Prospects of increasing the presence of Helianthemum kahiricum Dell. pastoral North African plant by means of micropropagation

Abstract

Helianthemum kahiricum has great potential in forage, in traditional medicine, for halting desert encroachment and stabilizing sand dunes through their excellent root systems development, and in the improvement of soil organic matter content. H. kahiricum is threatened with extinction because of overgrazing abuse and increasing human disturbance. For these reasons, in vitro propagation is essential for developing efficient conservation program. Several cytokinins: indole-3-acetic acid (IAA) ratios and a range of zeatin concentrations were evaluated for their effect on shoot multiplication from apical shoots and nodal segments. The type of cytokinin and the origin of the explants were the most important factors affecting shoot multiplication. The highest shoot multiplication rate was obtained from single-nodal explants on medium hormone free. Increasing zeatin concentrations promotes decreased shoot multiplication independently of explants type, although this effect tends to decrease with higher zeatin concentration. Shoot growth was higher in apical shoots and it was not stimulated by the presence of auxin. A number of experiments were conducted to identify suitable procedures for rooting of in vitro produced shoots. Although, rooting frequency rose to 98% by in vitro culture on an auxin-free medium, the survival of the plants after 6 months of acclimatization was good (90%).

In vitro Propagation to Conserve the Local Endemic and Endangered Medicinal Plant Helianthemum germanicopolitanum Bornm.

“…The shoot, node and apical parts of the plant were successfully used as an initial explant in tissue culture of Helianthemum sp. genera, as well as in many plants [24,25,26,27,28,29]. In the present study, depending on the development of explants, the media in which they were planted and the PGR combinations they contain, callus, shoot and root formations were observed.…”

“…Serrano-Martinez and coauthors (2012) used H. marminorense and observed the best root number and root development in the WPM medium without PGR [26]. Hamza and coauthors (2014) observed a significant growth in MS medium containing 1 mg/L IBA and MS medium with 1 mg/L NAA for H. kahiricum [28].…”

“…Hamza and coauthors (2013) added different doses of IBA and NAA to the MS medium in initial stage then achieved the highest rooting rate of 71.80% in MS PGR free medium in H. lippii L. var sessiliflorum [27]. Hamza & Neffati (2014) obtained the highest rooting (94 -98%) in H. kahiricum with the addition of 1 mg/L IBA and NAA to the ½ MS medium [28]. In H. almeriense, the sixth subculture achieved the highest rooting (92%) with a low cytokinin rate [24].…”

Micropropagation of Helianthemum lippii L.var sessifolium

“…Potted plantlets were placed in a growth chamber set at 80% relative humidity, 25 ± 2°C, with a 16 h photoperiod, for two months, then transferred to a greenhouse under natural daylight conditions at 25°C temperature. (Amina & Mohamed, 2014). These plantlets are growing well without any phenotypic aberrations.…”

“…After about 2-3 weeks the bags were removed and humidity decreased gradually. (Amina & Mohamed, 2014).…”