Effects of pollination cultivars on fruit quality of Yuluxiang pear

【Objective】The study aimed to investigate the effects of different pollination cultivars on the fruit quality of Yuluxiang pear (Pyrus bretschneideri Rehder) and identify suitable pollinizers for cultivation.【Methods】Eight years old Yuluxiang pear trees were used as test materials, the impacts of seven pollination cultivars on internal quality, external quality, and volatile compounds of the fruits were studied. Correlation analysis was performed on the measured indices, and principal component analysis (PCA) was applied for comprehensive evaluation.【Results】Different pollination cultivars had impact on the external fruit quality of Yuluxiang pear. Among them, fruits pollinated with Xueqing had the largest fruit length and single fruit weight, measuring 80.80 mm and 315.87 g, respectively. Although different pollination combinations affected the sugar-acid content of Yuluxiang fruits, they did not influence the solid- acid ratio. Different pollination cultivars also had a significant impact on the stone cell and lignin content of Yuluxiang fruits. Among these, the fruits resuited from pollination with Huangguan had the highest lignin and stone cell content, 1.80% and 8.37%, respectively, while those from pollination with Xueqing had the lowest content, 1.54% and 4.17%, respectively. The fruits from pollination with Xueqing had the highest a* redness and b* yellowness values, showing a higher degree of coloration compared with the fruits from other pollination cultivars. The fruits from pollination with Suli had lower values than those from other pollinater. The Yuluxiang fruits pollinated with Xueqing and Suli had higher fruit hue angle (h°) values (186.79 and 185.54, respectively), while thoae pollinated with Dunzili had the lowest value (176.62). The anthocyanin content of Yuluxiang pear fruits pollinated with Xueqing was highest (0.08 mg · kg- 1 ), while thoase pollinated with Huangguan, Yali, and Dunzili had lower values (0.059 mg · kg- 1 , 0.061 mg · kg- 1 , and 0.060 7 mg · kg- 1, respectively). The vitamin C (VC) content of Yuluxiang pear fruits pollinated with Xueqing and Mianli was higher (0.32 mg·kg-1 and 0.29 mg · kg- 1 ), significantly higher than that of other pollination treatments. A total of 23 volatile substances were detected in the fruits of Yuluxiang pear pollinated with 7 different cultivars, among them the main volatile substances in Yuluxiang pear fruit were hexanal and m-xylene. Principal component analysis (PCA) was used to comprehensively evaluate 25 physiological indicators. The correlation analysis results showed that the longitudinal diameter, transverse diameter, and single fruit weight were significantly and positively correlated with each other. Soluble solids showed a strong positive correlation with the color indices a* and b*. Lignin content was highly significantly positively correlated with stone cell content. The ratio of solid acids and starch content showed a significant negative correlation with the ester and olefin volatile substances. Through principal component analysis, 5 principal components were extracted from the 25 quality indicators of the fruits pollinated with 7 pollination cultivars, with a cumulative variance contribution rate of 97.18%.【Conclusion】Through correlation analysis and principal component analysis, the core indicators for evaluating the fruit quality of Yuluxiang pear were selected, including fruit length and diameter, stone cells, lignin, color indicators, starch, and volatile compounds such as ketones and hydrocarbons. Xueqing could be used as the most suitable pollination variety for Yuluxiang pear in Hebei Province dut to beneficial effect on fruits.