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.

A design of MnO-CNT@C3N4 cathodes for high-performance aqueous zinc-ion batteries.

Manganese oxides have been regarded as one of the most promising candidates in rechargeable aqueous zinc ion batteries due to their high specific capacity, high operating voltage, low cost and no-toxicity. Nevertheless, the grievous dissolution of manganese and the sluggish Zn2+ ions diffusion kinetics deteriorate the long cycling stability and the rate performance. Herein, we propose a combination of hydrothermal and thermal treatment strategy to design a MnO-CNT@C3N4 composite cathode material where MnO cubes are coated by carbon nanotubes (CNTs) and C3N4. Owing to the enhanced conductivity by CNTs and the alleviation of the dissolution of Mn2+ from the active material by C3N4, the optimized MnO-CNT@C3N4 exhibits an excellent rate performance (101 mAh g-1 at a large current density of 3 A g-1) and a high capacity (209 mAh g-1 at a current density of 0.8 A g-1), which is much better than its MnO counterpart. The energy storge mechanism of MnO-CNT@C3N4 is confirmed to be the co-insertion of H+/Zn2+. The present work provides a viable strategy for the design of advanced cathodes for high-performance zinc ion batteries.