Micropropagation protocol for coastal quinoa

Key message A micropropagation protocol has been developed for coastal cultivars of Chenopodium quinoa. Coastal cultivars are vital to increase the cultivation area of quinoa. Quinoa is a model halophyte plant, with seeds rich in proteins, fatty acids and lacking prolamines. There are two types of quinoa cultivars: highland and coastal. Coastal cultivars are used in breeding programs for warm-season quinoa production. Different biotechnological tools are useful for breeding and understanding the mechanisms involved in abiotic stress tolerance. However, micropropagation protocols have been developed only for highland cultivars. The aim of this research was to develop a micropropagation protocol for coastal cultivars. The initial explants were apical segments from two coastal cultivars (Cahuil and Villa). The regeneration rate in regeneration quinoa media 3 (QM-3: MS supplemented with 1 mg l(-1) KIN and 1 mg l(-1) BA) was acceptable (93 +/- 5% for Cahuil and 79 +/- 8% for Villa), but the number of regenerated shoots was low (2.14 +/- 0.93 and 1.43 +/- 0.73 respectively). We included a shoot multiplication stage using regeneration quinoa medium 1 (QM-1: MS supplemented with 2 mg l(-1) BA), obtaining 7.96 +/- 2.92 shoots per explant for Cahuil and 4.10 +/- 3.00 for Villa. Also, we obtained a higher number of acclimatized quinoa using ex vitro shoot rooting (73 +/- 8% for Cahuil and 77 +/- 8% for Villa) than in vitro shoot rooting (in quinoa rooting media 3 RQM-3, MS supplemented with 2 mg l(-1) IBA: 87 +/- 6% for Cahuil and 83 +/- 7% for Villa) and subsequent acclimatization (83 +/- 7% and 80 +/- 7% respectively). Furthermore, ex vitro rooting combines rooting and acclimatization in one step and requires less time. This is the first coastal cultivar micropropagation protocol reported and the starting point for development of other biotechnological tools.