[Influence of storage conditions on the seed development of Corydalis yanhusuo].

OBJECTIVE: To explore the influence of the storage conditions on the seed development of Corydalis yanhusuo. METHODS: The embryo formation process of the wild Corydalis yanhusuo was observed,and the germination rate of wild Corydalis yanhusuo seeds stored under different conditions was measured. RESULTS: The seed development of the wild Corydalis yanhusuo depended on the storage conditions. The seeds subjected to stratification had the highest germination percentage. Those stored in dry conditions would lose the vitality completely. The seeds in isothermal storage had very low germination rates. As revealed by slices, only the seeds after stratification treatment had the ability to form a complete embryo. CONCLUSION: The Corydalis yanhusuo seed is a kind of seed without fully developed embryo, and needs further after-ripening for its development. Its vitality has a great seasonal and annual dependence.

Temperature conditions control embryo growth and seed germination of Corydalis solida (L.) Clairv., a temperate forest spring geophyte.

Spring is often the most suitable period for seedling establishment of temperate woodland species. Different physiological mechanisms resulting in spring emergence have evolved in seeds of such plants. The aim of this study was to determine the requirements for breaking dormancy and for seed germination of the European perennial spring geophyte Corydalis solida (Fumariaceae). Ripe seeds of C. solida contain an underdeveloped embryo, consisting of no more than a clump of cells. As a consequence, the embryo has to differentiate and grow to a critical length before germination can occur. In nature, seeds are dispersed in spring, while growth of the embryo starts in the autumn and continues in winter. Germination starts in late winter, immediately after embryo growth is completed, resulting in seedling emergence in the following spring. Experiments in controlled conditions showed that temperature is the main factor controlling dormancy and germination. Incubation at autumn temperatures (15/6 degrees C; 20/10 degrees C) for at least 8 weeks is required to initiate embryo growth, while a transfer to 5 degrees C is needed for completion of embryo growth and germination. Growth of the embryo of C. solida occurs at different temperatures over an extended period, a feature typical of temperate forest herbs. Our results indicate that the dormancy mechanism in seeds of C. solida is very similar to mechanisms in other Corydalis species studied thus far, suggesting that stasis in the dormancy trait has occurred.