NrDNA internal transcribed spacer revealed molecular diversity in strains of red seaweed Porphyra yezoensis and genetic insights for commercial breeding

Abstract

Unraveling the cryptic genetic diversity and selective breeding network in various Porphyra strains is of significance for conservation and utilization of economically important nori crops, for both current and future needs. Here, we used nuclear ribosomal spacer (ITS1) region to investigate the genetic variation and intra-specific relatedness of 59 Porphyra yezoensis Ueda specimens worldwide using phylogenetic and parsimony genealogical approaches. 23 nrDNA ITS1 genotypes were revealed and clustering analysis grouped them into two distinct clades. High genetic diversity was detected in wild P. yezoensis strains from Miyagi and Hokkaido Prefectures in Japan, while the cultivated strains from China and South Korea exhibited relatively higher genetic diversity likewise, which provided crucial genetic insights for future commercial breeding of P. yezoensis on a global scale. In addition, phylogenetic study has revealed the genetic relationship of strains with unknown parentage to those with known parentage, and also ITS1 sequence pattern could be correlated with the geographic origin of P. yezoensis specimens. All these pedigree information generated from this research can be used to select parents for inter-specific or intra-specific selective breeding and cross breeding to maximize the preservation of stock resource and sustainable development of nori industry.

The complete nuclear ribosomal DNA (nrDNA) cistron sequence of Pyropia yezoensis (Bangiales, Rhodophyta)

“…With the rapid development of molecular biology, more and more investigators tend to adopt the molecular approaches to discriminate the various Pyropia species, which makes the identification and classification more efficient and accurate. In recent decades, the nuclear ribosomal DNA has been studied more for molecular classification system in marine algae (Patwary et al 1998;Broom et al 1999;Kunimoto et al 1999a, b;Harper and Saunders 2001;Milstein and de Oliveira 2005;Hu et al 2010;Saunders and Moore 2013).…”

Seaweed farming: A perspectives of genetic engineering and nano-technology application

“…The 59 Neopyropia yezoensis (formerly Porphyra yezoensis ) (Nori) (Rhodophyta) was studied for a selective breeding program of economically important nori crops using the ITS1 region. Selective breeding in Japan achieves most nori cultivar enhancement for aquaculture [ 33 ]. Eukaryo ABC (Algae Breeding Cultures) is a Norwegian organization that specializes in selective seaweed breeding to create cultivars or “varieties” with higher yields, better consistency, and stability than wild seaweed.…”

Seaweed breeding programs and progress in eastern Asian countries

“…The targeted agronomic characters of these cultivars included blade shape and colour, thallus thickness, amino-acid content, tolerance to higher temperature, and delayed reproduction which would delay harvesting. This process requires numerous steps: (1) isolation of single cells from a selected individual by enzymatic digestion; (2) regeneration of the cell into filaments; (3) induction of blades; (4) treatment with radiation (commonly 60 Co-γ); (5) selection of desired individuals; (6) serial tests of the candidates, 7further selection based on multiple characters; and (7) largescale cultivation trials in the sea (Dai et al 2004;Hu et al 2010;Wang et al 2000;Yan et al 2010). These screenings or mutation procedures may vary between different cultivars, but with the same fundamental concept, i.e.…”