Matsumoto Ryo, Ishikawa Haruki, Asfaw Asrat, Asiedu Robert
International Institute of Tropical Agriculture, Ibadan, Nigeria.
Front Plant Sci. 2021 Feb 19;12:629762. doi: 10.3389/fpls.2021.629762. eCollection 2021.
Yam ( spp.) is a major food security crop for millions of resource-poor farmers, particularly in West Africa. Soil mineral deficiency is the main challenge in yam production, especially with the dwindling of fallow lands for the indigenous nutrient supply. Cultivars tolerant to available low soil nutrients and responsive to added nutrient supply are viable components of an integrated soil fertility management strategy for sustainable and productive yam farming systems in West Africa. This study's objective was to identify white Guinea yam () genotypes adapted to available low soil nutrients and responsive to externally added nutrient supply. Twenty advanced breeding lines and a local variety (Amula) were evaluated under contrasting soil fertility, low to expose the crop to available low soil nutrient supply and high to assess the crop response to added mineral fertilizer (NPK) input at Ibadan, Nigeria. The genotypes expressed differential yield response to low soil fertility (LF) stress and added fertilizer input. Soil fertility susceptibility index (SFSI) ranged from 0.64 to 1.34 for tuber yield and 0.60 to 1.30 for shoot dry weight. The genotypes R034, R041, R050, R052, R060, R100, and R125 combined lower SFSI with a low rate of reduction in tuber yield were identified as tolerant to LF stress related to the soil mineral deficiency. Likewise, the genotypes R109, R119, and R131 showed high susceptibility to soil fertility level and/or fertilizer response. Genotypes R025 and R034 had the tuber yielding potential twice of that the local variety under low soil nutrient conditions. Shoot dry weight and tuber yield showed a positive correlation both under low and high soil fertility conditions ( = 0.69 and 0.75, respectively), indicating the vigor biomass may be a morphological marker for selecting genotypes of white Guinea yam for higher tuber yield. Our results highlight genotypic variation in the tolerance to low soil nutrients and mineral fertilizer response in white Guinea yam to exploit through breeding and genetic studies to develop improved genotypes for low and high input production systems in West Africa.
山药（薯蓣属）是数百万贫困农民的主要粮食安全作物，尤其是在西非。土壤矿物质缺乏是山药生产中的主要挑战，特别是随着用于自然养分供应的休耕地不断减少。耐现有低土壤养分且对添加养分供应有响应的品种是西非可持续高产山药种植系统综合土壤肥力管理策略的可行组成部分。本研究的目的是鉴定适应现有低土壤养分且对外部添加养分供应有响应的白几内亚山药（）基因型。在尼日利亚伊巴丹，对20个先进育种系和一个地方品种（阿穆拉）在对比土壤肥力条件下进行了评估，低肥力条件使作物暴露于现有低土壤养分供应，高肥力条件用于评估作物对添加矿物肥料（氮磷钾）投入的响应。这些基因型对低土壤肥力（LF）胁迫和添加肥料投入表现出不同的产量响应。块茎产量的土壤肥力敏感性指数（SFSI）范围为0.64至1.34，地上部干重的SFSI范围为0.60至1.30。基因型R034、R041、R050、R052、R060、R100和R125结合了较低的SFSI和较低的块茎产量降低率，被鉴定为耐与土壤矿物质缺乏相关的LF胁迫。同样，基因型R109、R119和R131对土壤肥力水平和/或肥料响应表现出高敏感性。在低土壤养分条件下，基因型R025和R034的块茎产量潜力是地方品种的两倍。在低土壤肥力和高土壤肥力条件下，地上部干重和块茎产量均呈正相关（分别为 = 0.69和0.75），表明活力生物量可能是选择白几内亚山药高块茎产量基因型的形态学标记。我们的结果突出了白几内亚山药对低土壤养分耐受性和矿物肥料响应的基因型变异，可通过育种和遗传研究加以利用，以开发适合西非低投入和高投入生产系统的改良基因型。
