The seed weight of Red Chestnut was heaviest; whereas, the longitudinal diameter and thickness of the seeds were much larger than other cultivars. The principal component analysis extracted a total of five principal components with a cumulative contribution rate of 87.240%.  Conclusion   The best comprehensive score was found in 'Red Chestnut'; whereas, the worst was found in 'Cream NL1'. This study provided a theoretical reference for rapid screening of germplasm resources and pumpkin breeding.