Preliminary study on Bioassay of Capparis spinosa L. seed extract and seed germination

The present study explored the germination inhibitors present in the seeds of Capparis spinosa L., a plant species that is known for its ecological significance in preventing wind erosion and fixing sand in desertified areas. Additionally, its roots, leaves, and fruits possess medicinal properties, and are used to treat a range of ailments such as rheumatism, tumors, and diabetes. However, the plant's low germination rate under natural conditions is a major limitation. We aimed to improve the germination of C. spinosa seeds by investigating the effects of various infusions of caper seeds on the germination and seedling growth of Chinese cabbage seeds. A range of chemical reagents, hormonal immersions, and sand storage treatments were used to determine the differences in the germination rate of C. spinosa seeds. Our results revealed that among the various water extract concentrations tested, 100% water extract exhibited the strongest inhibitory effect on the germination and growth of the cabbage seeds, with a germination rate of (70.00 ± 0.09)%. Furthermore, the inhibitory effects on the germination and growth of cabbage seeds were found to be strongest when treated with the extract solution 1, yielding a germination rate of (83.33 ± 0.02)%. Notably, the leaves of Chinese cabbage seedlings turned yellow-green and yellow after treatment with the extract solution. These findings highlight the potential inhibitory effects of C. spinosa seed extracts on seed germination and growth and suggest that further research is needed to better understand the underlying mechanisms. The results of the germination experiment with methanol extract showed a sharp decline in the germination rate of Chinese cabbage seeds treated with 50% methanol extract, to (4.67 ± 0.02)%. These findings indicate the presence of germination-inhibiting substances in caper seeds. The highest germination potential was observed when the caper seeds were soaked in 30% PEG, reaching 35.00%. The highest germination rate, 19.33%, was observed when the seeds were soaked in 250 mg/L GA₃ and 25 mmol/L NaCl. These results suggest that the germination inhibitor present in caper seeds affects the germination of cabbage seeds as well. The highest germination rate was achieved when the seeds were soaked with gibberellin. It is hoped that the research on the germination-inhibiting substances in caper seeds will provide a scientific foundation for improving and refining the artificial propagation and cultivation methods of this species.