Analysis of exogenous lactic acid bacteria on growth and development of different herbaceous peony varieties and rhizosphere soil nutrients

Abstract

There are replanting problems in the production of herbaceous peony. If ramet seedlings are replanted in the original planting hole, they weaken year-by-year until their death, which reduces the land utilisation rate and increases the production costs. In this study, exogenous lactic acid bacteria (LAB, the main component is Lactobacillus plantarum) were applied to improve the planting soil of herbaceous peony for the first time to alleviate the replanting problems, to reduce the production costs, and to provide a new way to promote the of the herbaceous peony industry. In this study, herbaceous peony main cultivars varieties ‘Dafugui’ ‘Hongxiuqiu’ and ‘Zifengyu’ were selected, and experiments were conducted using exogenous LAB. Morphological, rhizosphere soil, and root physiology indexes were measured by sampling at the end of the high-growth periods of herbaceous peony. The results showed that after LAB treatment, the plant height, flowering rate, other morphological indexes and root vitality of ‘Hongxiuqiu’ were increased, with a better promoting effect than that of ‘Dafugui’ and ‘Zifengyu’. The ‘Dafugui’ rhizosphere soil nutrient content and enzyme activity were improved, followed by ‘Hongxiuqiu’ and ‘Zifengyu’. The rhizosphere soil free salicylic acid content and root abscisic acid content decreased, whereas the soil bacterial abundance, root antioxidant enzyme activity, proline and paeoniflorin content increased in all varieties. This study found that LAB application can improve soil fertility and enzyme activity, promote the growth and development of herbaceous peony, increase the flowering rate and improve the ornamental value. However, the influence of LAB on different herbaceous peony varieties varied. Therefore, it is necessary to further expand the number of varieties, optimise the application concentration and frequency of LAB application, alleviate the replanting problems in herbaceous peony production, improve the utilisation rate of land, promote excellent varieties of herbaceous peony, and provide a new methods and references.Graphical abstract