Rashid Sultan Al-Obeed’s research while affiliated with King Saud University and other places

Fegra fig ( Ficus palmata ) is an important fruit-yielding crop and potential rootstock for grafting Ficus carica . The acclimatization phase is a pivotal step during the micropropagation of plants. During this study, the mycorrhization of micropropagated fegra fig plants with two arbuscular mycorrhizal fungi (AMF; Gigaspora margarita and Gigaspora albida ) to enhance their growth and survival during the acclimatization stage was investigated. The AMF were mixed in equal proportions and the acclimatizing fegra fig plantlets were treated for 8 weeks. The leaf pigments, i.e., chlorophyll a [2.56 mg·g ⁻¹ fresh weight (FW)], chlorophyll b (1.08 mg·g ⁻¹ FW), total chlorophyll (3.67 mg·g ⁻¹ FW), and carotenoid (1.34 mg·g ⁻¹ FW), of AMF-treated plants were higher than those of non-AMF plants. The number of stomata per unit was higher in the AMF-treated plants (16.00), the density of stomata per unit area (88.40 mm ² ) of AMF-treated plants was similar to that of non-AMF treated plants, and the number of epidermal cells (79.00) was higher in the AMF-treated plants. The AMF-treated plants were taller and had more leaves, a greater leaf area, and higher shoot FW and dry weight. The AMF-treated plants also had the greatest total root length values, greatest surface areas of roots, and greatest total root volume and diameter compared to those of non-AMF plants. Additionally, the AMF-treated plants had a 100% survival rate, whereas a survival rate of 95% was recorded for non-AMF plants. These findings emphasize the importance of biological acclimatization of micropropagated fegra fig plants with AMF.

Tissue culture is used to multiply Al-Taif rose (Rosa damascena f. trigintipetala (Diek) R. Keller) plants in order to meet the demands of the fragrance, cosmetic, and floriculture industries. The use of arbuscular mycorrhizal fungus (AMF) could potentially improve plant growth and acclimatization performance to ex vitro conditions. Thus, in the current study, we investigated how AMF Rhizophagus fasciculatus influences the growth, establishment, and physiological performance of micropropagated Al-Taif rose plants during the acclimatization stage. The growth and physiological parameters of the AMF-treated plants were evaluated after a 12 week growth period in the growth chambers. The plants treated with AMF exhibited greater height (25.53 cm) and biomass growth values for both shoot fresh weight (0.93 g/plant) and dry weight (0.030 g/plant), more leaves (11.3/plant), more leaf area (66.15 cm2), longer main roots (15.05 cm/plant), total root length (172.16 cm/plant), total root area (64.36 cm2/plant), and biomass from both fresh weight (383 mg/plant) and dry weight (80.00 mg/plant) of the plants. The plants treated with AMF also exhibited increased rates of net CO2 assimilation, stomatal conductance, and transpiration compared to the control plants. The proline content in the leaves and roots was significantly lower in the AMF-treated plants than untreated plants. The Fv/Fm ratio, which serves as an indicator of the intrinsic or maximal efficacy of Photosystem II (PSII) demonstrated a notable decline in the untreated Al-Taif rose plants. These results elucidate the advantageous impact of AMF colonization on micropropagated Al-Taif rose plants, thereby enhancing their resilience against adverse ex vitro conditions.

Cryopreservation allows for the long-term storage of biological materials, ensuring their viability for future use and preserving biodiversity. This study aimed to develop an efficient protocol for the long-term in vitro conservation of fegra fig. In vitro precultured shoot tips of fegra fig with 0.3 M sucrose showed the highest re-growth percentage (100%) before plunging into liquid nitrogen. After plunging into liquid nitrogen, the regrowth percentage was 43.33%. Following cryopreservation, the recovered shoots were rooted and acclimatized to ex vitro conditions. The genetic fidelity of the acclimatized 8-week-old fegra fig plantlets after cryopreservation with their mother plant was tested using randomly amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR), and start codon targeted (SCoT) molecular markers. Genetic similarity between the stored plantlets with their mother plant was 100% ensuring uniformity and true-to-type regenerated plants following cryopreser-vation. This study presents, for the first time, an efficient protocol for the genetic conservation of fegra fig.

