Name : Modise DM University: UNIVERSITY OF SOUTH AFRICA (UNISA) Country : PRETORIA. SOUTH AFRICA

1. 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

2. OUTLINE OF PRESENTATION • Introduction of crops • Research on cucumber and truffles • Potential for sustainable exploitation • Future research work

3. INTRODUCTION Why the interest in C. metuliferous and K pfeilii? (local and international interest) Above: C metuliferous Below: K pfeilii

4. Cucumis metuliferous E. May Ex. NaudMaxije (Polish) BRIEF DESCRIPTION • 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

5. Description and Uses (Continued) • Fully ripe cucumber Cross section of fully ripe fruit

6. 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

7. 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

8. 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

9. USES • 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

10. Symbionts • 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.

11. Plate 3 Sorghum bicolor field

12. Crack where truffle is located proximal to Citrullus spp.

13. 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.

14. 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.

15. Mineral studies cont’d

16. 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?

17. 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?

18. 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?

19. 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.

20. 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.

21. 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)

22. Acknowledgements • 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