Extensive Desiccation and Aging Stress Tolerance Characterize Gaillardia pulchella (Asteraceae) Seeds

Abstract

We investigated the response of Gaillardia pulchella seeds to desiccation and aging stress to gain some perspective on the germplasm storage potential and seed vigor of this species. Seed–water relations of mature, freshly harvested G. pulchella seeds were characteristic of desiccation-tolerant species. For example, initial seed water potential (−53 MPa) was well below the lethal water potential limit (−15 MPa) for desiccation-sensitive seeds. Desiccation tolerance was confirmed by high (>70%), rapid (t50 range 4–7 days), and uniform germination following equilibration drying. Likewise, post–saturated salt accelerated aging (SSAA) germination tests indicated a high degree of vigor of fresh seeds. The substantial level of desiccation and aging-related stress tolerance in G. pulchella seeds suggests that these organs potentially display orthodox storage physiology and an ability to endure variable seed bed conditions.