The aim of this study was to establish a standardized and unified method for identifying and evaluating jujube fruit texture quality and to provide a theoretical basis for determining the texture quality of jujube germplasm resources. The texture of 56 jujube germplasms was characterized via the texture profile analysis (TPA) method, and the texture and anatomical structure of three each of the hard- and soft-fleshed germplasms were analyzed. Cluster analysis was used to categorize the 56 germplasms into hard- (17) and soft-fleshed jujubes (39). Significant positive correlations were found between all other textural parameters of jujube fruits except adhesiveness. The hardness, springiness, and chewiness of the full-red period hard- and the soft-fleshed jujube fruit were lower than those of the half-red period. The hardness, adhesiveness, and chewiness of the hard-fleshed jujube fruits in the full-red period were 2.13–3.57, 3.00–4.99, and 4.39–9.58 times higher than those of the soft-fleshed jujube fruits, respectively. The findings of this study provide a theoretical foundation for the evaluation and classification of the texture and quality of jujube fruits and a basis for the breeding of new, high-quality jujube varieties with distinctive characteristics.

Chinese jujube (Ziziphus jujuba Mill.), an economically significant species in the Rhamnaceae family, is a popular fruit tree in Asia. The sugar and acid concentrations in jujube are considerably higher than those in other plants. Due to the low kernel rate, it is extremely difficult to establish hybrid populations. Little is known about jujube evolution and domestication, particularly with regard to the role of the sugar and acid components of jujube. Therefore, we used cover net control as a hybridization technique for the cross-breeding of Ziziphus jujuba Mill and ‘JMS2’ and (Z. acido jujuba) ‘Xing16’ to obtain an F₁ population (179 hybrid progeny). The sugar and acid levels in the F₁ and parent fruit were determined by HPLC. The coefficient of variation ranged from 28.4 to 93.9%. The sucrose and quinic acid levels in the progeny were higher than those in the parents. The population showed continuous distributions with transgressive segregation on both sides. Analysis by the mixed major gene and polygene inheritance model was performed. It was found that glucose is controlled by one additive-dominant major gene and polygenes, malic acid is controlled by two additive-dominant major genes and polygenes, and oxalic acid and quinic acid are controlled by two additive-dominant-epistatic major genes and polygenes. The results of this study provide insights into the genetic predisposition and molecular mechanisms underlying the role of sugar acids in jujube fruit.

This study investigates the effects of 1-methylcyclopropene (1-MCP) treatment on postharvest storage of winter jujube. The results indicate that after 1-MCP treatment, the pyruvate (PA) content in winter jujube decreased by 20% at 30 days compared to the control. The energy charge (EC), ATP, and ADP levels increased by 7%, 17%, and 27%, respectively. Activities of key enzymes involved in energy metabolism, including succinate dehydrogenase (SDH), cytochrome c oxidase (COX), H ⁺ -ATPase, and Ca ²⁺ -ATPase were elevated. Furthermore, the activities of acid invertase (AI) and neutral invertase (NI) were 27% and 26% lower, respectively, than those in the control. Sucrose synthase (SS) activity increased by 52%, while the activities of hexokinase (HK) and phosphofructokinase (PFK) decreased by 19% each. Activities of key antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione reductase (GR)-were significantly enhanced. Non-enzymatic antioxidants, including vitamin C (VC), flavonoids, total phenols, and reduced glutathione (GSH) contents, were effectively retained, and suppressing the accumulation of the hydrogen peroxide (H ₂ O ₂ ) and malondialdehyde (MDA). These findings suggest that 1-MCP treatment preserves the postharvest quality of winter jujube by enhancing energy metabolism, delaying sugar metabolism, and improving antioxidant capacity.

