Breeding report of a new early ripening pear variety Zaoyu

Abstract: Zaoyu is a new early ripening pear cultivar with quality fruits bred from the cross of Ganlizao 6 × Huangguan. The cross was made in 2009 and it was selected as a promising strain in 2015. The variety comparison tests and production adaptability tests were carried out with Zaosu pear as control from 2016 to 2020. It performed well in the field trials for the early ripening, superb quality, high and stable yield, strong resistance to adversity, wide adaptability, and excellent comprehensive traits. It passed the validation of forest tree species in Gansu Province in December, 2020 and was registrated by the Ministry of Agriculture and Rural Affairs as non-major crop varieties in January, 2022. In Zhangye area of Gansu Province, Zaoyu blossomed in late April and the fruits ripened in early August. The fruit development days were about 100 days, and the fruits ripening date was about 20 days earlier than that of Zaosu. The fruit was flat or round, with greenish- yellow skin. The average single fruit mass was 280.9 g. The fruit surface was smooth and clean, with no or very few rust spots and tiny fruit spots. The flesh was creamy white, fine, crispy, juicy, sour sweet and aromatic, with very few stone cells. The fruit heart was small. The soluble solids content was 12.4%-14.3%, soluble sugar content 8.4 g · 100 g^{- 1}, ti-tratable acid content 0.162 g·100 g^-1, vitamin C content 4.0 mg·100 g-1 pulp. The fruit quality was excel-lent. The shelf life of the fruits was 20 days and the fruits could be stored for more than 120 days under refrigerated conditions. The tree of the variety had a moderate growing vigor with high budding rate, low branching force, easy flowering, abundant spurs, high fruiting rate and strong continuous fruiting ability. It would be suitable for close planting cultivation and be easily maintained in cylindrical shape at full fruiting stage.