As a fundamental pillar of food security in sub-Saharan Africa (SSA), ensuring seed security is critical to empowering farmers in cultivating food and livestock feed, thereby fostering income generation from agricultural outputs. Among the crops cultivated by smallholders, legumes have the potential to deliver multifaceted benefits. Legumes are nutrient-dense and enhance soil health through their nitrogen-fixing qualities. However, in many instances, the development, release, and supply of improved legume varieties are insufficient to meet the needs of smallholder farmers in SSA. Here, we systematically reviewed the literature to (i) identify and categorize existing legume seed systems, (ii) map legume varieties available to smallholders, (iii) identify barriers hindering the adoption of various legume varieties, and (iv) identify potential strategies and opportunities for strengthening legume seed systems in SSA. Our results demonstrate the coexistence of formal and informal seed systems within legume seed supply chains in SSA, each employing unique seed distribution channels. Smallholders, however, are shown to predominantly depend on the informal seed system to source most legume seeds except for commercially available varieties. We also identified a diverse range of legume varieties available to smallholders in the region, with farmers having varying trait preferences based on crop type and gender. Notably, high yield and abiotic stress tolerance were the most preferred traits. The adoption of these varieties, however, is influenced by various factors, including lack of timely access to seeds in adequate quantities from the formal seed system, high seed costs, and limited information on new varieties. The reviewed literature highlighted that utilizing improved legume varieties had a positive effect on smallholders, leading to improved welfare, food security, dietary diversity, and income. We conclude that the effective scaling of legume systems in SSA is contingent upon the presence of supportive policy frameworks and well-established technical support structures.

Graphical Abstract

Packets of legume seeds within a legume germplasm and breeding program at the University of Zambia (Photo by Caitlin Breen, 2022).

中文翻译：

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撒哈拉以南非洲地区的豆类种子系统绩效：障碍、机遇和扩展选项。回顾

作为撒哈拉以南非洲 (SSA) 粮食安全的基本支柱，确保种子安全对于增强农民种植粮食和牲畜饲料的能力至关重要，从而促进农业产出创收。在小农种植的农作物中，豆类具有带来多方面效益的潜力。豆类营养丰富，通过其固氮特性增强土壤健康。然而，在许多情况下，改良豆类品种的开发、发布和供应不足以满足撒哈拉以南非洲小农的需求。在这里，我们系统地回顾了文献，以（i）对现有的豆类种子系统进行识别和分类，（ii）绘制可供小农户使用的豆类品种图，（iii）确定阻碍采用各种豆类品种的障碍，以及（iv）确定潜在的策略和加强撒哈拉以南非洲豆类种子系统的机会。我们的结果表明，SSA 豆类种子供应链中正式和非正式种子系统共存，每个系统都采用独特的种子分销渠道。然而，小农主要依靠非正式种子系统来获取除市售品种之外的大多数豆类种子。我们还确定了该地区小农可以使用的多种豆类品种，农民根据作物类型和性别有不同的性状偏好。值得注意的是，高产和非生物胁迫耐受性是最优选的性状。然而，这些品种的采用受到多种因素的影响，包括无法及时从正规种子系统获得足够数量的种子、种子成本高以及新品种信息有限。审查的文献强调，利用改良的豆类品种对小农具有积极影响，从而改善福利、粮食安全、饮食多样性和收入。我们的结论是，SSA 豆类系统的有效扩展取决于支持性政策框架和完善的技术支持结构的存在。

图形概要

赞比亚大学豆类种质和育种计划中的豆类种子包（摄影：Caitlin Breen，2022 年）。