Progress of collection, conservation and innovative utilization of Morella rubra resources in the National Prunus mume and Chinese Bayberry Germplasm Repository (Nanjing)

The Chinese bayberry belongs to the genus Myrica L. in the family Myricaceae. Plants of the family Myricaceae are mainly distributed in North and South America, Europe, East Africa and East Asia. There are 4 genus and about 50 species of Myricaceae in the world, but only 1 genus and 6 species of Myriceae in China. These include Morella rubra, Morella esculenta, Morella nana, Morella adenophora, Morella integrifolia, and Morella arborescens. Morella rubra is indigenous to the temperate and subtropical mountainous regions of China, characterized by a humid climate, and predominantly found in south of the Yangtze River basin. The cultivated Morella rubra originated in southeastern China and is one of the evergreen fruit trees with a long history of cultivation. It has been domesticated and cultivated for more than 7000 years. One of its most notable features is the abundant genetic diversity among local cultivars. Morella rubra is rich in vitamins, minerals, polyphenols such as myricetin and anthocyanins, and has high nutritional and economic value. As the origin and major producer of Morella rubra, China has developed many varieties that are adapted to different environments over a long period of evolution and cultivation, forming an extremely rich germplasm resource of Morella rubra, which pro-vides an important material guarantee for the development of China’s Morella rubra industry. Germplasm resources of fruit trees are an important material basis for supporting agricultural scientific and technological innovation and the development of modern seed industry. They are strategic resources for ensuring food security, building an ecological civilization, and supporting sustainable agricultural development. The National Prunus mume and Chinese Bayberry Germplasm Repository is the most well-preserved and standardized germplasm resource nursery in China. By the end of December 2024, the national Morella rubra resource nursery had preserved 254 germplasm resources. 180 germplasm resources were catalogued and preserved within the nursery. Specifically, 149 local varieties accounted for 82.7% of the catalogued resources. Additionally, 12 cultivars comprised 6.7% , 2 wild resources constituted 1.1%, 3 imported varieties represented 1.7%, and 14 strains accounted for 7.8% of the total. Morella rubra is commonly known as bayberry. The Morella rubra nursery had preserved many big fruit varieties such as Dongkui, Heijing, Xiangshanwuzi, etc. There are some early maturing varieties preserved, such as Tezaomei, Ruansi’anhai, Zaojia, Suyang No. 5, Wang 2 and Xishanzaoshu. There are 37 white fruit Morella rubra varieties preserved, including Shuijingtou, Shuibai, Longhaibaishuijing, etc. A new variety Zijing with high quality was selected and bred in the Morella rubra nursery. Germplasm resources of Morella rubra serve as crucial materials for fundamental scientific research, new variety breeding, production, and application. The sharing and utilization of these resources can significantly advance both the scientific research and industrial development related to Morella rubra germplasm. In the past 10 years, the national Morella rubra resource nursery has supplied 1359 samples to major universities, research institutions, and enterprises for various studies including introduction observation, storage experiments, fruit quality assessment, transcriptomics, metabolomics, and others. The completion of Morella rubra genome sequencing has promoted the development and technological innovation of genomics, transcriptomics, and molecular biology of Morella rubra. The promotion and utilization of Morella rubra resources have promoted the development of genomics and molecular markers as well as the progress in basic research on the phylogenetic development and genetic diversity of Morella rubra. Concurrently, research on fruit traits has enhanced fruit quality and supported breeding efforts. Moreover, adjustments in the industrial structure of Morella rubra cultivation have facilitated the sustainable development of rural economies. The diverse cultivars of Morella rubra, including Dongkui, Zijing, Zaojia, Ruansi’anhai, Xiaoyexidi, and Mashanwumei, exhibit superior fruit quality and align with the developmental requirements of the Morella rubra industry across various production regions. These varieties have been extensively promoted in cultivation practices, significantly contributing to the rapid and sustainable economic growth of regional economies. According to the current situation of the resource nursery, we shall carry out the work in the following aspects: (1) Enhancing the collection and conservation of Morella rubra germplasm resources along with protecting their original habitats; (2) Intensifying the identification, evaluation, and utilization of Morella rubra germplasm resources; (3) Improving preservation technologies and sharing mechanisms for Morella rubra germplasm resources; (4) Strengthening professional personnel training and technical team building. This paper introduces the development status of Morella rubra germplasm resources in the National Prunus mume and Chinese Bayberry Germplasm Repository, summarizes the conservation of Morella rubra germplasm resources and the innovative utilization of Morella rubra germplasm resources, such as the development of Morella rubra breeding and the development of Morella rubra industry in the past 10 years. In addition, the article analyzes the existing problems in the preservation and utilization of Morella rubra germplasm resources and puts forward suggestions. It also prospects and plans the research direction and working content of Morella rubra nursery in the future. Meanwhile, it can provide valuable reference information for the collection, protection, innovation and utilization of Chinese Morella rubra germplasm resources and the development of Morella rubra industry in the future.