Abstract:
Restoring native plant species on degraded landscapes is challenging. Symbiotic partners in the plant rhizosphere can aid in nutrient acquisition, pathogen protection, stress tolerance, and many other processes. However, these microbes are often absent in altered landscapes and need to be re-integrated to improve restoration efforts. We evaluated, within a laboratory setting, the ability of commercial and indigenous rhizobia strains to form nodules on lupine species used for rangeland seedings in the Great Basin region of the Western United States and ascertained if these strains could be applied through a seed coating. We also evaluated if a compost amendment applied via seed coating could further enhance the performance of the rhizobia strains. Our analysis showed that successful nodulation could occur using commercial and wildland-collected indigenous strains through either a liquid culture applied to seedlings or as a dry seed coating. However, the number of root nodules and the presence of a pink color (indicating nitrogen fixation) were typically higher in the commercial product than in the indigenous strains. Compost did not improve nodulation or the performance of the nodules; however, this treatment alone improved shoot growth. Overall, these results suggest that commercial rhizobium may be more effective in improving plant growth, and future research with native rhizobia may want to consider identifying strains compatible with seed-coating delivery. Longer-term studies are now merited for assessing how the rhizobia strains evaluated in this study influence plant growth, particularly in a field setting.
摘要:
在退化的景观上恢复本地植物物种具有挑战性。植物根际的共生伙伴可以帮助获得营养,病原体保护,应力耐受性,和许多其他过程。然而,这些微生物在改变的景观中通常不存在,需要重新整合以改善恢复工作。我们评估,在实验室环境中,商业和本地根瘤菌菌株在美国西部大盆地地区用于牧场播种的羽扇豆物种上形成结核的能力,并确定这些菌株是否可以通过种子包衣施用。我们还评估了通过种子包衣施用的堆肥改良剂是否可以进一步增强根瘤菌菌株的性能。我们的分析表明,通过应用于幼苗的液体培养物或作为干燥的种子包衣,使用商业和野外收集的本地菌株可以成功结瘤。然而,商业产品中的根瘤数量和粉红色(表明固氮)的存在通常比本地菌株高。堆肥并没有改善结瘤或结节的性能;然而,仅此处理即可改善芽生长。总的来说,这些结果表明,商业根瘤菌可能更有效地改善植物生长,未来对天然根瘤菌的研究可能需要考虑确定与种子包衣递送相容的菌株。现在值得进行长期研究,以评估本研究中评估的根瘤菌菌株如何影响植物生长,特别是在现场设置。