The Deterioration of Morocco’s Vegetable Crop Genetic Diversity: An Analysis of the Souss-Massa Region

Crop domestication and breeding efforts during the last half-century in developed countries has significantly reduced the genetic diversity in all major vegetable crops grown throughout the world. This includes developing countries such as Morocco, in which more than 90% of all farms are less than 10 ha in size, which are generally maintained by subsistence farmers who try to maximize crop and animal productivity on a limited land area. Near Agadir, in the remote Anti-Atlas mountain areas of the Souss-Massa region, many small landowner vegetable growers are known to still utilize crop populations (landraces). Thus, an assessment of the current status of vegetable landraces was made in this mountainous region of Southwestern Morocco during 2014. This assessment indicated that a significant loss of vegetable crop landraces has occurred in the last 30 years in this region of Morocco. Although many vegetable crops are still maintained as landrace populations by small subsistence farmers in remote areas in the Souss-Massa region, only 31% of these farmers cultivated landraces and saved seed in the villages assessed, with the average farmer age cultivating landraces being 52 years old. Moreover, the approximated loss of vegetable crop landraces over the last 30 years was an astounding 80 to 90%. Vegetable crops notably lost during this time period included carrot ( Daucus carota ), fava beans ( Vicia faba ), melon ( Cucumis melo ), pea ( Pisum sativum ), watermelon ( Citrullus lanatus ), and tomato ( Solanum lycopersicon ). The most significant loss was tomato as no landraces of this crop were found in this region. The vegetable crop landraces that are still widely grown included carrot, melon, onion ( Allium cepa ), turnip ( Brassica rapa var. rapa ), and watermelon, while limited amounts of eggplant ( Solanum melongea ), fava bean, pea, pepper ( Capsicum annuum ), and pumpkin ( Cucurbita moshata and C. maxima ) were found. This recent genetic deterioration will have a profound influence on future Moroccan agricultural productivity, as the genetic diversity within these landraces may be the only resource available to allow these smaller subsistence farmers to cope with changing environmental conditions for the optimization of crop production in their harsh climate.