Why are the seeds of this species difficult? This species may have physiological dormancy, which can be overcome by mimicking the seasonal patterns of the species' native habitat.
This species most probably has Orthodox seeds (based on other species in the same genus) - dry to 15-20% eRH and store at -20ºC, or as cool as possible.
Based on the germination requirements for other species in the same genus: germinate on agar, germination paper or sand under an alternating temperature regime of 25/15ºC (with an 8/16hr photoperiod).
The seeds of this species may be Physiologically Dormant (based on other species in the same genus). If germination is low, overcome dormancy by mimicking the seasonal patterns of the species' native habitat. Use a moist pre-chill or pre-heat treatment (depending on local climatic conditions) or a dry after-ripening treatment, before germinating the seeds on agar, germination paper or sand at their optimum temperature. If this does not work, you can perform delicate surgery to enable the embryo to grow. Excise the tissue near the root tip.
Accepted name: Rorippa nudiuscula (E.Mey. ex Sond.) Thell.
Synonyms: Nasturtium elongatum E.Mey. ex Burtt Davy, Nasturtium fluviatile var. brevistylum Sond., Nasturtium integrifolium Szyszyl., Arabis nudiuscula E.Mey. ex Sond., Nasturtium elongatum var. serratum Burtt Davy, Rorippa nudiuscula subsp. serrata (Burtt Davy) Exell
References and Links
- Food and Agriculture Organization of the United Nations and International Plant Genetic Resources Institute (1994). Genebank Standards. FAO/IPGRI, Rome, Italy.