Glato Kodjo, Aidam Atsou, Kane Ndjido Ardo, Bassirou Diallo, Couderc Marie, Zekraoui Leila, Scarcelli Nora, Barnaud Adeline, Vigouroux Yves
University of Lomé, Lomé, Togo.
Institut Sénégalais de Recherches Agricoles (ISRA), Dakar, Sénégal.
PLoS One. 2017 May 26;12(5):e0177697. doi: 10.1371/journal.pone.0177697. eCollection 2017.
Sub-Saharan agriculture has been identified as vulnerable to ongoing climate change. Adaptation of agriculture has been suggested as a way to maintain productivity. Better knowledge of intra-specific diversity of varieties is prerequisites for the successful management of such adaptation. Among crops, root and tubers play important roles in food security and economic growth for the most vulnerable populations in Africa. Here, we focus on the sweet potato. The Sweet potato (Ipomoea batatas) was domesticated in Central and South America and was later introduced into Africa and is now cultivated throughout tropical Africa. We evaluated its diversity in West Africa by sampling a region extending from the coastal area of Togo to the northern Sahelian region of Senegal that represents a range of climatic conditions. Using 12 microsatellite markers, we evaluated 132 varieties along this gradient. Phenotypic data from field trials conducted in three seasons was also obtained. Genetic diversity in West Africa was found to be 18% lower than in America. Genetic diversity in West Africa is structured into five groups, with some groups found in very specific climatic areas, e.g. under a tropical humid climate, or under a Sahelian climate. We also observed genetic groups that occur in a wider range of climates. The genetic groups were also associated with morphological differentiation, mainly the shape of the leaves and the color of the stem or root. This particular structure of diversity along a climatic gradient with association to phenotypic variability can be used for conservation strategies. If such structure is proved to be associated with specific climatic adaptation, it will also allow developing strategies to adapt agriculture to ongoing climate variation in West Africa.
撒哈拉以南非洲地区的农业已被认定易受当前气候变化的影响。有人建议通过农业适应措施来维持生产力。更好地了解品种的种内多样性是成功管理此类适应措施的先决条件。在农作物中，根茎类作物对非洲最脆弱人群的粮食安全和经济增长起着重要作用。在此，我们聚焦于甘薯。甘薯（Ipomoea batatas）原产于中美洲和南美洲，后来被引入非洲，如今在整个热带非洲地区都有种植。我们通过对从多哥沿海地区到塞内加尔萨赫勒北部地区的一个区域进行采样，评估了其在西非的多样性，该区域代表了一系列气候条件。我们使用12个微卫星标记，沿着这个梯度评估了132个品种。还获得了在三个季节进行的田间试验的表型数据。结果发现，西非的遗传多样性比美洲低18%。西非的遗传多样性被分为五个组，其中一些组存在于非常特定的气候区域，例如热带湿润气候或萨赫勒气候条件下。我们还观察到在更广泛气候范围内出现的遗传组。这些遗传组也与形态分化有关，主要是叶片形状以及茎或根的颜色。这种沿着气候梯度的特殊多样性结构及其与表型变异性的关联可用于保护策略。如果这种结构被证明与特定的气候适应性相关，它还将有助于制定使西非农业适应当前气候变化的策略。