Micropropagation facilitates the rapid production of roses. Nevertheless, in vitro rhizogenesis of essential oil roses has presented significant challenges, primarily attributed to low rates of rooting and poorer acclimatization compared to ornamental rose varieties. This study reports the optimization of in vitro rooting of Al-Taif rose (Rosa damascena f. trigintipetala (Diek) R. Keller) microshoots with the aim of increasing survival rate during acclimatization. We also investigated the effects of various parameters, including type and concentration of auxin (i.e., 2,4-Dichlorophenoxyacetic acid (2,4-D), indole acetic acid (IAA), indole butyric acid (IBA), and naphthaleneacetic acid (NAA) at concentrations of 0, 0.05, 0.1, 0.2, and 0.4 mg/L), salt strength (i.e., full- and half-strength Murashige and Skoog (MS) medium), sucrose concentration (i.e., 20, 30, 40, 60, and 80 g/L), light spectra (a 2:1 or 1:2 blue/red spectral ratio, cool or warm white light at a 1:1 ratio, and fluorescent light), light intensity (photosynthetic photon flux density (PPFD) values of 25, 50, and 100 µmol·m−2·s−1), and activated charcoal (i.e., 0 and 0.5 g/L) on the rooting and growth of in vitro regenerated Al-Taif rose axillary shoots. We found that half-strength MS medium supplemented with 0.2 mg/L NAA, 80 g/L sucrose, 0.5 g/L activated charcoal, and 50 μmol·m−2·s−1 PPFD were the optimal conditions for 100% induction of adventitious roots. Next, micropropagated Al-Taif rose plantlets were successfully transferred to a potting medium containing perlite/peatmoss (in a 1:1 ratio). We found that 98% of plants survived ex vitro conditions. The genetic fidelity of micropropagated Al-Taif rose clones along with their mother plant was tested using the inter-simple sequence repeats (ISSR) molecular marker. The genetic similarity between the micropropagated plantlets and the mother plant of Al-Taif rose plants was 98.8%, revealing high uniformity and true-to-type regenerated plants. These findings may therefore contribute toward the commercial micropropagation of Al-Taif roses.

Rose is a widely favored floriculture crop that is commercially propagated through the application of tissue culture techniques. Here, we report an effective method for axillary shoot proliferation in Al-Taif rose, an important cultivar for rose oil industry. Stem nodes were excised from an adult donor Al-Taif rose shrub and cultured for 4 weeks on Murashige and Skoog’s (MS) medium supplemented with 6-benzylaminopurine (BAP) or gibberellic acid (GA3) at 0 and 3 mg·L−1 to induce the sprouting of axillary shoots. Al-Taif rose shoots were cultured in vitro for 6 weeks on MS medium fortified with different concentrations of cytokinins, light/dark incubation and different culture types (gelled and liquid/bioreactor culture). The culture conditions that were applied had a noteworthy impact on the responses of Al-Taif rose shoot proliferation. The supplementation of the medium with 6-benzylaminopurine (BAP) resulted in an augmented rate of shoot proliferation in comparison to other cytokinins. Additionally, dark incubation limited foliage growth, leaf yellowing and abscission and favored shoot proliferation compared with light incubation. Liquid culture using bioreactors provided higher axillary shoot proliferation and growth as compared with gelled culture. A continuous immersion system with a net provided the highest axillary shoots (four shoots per explant) and shoot length (16.5 cm), whereas an immersion system without a net provided the highest fresh weight of axillary shoots (499 mg per explant). These findings will improve commercial propagation and contribute to the rose oil industry of Al-Taif rose.