HUANG Jinxia, JIANG Xin, ZHU Mingliang, YAN Liming, LI Yadong

Blueberries are native to North America and belong to the Vaccinium genus of the Ericaceae family. During the late 19th to the early 20th centuries, American agricultural scientists began systematically selecting and cultivating varieties, gradually developing the main varieties of modern commercial blueberries, including highbush and lowbush blueberries. In the 1980s, Jilin Agricultural University pioneered the introduction of highbush blueberry varieties from the United States, marking the beginning of scientific introduction and trial cultivation research of blueberries in China. Between 2000 and 2010, blueberry cultivation techniques were systematically accumulated, laying the foundation for the commercialization of blueberries. Since 2010, China's indigenous blueberry industry has experienced rapid development, characterized by a continuous expansion of cultivation areas, a significant increase in production, and the gradual establishment of independently cultivated varieties. Ziyue No. 6 is a mediumlate maturing variety of table blueberry with an excellent appearance. It was developed by Anhui Ziyue Seed Industry Co., Ltd. using the offspring of blueberry L4 imported from Peru. The breeding process commenced with sowing in an artificial climate chamber in December 2016. In 2017, the plants were transplanted into a substrate-based cultivation system. By 2018, with a focus on large fruit size, superior quality, and transportability, a comprehensive evaluation was conducted on plant morphology, flowering and growth habits, as well as fruit characteristics. Following this series of assessments, the superior individual plant designated as ZY04 was preliminarily selected. From 2020 to 2022, regional trials were carried out to evaluate the adaptability of ZY04 under the plateau monsoon climate conditions (characterized by an average annual temperature of 15.7 ℃ and annual precipitation of 1100 mm). After the thorough evaluation and analysis, it was determined that ZY04 exhibited consistent performance across groups, large fruit size, firm and crisp texture, balanced sweet and sour flavor, and high and stable yield. In 2022, the company officially submitted an application for variety protection to the relevant authorities. Subsequently, in 2024, ZY04 was granted a plant new variety right certificate by the National Forestry and Grassland Administration and officially named Ziyue No. 6. This variety reaches a height of approximately 2 meters, features an open crown, and exhibits vigorous growth. Young branches are green and smooth, glabrous, gradually turning reddish-brown and becoming rough. Leaves are oblong, acuminate, 5-8 cm long, 4 cm wide, with serrated edges. Flowers are milky white, and 1-2 cm long. Fruits are predominantly oblate in shape, with a medium-blue peel. The flesh is light green, crisp, juicy, hard-textured, and aromatic. The average fruit weight is 3.79 g, the maximum fruit weight is 7.90 g, and the fruit shape index is 0.65. The fruit stalk scars are small and can be either dry or wet. The soluble solids content is 13.30%, the hardness is 17 kg·cm-2 , and the Vitamin C content is 0.24 mg·g-1 . The variety has a long storage life, and the fruit retains a rich aroma even after prolonged storage. The fruit development period is 45 d and it matures at the mid-February in the Shilin area of Yunnan. This variety exhibits a certain level of resistance to downy mildew, powdery mildew, aphids, and thrips. However, it is essential to implement timely control measures during the early stages of gray mold, powdery mildew, aphid infestations, and thrips attacks. Ziyue No. 6 is well-suited for substrate cultivation in greenhouses located in the southwestern and northern regions of our country. Seedlings should be carefully selected based on their vigor, disease resistance, uniformity in purity, and age of 1 to 2 years. It is recommended that the row spacing and plant spacing be set at (2.5-3.0) × (0.5-1.0). Adequate irrigation should be performed both before and after planting. Daily water and fertilizer management should be adjusted appropriately according to bush growth and weather conditions, with careful control over the frequency and amount of watering and fertilization. During the vegetative growth phase, pruning primarily involves pinching to promote bushier growth, while after fruit harvest, pruning focuses on rejuvenation through cutting back to control bush size and maintain its vigor.