The percent study describes the in vitro responses of mature zygotic embryos of Boscia senegalensis to different concentrations (0.0–5.0 mg/L) of 6-benzyladnine (BA), Thidiazuron (TDZ), α-Naphthalene acetic acid (NAA), and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) supplemented on Murashige and Skoog medium (MS). The plant growth regulators (PGRs) were considerably affected the morphogenetic responses. BA produced adventitious shoots through two ways: direct organogenesis and auxiliary shoot formation. Both 2, 4-D and TDZ tend to produce callus, whereas NAA improve the development of embryos to seedlings. Maximum number of shoots/explant (14.8 ± 0.6) was obtained on MS medium supplemented with 3.0 mg/L BA. 67.0% of excised shoots were rooted either on 1/2 MS medium augmented with or without 0.25 mg/L IBA. The highest number of roots (1.2 ± 0.4) and root length (0.5 ± 0.2 cm) was produced on 0.25 mg/L IBA-containing medium. Regenerated plants were successfully acclimatized and transferred to the green house with 70% survival rate. All the plants appeared morphologically uniform with normal growth pattern. A rapid (30 days), efficient and without subculturing protocol for in vitro regeneration of B. senegalensis was developed.

Grewia tenax is an important nutraceutical plant threatened due to excessive fruit collection and physiological dormancy of seeds. In vitro propagation is required for ex situ conservation of this neglected plant. Improving germination rate is vital for providing the uniform explant material required for propagation and in vitro studies. The aim of this study was to optimize cultivation conditions for in vitro seed germination and micropropagation of G. tenax. Full seed germination was achieved in all treatments. Tests in distilled water medium showed the least number of days for germination and highest seedling length. Full Murashige and Skoog medium produced the maximum number of nodes. Darkness promoted germination rate and seedling length, but decreased the number of nodes per seedling. Benzyladenine and kinetin slightly increased the number of nodes compared to the control. Each uninodal explant cultivated on Murashige and Skoog medium free of plant growth regulators developed into a plantlet within one week. Well-rooted plants were successfully established in a greenhouse with 95% survival rate. This plant growth regulator-free system can successfully overcome seed dormancy and provide a rapid-continuous supply of plant material of G. tenax.

This report describes in vitro micropropagation of Boscia senegalensis, so-called famine foods, that helped the people in Darfur and Kordofan, Sudan survive during the 1984-1985 famine. Four types of explants prepared from green mature zygotic embryos were cultured on Murashige and Skoog (MS) medium augmented with 1-5 mg/L 6-benzyladenine (BA). The highest number of shoots per explant (14.3±0.9) was achieved on MS medium supplemented with 3 mg/L BA, while the highest shoot length [(3.5±0.4) cm] was obtained with 1 mg/L BA. The shoot cluster, when subcultured to its same medium, significantly increased the rate of shoot multiplication by the end of the third subculture. The maximum mean number of shoots per explant (86.5±3.6) was produced after three multiplication cycles on 3 mg/L BA-supplemented medium. In vitro induced shoots were excised and rooted on half strength MS medium fortified with 0.25 mg/L indole-3-butyric acid (IBA) to obtain complete plantlets. B. senegalensis-regenerated plantlets obtained in vitro for the first time, were hardened and 95% survived under greenhouse conditions.

No abstract

Striga hermonthica is an obligate, root parasite, that limits cereal production in sub-Saharan Africa. Successful control depends on eliminating its seed reserves in soil, thereby preventing parasitism. Two experiments were conducted to evaluate the effects of salinity on germination traits and seedling growth of sorghum (cultivar Wad Ahmed) and S. hermonthica. The experiments were conducted in a factorial arrangement on the basis of completely randomized design (CRD) with 4 replications. In the first experiment, sorghum height, leaf area, and shoot and root dry weights were examined. The results displayed that, with increasing salinity level, leaf area and dry biomass were increased, while the height was decreased. In the second experiment, Striga germination and haustorium initiation percentages were examined. Among all salts, C2H4O2·NH3 inhibited Striga germination (0–15%) during conditioning or (0–25%) at germination compared to the control (75%). However, salt MgSO4·7H2O improved germination during conditioning up to 70%, while during germination CH3COONa·3H2O recorded 65% germination. Regarding haustoria initiation, results showed that C2H4O2·NH3 at all concentrations inhibits haustorium formation by 100%, while CH3COONa·3H2O at 10 µM improved haustorium formation up to 64% but still below the control (70%). Osmotic potential may significantly affect germination and radicle elongation of the parasitic weed.