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The flowers of selected Camellia yuhsienensis Hu specimens were studied at different stages of flowering to determine the volatile components of floral fragrance and how their concentrations changed during efflorescence. The mechanism of fragrance formation and release was also studied in order to provide a theoretical basis for the practical use of C. yuhsienensis Hu flowers. Headspace solid‐phase microextraction (HS‐SPME) was used to extract the natural floral volatile oils of C. yuhsienensis Hu at the different stages, and the floral fragrance components were analysed by gas chromatography–mass spectrometry (GC–MS). A total of 31, 59 and 55 compounds were detected at the budding, early‐blooming and full‐blooming stages respectively. These floral fragrance components included terpene alcohols, as well as other aromatic and aliphatic compounds, and the relative concentrations of the various compounds at different stages of flowering, were different, and those of fatty alcohols and terpene alcohols having higher relative contents at all stages. The main component at the budding stage of C. yuhsienensis Hu was ocimene, which has a grassy fragrance, accompanied by the scent of neroli oil, which gives it a refreshing, gentle and sweet, and explains why the floral fragrance of C. yuhsienensis Hu at the budding stage is extremely thin: the main component during the early‐blooming stage was 3‐carene. A higher percentage of 3‐carene increased the sweetness of the scent, manifesting the typical fragrant characteristics of C. yuhsienensis Hu. The main identified compound at the full‐blooming stage was α‐farnesene, which has a delicate fragrance, accompanied by a balsamic aroma, similar to the scent of gardenia, which is consistent with the sensory characteristics of C. yuhsienensis Hu. [ABSTRACT FROM AUTHOR]

Kadsura coccinea (Lem.) A. C. Smith is a significant tree species of non-timber forest. However, the low germination percentage and lengthy germination time of its seeds pose obstacles to industry development. Aiming at the problem of seed dormancy, this study first determined the seed dormancy period through seed germination test, and then comprehensively evaluated the dormancy characteristics by observing the seed coat structure, measuring endogenous inhibitors, and in vitro embryo culture. The results indicated the dormancy of K. coccinea seeds, and that the germination period was up to 80 days. Its seed coat is composed of exotesta and endotesta. The dense seed coat structure causes water absorption and air permeability obstacles to the seeds and causes mechanical restraint to the development of the embryo. Meanwhile, its seeds have substances that inhibit seed germination, and there are germination inhibitors in distilled water, methanol, petroleum ether, and ethyl acetate extracts of kernels and seed coats. The inhibitory activity of kernel petroleum ether extract was the highest, and the inhibitory activity of seed coat methanol extract was the highest. In addition, the embryo of K. coccinea developed completely and could germinate normally under in vitro conditions. This study has basically proved that the dormancy of K. coccinea seeds is caused by the seed coat (physical dormancy) and endogenous inhibitors (physiological dormancy), which provides a scientific theoretical basis to further explore the method of seed dormancy release of K. coccinea. [ABSTRACT FROM AUTHOR]