Axenic Culture of Orchids in the Age of Extinction
Our lab in New Hampshire is developing a conservation program to not only rescue the regionally endangered showy lady's slipper, Cypripedium reginae, from extinction, but also serve as a model of conservation efforts for other plant species. To provide us with sufficient numbers of plants to study and eventually transplant in protected locations (sanctuaries) in the wild, we propagate large numbers of the slippers using axenic seed culture. This speeds time to maturity from ten years to about four years and ensures far more genetic diversity than vegetative propagation. We currently have over 2,000 seedlings in culture, about 400 in vernalization, and about 80 planted in soil. The plants in soil are in a cold frame that mimics the conditions of a fen. These plants are expected to flower in the summer of either 2015 or 2016. It was found that if seedlings were moved directly from unvernalized cultures to soil, there was approximately a 5% survival rate. Survival is about 50% for seedlings in outdoor sites if seedlings were vernalized at 5 °C for 2-4 months prior to transplantation. The most successful medium for vernalization we have studied has been composted soil. Unfortunately, results for groups of plants after vernalization produces erratic results, ranging from 0% survival to 100% survival after 3-4 months. We are currently investigating variables of seedling preparation prior to vernalization, including moisture of medium and different types of media for vernalization. We have two sanctuaries in New Hampshire with healthy plants. We are in the process of creating two to three additional outdoor sites in New Hampshire. We have most recently begun experiments to evaluate germination rates of seeds stored for one month, one year, two years, and three years in order to both improve our seedling production and provide information on seed viability in case of extinction. Using our standard sterile axenic culture procedure for germination and development of Cyp. reginae, we expect seeds stored for two or more years will have lower germination rates than those stored for one month and one year. Results are expected by February of 2015.