Breeding report of a new high-quality peach cultivar Shijizhixing

Abstract: Shijizhixing is a new high-quality and late-ripening peach variety derived from a cross between 21 Century and Jiucui in 2003 at experimental field. The male parent, 21 Century is a late-ripening variety with good storability, high total soluble solids and good coloration, but its poor cold resistance limits its cultivation area. The female parent Jiucui has a good storability and is cold resistant. Both of them were bred by the peach breeding team of Hebei Normal University of Science & Technology. The cross-pollination was performed in 2003, and the hybrid seeds were collected and sown in the same year. 389 seedlings were planted at experimental field in Hebei Normal University of Science & Technology, and the seedlings fruited in 2008. In the early January of 2010, the northern part of China experienced an extreme low temperature, which dropped to 21.1 degrees below zero in Changli county. Thirty-six 21 Century trees planted in the same experimental field were frozen to death, and 194 of the seedling trees were eliminated. J3-1 was selected from the survived seedling trees for its strong cold resistance and good fruit characters. From 2010 to 2020, the continuous observation was performed in Baoding, Qinhuangdao, Tangshan (Hebei province) and Beijing. In the early January of 2021, J3-1 experienced a freezing stress with the lowest temperature reached 21 degrees below zero in Changli county. The flower buds of all peach varieties except J3-1 were damaged by freezing. In a word, the fruit characters of J3-1 were consistent in the past 10 years. J3-1 has passed the examination and approval of Hebei Forest Tree Variety Committee, and was named Shijizhixing in April, 2021. The trees of Shijizhixing are moderately vigorous and open in canopy, with a smooth and gray-brown trunk, bark of which has transverse cracks in the old trees. All types of fruit branches can bear fruit. The leaves are broadly lanceolate with a short petiole. The flower buds are plump and conical in shape with extremely short pedicels about 6-8 mm. The spherical fruit is bilaterally symmetry with an average weight about 350 g. The maximum single fruit weight can be up to 589.2 g. From 2018 to 2020, the output of Shijizhixing in Department of Forestry of Mancheng was 2242 kg per 666.7 m2 , 2236 kg per 666.7 m2 , 2110 kg per 666.7 m2 , respectively. The base color of fruit is yellowish white with 75% bright red peel. Its flesh is white, also partly red when ripe. The fruit hardness is 8.9 kg · cm- 2 . The fruit is of good taste with aromatic flavor, and the soluble solids content is 16.0%. It has a good tolerance to cold and storability. The fruit growth period is 125 d. The fruit ripens from late August to early September in Qinhuangdao and Tangshan, Hebei Province. Shijizhixing trees perform well in neutral sandy soils with good moisture and fertilizer holding ability. The spacing recommended is (2-3) m × (4-5) m with opencentered training or Y-type training. The opening angle of sapling should be 30°-45°, and water supply should be controlled one month before fruit ripening. The stamens could produce viable pollen and doesnt need a pollinating tree. The trees have no special diseases and insects or pests.