Genetically optimizing soybean nodulation improves yield and protein content.

Symbiotic nitrogen fixation in legume nodules requires substantial energy investment from host plants, and soybean (Glycine max (L.) supernodulation mutants show stunting and yield penalties due to overconsumption of carbon sources. We obtained soybean mutants differing in their nodulation ability, among which rhizobially induced cle1a/2a (ric1a/2a) has a moderate increase in nodule number, balanced carbon allocation, and enhanced carbon and nitrogen acquisition. In multi-year and multi-site field trials in China, two ric1a/2a lines had improved grain yield, protein content and sustained oil content, demonstrating that gene editing towards optimal nodulation improves soybean yield and quality.

Genome-wide association study for biomass accumulation traits in soybean.

Soybean is one of the most versatile crops for oil production, human diets, and feedstocks. The vegetative biomass of soybean is an important determinant of seed yield and is crucial for the forage usages. However, the genetic control of soybean biomass is not well explained. In this work, we used a soybean germplasm population, including 231 improved cultivars, 207 landraces, and 121 wild soybeans, to investigate the genetic basis of biomass accumulation of soybean plants at the V6 stage. We found that biomass-related traits, including NDW (nodule dry weight), RDW (root dry weight), SDW (shoot dry weight), and TDW (total dry weight), were domesticated during soybean evolution. In total, 10 loci, encompassing 47 putative candidate genes, were detected for all biomass-related traits by a genome-wide association study. Among these loci, seven domestication sweeps and six improvement sweeps were identified. Glyma.05G047900, a purple acid phosphatase, was a strong candidate gene to improve biomass for future soybean breeding. This study provided new insights into the genetic basis of biomass accumulation during soybean evolution. Supplementary information: The online version contains supplementary material available at 10.1007/s11032-023-01380-6.

Effect of Raw Material Particle Size on the Synthesis of La2Zr2O7 by the Molten Salt Method.

In this study, a process based on the molten salt method was proposed to prepare La2Zr2O7 for improving the kinetic conditions of synthesis. Considering that the particle size of raw materials is an important factor that may have an effect on the kinetic process of synthesis, ZrO2 and La2O3 with different particle sizes are used as raw materials, and the synthesis experiment is carried out at 900-1300 °C through the combination of raw materials with different particle sizes. The results show that the particle size of ZrO2 plays an important role in the synthesis of La2Zr2O7. The "dissolution precipitation" mechanism of the synthesis process in the NaCl-KCl molten salt was confirmed by SEM image observation. Furthermore, the influence of the dissolution rate of each raw material on the synthesis reaction was studied by introducing the Noyes-Whitney equation and testing the specific surface area and solubility of each raw material, and it was confirmed that the particle size of ZrO2 was the limiting condition of the synthesis reaction, and use of ZrO2(Z50) with a nominal particle size of 50 nm could significantly improve the kinetic condition of the reaction, thus reducing the synthesis temperature, which can help realize the energy-saving and -efficient synthesis of pyrochlore La2Zr2O7.