Variations in Morphological Characters and Antioxidant Potential of Different Plant Parts of Four Ziziphus Mill. Species from the Cholistan

Genus Ziziphus (Z.) contains various important species in tropical and subtropical regions that are globally famous for their food and medicinal uses. However, no comprehensive study was available on the morphology and phytochemistry of Ziziphus species, mainly under different growth conditions, i.e., irrigated and desert (Cholistan). Therefore, this study was carried out to evaluate the morphological and phytochemical characteristics of Ziziphus species, i.e., Z. jujuba, Z. mauritiana, Z. spina-christi, and Z. nummularia, found in the irrigated and desert conditions. Our results revealed significant variations for most of the measured parameters, showing a large-scale diversity among Ziziphus species under irrigated and desert conditions. Specifically, Ziziphus species showed better morphology of all measured parameters of leaves and fruits under irrigated conditions compared to desert conditions, indicating that the optimum water availability in irrigated conditions improved the morphological parameters of Z. species. Meanwhile, among all Ziziphus species, the maximum leaf length (7.4 cm), leaf width (4.1 cm), leaf area (30.6 cm²), and leaf petiole length (1.3 cm) were observed for Z. jujuba, and the highest leaf dry weight (55.4%) was recorded for Z. mauritiana. Similarly, the highest fruit length (3.9 cm), fruit stalk length (1.5 cm), fruit diameter (3.6 cm), fruit width (3.8 cm), fruit area (66.1 cm²), seed length (2 cm), and seed diameter (1.1 cm) were measured for species Z. jujuba, while the maximum fruit dry weight (49.9%) and seed width (1.4 cm) were recorded for species Z. nummularia. Interestingly, compared to irrigated conditions, higher values of bioactive contents, i.e., phenol, flavonoid, and antioxidant activity, in fruits and leaves of Ziziphus species under desert conditions indicated the positive impact of desert climate on the phytochemistry of the Z. plants. Among Ziziphus species, Z. nummularia accumulated the maximum fruit phenols (304.4 mg GAE/100 g), leaf phenols (314.2 mg GAE/100 g), fruit flavonoids (123.7 mg QE/100 g), and leaf flavonoids (113.4 mg QE/100 g). Overall, this study demonstrated the significant morphological and phytochemical variations of the Ziziphus species under irrigated and desert conditions, which could be utilized for future studies to improve the production and medicinal potential of the Ziziphus, especially in desert areas.

Morphological characteristic of fruit, drupes and seeds genotypes of Ziziphus jujuba Mill

The aim of this work is to discriminate 28 Ziziphus jujuba Mill. genotypes (ZJ-01 - ZJ-28) based on weight and morphological characteristics of fruit, stones and seeds. These genotypes maintained in a clone repository (Nova Kachovka, Ukraine) were chosen for investigation as potential species for cultivation and use in Slovakia. The fruits were collected at the period of their full maturity (October); their morphometric parameters were following: weight from 2.90 g (ZJ-13) to 28.99 g (ZJ-22), length from 20.73 mm (ZJ-08) to 44.84 mm (ZJ-04), and width from 16.64 mm (ZJ-13) to 38.87 mm (ZJ-22). Isolated stones were also analysed, and their weight was from 0.173 g (ZJ-07) to 0.731 g (ZJ-20), length from 12.84 mm (ZJ-08) to 28.67 mm (ZJ-04), and width from 5.06 mm (ZJ-07) to 9.74 mm (ZJ-01). The weight of the seeds was ranging from 20.00 mg (ZJ-25) to 69.11 mg (ZJ-12), length from 7.24 mm (ZJ-15) to 11.85 mm (ZJ-04), and width was from 3.86 mm (ZJ-05) to 6.84 mm (ZJ-12). Significant differences in the size, shape and color of fruits, stones and seeds were also identified. The pulp, seedless stones and seeds constitute 92.81% (ZJ-26) - 98.32% (ZJ-04), 1.36% (ZJ-04) - 6.27% (ZJ-20), and 0.25% (QA-24, QA-25) - 1.21% (ZJ-16) of the total fruits weight, respectively The shape index of the fruits was found in the range of 1.04 (ZJ-08) to 2.00 (ZJ-12 and ZJ-25). The shape indexes of stones and seeds were found ranging from 1.74 (ZJ-08) to 4.53 (ZJ-05) and from 1.32 (ZJ-23) to 2.74 (ZJ-04), respectively. The relative weight of pulp was determined in the range from 92.76% (ZJ-13) to 98.32% (ZJ-04) and the relative weight of seed was determined in the range of 0.25% (ZJ-24 and ZJ-25) to 1.16% (ZJ-26). The Chinese jujube genotypes of this study were grouped based on hierarchical clustering of the fruit, stone and seed characteristics.