Abstract
Background: Cotton is one of the most genotype-dependent plants for regeneration, in order to expand cotton regeneration genotypes and establish efficient regeneration system platform, Jiwu 2031 (glandless cotton), ND 58 and CAU 102, were selected for studying the highly efficient somatic embryos formation and regeneration via solid-liquid alternating culture system.Results: In present research, the MSB medium (MS salts adding B5 vitamins) containing 0.571 µM indole-3-acetic acid (IAA), 0.465 µM kinetin (KT) and 0.904 µM 2, 4-dichlorophenoxyacetic acid (2, 4-D) was effective for callus initiation of fourteen Upland cotton with ‘Corker 201’ as the control. ‘Jiwu 2031’, ‘ND 58’ and ‘CAU 102’ could form somatic embryos and regenerate fertile plants in a solid MSB medium containing 10.31 mM NH4NO3, and supplemented with 0.027 mM glycin, 2.460 µM indole-3-acetic acid (IBA), 0.930 µM KT, 3.784 mM asparagine and 6.843 mM glutamine. Under the solid-liquid alternating culture system, the non-embryonic callus was induced to form embryonic callus and the identical status somatic embryos were obtained in 42 days, and the period for plants regeneration was shortened to 90~120 days, with the higher proportion of normal plant regeneration.Conclusions: The solid-liquid alternating culture method could increase the rate of embryogenesis and shorten the period of plants regeneration of Upland cotton. This work provides the evidence that the glandless cotton is beneficial for somatic embryogenesis (SE) and plant regeneration.