Seed Dormancy Release and Germination Requirements of Cinnamomum migao, an Endangered and Rare Woody Plant in Southwest China

Abstract

Seed dormancy is a complex adaptive trait of plants that are influenced by several physiological and environmental factors. The endangered plant Cinnamomum migao is also known to exhibit seed dormancy and low germination, which may influence its regeneration; however, these characteristics remain unexplored. To our knowledge, this study is the first to examine the type of dormancy and improve the germination percentage of C. migao seeds. We evaluated the structure and characteristics of the embryo and endocarp of C. migao seeds as well as the effects of endogenous inhibitors. Furthermore, we assessed the effects of light, stratification, alternating temperature, and gibberellic acid 3 (GA3) on the dormancy release of these seeds. The embryo was well developed the endocarp was water-permeable, and no obvious mechanical hindrance to germination was observed. However, the endocarp and embryo contained phenols and other germination inhibitors. The seed extracts of C. migao delayed the germination of cabbage and ryegrass seeds, which indicates the presence of endogenous inhibitors. These findings suggest that C. migao seeds exhibit physiological dormancy. Light and an alternating temperature (15/20°C) did not influence germination. However, GA3 pretreatment, alternating temperatures, and warm stratification relieved dormancy. GA3 pretreatment combined with the 15°C stratification treatment was most effective in rapidly releasing the C. migao seed dormancy. Our findings may facilitate the storage and conservation of this endangered plant, which is currently underrepresented in ex situ collections.

Seed Dormancy and Germination in Alfalfa (Medicago falcata L.)

“…When treated with 80% and 100% extract concentration, the GR of B1 was reduced by 10.07% and 9.48%, respectively, compared to the control, but there was no significant (p>0.05) difference in seedling GP, seedling growth potential or seedling length at 80% and 100% concentrations compared to the control treatment (Fig 2 B1). This indicates that the high concentration of seed inhibitor hinders the germination of alfalfa seeds, the finding that is in agreement with Zhao et al (2019) and Chen et al (2022). GR of M2 seeds after 20%, 40% and 60% concentration treatments were unchanged compared to the control and all treatments had a GR of approximately 24%, while GR after 80% and 100% treatments were 7.02% and 7.86% lower than the control, respectively.…”

“…Some secondary metabolites present in plant seeds may prevent germination. For example, 58 endogenous compounds were identified in the endocarp of Cinnamomum migao seeds, including a phenolic compound, aldehydes, ethers and lipids, among others (Chen et al, 2022).…”

Arbuscular Mycorrhizal Fungi Improve the Growth, Water Status, and Nutrient Uptake of Cinnamomum migao and the Soil Nutrient Stoichiometry under Drought Stress and Recovery

“…The wood of C. migao is used as a bioenergy resource, and the tree is also used as an ethnic medicinal plant [ 18 ]. However, many natural populations of C. migao have disappeared because of allelopathy and autotoxicity [ 19 , 20 ]. Additionally, C. migao is very sensitive to drought stress [ 21 , 22 ].…”

Exogenous gibberellin can effectively and rapidly break intermediate physiological dormancy of Amsonia elliptica seeds

“…Treatment with exogenous GA in some dormant seeds can use this opportunity to break dormancy, allowing for faster seedling production. Exogenous GA treatment was effective for breaking dormancy in Cinnamomum migao ( Chen et al., 2022 ), Leymus chinensis ( He et al., 2016 ), and Thalictrum Uchiyama ( Lee et al., 2018 ) seeds, although Clematis terniflora ( Jang et al., 2023 ) and Ferrula assa-foetida ( Hassani et al., 2009 ) seeds were unaffected. Many previous studies have applied GA to promote dormancy breakage, although responses to this have shown variation with plant species, dormancy class, forms of GA, concentration, and treatment length.…”