Sithole Nonkululeko, Tsvuura Zivanai, Kirkman Kevin, Magadlela Anathi
School of Life Sciences, College of Agriculture, Engineering and Science, Westville Campus, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa.
School of Life Sciences, College of Agriculture, Engineering and Science, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa.
Plants (Basel). 2021 Aug 25;10(9):1762. doi: 10.3390/plants10091762.
(L.) Willd. Ex Del. is a multipurpose leguminous tree that is common in grassland and savanna ecosystems in southern and eastern Africa. These ecosystem soils are reported to be acidic and nutrient-limited, specifically with regards to nitrogen (N) and phosphorus (P). The presence of this plant in these terrestrial ecosystems improves soil fertility benefiting the surrounding vegetation due to its ability to fix atmospheric N. This study seeks to understand the N-fixing bacteria symbiosis and physiological adaptations of in these acidic and nutrient-deficient KwaZulu-Natal soils. The soils used for this study were collected from the Ukulinga Grassland Nutrient Experiment located at the Ukulinga research farm of the University of KwaZulu-Natal, Pietermaritzburg, South Africa. Due to long-term soil nutrient addition treatments, these soils offered a diverse nutrient variation for better understanding the effects of acidity and nutrient variation on microbial symbiosis, plant nutrition, and biomass accumulation of . was able to maintain growth by relying on both atmospheric and soil-derived N across all treatments decreasing carbon (C) growth costs. There was an increased reliance on atmospheric-derived N of un-nodulated high N-treated plants. The plants grown in high N + P soils were able to nodulate with various species from the genus, which resulted in increased biomass compared to other plants. The results of this study show that can alter N sources to reduce C growth costs. In addition, both nodulating and free-living soil N fixing bacteria such as , sp. and identified in the experimental soils may play an important role under P-deficient conditions.
(L.) Willd. Ex Del.是一种多用途豆科树木，在非洲南部和东部的草原和稀树草原生态系统中很常见。据报道，这些生态系统的土壤呈酸性且养分有限，特别是在氮（N）和磷（P）方面。由于这种植物能够固定大气中的氮，它在这些陆地生态系统中的存在提高了土壤肥力，有利于周围的植被。本研究旨在了解这种植物在夸祖鲁 - 纳塔尔省这些酸性和养分缺乏土壤中的固氮细菌共生关系和生理适应性。本研究使用的土壤取自位于南非彼得马里茨堡夸祖鲁 - 纳塔尔大学乌库林加研究农场的乌库林加草原养分实验地。由于长期的土壤养分添加处理，这些土壤提供了多样的养分变化，以便更好地了解酸度和养分变化对微生物共生、植物营养以及该植物生物量积累的影响。在所有处理中，该植物能够通过依靠大气和土壤来源的氮来维持生长，从而降低碳（C）生长成本。未结瘤的高氮处理植物对大气来源氮的依赖增加。在高氮 + 磷土壤中生长的植物能够与该属的各种物种结瘤，与其他植物相比，这导致生物量增加。本研究结果表明，该植物可以改变氮源以降低碳生长成本。此外，在实验土壤中鉴定出的结瘤和自由生活的土壤固氮细菌，如 、 属细菌和 ，在缺磷条件下可能发挥重要作用。
