MICROPROPAGATION OF GLOBE ARTICHOKE PLANT (Cynara scolymus L.). 1- EFFECT OF SODIUM HYPOCHLORITE CONCENTRATIONS, CYTOKININS AND SUBCULTURES NUMBER ON SHOOTS MULTIPLICATION RATE.

Abstract

An efficient protocol for both development of aseptic tissue cultures and shoots regeneration for Cynara scolymus L. cv. Herious was established by using in vitro micropropagation technique. Meristem tips of good young offshoots from selected globe artichoke plants were used as explants. Dipping shoot tips (1-2 cm length) in 70% ethanol for 5-10 seconds followed by 0.1% HgCl2 (W/v) for 2 minutes and then in 3% sodium hypochlorite for 20 minutes was the most effective sterilizing and disinfectant treatment for surviving the majority of meristem tip cultures after 5 weeks of culturing. In the establishment stage, adding 0.5 mg thidiazuron (TDZ) /l to MS basal medium gave the best values for both shoots and leaves number but registered middle values for average shoots length compared to the other treatments. Concerning the multiplication stage, among the different cytokinin types and concentrations used such as 2iP, BA and Kin (at 0.5, 2.5 and 5.0 mg /l for each) and TDZ (at 0.05, 0.5 and 1.0 mg /l) in addition to control treatment (hormone-free MS medium), 2iP with all concentrations recorded the highest values in this respect in terms of shoots and leaves number and average shoots length. The multiplication rate of proliferated globe artichoke shoots and average shoots length were markedly increased with increasing subcultures number on MS basal medium augmented with 5.0 mg 2iP /l + 1.0 mg IAA /l till the fourth subculture then declined thereafter during the fifth one.

Comparative study on in vitro micropropagation response of seven globe artichoke [Cynara cardunculus var. scolymus (L.) Fiori] cultivars: open-pollinated cultivars vs F1 hybrids

“…The micropropagation was conducted with two media combinations until 3 rd subculture. In previous studies, it was stated that MS basic medium supports in vitro shoot formation in globe artichoke (De Leo and Greco, 1973;Ancora et al, 1981;Pécaut et al, 1983;Iapichino, 1996;Alp et al, 2010;El-Zeiny et al, 2013;López-Pérez and Martínez, 2015;Dawa et al, 2018). Throughout the experiments, media combinations were carried out with MS basic medium and it was found that MS basic media supplemented with 0.05 mg L -1 BA + 0.005 mg L -1 IBA combination (No.1) was more successful than media combination of 0.25 mg L -1 BA + 0.025 mg L -1 IBA (No.2) in terms of general appearance, growth and development of plantlets.…”

“…El-Zeiny et al (2013) reported that they recorded an increase in in vitro production until the 5 th subculture in a total of 7 subcultures conducted in their study. Similarly, Dawa et al (2018) stated that when the number of subcultures was increased in vitro multiplication rate also increased until a certain number of subcultures. It is thought that decision of how many subcultures needed to reach to certain number of plants should be done heavily depends on the cultivars used for in vitro micropropagation.…”

“…Offshoot or ovoli is used for vegetative propagation. However, vegetative propagation has some difficulties such as transferring some diseases and pests through the main plants used in the reproduction, the low reproduction rate during the growing period hinders genetic and agronomic development, physiological differences between shoots taken from the same parent plant and being less suitable for the mechanization (Ancora, 1986;Ordás et al, 1990;Morzadec and Hourmant, 1997;Rey et al, 2013;Saccardo et al, 2013;Bekheet et al, 2014;Campanelli et al, 2014;Dawa et al, 2018;Mazzeo et al, 2020).…”

“…Homogenous, free from diseases and pests, healthy plants can be obtained by in vitro micropropagation method, while this method also provides a high reproduction rate. In previous micropropagation studies shoot tip, meristem and seeds were used as explants (Ancora et al, 1981;Pécaut et al, 1983;Rossi and De Paoli, 1992;El Boullani et al, 2012;Bekheet et al, 2014;Dawa et al, 2018). Due to the infection problem encountered in shoot tip culture, researchers decided to use meristem culture in order to obtain healthy, virus and other pathogens free plantlets.…”