Effects of stratification duration and seed quality on germination success in Viola purpurea

DeRosa University Center, Ballroom

Many Speyeria butterfly species are in decline across North America in recent years due to factors including habitat and host plant loss. Speyeria adiaste is a declining species endemic to the southern California coast ranges and has had one subspecies go extinct. Recent work in our lab has focused on providing ecological information about this species to help better understand its status since it is currently unprotected. Since S. adiaste larvae rely on their native host plant, Viola purpurea, the availability of the host is critical for this species. Restoration of the host plant species could help prevent the extinction of S. adiaste but little research has been done on V. purpurea. This project therefore aimed to establish methods for successful germination and propagation of V. purpurea. We examined the length of stratification (1, 5, or 10 weeks) that would give the Viola purpurea seeds optimal conditions for germination. Variation was encountered in coloration of collected seeds and so effect of seed quality on germination was also investigated. We placed the seeds into three groups based on the seed color and pattern (A, B, C), where group A were the largest, darkest, unpatterned seeds of assumed best quality. Preliminary results indicate that germination is successful during stratification starting at 5 weeks and that both A and B grade seeds germinated well. Our results are very promising for creating lab-grown V. purpurea that can aid in enhancing and restoring wild populations to support the declining butterfly.