Seed Bulking of Three Rare Species of Atriplex (Chenopodiaceae)

Billy Sale, Califonia Botanic Garden

California Botanic Garden (CalBG) is in the process of seed bulking three rare species of Atriplex from populations originating in southern California. Atriplex coronata var. notatior (G4T1), Atriplex parishii (G2G3) and Atriplex serenana var. davidsonii (G5T1). To better inform the project, propagation trials were performed prior to seed bulking in order to examine germination pretreatments. Gibberellic acid was identified as the most effective pretreatment for all three species and used to initiate seed bulking efforts. This project additionally sought to examine growth in four container sizes and three different soil types for seed production. Each species was planted in four container sizes (6 inch treepots, 6 inch squares, 3 gallons, and 4 inch trays) and three different soil types (restoration potting mix, restoration with lime, and restoration with additional peat moss), which were replicated in all pot sizes in order to see how seed production was impacted. Seed produced from each container was collected separately. Preliminary results and methods will be shared.