A super-early maturing new blueberry cultivar Ruixing suitable for cluster harvesting

Ruixing is a new cultivar of Northern-highbush blueberry derived from the offspring of Bluetta. In 2009, the seeds from the offsprings of Bluetta were sown. In 2015, a superior individual plant (designated as FH12) was selected from this populations, characterized by its excellent characteristicsextremely early ripening, high productivity, and favorable fruit flavor. Then it was subsequently selected for propagation via tissue culture and cuttings. In 2019, regional trials were conducted simultaneously across three locations: Changchun, Tonghua, and Liaoyuan. During 2021 and 2022, key phenotypic traits were measured usingsamples collected from the three cultivation locations, demonstrating that FH12 exhibited superior overall performance. In 2024, this cultivar was officially recognized under the Non-Major Crop Variety Recognition Certificate of Jilin Province, with the recognition number Ji Ren Guo 2024002. The variety exhibits a small shrub-like growth habit, with both plant height and canopy spread measuring approximately 1 meter. One-year-old branches are light green, whereas three-year-old branches exhibit a grayish-brown color and a relatively rough surface texture. Leaves are alternate, simple, and short- petioled, with an ovate and asymmetrical shape. The leaf shape index is approximately 1.92. The leaves margins are entire and the leaves are green in color, and smooth on the upper surface, featuring a flat apex without curling. The lower surface is glabrous. The inflorescence is a raceme, bearing 7 to 15 flowers per raceme, and the corolla is campanulate in form. The mean individual fruits weight of this variety is 2.65 g, with the maximum recorded weight reaching 3.66 g. The fruit is oblate in shape with a shape index of 0.73. The fruit bloom (waxy coating) is of excellent quality, presenting a vibrant blue hue. The calyx basin of the fruit is of moderate depth, and the picking scar is of moderate size and dry. Upon ripening, the fruit flesh is firm, offering a pleasant balance of sweetness and acidity with a harmonious flavor profile. The soluble solids content is 12.54%, soluble sugar is 9.05%, titratable acid is 0.33%, anthocyanins is 1.75 mg · g-1 , and vitamin C is 142.6 μg · g-1 . The fruit development period is approximately 30 days, demonstrating characteristics of extreme earliness. In the Changchun region, harvest of the Ruixing variety typically occurs in late June. Each fruiting cane can produce 3 to 5 flower buds, resulting in a flower bud formation rate of 17.7%. Each fruit cluster typically bears between 7 and 13 fruits, with a natural fruit set rate of approximately 90%. The fruit clusters are densely packed, and the ripening process is consistent, making them suitable for efficient cluster harvesting. The fresh fruits exhibit a shelf life of approximately one week under ambient conditions and remains stable for up to one month when refrigerated at 4 ℃. This variety exhibits poor waterlogging tolerance and moderate drought tolerance; furthermore, to date, it has not been significantly affected by any serious diseases. This cultivar is well adapted to the three major production regions—Changbai Mountain, the Liaodong Peninsula, and the Jiaodong Peninsula. It enters full reproductive maturity in the third growing season, showing consistent fruit yield and excellent quality for fresh-market consumption. For openfield cultivation, both traditional ground planting and substrate cultivation can be adopted. For traditional ground planting, a spacing of 1.0 m × 2.5 m is recommended, and ammonium-based nitrogen sources should be used while the application of chlorine-containing fertilizers must be avoided. When the trees age, timely rejuvenation pruning or replanting becomes necessary. In winter, soil should be mounded around the plants for cold protection. For substrate cultivation, special attention should be paid to the frequency of nutrient solution supply and the EC value. After 7 to 8 years of planting, the plants need to be transplanted to the open field for re-planting, or the root system should be pruned and the substrate and container should be replaced. During winter, plants should be carefully laid down in an interlaced and overlapping arrangement, then covered with a greenhouse plastic film followed by an insulating thermal blanket to ensure successful overwintering.