RESULTS OF IN VITRO ANDROGENESIS UNDER INCREASING SALINITY CONDITIONS FOR THREE MOROCCAN SPRING BARLEY VARIETIES (HORDEUM VULGARE L.)

Abstract

In vitro androgenesis process under salt pressure is recognized as being a valuable method for quick production of salt stress tolerant doubled haploid lines, enabling yield improvement of plants cultivated in dry climates. This study aimed to investigate the effect of salt stress on in vitro androgenetic regeneration, and the production of salt tolerant barley doubled haploid lines. Moroccan barley varieties, Arig, Asni and Tamelalt were used as RS0, and after one round of selfing (RS1) or two (RS2). These successive generations made possible to verify genetic stability or possible accidental heterozygosity, and to obtain plants presumably more tolerant to salinity. After culture of 11,340 anthers on induction medium, 2,270 calluses or embryos were generated. According to the induction rate of these formations, the three generations of each variety were not significantly different, pointing out the genetic stability after two selfings. Tamelalt and Arig had similar in vitro response, while for Asni, the three generations behaviour differed from the previous ones and constitute a statistically separate group. After transfer of the formations on regeneration medium either salt free, as control, or supplemented by increasing concentrations of NaCl, ranging from 2.5 to 13 g.L^-1, 170 regenerants were produced. Asni (RS1) showed to be the most salt tolerant, bearing the maximal NaCl concentration of 12 g.L^-1, but the single regenerated plant obtained was albino, as most of the regenerated plants from any genotype and generation. However, RS1 and RS2 generations of Asni regenerated one green plant each, with NaCl concentration of 5 g.L^-1, resulting in two new Asni doubled haploid fertile lines.