Breeding report of a new pear cultivar Jingmi

Pear (Pyrus spp.), with over 3000 years of cultivation history, is the third largest fruit in China with high nutritional value and economic value. As a prominent pear cultivar, Jingbaili (Pyrus ussuriensis Maxin.‘Jingbaili’) has been cherished for its high economic value and value of material cultural heritage. However, its after-ripening characteristic limits pick-your-own function, due to requirement of 2 weeks of natural after-ripening to achieve the best fruit quality. In order to improve this character, of the Fruit Tree Germplasm Innovation and Green Production Team of the China Agricultural University carried out a breeding program targeting earlier- ripening pears with superior appearance, internal quality, high yield and storage capability. In 2002, a cross was made between Jingbaili (female parent) and Nijisseiki (male parent). 562 hybrid seeds were obtained. 450 seedlings were established in 2003. In 2010—2012, one superior strain, 4-14, was selected for early flowering, reliable cropping and outstanding fruit quality. The secondary evaluation on top-grafted trees during 2012—2014 confirmed the stability of these traits. From 2015 to 2020, clonal trees were propagated by budding onto Pyrus betulaefolia rootstocks and evaluated in regional trials across Beijing, Hebei and Liaoning. The superior strain 4-14 was testified distinctive, uniform and stable through consecutive observation on its geographical adaptivity, phenological phases and fruit economic traits. It was officially named Jingmi and was registered by the Ministry of Agriculture and Rural Affairs in April 2024 (Registration No. CNA20201000017). The trees were vigorous, and upright- spreading. The one- year- old shoots were wavy with short-internode (≈3.5 cm) and densely pubescent . The leaves were 9.57 cm long and 7.64 cm wide on average, with acutely serrated margins, wide wedge-shaped leaf bases, and acuminate apices. The flower swere white, 5-7 per corymb, blooming in mid to late April. The fruit was conical in shape, the shape index was 0.93, and the average single fruit weight was 233.0 g. The peel was thin, smoothy, and golden-yellow in color at maturity, with small, dense lenticels and minimal russets. The flesh was yellowish white in color, crispy and juicy, and low in stone cells. The soluble solid content was 14.22%, the titratable acidity was 0.12%, the firmness was 3.85 kg· cm-2 . The bud burst was in early April, the fully blooming was in mid to late April. The fruits were harvestable in late August. The period of fruit development was 140 days. The fruits showed good storage capability under cold temperature storage. It could be cultivated in the areas with similar climates to Beijing-Tianjin-Hebei and Northeast China. The spacing would be 2.5 m×4.0 m, and the proper pollinizers should be Zaosu, and Yali. The spindle form should be recommended.