Assessment of genetic diversity within eucheumatoid cultivars in east Sabah, Malaysia

Pui-Ling Tan,Sze-Wan Poong,Ji Tan,Phaik-Eem Lim,Claire Gachon,Janina Brakel,Ahemad Sade,Juliet Brodie

doi:10.1007/s10811-021-02608-8

Abstract

Studies have shown that cultivars of the carrageenophytes Kappaphycus and Eucheuma are clones of a limited number of strains originally domesticated from wild populations. For the development and selection of new cultivars, it is important that a comprehensive record of available variants exists. This study was conducted to provide up-to-date analysis and compilation of the current state of cultivars as the last list of cultivars was compiled nearly a decade ago. The present study analyzed the cox2–3 spacer and cox1 (1356 bp) genetic diversity of cultivars collected from 2019 to 2020 from the east coast of Sabah where the seaweed farms are concentrated. These data were compared with cultivars reported from 2010 to 2012 to assess changes, if any, to the gene pool of farmed eucheumatoid in Malaysia. Kappaphycus alvarezii, K. striatus, and K. malesianus are currently cultivated while Eucheuma denticulatum is no longer an important cultivar compared to a decade ago, probably due to its lower price. Analysis of the cox2–3 spacer revealed a new haplotype, LBT10, and, by including published GenBank data, a further four previously unnamed haplotypes were recognized from Sabah. This study confirms that there is a limited gene pool within cultivars in Malaysia and suggests the need for new or genetically diverse cultivars which can adapt to a changing environment, to ensure a more sustainable carrageenan industry.

Highlights

Kappaphycus and Eucheuma are commercially important red (Rhodophyta) seaweeds valued for carrageenan, a useful phycocolloid especially in the food and cosmetic industries
Note that Thien et al (2020) only mentioned Semporna and Pulau Gaya as the collection sites to any form of marker-assisted selection or cultivar development, the present study (i) assesses the cox1 and cox2–3 spacer genetic diversity of eucheumatoid cultivars from key farming localities in Sabah, Malaysia, and (ii) compares the genetic variation of these cultivars against those collected over the past decade
The least cultivated species K. malesianus was only found in two cultivation sites in Semporna viz. Karindingan and Pallang-pallang

Summary

Introduction

Kappaphycus and Eucheuma ( referred to as eucheumatoids) are commercially important red (Rhodophyta) seaweeds valued for carrageenan, a useful phycocolloid especially in the food and cosmetic industries. Note that Thien et al (2020) only mentioned Semporna (in general) and Pulau Gaya as the collection sites to any form of marker-assisted selection or cultivar development, the present study (i) assesses the cox1 and cox2–3 spacer genetic diversity of eucheumatoid cultivars from key farming localities in Sabah, Malaysia, and (ii) compares the genetic variation of these cultivars against those collected over the past decade.

Results

Conclusion