Different Age-Induced Changes in Rhizosphere Microbial Composition and Function of Panax ginseng in Transplantation Mode

Abstract

Transplantation is a cultivation mode widely applied in perennial plant growing. This method might be an effective way to alleviate problems associated with continuous cultivation (4-6 years) in ginseng production, but the alleviating mechanism and effects on soil microbial community is unclear. To study this issue, non-transplanted 2-year-old, and 5-year-old (transplantation mode: 2 + 3) and 9-year-old (transplantation mode: 3 + 3 + 3) ginseng rhizosphere soils were analyzed <i>via</i> MiSeq sequencing. The results showed that 9-year-old ginseng rhizosphere soil had lower available nitrogen and the lowest pH, available phosphorus, observed species and community diversity and richness (Chao1, and ACE) among all samples (<i>p</i> < 0.05). The abundances of some bacterial classes (Thermoleophilia, Bacilli, and Nitrospira) and fungal genera (<i>Mortierella</i>, <i>Epicoccum</i>, and <i>Penicillium</i> spp.) and functional richness associated with nutrient element cycles and antifungal activity decreased, while abundances of some fungal genera (<i>Ilyonectria</i>, <i>Tetracladium</i>, and <i>Leptodontidium</i> spp.) increased with increasing age of ginseng plants (<i>p</i> < 0.05 or <i>p</i> < 0.01). However, there was greater similarity between soil samples of 2-year-old and transplanted 5-year-old ginseng plants and the increase in cultivation time from 2 to 5 years did not significantly influence the microbial community, suggesting that transplantation is a viable strategy for suppressing soil-borne diseases in <i>Panax ginseng</i> plants over long growth periods.