Cultivar Development of Kelps for Commercial Cultivation—Past Lessons and Future Prospects

Abstract

Cultivated kelps and other macroalgae have great potential in future provision of food, feed, bioenergy, fertilizer, and raw material for a range of chemical products including pharmaceuticals, food and feed additives, and cosmetics. Only a few species are currently cultivated, almost exclusively in Asia. There is a range of species that could be utilized in different parts of the world, providing that protocols for reproduction, propagation, and cultivation are developed. Domestication of species involves selection of traits that are desirable in cultivation and in the utilization of the harvested biomass. Genetic improvement of cultivated species through recombination of alleles and selection (breeding) has ensured high productivity and product quality in both agri-and aquaculture and will likely do so for macroalgae cultivation and use as well. According to the published literature, genetic improvement of kelps in Asia has so far largely relied on utilization of heterosis expressed in certain combinations of parental material, sometimes species hybrids. Here, we explore and evaluate the various methods that could be used in kelp breeding and propose an initial simple and low-cost breeding strategy based on recurrent mixed hybridization and phenotypic selection within local populations. We also discuss the genetic diversity in wild populations, and how this diversity can be protected against genetic pollution, either by breeding and cultivating local populations, or by developing cultivars that are not able to establish in, or hybridize with, wild populations.

Genomic signatures of clonality in the deep water kelp Laminaria rodriguezii

“…Even if we do not know the importance of self incompatibility in this species, self fertilisation (i.e. fertilisation between male and female gametophytes originating from a single sporophyte parent), was reported to be possible experimentally in most studied species of Laminariales (see the recent review of Goecke et al, 2020). Laminaria rodriguezii then presents a mixed reproductive system, for which the genetic consequences have not been studied.…”

Population Genetics of Sugar Kelp Throughout the Northeastern United States Using Genome-Wide Markers

“…Besides their important ecological roles and the wellestablished kelp cultivation practices in coastal Asian countries, there is growing interest in macroalgal cultivation in Europe, South America, and throughout the United States of America (Augyte et al, 2017;Buschmann et al, 2017;Campbell et al, 2019;Grebe et al, 2019;Kim et al, 2019;Goecke et al, 2020). Specifically, there are efforts to selectively breed kelp for large-scale food and bioenergy production (Bjerregaard et al, 2016;Hwang et al, 2019;Goecke et al, 2020) and increasing demand for germplasm banking to support future cultivation as well as restoration research (Barrento et al, 2016;Wade et al, 2020). To assist in the establishment of this nascent industry in Northeastern United States, an understanding of genetic and phenotypic variation across wild kelp populations is essential.…”

“…To aid selective breeding efforts of sugar kelp in the Northeastern United States, it is also important to understand whether variation in commercially valuable traits has a genetic basis or mostly is a result of phenotypic plasticity (Gerard and Mann, 1979;Koehl et al, 2008). Therefore, the objectives of this study were twofold: (1) to explore the finer population structure of sugar kelps in Northeastern United States and (2) to investigate phenotypic variation of commercially valuable traits and test for marker-trait associations.…”

The Evolution Road of Seaweed Aquaculture: Cultivation Technologies and the Industry 4.0

“…The global annual production of seaweeds does not stop growing, reaching, in 2016, 31.2 million tons (fresh weight) [ 1 ]. Of this, just 3.5% was harvested from natural populations, in the time that 96.5% was produced in aquaculture, representing 27% of the worlds’ total aquaculture production [ 257 ]. The majority of this production happened in China, Indonesia and other Asian countries (47.9%, 38.7% and 12.8% of the worldwide production in 2016, respectively), mainly for human food and food additives [ 257 ].…”

“…Of this, just 3.5% was harvested from natural populations, in the time that 96.5% was produced in aquaculture, representing 27% of the worlds’ total aquaculture production [ 257 ]. The majority of this production happened in China, Indonesia and other Asian countries (47.9%, 38.7% and 12.8% of the worldwide production in 2016, respectively), mainly for human food and food additives [ 257 ]. The total aquaculture production of seaweeds exceeded more than the double in the last 20 years [ 1 ], and the total potential has been suggested to be 1000–100,000 million tons [ 258 ], but the main practice outside Asia is still to harvest natural stocks [ 57 ].…”