BackgroundBapedi traditional healers of Blouberg are custodians of indigenous knowledge on medicinal plants of this region. They provide primary health care to a large number of people in the Blouberg area of South Africa. There is concern that this profession is dying out, which may be detrimental to the Blouberg community and to biodiversity conservation in the area.MethodsThirty two healers and 30 community members were interviewed between March 2011 and July 2013 around Blouberg Mountain in the Blouberg Municipality. A semi-structured questionnaire was used to elucidate socio-cultural and demographic variables and healing customs of practicing healers. Attitudes to sustainable management of medicinal plants were captured. A second semi-structured questionnaire was used to gather information on community members’ views of traditional healers and their practices.ResultsSixty seven percent of interviewed community members visited traditional healers. Female traditional healers dominated (80%) the profession. Sixty four percent of the healers have no formal education, with only 4% having secondary school education. Seventy nine percent of healers see between 15 and 20 patients per month. Clinics and a hospital in the vicinity have resulted in a shift by the community from using tradition-based healing to that of allopathic health care. Most interviewed traditional healers (71%) are in favour of conservation actions to prevent over-harvesting, as 86% believe that indiscriminate collecting is compromising the flora of the area. Most (93%) are willing to use cultivated plants.ConclusionsState health care has negatively influenced the practice of traditional healing as patients now first consult government health centres before turning to traditional healers. In the past, traditional healing has been ignored because, as an oral history, it could not be included in school curricula or government policy documents. Those traditional healers who learn to write will have the skills to document and safeguard their own knowledge. This can help to prevent the erosion of knowledge around Blouberg’s medicinal plants and support the conservation of natural resources in the area. Adult learning programmes might therefore be worth implementing amongst healers.

Desiccation tolerance (DT) is observed across all biological kingdoms and is a relevant phenomenon in an ecological, social and economic context. In face of imminent climate changes DT will become a highly relevant trait for crop production, as well as for wild plant species conservation. When did desiccation tolerance first appear? How can any organism survive complete drying? What are the structural, molecular, biochemical and genetic principles involved in this phenomenon? Are the mechanisms orchestrating DT conserved among the biological kingdoms? Inspired by these questions and the proven complexity of this trait we have developed an experimental system to re-establish DT in Arabidopsis thaliana seeds. We show that the incubation of desiccation sensitive (DS) germinated Arabidopsis seeds in a polyethylene glycol (PEG) solution, in exogenous abscisic acid (ABA), or a combination of both, re-activates the mechanisms necessary for expression of DT. By using this model of loss and reestablishment of DT in combination with ABA-deficient and -insensitive mutants, we prove that ABA is necessary for the reestablishment of DT and hypothesize that the events upstream of ABA signaling are not necessary to rescue DT. Furthermore, we demonstrate that ABA sensitivity correlates with the developmental window of the seed/seedling in which DT can be rescued. We also explored this system to investigate the transcriptome, the primary metabolome and the total proteome involved in DT as a first attempt to uncouple osmotic and ABA specific pathways that are regulating this trait.

Hibiscus coddii subsp. barnardii is an endemic South African plant species with ornamental potential. The limited plant availability in nature and restrictions on the collection of living plant material (cuttings) for cultivation purposes, necessitated the development of a protocol for in vitro seed propagation to ensure all year round ex vitro establishment of plants. The effect of culture medium on seed germination and seedling performance was therefore studied. Various types of sterile seed cultures, namely moist filter paper bridges, five different strengths (¼, ½, –, full, 1¼) of PGR-free Murashige and Skoog medium (MS) and solid Gelrite® medium (control) were investigated. High germination percentages (85%-98%) were found in all three seed cultures, although seeds germinated on filter paper, Gelrite ® and lower strengths (¼, ½, –) of MS medium had shorter mean germination times (1.6-2.8 days) than those germinated on full and 1¼ strengths (3.5-4 days) of MS medium. Furthermore, the growth performance of seedlings varied with the strength of MS medium and was best supported on full strength MS medium, whereas ¼ and ½ strength MS media and Gelrite® cultures were detrimental for seedling growth.

In vivo and in vitro grown plants of Hibiscus coddii subsp. barnardii were used as explant source for establishment of in vitro cultures. Nodal shoot explants derived from in vivo grown plants, both naturally and under controlled environmental conditions, showed high sensitivity to the surface disinfection treatment and poor survival in in vitro culture. In vitro grown seedlings proved successful as aseptic source of apical and basal shoot explants to establish contamination-free in vitro cultures. Sprouting of axillary buds was observed on 90% of apical shoot explants after four weeks of culture on full strength, plant growth regulator (PGR)-free Murashige and Skoog (MS) medium. However, further proliferation of short shoots, limited to the bud sprout at the explant base, occurred on only 50% of these explants. In contrast, all basal shoot explants attained 3-5 single primary axillary shoots (30-40 mm in length) while a clump of short (5-10 mm) shoots also formed at the base in 60% of these explants. In both explant types, addition of 0.25-1 mg L-1 6-Benzylaminopurine (BAP) to the MS medium resulted in a low frequency (10%-60%) of explants with short shoots (5-10 mm) that showed no further elongation. Moreover, explants cultured in the presence of BAP showed a high frequency of callus formation (up to 90%) and low survival (20%-60%). A lower frequency of callus formation (30%-40%) and higher survival (90%-100%) of both explant types occurred on BAP-free medium. Further subculturing of primary and secondary axillary shoots onto fresh MS medium (with and without BAP) did not improve shoot multiplication. Regenerated plantlets from PGR-free MS medium were successfully acclimatized and hardened-off.

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