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

Abstract

Tissue culture technique can be an important approach for the rapid propagation of Humulus lupulus L. (hop plant). The present study evaluated different culture media for hop plants (cv. Columbus) in vitro shoots multiplication, as well as ex vitro rooting and plantlets establishment under field conditions at Southern Brazil. The culture medium containing the plant growth regulator thidiazuron (TDZ) resulted in greater in vitro shoots multiplications (five shoots per explant). For microcuttings ex vitro rooting, indole-3-butyric acid (IBA) application at a concentration of 3000 mg L -1 resulted in higher rooting and survival percentages during acclimatization. After 90 days of acclimatization, the plantlets were transplanted under field conditions and had their development and productivity evaluated 122 days after transplanting. Micropropagated plants achieved 100% survival under field conditions. Nitrogen supply is highly necessary for hop plants initial development at Southern Brazil. Micropropagation is a viable technique for quality plantlet production of H. lupulus cv. Columbus.

Growth regulators and their reflection on different hop genotypes cultivated under in vitro conditions

“…In tissue culture, in addition to the different responses obtained between species, variation between genotypes are usually reported. However, the most studies with the hop are based only a single genotype (Machado et al, 2018;Peredo et al, 2006;Roy et al, 2001). To be successful in the micropropagation technique, we must study the behavior of hop genotypes.…”

Establishment of an Efficient Micropropagation System for Humulus lupulus L. cv. Cascade and Confirmation of Genetic Uniformity of the Regenerated Plants through DNA Markers

“…It is worth mentioning that previous micropropagation protocols for different hop varieties were established starting from different explants and based on the intermediate formation of the callus, which makes the regeneration prone to undesirable somaclonal variations [21,60], in contrast to the results of this research when plants were proliferated by the direct organogenesis of shoots.…”

“…Traditionally, the plant is propagated by rhizome fragments or herbaceous stem cuttings, especially during autumn or spring [21]. However, these methods cannot satisfy the increasing demand for plant material of the farmers.…”

“…The most important objective of any successful tissue culture is to establish an effective protocol including all stages, starting from the in vitro multiplication until the hardening stage of the plants, which may vary significantly among species and are variety specific. Although some previous research have been conducted for in vitro culture of H. lupulus [21,26,27], considerable efforts are still needed to improve the micropropagation protocols to make them more efficient for practice [3].…”

Auxin type and dilution vehicles on vegetative propagation of Varronia curassavica Jacq. and Melaleuca alternifolia Cheel

“…The application of IBA, diluted in both ethanol and NaOH, was superior to the other treatments for this variable. It is known that the application of exogenous auxins in species serves to increase the percentage, speed, quality and uniformity in rooting (Pigatto et al, 2018;Machado et al, 2018;Gomes and Krinski, 2020). In this sense, indolebutyric acid is one of the most used because it is one of the most efficient due to the characteristics of being photostable, not presenting toxicity over a wide concentration range, having greater chemical stability and being immune to biological action (Tofanelli et al, 2002;Hartmann et al, 2011).…”