Progress of collection, conservation and utilization of peach germplasm resources at the National Grape and Peach Germplasm Repository (Zhengzhou)

Peach (Prunus persica L.) ranks among the most economically significant temperate fruit crops globally, with China universally acknowledged as its primary center of origin, domestication, and genetic diversity. For over six decades, the National Peach Germplasm Repository in Zhengzhou has been established and sustained under the stewardship of the Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences. Throughout this period, it has evolved into the world’s largest and most comprehensive peach germplasm collection, characterized by exceptional genetic diversity and high-standard conservation practices. Through persistent efforts in germplasm exploration, conservation, characterization, and utilization, the Repository has established an integrated innovation system that underpins fundamental research and breeding advancements in China while making substantial contributions to global peach science. Extensive germplasm surveys conducted since the 1970s across key ecological regions, including the Qinghai-Xizang Plateau, the Tianshan and Tarim Basin, the Loess Plateau, and various montane, which have elucidated the geographical distribution, ecological differentiation, and evolutionary relationships among wild relatives and landraces of P. persica. These long-term investigations have reinforced China’s status as the primary center of peach diversity and supplied in-valuable raw materials for genetic enhancement. Through systematic collection, international introductions, rescue-based retrieval, and national germplasm censuses, the Repository currently conserves a total of 3194 germplasm accessions, comprising 2356 living accessions and 838 seed accessions stored at -18 ℃, constituting the most comprehensive global repository of peach and related species. To ensure the stability, security, and long-term viability of conserved materials, the Repository has undergone three major phases of orchard reconstruction. These upgrades have optimized rootstock systems, mitigated replanting obstacles, enhanced orchard layout and health management, and eliminated redundant materials through phenotypic and genotypic screening. Complementary conservation approaches, including a DNA archive of over 1300 samples, constitute a multi-tiered preservation framework that integrates field orchards, seed banks, and molecular backups. This multi-tiered conservation system substantially improves the security of germplasm resources and preserves their genetic integrity, which is crucial for sustaining long-term research and breeding programs. A hallmark achievement of the repository is the establishment of a standardized system for peach germplasm characterization that aligns with international norms. The research team spearheaded the formulation of national and industry standards encompassing germplasm description, trait evaluation, SSR- based variety identification, and quality assessment for fresh consumption, processing, and ornamental applications. These initiatives have resulted in one of the most comprehensive phenotypic databases for peach, which includes data on morphology, phenology, stress resistance, fruit quality, metabolic attributes, and postharvest characteristics. Complementing the phenotyping work, large- scale genome sequencing has fundamentally transformed the depth and scope of peach germplasm evaluation. Through sequencing wild species, landraces, breeding lines, and modern cultivars, researchers have compiled the most extensive catalog of peach genomic variations to date, encompassing SNPs, InDels, structural variants, transposable element insertions, presence-absence variations, and copy number variations. Leveraging this foundation, a global peach panvariome has been assembled, providing a new conceptual framework for gene discovery in perennial fruit crops. Novel analytical strategies, including pan-GWAS (GWAS_PV) and genome-environment interaction mapping, have significantly enhanced the resolution of genetic dissection for traits governed by both genotype and ecological adaptation. These endeavors have led to the identification of 567 loci associated with major agronomic traits and the functional characterization of 27 key causal genes, representing a substantial proportion of all peach functional genes reported worldwide. Through integrated phenotypic and genomic analyses, the Repository has identified over 137 elite germplasm resources with significant breeding potential. These comprise low- chill accessions, disease- and pest- resistant lines, materials with exceptional fruit quality, red-fleshed germplasm, high-nutritional-value resources, unique fruit-shape mutants, and cytogenetic resources such as haploids and triploids. These elite accessions form essential parental pools for developing cultivars adapted to diverse production regions, resilient to climate- change scenarios, and aligned with consumer preferences. The Repository's impact on breeding innovation has been profound. Over the past three decades, a substantial proportion of major peach cultivars released in China, including nectarines, flat peaches, flat nectarines, processing peaches, and ornamental peaches, can be directly traced to parental materials conserved in the Repository. Iconic cultivars such as Zhongpan 11, Zhongyou 4, and Zhongyoupan 9 have played pivotal roles in reshaping the national industry structure and fostering the development of regional brands. Furthermore, the successful development of China's first rootstock, Zhong Tao Kang Zhen 1, resistant to replant disease, represents a significant breakthrough in rootstock breeding. In the ornamental sector, 47 flowering peach cultivars developed from repository materials have been extensively used in landscaping and ecological restoration projects. Beyond breeding applications, germplasm resources have facilitated major discoveries in peach genetics and genomics, including elucidating the evolutionary history of peach wild relatives, identifying chilling requirement genes (e.g., PpDAM6), uncovering the structural variant controlling flat peach shape (PpOFP1 with a 1.67 Mb inversion), and deciphering metabolic and quality-related regulatory networks. These advancements have supported numerous national key R&D projects, international collaborations, and high- impact scientific publications, establishing the Repository as a global leader in peach genomics and molecular breeding. Over the past two decades, this Germplasm Repository has distributed a cumulative total of 27 310 accessions to 110 recipient institutions, including universities, research institutes, agricultural technology extension stations, enterprises, cooperatives, and individual growers. Looking ahead, the repository is well positioned to enhance its global impact by strengthening the acquisition of international germplasm, advancing cryopreservation and tissue- culture backup systems, and applying AI-enabled multi-omics integration to accelerate gene identification. Simultaneously, the profound cultural significance of peach in China, associated with longevity, harmony, and prosperity, creates opportunities to integrate germplasm conservation with cultural heritage preservation, science communication, ecological tourism, and rural revitalization. In summary, the National Peach Germplasm Repository (Zhengzhou) has established a globally leading, comprehensive system that spans germplasm exploration, secure preservation, standardized evaluation, genomic mining, breeding innovation, and industrial application. Its accomplishments provide a strategic foundation for safeguarding China's seed sovereignty, advancing global peach research, and promoting the high-quality and sustainable development of the peach industry amidst climate variability and future agricultural challenges.