Breeding report of a new blueberry cultivar Lingwu

Lingwu is a novel northern highbush blueberry cultivar derived from Patriot seedlings. In the autumn of 2011, our team collected 230 seedlings, which were subsequently planted in the spring of 2012. By the first half of July 2015, the fruits had ripened, and a superior progeny, designated as Senmao 300, was carefully selected. Upon thorough test and evaluation, this cultivar was found to bear large, oblate, light blue berries in thick and uniformly textured clusters. The fruit are characterized by sweetness, delicate texture, juiciness, and pleasant, fragrant flavor. They also exhibit medium hardness and good productivity, making them an exceptional choice for fresh consumption. From July 2017 to July 2018, a comprehensive assessment of the traits of this cultivar and its asexually propagated progeny was conducted. The results demonstrated that the cultivars overall characteristics, including plant morphology, flowering and fruiting traits, fruit yield and quality, were consistent and stable. On July 29, 2020, this cultivar was registered as Lingwu and granted a New Cultivar Right Certificate by Chinas State Forestry and Grassland Administration (SFA). This cultivar features an upright tree body with vigorous growth. The leaf blade is elongated and oval- shaped, with an average leaf area of 14.92 cm², a leaf shape index of 1.80, and a dark green color with an entire margin. The average length of a new fruiting shoot is 11 cm, with each shoot bearing an average of 8 fruit. The fruit are oblate and densely packed on a thick and uniformly textured inflorescence that is light blue (101- A). The calyx scar is small and shriveled, and the fruit firmness is of a moderate level (2.7). The fruit have average dimen-sions of 1.4 cm × 1.83 cm, with a maximum weight of 4.03 g and an average weight of 2.99 g per fruit. The fruit contains 9.73% soluble solids (°Brix) and has relatively high acidity levels. Fruit ripening begins in early July, making this variety particularly suitable for cultivation in regions north of the Yangtze River or high-altitude zones. For optimal growth, deep, loose soils with high fertility and good drainage are required. The soil should hold moisture without waterlogging tendencies. Preferred soil textures include loam or sandy loam with an acidic pH (4.0-5.5) and an organic matter content exceeding 3.0%. Cultivation needs 600-1200 cumulative chilling hours. Prior to planting, thorough tillage to a depth of 20-30 cm, land leveling, and soil conditioning should be carried out to meet the specified physical and chemical properties. 2- or 3-year-old potted seedlings or bare-root seedlings that are at least 40 cm tall and have a main stem base diameter above 0.4 cm, are used for garden establishment. For soil and fertilizer management, soil mulching with straw, wood debris, and pine needles is applied. The thickness of the mulch should exceed 10 cm, which helps in moisturizing, increasing the soils organic matter content, and improving soils physical and chemical properties. Mulching with black sheet effectively controls weed growth. Before planting, well-fermented organic fertilizer is applied to the seedlings.