Development of a shoot multiplication system for hop (Humulus lupulus L.)

Abstract

Nodal explants from hop were exposed to plant growth regulators to determine suitable media for initiation from axillary buds and subsequent micropropagation. Efficient culture establishment (96.6% of explants) was achieved on Murashige and Skoog (MS) medium (modified to contain 1 mg l 2l thiamine hydrochloride) supplemented with 0.57 mM indoleacetic acid (IAA) and 2.22 mM 6-benzylaminopurine (BA). Subsequent transfer of explants to treatments containing an auxin ([1-naphthaleneacetic acid] NAA or IAA) and BA, 6-[g,g-dimethylallylamino]purine (2iP), kinetin (KIN) or thidiazuron (N-phenyl-N H -1,2,3-thidiazol-5-ylurea [TDZ]) resulted in significantly different amounts of multiplication. Optimal TDZ-supplemented media elicited a greater than threefold increase in the number of shoots and nodes generated per explant compared to optimal media containing BA, 2iP and KIN. Shoots were successfully rooted using half-strength MS supplemented with 5.71 mM IAA and 4.9 mM indolebutyric acid (IBA), and regenerated plants were successfully transferred to soil. An overall micropropagation schedule, which can be implemented into hop commercialization programs, includes: (i) establishment in MS with 0.57 mM IAA and 2.22 mM BA; (ii) multiplication in MS with 0.57 mM IAA and 2.27 mM TDZ; (iii) elongation in MS; and (iv) rooting in half-strength MS with 5.71 mM IAA and 4.9 mM IBA.

An Efficientin vitroLeaf-based Regeneration and Evaluation of Genetic Fidelity Using ISSR Markers inWoodfordia fruticosa(L.) Kurz

“…The results were consistent with previous reports where the applicability of half-strength MS medium with IBA was found to be superior for in vitro root induction (12,35).…”

Germination and in vitro multiplication of Helianthemum kahiricum, a threatened plant in Tunisia arid areas

“…The addition of growth hormones does not improve the rooting or the rooting period compared to the control environment. Similar results were also reported by Souayah et al (2003) in A. halimus for which the root is obtained on media without growth regulators with a rooting rate improved by diluting the mineral medium; while, the work of Roy et al (2001) on Humulus lupulus and Armstrong and Johnson (2001) on Ceratopetalum gummiferum showed that in the absence of any growth regulator, rooting could not be obtained. This may be due to the richness of this species in endogenous growth regulators.…”

Micropropagation and Establishment of Humulus lupulus L. Plantlets Under Field Conditions at Southern Brazil

“…The number of leaves on new shoots was also higher in the M4 medium, reaching about 11 leaves per shoot. TDZ-supplemented media was previously reported as promoting higher numbers of leaves and nodes on explants in a micropropagation system developed for H. lupulus (Roy et al, 2001). In other species, such as Rauvolfia serpentine, TDZ was also effective in in vitro multiplication (Alatar, 2015).…”