A superior cultivar of dried jujube in China is ‘Huizao’ (HZ) jujube. Nonetheless, detailed evaluations of the texture quality of HZ fruit have been the subject of few studies. Texture is a significant indicator of the sensory and processed quality of a fruit. Here, we differentiate and characterize the texture quality of HZ fruit from the four primary producing regions in southern Xinjiang, as well as develop a system for assessing the texture quality of HZ fruit. Correlation investigation indicated strong relationships between the springiness, chewiness, cohesiveness, gumminess, and hardness of HZ fruit. Furthermore, according to the factor molecules, the texture quality of HZ fruit in the four production areas was evaluated as Bazhou (1.24) > Hotan (0.773) > Kashi (−0.577) > Aksu (−0.852). RDA analysis of six texture quality parameters and 24 climate conditions identified higher mean temperature (TEM) and lower relative humidity (RHU) as the primary factors contributing to the improved texture quality of HZ fruit in Xinjiang. This study identified the variations in the texture of HZ fruit in the four primary producing regions of Southern Xinjiang. The HZ fruit in Hotan and Bazhou exhibit superior springiness and stickiness, while the fruit in Aksu and Kashi exhibit greater hardness. The texture of HZ fruit is significantly influenced by springiness, hardness, and adhesiveness, and a comprehensive evaluation model has been established through this research. This will provide a theoretical foundation for optimizing the dominant producing areas and regional production of HZ varieties in Xinjiang.

Fruit cracking in jujube is a major constraint on the sustainable development of the jujube industry. In this study, 60 mg L⁻¹ of 6-Benzylaminopurine (6-BA) was foliar-sprayed at the early fruit stage. Fruit cracking incidence was recorded during the green and white fruit periods, and these observations were integrated with transcriptomic and metabolomic analyses to explore the potential mechanisms by which 6-BA influences fruit cracking. The results showed that the fruit cracking in the treatment groups was 53% and 18% of that in the control group during the green period and the white period, respectively. In jujube peel, catalase (CAT) activity was significantly increased in the treated peel during both periods. In the peel metabolites, compounds belonging to the cytokinin (CTK) category exhibited significant accumulation in both periods. Transcriptomic analysis showed that differentially expressed genes (DEGs) were enriched in pathways related to starch and sucrose metabolism, plant hormone signal transduction, and cellular polysaccharide metabolism. These findings suggest that 6-BA treatment may alleviate jujube fruit cracking by enhancing antioxidant capacity, modulating hormone homeostasis, and upregulating genes associated with carbohydrate and cell wall metabolism.

A superior variant of dried jujube in China is ‘Huizao’ (HZ) jujube. Nonetheless, detailed evaluations of the texture quality of HZ fruits have been the subject of few studies. Texture is a significant indicator of the sensory and processed quality of a fruit. Here, we differentiate and characterize the texture quality of HZ fruits from the four primary producing regions in southern Xinjiang, as well as develop a system for assessing the texture quality of HZ fruits. Furthermore, five texture indices of HZ fruits from 109 plantations were exhaustively evaluated utilizing principal component analysis, Pearson correlation analysis, and hierarchical clustering analysis. Consequently, by the 10th, 30th, 70th, and 90th percentiles, each index was classified into five grades—lower, medium, high, and higher. Correlation investigation indicated strong relationships between the springiness, chewiness, cohesiveness, gumminess, and hardness of HZ fruits. Springiness, hardness, and adhesiveness are essential indicators that influence the texture of HZ fruits. We used clustering analysis to separate the six texture indices into three major categories (hard factor, stick-elastic factor, and adhesive factor), with indices representing hardness, springiness, and adhesiveness, respectively. Furthermore, according to the factor molecules, the texture quality of HZ fruits in the four production areas was evaluated as Bazhou (1.24) > Hotan (0.773) > Kashi (-0.577) > Aksu (-0.852). RDA analysis of six texture quality parameters and 24 climate conditions identified higher mean temperature (TEM) and lower relative humidity (RHU) as the primary factors contributing to the improved texture quality of HZ fruits in Xinjiang. This study identified the texture quality characteristics of HZ fruits in four major producing areas of Southern Xinjiang, and it offered a theoretical foundation for optimizing the dominant producing areas and regional production of HZ varieties in Xinjiang.