Using native wildflowers for restoring marginal lands has gained considerable popularity. Establishment of wildflowers can be challenging due to several environmental factors. Restoring the microbial community in degraded habitats can potentially result in the native plant performance and habitat restoration. This study was conducted to investigate the impact of native soil microbes and seeding depth on germination of south Texas native wildflowers. Two wildflower species, Ratibida columnifera (Nutt.) (Mexican Hat) and Verbesina encelioides (Cav.) (cowpen daisy), were treated with microbial wash extracted from native soils, and germination rate was recorded for 14-day period. We further analyzed the growth, biomass allocation, and root colonization by mycorrhizal fungi in these two plants growing them in a plant growth chamber for 6 weeks. To determine the impact of seeding depth, we planted the seeds of the two plant species at 2-cm, 6-cm, and 12-cm depth and monitored germination and plant growth. The two species responded differently to the seeding depth and microbial wash treatments. Microbial wash treatment resulted in higher germination rate in R. columnifera compared to control, while it did not have any impact on V. encelioides seed germination. While microbial treatment did not influence the total biomass, it had a significant impact on the biomass allocation in both the plant species. R. columnifera seeds germinated at both 2-cm and 6-cm depth and did not germinate at 12 cm, while the V. encelioides seeds germinated only at 2 cm and did not germinate at 6-cm or 12-cm seeding depth. While our results are species specific, our results indicate that native soil microbes can potentially improve the seed germination and growth of wildflowers. Our results also indicate the importance of specific seeding depth when sowing wildflower seeds for habitat restoration.

中文翻译：

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微生物引发和播种深度对天然野花萌发和生长的影响

使用本地野花恢复边缘土地已获得相当大的欢迎。由于多种环境因素，野花的建立可能具有挑战性。在退化的生境中恢复微生物群落可能会导致本地植物生长和生境恢复。进行这项研究以调查当地土壤微生物和播种深度对南德克萨斯州本地野花发芽的影响。用从天然土壤中提取的微生物洗液处理了两种野花种，即Ratibida columnifera（Nutt。）（墨西哥帽）和Verbesina encelioides（Cav。）（cowpen daisy），并记录了14天的发芽率。我们进一步分析了这两种植物中菌根真菌的生长，生物量分配和根部定植，它们在植物生长室内生长了6周。为了确定播种深度的影响，我们以2 cm，6 cm和12 cm的深度播种了两种植物的种子，并监测了发芽和植物生长。这两个物种对播种深度和微生物洗涤处理的反应不同。与对照相比，微生物洗涤处理导致R. columnifera的发芽率更高，而对圆叶肠杆菌的种子发芽没有任何影响。尽管微生物处理不影响总生物量，但对两种植物中的生物量分配都有重大影响。柱状芽孢杆菌种子在2厘米和6厘米深度处均发芽，且在12厘米处不发芽，而圆叶猴种子仅在2厘米处发芽且在6厘米或12厘米的播种深度处不发芽。虽然我们的结果是针对特定物种的，我们的结果表明，原生土壤微生物可以潜在地改善种子的发芽和野花的生长。我们的结果还表明，播种野花种子对于恢复生境具有特定播种深度的重要性。