Micropropagation of Tulip via Somatic Embryogenesis

Abstract

An effective method of tulip regeneration via somatic embryogenesis (SE) was developed. Explants, flower stem slices excised from cooled bulbs were incubated in darkness on MS modified media containing auxins alone (2,4-dichlorophenoxyacetic acid—2,4-D, 1-naphthalene acetic acid—NAA and 4-amino-3,5,6-trichloro-2-pyridine carboxylic acid—picloram) or combined with thidiazuron (TDZ) at 0.1 and 0.5 mg L−1. Yellowish-white callus with a granular structure was developed in the presence of all auxins on the cut surface from the tissues of the vascular bundles. From this, lines of embryogenic calli were derived. The addition of TDZ to the medium with auxins significantly stimulated somatic embryo formation. Cyclic and the most intensive proliferation of embryogenic callus as well as embryo formation was obtained in the presence of 2,4-D at 0.1 mg L−1 combined with TDZ at 0.5 mg L−1. Addition of proline enhanced either callus proliferation rate or frequency of embryo formation. The best quality embryos with cotyledons longer than 10 mm able to form bulbs were recorded when TDZ was replaced with 6-benzylaminopurine (BAP) at the concentration of 0.1 mg L−1. Histomorphology showed that the development of somatic embryos could have either external or internal origins. Embryos of external origin were initiated by cell division on the edge of embryogenic calli. Embryos of internal origin resulted from the division of parenchyma cells inside the tissue. Embryonic cells were characterized by their small volume, regular shape, dense cytoplasm and large nuclei. The globular embryos were covered by a distinct layer of periderm. Then, the embryos developed into structures having leaf-shaped cotyledons with a procambial strand and a sideward-orientated meristem of the vegetative apex (stolon). Cotyledon embryos did not show vascular connections with the parent tissue, and they did not develop embryonic roots.

Influence of Temperature on Seed Germination of Five Wild-Growing Tulipa Species of Greece Associated with Their Ecological Profiles: Implications for Conservation and Cultivation

“…Although the asexual propagation of tulips is efficiently described in the literature (e.g., [ 4 , 5 , 6 , 7 , 8 ]), the knowledge about the requirements for the seed germination of numerous wild-growing tulip species remains limited. Low temperatures have been reported to promote the seed germination of several tulips such as Tulipa systola Stapf [ 9 ], T. iliensis Regel [ 10 , 11 ], and T. kaufmanniana Regel [ 12 ], as well as other wild-growing Tulipa spp.…”

A Review on Flower Bulb Micropropagation: Challenges and Opportunities

“…While petiole explants produced the most callus, ovary explants were most efficient in forming somatic embryos. Recently, an efficient method for tulip regeneration via SE was developed [167,168]. Some reports on SE are also available by using leaf, petiole, ovary, anther, roots, and aseptic seedling tissues as explants in cyclamen [166,[169][170][171][172][173][174].…”

Application and Improvement of In Vitro Culture Systems for Commercial Production of Ornamental, Fruit, and Industrial Plants in Poland

“…is novel method has enabled quick, virus-free multiplication of several Polish tulip cultivars. Recently, an effective method for tulip regeneration via somatic embryogenesis (SE) was developed (Podwyszyńska & Marasek-Ciolakowska, 2020). Successful results in tulip SE have also been reported by a team from the University of Agriculture in Cracow (Bach & Ptak, 2001;Maślanka & Bach, 2016;Ptak & Bach, 2007).…”