Recently, many control methods have been tried and applied in the Fusarium wilt disease control of banana and have achieved definite progresses. In this study, by using ‘Zhongjiao No.3’ and ‘Zhongjiao No.4’ banana seedlings as materials, the effects of Serendipita indica and bamboo fungus (Dictyophorae echinovolvata) culture substrates on the growth and Fusarium wilt disease resistance of banana were investigated. Results showed that the plant height, leaf length, leaf width, root length and root thickness, aboveground part fresh weight, root fresh weight, and relative chlorophyll content and nitrogen content in leaves of banana seedlings colonized with S. indica were all greater than those of non-colonized controls, while these parameters of banana seedlings grown in nutrient soil containing D. echinovolvata culture substrates were significantly suppressed. Both S. indica non-colonized and colonized seedlings cultivated in nutrient containing 1/4 D. echinovolvata culture substrates showed much milder symptoms compared with those cultivated in normal nutrient soil, indicating that the addition of bamboo fungus substrates to the soil can enhance the Fusarium wilt resistance of banana. The results obtained in this study can provide a basis for the application of S. indica and bamboo fungus in the prevention and control of banana Fusarium wilt disease.

As an endophytic fungus, the growth-promoting effects of Piriformospora indica have been widely confirmed in many of its host plants. In this study, we investigated the influences of P. indica colonization on the growth of the daughter plants of two strawberry cultivars, ‘Benihoppe’ and ‘Sweet Charlie.’ The results showed that the fungus colonization significantly promoted the growth of the daughter plants of both of the two strawberry varieties. Its colonization greatly improved almost all of the growth parameters of the ‘Benihoppe’ daughter plants, including the above-ground fresh weight, above-ground dry weight, root fresh weight, root dry weight, plant height, petiole length, leaf area, number of roots and chlorophyll content. However, the fungus colonization showed significant improving effects on only the above-ground fresh weight, root fresh weight and root dry weight of ‘Sweet Charlie.’ Surprisingly, the average root length of ‘Benihoppe’ and ‘Sweet Charlie’ was suppressed by about 14.3% and 24.6%, respectively, by P. indica. Moreover, after P. indica colonization, the leaf nitrate reductase activity and root activity upregulated by 30.12% and 12.74%, and 21.85% and 21.16%, respectively, for the ‘Benihoppe’ and ‘Sweet Charlie’ daughter plants. Our study indicated that P. indica could promote the growth of strawberry daughter plants by improving rooting, strengthening photosynthetic pigments production and nutrient absorption and accelerating biomass accumulation. The fungus shows great potential to be used in the strawberry industry, especially in the breeding of daughter plants.

Organic manure and grass mulching are widely recognized as modifiers of soil microbial communities and nutrient dynamics; however, the combined effects of these practices on nitrogen fractionation and microbial functionality in orchard ecosystems remain poorly understood. This study conducted a comprehensive evaluation of soil nitrogen fractions, enzymatic activity, microbial diversity and functional traits in walnut orchards under three management practices: organic manure (OM), grass mulching combined with manure (GM), and chemical fertilization (CF) in China’s Loess Plateau. The results revealed that OM and GM significantly enhanced soil nutrient pools, with GM elevating total nitrogen by 1.96-fold, soil organic carbon by 97.79%, ammonium nitrogen by 128%, and nitrate nitrogen by 54.56% relative to CF. Furthermore, the OM significantly increased the contents of total hydrolysable nitrogen, amino sugar nitrogen, amino acid nitrogen, ammonia nitrogen, hydrolysable unidentified nitrogen, non-acid-hydrolyzable nitrogen compared to the CF and GM treatments. Meanwhile, ASN and AN had significant effects on mineral and total nitrogen. The OM and GM had higher activities of leucine aminopeptidase enzymes (LAP), α-glucosidase enzyme, β-glucosidase enzyme (βG), and N-acetyl-β-D-glucosidase enzyme (NAG). Microbial community analysis revealed distinct responses to different treatments: OM and GM enhanced bacterial Shannon index, while suppressing fungal diversity, promoting the relative abundance of copiotrophic bacterial phyla such as Proteobacteria and Chloroflexi. Moreover, GM favored the enrichment of lignocellulose-degrading Ascomycota fungi. Functional annotation indicated that Chemoheterotrophy (43.54%) and Aerobic chemoheterotrophy (42.09%) were the dominant bacterial metabolic pathways. The OM significantly enhanced the abundance of fermentation-related genes. Additionally, fungal communities under the OM and GM showed an increased relative abundance of saprotrophic taxa, and a decrease in the relative abundances of potential animal and plant pathogenic taxa. The Random forest model further confirmed that βG, LAP, and NAG, as well as Basidiomycota, Mortierellomycota, and Ascomycota served as pivotal mediators of soil organic nitrogen fraction. Our findings demonstrated that combined organic amendments and grass mulching can enhance soil N retention capacity, microbial functional redundancy, and ecosystem stability in semi-arid orchards. These insights support the implementation of integrated organic management as a sustainable approach to enhance nutrient cycling and minimize environmental trade-offs in perennial fruit production systems.

The effects of γ-aminobutyric acid (GABA) on the growth and physiology of ‘Miaoxiang No.7’ strawberry (Fragaria × ananassa Duch.) seedlings under alkaline salt stress were investigated in this study. The experiment utilized varying doses of GABA through foliar spray and root drenching to assess its impact on osmotic regulating chemicals, biomass buildup, root structure, and antioxidant enzyme activity in the strawberries. The results showed that exogenous application of GABA significantly increased the biomass of the strawberries, with the greatest effect observed at a concentration of 5 mmol/L when applied to the roots. Additionally, GABA reduced damage to the strawberry roots under alkaline salt stress and increased antioxidant enzyme activity, while decreasing the production of malondialdehyde and increasing the relative conductivity of the leaves. Furthermore, Exogenous GABA caused a significant decline in the soluble protein content of strawberry seedlings under alkaline salt stress conditions, indicating an improved ability of the seedlings to withstand salt and alkali stress.