Saharan wheats: before they disappear

Abstract

Wheat landraces cultivated in the Saharan oases have been submitted during centuries to drought, heat and salinity and are expected to have developed tolerance to these constraints. The different forms present in the oases of Libya, Algeria and Morocco have been collected and described by several authors who highlighted the peculiarity and diversity of this germplasm, on the basis of spike and grain morphology. The origin, date and way of introduction of wheat in the Saharan oases are however largely unknown. Most landraces may have been introduced from Egypt, possibly during wet climatic episodes. Spike morphological traits of some landraces suggest an Asiatic origin (Iran, Turkestan and Afghanistan). More recent introductions have also probably occurred. This lack of information as well as the potential interest of this germplasm for wheat improvement would merit further studies. Marker-based diversity analysis of Saharan wheats and comparison with North-African and Asian wheats might permit to precise their classification and confirm their origin. Evaluation for tolerance to abiotic constraints would allow a better understanding of their adaptation to the oases environments and identification of potential progenitors to be used by wheat breeders. Such studies are urgent considering the quick genetic erosion of this germplasm due to drastic ecological and socio-economic changes affecting Saharan oases and their cropping systems.

Appendix

Index of geographical names cited in the text

Adrar: capital of Adrar Province (Algeria) based around an oasis in the Touat region, at an elevation of 258 m above sea level.

Aoulef: town in the Tidikelt region (Algeria).

Bechar: capital of Bechar Province (Algeria). Bechar lies at an elevation of 747 m, on the banks of Oued Bechar. To the East are the rocky highlands of the Djebel Bechar (1,206 m) and to the North-East the Djebel Antar (1,953 m). Main cultivated crop in Bechar are dates, vegetables, figs, cereals and almonds.

Beni-Abbes: capital of the Beni-Abbes district, on the South-West of the Bechar province (Algeria).

Biskra (Beskra): capital city of Biskra province (Algeria), located on the northern edge of the Sahara, at 87 m above sea level. It is the centre of the Zab (Ziban) group of oases south of a wide, open depression between the Aures Massif and the Tell Atlas Mountains. Darb el-Arbain: trade route running North–South between Middle Egypt and the Sudan, used from as early as the Old Kingdom of Egypt for the transport and trade of gold, ivory, spices, wheat and animals.

Djanet: oasis and capital of Djanet District, in Illizi Province, South-East Algeria. It is located 412 km South of the provincial capital, Illizi. Djanet lies at an altitude of 1,035 m in a valley carved by the Oued Idjeriou through the South-West edge of the Tassili n’Ajjer mountain range.

El Golea (or El Menia): oasis town located at the eastern border of the Grand Erg Occidental at an elevation of 380 m, capital of El Menia District, Ghardaia Province (Algeria). El Golea oasis grows many agricultural products, particularly palm trees.

Fezzan: desert at the South-West of Libya, broken by mountains, uplands, and dry river valleys (wadis) in the North. Fezzan is crossed in the North by the Ash-Shati Valley (Wadi Al Shatii) and in the West by the wadi Irawan. These two areas as well as portions of the Tibesti Mountains crossing the Chadian border and a sprinkling of oases are the only parts of the Fezzan able to support settled populations. Ergs cover most of the remaining land.

Ghardaia: oasis located within the Sahara Desert (North-Central Algeria), founded by the Mozabites (a Muslim Ibadi sect of non-Arabic Muslims) a thousand years ago in the M’Zab valley.

Ghat: oasis in the Fezzan (Libya). In historical times, Ghat was a major terminal point on the Trans-Saharan trade route.

Gourara: region of Algeria on the North of Touat that contains oases with date palms irrigated by foggaras. The largest town, Timimoun, is a little oasis, 162 km North-East of Adrar, located at the edge of the plateau of Tadmaït.

Hoggar (or Ahaggar): highland region in central Sahara (Southern Algeria), with an average altitude of more than 900 m. The highest peak is at 3,003 m (Mount Tahat). The main city nearby the Hoggar is Tamanrasset, built in a desert valley or wadi. The main oases are Silet, Ideles, Abelassa and In Amguel.

Illizi: town situated in the south-eastern part of Algeria. Also name of the sedimentary basin to the North of Tassili n’Ajjer.

In Salah (Ain Salah): oasis town in central Algeria and important trade link of the trans-Saharan caravan route. Main crops are date palms, fruits and vegetables.

Murzuk (also Murzuq): oasis and capital of the Murzuk District in the Fezzan region of South-West Libya. Murzuk lies on the northern edge of the Murzuk Desert, a desert of ergs or great sand dunes. Murzuk was an important stop on the North–South trade route across the Sahara.

Ouargla (also Wargren or Wargla): town in southern Algeria, surrounded by five small oases: Beni Thour, Sidi Khouiled, Chott, Rouissat, Said Otba and N’goussa.

Saoura: valley in South-West Algeria. The Oued Saoura is formed from the confluence of the Oued Guir and Oued Zouzfana at Igli.

Tafilalt (also Tafilet): most important oasis of the Moroccan Sahara and considered one of the largest oases in the world, the oasis is entirely located along the Ziz River. In Ifli, the central portion, formerly existed the town of Sijilmasa, founded by Miknasa Berbers in 757. It was on the direct caravan route from the Niger to Tangier.

Taghit: oasis in the Bechar Province, on the eastern bank of the Oued Zouzfana, in West Algeria.

Tamanrasset (also Tamanghasset or Tamenghest): oasis town and capital of Tamanrasset Province in South Algeria, in the Hoggar Mountains, located at an altitude of 1,320 m. Main cultivated crops are citrus fruits, apricots, dates, almonds, cereals, corn, and figs.

Tassili n’Ajjer: vast plateau in South-East Algeria at the borders of Libya and Niger. The highest point is Adrar Afao, 2,158 m, and the nearest town is Djanet, about 10 km South-West of the range.

Tell: Arabic word (height) referring to the entire Maghreb fringe ‘useful’ reliefs near the coast, in opposition to the Sahara and the High Plains steppe.

Tibesti: mountain range in the central Sahara, primarily located in the extreme North of Chad, with a small extension into southern Libya.

Tidikelt: region in the center of Sahara. Its boundaries are to the West, the Touat and the valley of Saoura, to the East, Tassili n’Ajjer, to the North the Tademait and to the South the foothills of the Mouydir and Ahnet mountains. From the North to the South can be distinguished a sandy depression that houses Saharan villages and the southern plains crossed by wadis. The main cities are In Salah and Aoulef.

Timimoun: little oasis town and capital of Timimoun District in Adrar Province, Gourara region (Algeria), located at the edge of the plateau of Tademait, at an elevation of around 288 m above sea level.

Touat (also Tuwat and Tuat): a desert region of central Algeria, located to the South of the Grand Erg Occidental, to the East of the Erg Chech and to the South-East of the Tademait Plateau. It contains a string of small oases distributed along the eastern edge of the Wadi Messaoud, a continuation of the Wadi Saoura. The oases extend over a distance of 160 km from the district of Bouda in the North to Reggane in the South. The largest town in the region is Adrar, 20 km South-East of Bouda.

Tsabit: capital of Tsabit District, Adrar Province (Algeria) located near a string of oases, at the southern end of the Gourara region, at an elevation of around 257 m above sea level.

Wadi al Shatii (also ash Shati): one of the districts of Libya in the central-western part of the country. To the West, Wadi al Shatii borders the Illizi Province of Algeria. Wadi al Shatii District is named after the depression Wadi ash-Shati.