The functional identification and evaluation of endophytic bacteria sourced from the roots of tolerant Achyranthes bidentata to overcome monoculture problems of Rehmannia glutinosa.

The isolation and identification of plant growth-promoting endophytic bacteria (PGPEB) from Achyranthes bidentata roots have profound theoretical and practical implications in ecological agriculture, particularly as bio-inoculants to address challenges associated with continuous monoculture. Our research revealed a significant increase in the abundance of these beneficial bacteria in A. bidentata rhizosphere soil under prolonged monoculture conditions, as shown by bioinformatics analysis. Subsequently, we isolated 563 strains of endophytic bacteria from A. bidentata roots. Functional characterization highlighted diverse plant growth-promoting traits among these bacteria, including the secretion of indole-3-acetic acid (IAA) ranging from 68.01 to 73.25 mg/L, phosphorus and potassium solubilization capacities, and antagonistic activity against pathogenic fungi (21.54%-50.81%). Through 16S rDNA sequencing, we identified nine strains exhibiting biocontrol and growth-promoting potential. Introduction of a synthetic microbial consortium (SMC) in pot experiments significantly increased root biomass by 48.19% in A. bidentata and 27.01% in replanted Rehmannia glutinosa. These findings provide innovative insights and strategies for addressing continuous cropping challenges, highlighting the practical promise of PGPEB from A. bidentata in ecological agriculture to overcome replanting obstacles for non-host plants like R. glutinosa, thereby promoting robust growth in medicinal plants.

Physiological Properties of Perennial Rice Regenerating Cultivation in Two Years with Four Harvests.

Crop perennialization has garnered global attention recently due to its role in sustainable agriculture. However, there is still a lack of detailed information regarding perennial rice's regenerative characteristics and physiological mechanisms in crop ratooning systems with different rice stubble heights. In addition, the response of phytohormones to varying stubble heights and how this response influences the regenerative characteristics of ratoon rice remains poorly documented. Here, we explored the regenerative characteristics and physiological mechanisms of an annual hybrid rice, AR2640, and a perennial rice, PR25, subjected to different stubble heights (5, 10, and 15 cm). The response of phytohormones to varying stubble heights and how this response influences the regenerative characteristics of ratoon rice were also investigated. The results show that PR25 overwintered successfully and produced the highest yield, especially in the second ratoon season, mainly due to its extended growth duration, higher number of mother stems, tillers at the basal nodes, higher number of effective panicles, and heavier grain weight when subjected to lower stubble heights. Further analysis revealed that PR25 exhibited a higher regeneration rate from the lower-position nodes in the stem with lower stubble heights. this was primarily due to the higher contents of phytohormones, especially auxin (IAA) and gibberellin (GA3) at an early stage and abscisic acid (ABA) at a later stage after harvesting of the main crop. Our findings reveal how ratoon rice enhances performance based on different stubble heights, which provides valuable insights and serves as crucial references for delving deeper into cultivating high-yielding perennial rice.

Spatial distribution and influencing factors of China's household biogas: evidence from provincial-level data.

To address the adjustment of the Chinese agricultural industry and to better promote the development of Chinese household biogas, this article summarizes and analyzes the spatial distribution characteristics and influencing factors of the type and number of biogas digesters, biogas production, biogas fermentation materials, and methods of fermentation residue utilization and ecological agriculture with household biogas by compiling a dataset covering 31 provincial administrative regions in China. The results show that hydraulic biogas digesters are distributed mainly in northwestern and northeastern China; in addition, continuously stirred biogas digesters and bottom-discharging biogas digesters are distributed mainly in southern and northern China, respectively. Because of temperature and population, the Sichuan and Henan Provinces have the highest number of biogas digesters and biogas production. The type of biogas fermentation materials depends on the local raw materials. Biogas slurry and residue are widely used as fertilizers; furthermore, biogas slurry is used for seed soaking in northeastern and southern China, and biogas residue is used as feed in central southern and northern China. The "Three-in-one" and "Four-in-one" biogas ecological models are used mostly in southern and northern China, respectively, and both are mainly affected by temperature. Finally, we propose various problems and countermeasures to enhance the development of the household biogas industry in China. Our findings are critical for China's policymakers to adopt effective measures for promoting the development of cleaner energy and the layout of the agricultural industry.