Dormancy breakage in Cercis chinensis seeds

Abstract

The seeds of Cercis chinensis are important for reproduction and propagation, but strong dormancy controls their germination. To elucidate the causes of seed dormancy in C. chinensis, we investigated the permeability of the hard seed coat, the contribution of the endosperm to physical dormancy, and we examined the effect of extracts from the seed coat and endosperm. In addition, the effectiveness of scarification methods to break seed dormancy were compared. C. chinensis seeds exhibited physical and physiological dormancy. The hard seed coat played an important role in limiting water uptake, and the endosperm acted as a physical barrier that restricted embryo development in imbibed seeds. Germination percentage of Chinese cabbage seeds was reduced from 98.0% (control) to 28.3% and 56.7% with a seed-coat extract and an endosperm extract, respectively. This demonstrated that both the seed coat and endosperm contained endogenous inhibitors, but the seed coat extract resulted in stronger inhibition. Mechanical scarification, thermal scarification, and chemical scarification had positive effects on C. chinensis seed germination. Soaking non-scarified seeds in Gibberellic acid (GA3) solution did not promote germination, however, treatment with exogenous GA3 following scarification significantly improved germination. The optimal method for promoting C. chinensis seed germination was soaking scarified seeds in 500 mg·L−1 GA3 for 24 h followed by cold stratification at 5 °C for 2 months.

Effects of dormancy breaking methods on germination of Cercis siliquastrum and Spartium junceum and seedling growth

“…The highest Coefficient Velocity Germination (CVG) and Average Germination Rate (MGR) were obtained in 30 min of immersion in sulfuric acid with 1,000 mg L −1 gibberelic. This conclusion agrees with Gao et al (2020) pointed out that treatment with exogenous GA 3 following scarification a c b significantly improved germination in C. chinensis seeds. Thermal scarification, mechanical scarification, and acid scarification are effective in breaking seed-coat dormancy because the treatments cause disruption of the seed coat, resulting in rapid imbibition.…”

“…However, the current results reach agreement with those of previous studies in which scarification combined with GA 3 application is described to have a synergistic effect in accelerating seed germination and to be effective in increasing seed germination in many species (Gao et al, 2020;Rusdy, 2017;Pipinis et al, 2011). Since, the physical and chemical treatments improved germination, it is proposed that there was an external dormancy which was perhaps due to the impermeable seed coat (Maleki et al, 2007).…”

“…Structural studies of hardcoated seeds are significant for enhanced considerate of the reasons and release of seed dormancy. Longitudinal segments of C. chinensis seeds shown a thin condensed layer of colloid material located between the inner surface of the test and the embryo, which is the remnant tissue of the endosperm (Gao et al, 2020).…”

“…Methods of breaking seed dormancy thermal scarification, mechanical scarification and acid scarification are effective in breaking the dormancy of hard-coated seeds. These treatments might crack the seed coat, increasing permeability and permitting absorption of water (Gao et al, 2020). Spanish broom (S. junceum L.) grows naturally on rocky ground or over steep slopes near the sea.…”

Physiological dormancy and dormancy release of Sassafras tzumu, a colored-leaf tree species with high landscape and economic value

“…All extract solutions were concentrated to 100 mL. The Brassica campestris seeds were used to test the germination inhibitory substances activity (Bian et al 2018, Gao et al 2020. Two pieces of filter paper were placed in each petri dish, and 3 mL of the extracts were added to the dishes.…”