Variation in seed dormancy among accessions of chile piquin (Capsicum annuum var. glabriusculum)

Chile piquin (Capsicum annum cv. glabriusculum) consumed in Mexico is usually harvested from wild grown plants. This activity might threaten the genetic diversity in this species. However, chile piquin germination has traditionally been difficult for intensive greenhouse sowing. The causes for such behavior are unknown. Accessions from seven production zones in the country and Southern USA were collected, and studied. Morphological studies determined there are no significant morphological differences or barriers among accessions that might prevent seed germination. An imbibition kinetic study showed no limitations for water penetration into seed tissues. Yet the seed germination rate varied among the 16 accessions (0 to 66%) with an average of 15%. Seed conditioning with AG(3) at 5,000 ppm increased mean germination rate to 59% in 14 out of 16 accessions. Hydrogen peroxide and potassium nitrate did not increase germination rates of viable seeds, except on two and four accessions, respectively. This work corroborates that chile piquin seed germination is restricted by physiological dormancy that giberellic acid pre-conditioning can overcome with varying degrees among accessions.