In Vitro Propagation of Humulus lupulus through the Induction of Axillary Bud Development

Abstract

Humulus lupulus (hop) is a necessary material for beer brewing. Improved breeding cultivars of hops with enhanced tolerance to environmental stresses, such as drought and heat stress, accompanying climate change have been developed. However, a propagation system, which is needed for the proliferation of new cultivars, is not currently available for hops. In this study, we found that treatment of stem explants with 0.01–0.05 ppm gibberellic acid (GA3) induced the development of axillary buds in the hop cultivar Kirin-2, resulting in the proliferation of shoot branching. Additionally, 0.01 ppm benzyl adenine (BA) enhanced the development of axillary buds formed in response to 0.05 ppm GA3 in various hop cultivars, particularly Nugget. The development of axillary buds was strongly repressed by the application of 0.05 ppm BA at a concentration equal to the 0.05 ppm GA3 concentration, which showed the possibility that a high concentration of cytokinin preferentially prevents the effect of GA3 on the development of axillary buds in hops. These results indicated that combined treatment of stem explants with GA3 and cytokinin at appropriate concentrations is effective for the propagation of proliferated hop cultivars through shoot branching.

Ölmez Otu (Helichrysum italicum (ROTH) G. DON) Bitkisinin in vitro Mikroçoğaltımı

“…According to the results, while 75% rooting occurred in the control medium, 100% rooting was observed in the medium containing 1.5 mg L -1 IBA, 1 mg L -1 NAA and 1.5 mg L -1 NAA (El-Banna, 2017). Hirakawa and Tanno reported that they reached the best rooting rate within 2 weeks in ½MS nutrient medium containing 0.05 mg L -1 NAA in their study on hops (Hirakawa and Tanno, 2022). In the study of Petrova et al on lemon balm, 100% rooting was obtained in the control medium without plant growth regulator (Petrova et al, 2021).…”

“…Hirakawa and Tanno experimented with BA and GA plant growth regulators at different concentrations added to ½MS in their micropropagation study in hops. According to the results they obtained, the best shoot growth was obtained in the medium containing BA (0.01 mg L -1 ) at a lower concentration (Hirakawa and Tanno, 2022). In a study conducted by Yesmin (2019) on sugar grass, media were prepared with the combinations of BAP, KIN and NAA added to MS.…”

“…In this study, this step was carried out by irrigating sterile peat with distilled water. Hirakawa and Tanno performed the acclimatization process of hops by irrigation with distilled water in a soil mixture containing 3:1:1 peat, vermiculite and akadama (Hirakawa and Tanno, 2022). Petrova et al, on the other hand, carried out the acclimatization stage of lemon balm by irrigating a soil mixture containing soil, peat, perlite, and sand at a ratio of 2:1:1:1 with pure water (Petrova et al, 2021).…”

N-Acetylglutamic Acid Enhances Tolerance to Oxidative and Heat Stress in Humulus lupulus

“…'Saaz' and 'Hersbrucker' were used as materials in this study. In vitro hop plants were established as previously described [16]. Stem explants were isolated from plants and sterilised with 70% (v/v) ethanol and 1% (v/v) sodium hypochlorite for 1 min and 5 min, respectively.…”

Micropropagation and Synthetic Seeds Production of Humulus lupulus L. var. Mapuche: Optimization, Advances, and Agricultural Applications

“…We have established an efficient propagation protocol that guarantees the phytosanitary quality and availability of plants in a short period of time, and facilitates the transport and exchange of material. On the other hand, numerous studies have addressed plant tissue culture and explored various pathways of hop regeneration, and have evaluated the response of different types of explants and varieties [22][23][24][25][26][27][28][29][30][31][32]. In addition, other studies have been conducted on organogenic callus production and regeneration [33][34][35], virus elimination by thermotherapy and meristem culture [36], and encapsulation of nodal segments and shoot tips to obtain synthetic seeds [26,37,38].…”