Cultivation history, utilization status and research progress in green jujube (Ziziphus mauritiana Lam.)

Green jujube (Ziziphus mauritiana Lam.), a notable species of the genus Ziziphus within the family Rhamnaceae, is typically a small evergreen tree or a large shrub with numerous branches, though it can occasionally grow into a tall arbor tree. It is one of the oldest cultivated fruit crops in the world, with a history of utilization and cultivation dating back approximately 11 000 years ago to the Neolithic Age on the Indian subcontinent; hence it is also known as“Indian jujube”or“ber”. Renowned for its high nutritional and medicinal value, green jujube is considered superior and rare fruit in tropical and subtropical regions. Coupled with its strong adaptability to the environment, easy management, minimal input requirements, and high drought, flood and salt tolerance, it is widely distributed in over 100 countries or regions across five continents: Asia, Africa, Oceania, North America, and South America. In China, green jujube is consumed as a rare tropical fruit for its delightful taste and texture, characterized by crispness, juiciness, and sweetness. However, its role is even more crucial in arid and semi-arid tropical regions such as India, Pakistan, and Africa, where it supports local livelihoods through its serv- ing as a critical source of food, nutrition, and income for rural communities with its environmental resilience, and low-input cultivation requirements. Recent data indicate that a global annual production of green jujube exceeds 900 000 tons. Among the major producers, the cultivation area of China is 21 000 hectares with an annual yield about 200 000 tons, 90 000 hectares in India with annual yield approximately 700 000 tons, and 5425 hectares in Pakistan with an annual yield about 28 000 tons. Therefore, in terms of economic, ecological, and social value, green jujube is vital species within the large family Rhamnaceae, second only to the common jujube (Z. jujuba Mill.) in importance. Despite its considerable scale of cultivation worldwide, green jujube remains a“neglected and underutilized plant species”, receiving limited attention from policies, research, and markets. Firstly, over the past decades, green jujube has undergone significant transformation through genetic improvement and selective breeding efforts by horticultural experts, and cultivated varieties have diverged markedly from their wild relatives. Many characteristics of cultivated varieties have changed considerably, with notable variations including larger leaf size, diminished stipular spines, larger fruit size and accelerated growth rate. By contrast, germplasm from the Indian subcontinent, the center of origin, largely retains wild characteristics. The review further highlights the diverse uses of green jujube, as fruit and food, and means of livelihood. In particular, the cultivation of green jujube is vital for maintaining the normal life of local people living in undeveloped regions of arid and semi-arid tropical, mitigating the impact of climate change and alleviating the food crisis. Fundamental research on green jujube, however, still needs to be strongly strengthened because the past studies focused mainly on fields such as photobiology, palynology, tissue culture, cytogenetics, molecular marker technology, post-harvest physiology, omics research, ecology, biomedicine and natural products. The green jujube has a long history of use in traditional medicine across China, India, and Pakistan, and its fruit, seed, leaf, bark, and root all employed for therapeutic purposes. Recent phytochemical studies through modern chemical analysis techniques to elucidate the bioactive compounds of green jujube have been continuously emerging. Bioactive compounds such as polyphenols, flavonoids, alkaloids, glycosides, tannins, and saponins, with demonstrated pharmacological activities including antidiabetic, anti-inflammatory, and antibacterial properties, have been found in the various parts of green jujube. Pharmacological studies on natural extracts from different parts of green jujube also indicate that their functions such as antioxidant, anti-cancer, antidiabetic, wound healing, and immunomodulation. As expected, green jujube can serve as a natural product for artificially synthesized chemicals in medicine, petrochemicals, food, and environmental protection industry due to its many bioactive compounds, meeting with the current concepts of environmental protection and sustainable development, and therefore it has broad application potential in the industrial field. Furthermore, it is an ideal tree species for local ecological agriculture and the conversion of farmland to forests. A landmark breakthrough was achieved in 2024 when haplotype-resolved, telomere-to-telomere (T2T) genomes of green jujube were successfully assembled. This remarkable advancement has greatly facilitated research endeavors in the field of molecular biology, opening new avenues for the exploration and utilization of this valuable species. Therefore, there is an urgent need to carry out more systematic and in-depth exploration to provide a solid scientific foundation and technical support for the healthy development of the green jujube industry. However, the green jujube industry faces multiple challenges, including the lack of systematic germplasm resource surveys, poorly defined variety systems, limited region-specific cultivars, extensive and non-standardized cultivation practices, and insufficient post-harvest infrastructure. These lead to inconsistent fruit quality, high losses, short shelf life, and limited market reach. To support sustainable development of the green jujube industry, we propose the following integrated strategy: (Ⅰ) Strengthen germplasm collection, evaluation, and breeding of high-quality and stress-resistant varieties adapted to different ecological regions. (Ⅱ) Develop and extend standardized cultivation protocols, including integrated water-fertilizer management, green pest control, and proper training systems. (Ⅲ) Improve post-harvest handling, cold chain facilities, and preservation technologies to reduce losses and extend marketability. (Ⅳ) Promote deep processing and high-value product development, such as functional foods, fruit wines, and nutritional extracts. (Ⅴ) Enhance basic research using multi- omics and genomics to uncover molecular mechanisms underlying key agronomic and nutritional traits. (Ⅵ) Boost international cooperation under South-South collaboration frameworks to share improved varieties, cultivation techniques, and processing technologies.