A Regeneration System for Cotton Variety Xinluzao 45 via Somatic Embryogenesis

Objective] The purpose of this study was to expand upland cotton genotypes suitable for regeneration via somatic embryogenesis, so as to provide excellent receptor materials for the genetic transformation of cotton. Method] Six different hormone combinations were studied to establish a somatic embryo regeneration system for hypocotyl explants of Xinluzao 45, a widely planted variety in Xinjiang Province. Result] Faint yellow callus was induced on a medium consisting of hormone combinations C1 (0.1 mg·L^－1 acetic acid dichlorobenzene oxide 2, 4-D] + 0.1 mg·L^－1 kinetin KT]) or C5 (0.1 mg·L^－1 2, 4-D + 0.5 mg·L^－1 indo-3-butyric acid + 0.1 mg·L^－1 KT). The generated callus was able to successfully induce embryogenic callus on hormone-free medium containing doubled KNO3. The embryogenic callus then developed into somatic embryos and regenerated plants. Maximum rates of callus induction and regeneration were 92.2% and 40.3%, respectively. Although no significant difference was observed in the rate of callus induction of Xinluzao 45 hypocotyls between hormone combinations C1 and C5, the incidence of induced embryonic callus was higher on C1 than on C5. Conclusion] The somatic embryo regeneration system developed in this study provides technical support that will facilitate Agrobacterium-mediated transformation of upland cotton Xinluzao 45.