Skinny kelp (Saccharina angustissima) provides valuable genetics for the biomass improvement of farmed sugar kelp (Saccharina latissima)

Authors: LI, YAOGUANG - University Of Connecticut; UMANZOR, SCHERY - University Of Connecticut; NG, CRYSTAL - University Of Connecticut; HUANG, MAO - Cornell University; MARTY-RIVERA, MICHAEL - University Of Connecticut; BAILEY, DAVID - Woods Hole Oceanographic Institute (WHOI); AYDLETT, MARGARET - Woods Hole Oceanographic Institute (WHOI); Jannink, Jean-Luc; LINDELL, SCOTT - Woods Hole Oceanographic Institute (WHOI); YARISH, CHARLES - Woods Hole Oceanographic Institute (WHOI)

Submitted to: Journal of Applied Phycology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2022
Publication Date: 8/20/2022
Citation: Li, Y., Umanzor, S., Ng, C., Huang, M., Marty-Rivera, M., Bailey, D., Aydlett, M., Jannink, J., Lindell, S., Yarish, C. 2022. Skinny kelp (Saccharina angustissima) provides valuable genetics for the biomass improvement of farmed sugar kelp (Saccharina latissima). Journal of Applied Phycology. 34:2551-2563. https://doi.org/10.1007/s10811-022-02811-1.
DOI: https://doi.org/10.1007/s10811-022-02811-1

Interpretive Summary: Saccharina latissima (sugar kelp) is one of the most widely cultivated brown kelps in the North Atlantic and the eastern North Pacific Oceans. To meet the expanding demand of the kelp mariculture industry, selecting and breeding sugar kelp that is suited to offshore farm environments is necessary. Kelp has both haploid (gametophyte) and diploid (sporophyte) life phases. We generated sporophytes using 203 unique gametophyte cultures derived from wild-collected kelp for two seasons of farm trials (2019–2020 and 2020–2021). The wild sporophytes were collected from 10 different locations within the Gulf of Maine (USA) region, including two kelp species, sugar kelp (Saccharina latissima) and skinny kelp (Saccharina angustissima). We found that farmed kelp plots with skinny kelp ancestry had an average increased yield over the mean (wet weight 2.48'±'0.90 kg m-1 and dry weight 0.32'±'0.10 kg m-1) in both growing seasons. We also found that blade length positively correlated with biomass in both skinny kelp x sugar kelp and pure sugar kelp crosses. The skinny x sugar progenies had significantly longer and narrower blades than the pure sugar kelp progenies in both seasons. These findings suggest that sugar x skinny kelp crosses provide improved yield compared to pure sugar kelp crosses.

Technical Abstract: Saccharina latissima (sugar kelp) is one of the most widely cultivated brown marine macroalgae species in the North Atlantic and the eastern North Pacific Oceans. To meet the expanding demands of the sugar kelp mariculture industry, selecting and breeding sugar kelp that is best suited to offshore farm environments is becoming necessary. To that end, a multi-year, multi-institutional breeding program was established by the U.S. Department of Energy's (DOE) Advanced Research Projects Agency-Energy (ARPA-E) Macroalgae Research Inspiring Novel Energy Resources (MARINER) program. Hybrid sporophytes were generated using 203 unique gametophyte cultures derived from wild-collected Saccharina spp. for two seasons of farm trials (2019–2020 and 2020–2021). The wild sporophytes were collected from 10 different locations within the Gulf of Maine (USA) region, including both sugar kelp (Saccharina latissima) and the skinny kelp species (Saccharina angustissima). We harvested 232 common farm plots during these two seasons with available data. We found that farmed kelp plots with skinny kelp as parents had an average increased yield over the mean (wet weight 2.48'±'0.90 kg m-1 and dry weight 0.32'±'0.10 kg m-1) in both growing seasons. We also found that blade length positively correlated with biomass in skinny kelp x sugar kelp crosses or pure sugar kelp crosses. The skinny x sugar progenies had significantly longer and narrower blades than the pure sugar kelp progenies in both seasons. Overall, these findings suggest that sugar x skinny kelp crosses provide improved yield compared to pure sugar kelp crosses.