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The African horned cucumber ( Cucumis metuliferous) and the Kalahari Desert Truffles ( Kalaharituber pfeilii ): Prospects and Potential for research & sustainable exploitation. Name : Modise DM University: UNIVERSITY OF SOUTH AFRICA (UNISA) Country : PRETORIA. SOUTH AFRICA.

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name modise dm university university of south africa unisa country pretoria south africa

The African horned cucumber (Cucumis metuliferous) and the Kalahari Desert Truffles (Kalaharituber pfeilii): Prospects and Potential for research & sustainable exploitation

Name : Modise DM



outline of presentation
  • Introduction of crops
  • Research on cucumber and truffles
  • Potential for sustainable exploitation
  • Future research work

Why the interest in C. metuliferous and K pfeilii?

(local and international interest)

Above: C metuliferous Below: K pfeilii

cucumis metuliferous e may ex naud maxije polish
Cucumis metuliferous E. May Ex. NaudMaxije (Polish)


  • Annual herb with climbing stems
  • Fruits covered in large soft spines (horns)
  • Bitter and sweet cultivars in the wild and cultivated. Morphologically indistinguishable
  • USES
  • Eaten (fruit, seed and leaves)
  • Medicinal properties (anti-tumour & inflammation), Prevent difficult childbirth in Africa
  • Ornamental with long shelf life
description and uses continued
Description and Uses (Continued)
  • Fully ripe cucumber

Cross section of fully ripe fruit


Research Summary: Performance under shade net, greenhouse and field conditions during hot dry growing conditions. Normal experimental procedures undertaken.

Table 1(Right): Emerge and grow well under shade

Table 2 (Below): Sweeter fruit when mature

deductions on c metuliferous
Deductions on C. metuliferous
  • Does grow under cultivation in Southern Africa
  • Thrives under shade as under natural conditions
  • Becomes sweeter with maturity
  • There is great potential for commercialisation as New Zealand & California already does
kalaharituber pfeilii trappe description
Kalaharituber pfeilii Trappe Description
  • Macrofungi commonly found in the Kalahari and Namib Desert
  • • Fleshy subterranean fruiting bodies of fungi (pungent smell), enclosed spores
  • Symbionts forming mychorrhizal association with other plants

Plate 1: Truffles also called Sand-potato

Plate 2: Cross section of a truffle

  • Source of income for communities
  • Highly nutritious esp. in micro, macronutrients
  • Believed to have aphrodisiac properties (sexual libido)
  • Eaten to sustain lives by purging hunger
  • spp. of Cynodon, Eragrostis although there is varied opinion on mycorrhization (monocots).
  • Acacia spp., Grewiaflava, mostly on undisturbed desert soils.
  • Recently harvesting some in Sorghum bicolor (Plate 3) and Citrullus lanatus (Plate 4) plantings on arenosols.
research on truffles
Research on truffles
  • Synonyms: Terfezia pfeilii Aviram et al.(Ben Gurion University, Israel, 2005) after phylogenetic studies to determine generic placement.
  • Both Terfezia pfeilii. and K. pfeilii placed as Pezizaceae since ITS region of RNA placing was similar.

Chang and Mshigeni (2001) determined that the truffles contain proteins (20-28%), 3-7% fat, 7-13% crude fibre & 60 % CHO, ↓vitamin but ↑ K and P.

preliminary studies on mineral content faculty of agriculture foa botswana collaborators and unisa
Preliminary Studies on mineral contentFaculty of Agriculture (FOA)- Botswana collaborators and UNISA
  • FOA & collaborators also carried out studies on effect of the size of the truffles on some macro/micronutrients.
  • ~ 1 ton fruiting bodies were harvested and sorted into batches according to 5 different sizes (40-200g), oven dried and the measurements determined.

- Fe, Zn, Cu, and Mn determined by AAS and macronutrients by flame photometer. AOAC.

significance of the nutritional studies
Significance of the nutritional studies
  • There were no significant differences in K and P among the sizes, suggesting that weight or size does not matter.
  • Other minerals suggest a general increasing trend particularly at 160-200g.
  • Unknown: Since truffles are pungent and strongly aromatic, does size matter on aroma volatile compounds?

Are there any anti-nutritional factors?

truffles as potential antioxidants
Truffles as potential antioxidants
  • Collaborators at the FOA are engaged in evaluating antioxidant activity of aqueous truffle extract on ability to scavenge free radicals, and on the inhibition of lipid peroxides. Established bio-protocols followed.
  • The effect of extracts on antioxidant enzymes such as superoxide dismutase (SOD), CAT etc. and antioxidants such as GSH are being investigated.
  • Indications are that oxidative stress/damage induced by alcohol, can be prevented by use of truffle extract. Rats are used in the experiments.
  • Oxidative stress is pathogenitical and associated with liver injury due to ethanol administration.
  • Unknown: Could truffles be eventually used to prevent damage to the liver when induced by alcohol? Alcohol abuse?
veld products research develop nt instit botswana mychorrhizal association
Veld Products Research Developnt Instit. (Botswana) – Mychorrhizal association
  • In collaboration with Ben Gurion University determined that certain grass spp. and Curcubitaceae formed positive association in the roots by PCR identification of DNA.
  • When P levels are ↑in soil mychorrhization is ↓, plant does not need fungal assistance in absorption of P. (5mmol/kg VS > 50mmol/kg). Endomycr formed versus Ectomycr.
  • Unknown: From mycorhization to fruit-bodies formation, how long does it take?

Are truffles annuals?

university of namibia unam
University of Namibia (UNAM)
  • UNAM have been working on promoting sustainable use and marketing potential of mushrooms such as Ganoderma lucidum and the Kalahari desert truffles.
  • Also use of various Citrullus and Acacia spp. inoculated with truffle slurry and results have shown that:
    • Larger watermelons
    • Larger canopy of trees
    • Reason for better performance of inoculated plants is not clear.
the arab world
The Arab World
  • Kingdom of Bahrain and Iraq have conducted ethnomycological studies on truffles.
  • Findings confirmed truffles are a source of financial relief, eating and medicinal value i.e. if recommended by physician.
  • Preservation methods such as freezing and pickling are utilised by communities.
future work
Future work
  • Identification and molecular work to improve sweetnes in cultivars of C. metuliferous
  • Commercial production systems for Southern Africa
  • Nutritional studies– volatile compounds & essential oils
  • Antioxidant studies – application to life.
  • Mychorrizhal association and fruiting-body development. What triggers fruiting?
  • Follow up to determine if the truffles are annuals or not.
  • Processing and shelf life.
  • Market interventions to benefit the rural communities at the truffle areas (add value)
  • Professor E. B. Khonga (FOA) - Botswana)
  • Dr. K. K. Mogotsi (Ibid), also provided photographs and literature
  • Mr. S. Machacha (Ibid)
  • Mrs. I. George (Ibid)
  • Professor Kagan Varda Zur – Ben Gurion University, Israel
  • UNISA for travel grant