On February 20, 2025, the first batch of early-maturing materials from the double haploid (DH) winter wheat generation advancement trial, planted by the Peking University Institute of Advanced Agricultural Sciences at the Sanya Winter Nursery in Hainan, reached maturity and was successfully harvested. This achievement marks a significant breakthrough in winter wheat breeding research, opening a new pathway for rapid breeding and germplasm innovation, which holds profound implications for ensuring national food security.

On November 13, 2024, about one month later than the normal sowing time in Shandong, the research team directly sowed 126 double haploid (DH) winter wheat seed lines in the breeding trial fields in Sanya, Hainan (for details, see the earlier report: Breakthrough Progress in the Propagation and Evaluation of Winter Wheat DH Lines at the Sanya Breeding Station, link: https://en.pku-iaas.edu.cn/NU/1867.html ). Over the following three months, the researchers meticulously observed and managed the wheat seedlings. However, heavy rainfall in Sanya during October and November 2024 led to excessively high soil moisture levels, which posed significant challenges to seedling emergence and early growth, making the first-generation advancement of double haploid winter wheat particularly difficult.

Under the careful management of the research team, the early-maturing varieties finally matured on February 20, 2025, nearly four months earlier than winter wheat sown in October in Weifang, Shandong. During the generation advancement process in Sanya, these double haploid winter wheat lines exhibited significant phenotypic traits that were difficult to observe in Weifang, particularly in terms of maturity and rust resistance, with notable differences among the materials. Among them, the superior lines displayed robust plants, vigorous tillering, and large, well-filled spikes, providing rich material for selecting new varieties with exceptional traits surpassing those of both parent lines. Preliminary results indicate that the germinated seed vernalization and direct seeding technology for winter wheat is feasible in Hainan and other warm regions. The successful application of this technology will save significant time and labor for winter wheat generation advancement in southern regions, greatly advancing winter wheat germplasm innovation.

Figure 1: Growth and Harvest of Winter Wheat DH Lines at the Sanya Winter Nursery

Winter nursery in Hainan is a critical component of agricultural research in China. Leveraging Hainan’s unique tropical climate, it enables generation advancement of crops, significantly shortening breeding cycles. Over the years, numerous researchers have worked diligently here, cultivating a large number of superior varieties. However, winter wheat flowering requires a low-temperature vernalization stage, which Hainan’s winter temperatures cannot provide. Traditionally, winter wheat seedlings, after undergoing vernalization, are transplanted to Hainan in late autumn or early winter to complete their growth. However, this method is costly, time-consuming, and labor-intensive, making it difficult to scale for large populations. Therefore, the institute’s innovative germinated seed vernalization technology and cultivation methods are of great significance for winter wheat breeding.

Building on the initial trial, the Crop Genetics and Breeding Platform continues to optimize wheat vernalization methods and planting management practices. On January 11, 2025, the second batch of winter wheat DH lines was sown, showing uniform emergence, rapid growth, strong tillering, and clear segregation of agronomic traits. Many materials entered the flowering stage just 40 days after sowing, and seeds from early-maturing materials are expected to be harvested within three months. This will significantly reduce the cost and improve the efficiency of winter wheat generation advancement in southern regions (as shown in Figure 2).

 Figure 2: Growth and Performance of First and Second Tial of Winter Wheat DH Lines at the Sanya Breeding Nursery

A representative from the Peking University Institute of Advanced Agricultural Sciences stated, “The successful cultivation and maturation of winter wheat at the Hainan Winter Breeding Nursery is of great significance. Not only does it shorten the breeding cycle—compressing what used to take several years into a much shorter timeframe—but it also enables the selection of varieties better adapted to complex environments, providing a strong guarantee for addressing food security challenges in the context of global climate change.”

Looking ahead, the Peking University Institute of Advanced Agricultural Sciences will continue to increase investment in winter wheat breeding research, further optimize cultivation techniques, and explore more methods to utilize Hainan’s light and heat resources. At the same time, it is hoped that this breakthrough will attract more researchers to join the field of winter wheat breeding, contributing collectively to China’s food security and agricultural modernization.