Abstract:

In this study，a total of 296 pear germplasms from National Horticulture Germplasm Resources Center Pear Branch Center（Zhengzhou）were collected for fruit spots observation，data collection and photography. During fruit harvesting period，the indicated pear germplasms were sampled and different fruit spot traits，including fruit spots size，fruit spots density，fruit spots height，and the fruit spots area in unit area were comprehensively analyzed. Additionally，sensory evaluation of fruit appearance quality associated with fruit spots in different pear germplasms was performed，and the apperance quality of different pear germplasms was evaluated by grey relation analysis（GRA）and cluster analysis（CA）to establish a comprehensive evaluation model for pear fruit spot traits. The results showed that the relative correlation degree of fruit spots of 296 pear resources ranged from 0.3158 to 0.6526，and the 296 resources were classified into five grades：excellent，good，medium，poor，and extremely poor. Pear varieties including‘Autumn Red’‘Silk Red’‘Red Sensatian’‘Zhongli Meicui’‘Barlett’and‘Dabali’were screened out with excellent fruit spot traits，which have good appearance quality and were consistent with the actual production fruit exterior. On the contrary，pear varieties including‘Puguali’‘Xihuamake’‘Chili’and‘Enli’were screened out with extremely poor fruit spot traits，which have poor appearance quality. Furthermore，the fruit spot traits of 296 pear germplasm resources were divided into five grades by cluster analysis，including excellent，good，medium，poor and extremely poor，which accounted for 7.8%，8.8%，37.1%，34.1% and 12.1% of the tested materials，respectively. Above all，the germplasm resources with excellent fruit spot traits will lay the foundation for the improvement of pear appearance quality，and the germplasm resources with poor fruit traits will be helpful for the investigation of the formation and regulation mechanism underlying pear fruit spots.

Key words: pear, germplasm, fruit spot, comprehensive evaluation