Annonaceae seeds: Desiccation tolerant with unusual physiologies

Authors: Volk, Gayle; Bonnart, Remi; Walters, Christina

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/16/2009
Publication Date: 5/1/2009
Citation: Volk, G.M., Bonnart, R.M., Walters, C.T. 2009. Annonaceae seeds: Desiccation tolerant with unusual physiologies. Seed Technologists Newsletter. 83 (2):18-19. Association of Official Seed Analysts and Society for Commercial Seed Technologists. May 29-June 4, 2009. Fort Collins, Colorado. Meeting Abstract.

Interpretive Summary: Paw paw (Asimina triloba) is the only temperate species of the Annonaceae family. Wild paw paw trees can be found along the river valleys of the eastern and central United States and produce the largest fruits of any species native to North America. Paw paw seeds are reported to be classified as recalcitrant, with small embryos buried within a reticulate endosperm and a hard seed coat. We performed desiccation and low-temperature exposure experiments to determine if paw paw seeds have the potential for storage in ex situ genebanks. Germination was determined for seeds desiccated to between 3 and 35% moisture content (fresh weight basis) after either 7 or 15 weeks of stratification at 4oC. Seeds with 3% moisture content were also cooled to -18oC. Our research revealed that paw paw seeds had high germination levels after -18oC exposure for 24 h when stratified either before or after the desiccation treatment. Desiccation tolerance was also investigated for several tropical members of the Annonaceae family. Annona reticulata, Annona glabra, and Annona muricata seeds successfully germinated after desiccation, -18oC exposure, and gibberellic acid treatments. Additional seed storage experiments will determine how long Annonaceae seeds can be successfully stored within genebanks.

Technical Abstract: Paw paw (Asimina triloba) is the only temperate species of the Annonaceae family. Wild paw paw trees can be found along the river valleys of the eastern and central United States and produce the largest fruits of any species native to North America. Paw paw seeds are reported to be classified as recalcitrant, with small embryos buried within a reticulate endosperm and a hard seed coat. We performed desiccation and low-temperature exposure experiments to determine if paw paw seeds have the potential for storage in ex situ genebanks. Germination was determined for seeds desiccated to between 3 and 35% moisture content (fresh weight basis) after either 7 or 15 weeks of stratification at 4oC. Seeds with 3% moisture content were also cooled to -18oC. Our research revealed that paw paw seeds had high germination levels after -18oC exposure for 24 h when stratified either before or after the desiccation treatment. Desiccation tolerance was also investigated for several tropical members of the Annonaceae family. Annona reticulata, Annona glabra, and Annona muricata seeds successfully germinated after desiccation, -18oC exposure, and gibberellic acid treatments. Additional seed storage experiments will determine how long Annonaceae seeds can be successfully stored within genebanks.