China is one of the four major centers of agricultural origin in the world, where two distinct agricultural systems were established: the rice-based system represented by the middle and lower reaches of the Yangtze River, and the dryland farming system represented by the Yellow River basin. Historical records and archaeological evidence indicate that as early as the Shang Dynasty, oracle bone inscriptions already mentioned crops such as millet (Setaria italica), broomcorn millet (Panicum miliaceum), wheat, rice, and soybeans. During the pre-Qin period, the concept of the ‘Five Grains’ was established, and in The Book of Songs (Shijing), the broader term ‘Hundred Grains’ also appeared as a general reference to food crops. However, it is noteworthy that buckwheat, a crop native to China, has long been absent from these documented grain systems. This omission is inconsistent with the fact that buckwheat is an indigenous Chinese crop with high genetic diversity, significant local variation, and a long history of cultivation and domestication in cold mountainous regions. This study conducts a systematic review of the literature related to the origin, evolution, and spread of buckwheat, integrating recent findings in archaeobotany and genetic diversity analysis. Following internationally accepted principles for identifying crop origin centers, and drawing on historical texts, biological characteristics, and distribution patterns, the study presents comprehensive evidence supporting the hypothesis that southwestern China-particularly Yunnan, Sichuan, Guizhou, and the southern fringe of the Qinghai-Tibet Plateau-is the center of origin, genetic diversity, and domestication for Fagopyrum species. There are 23 species of Fagopyrum identified in China, including three cultivated species-common buckwheat (F. esculentum), tartary buckwheat (F. tataricum), and golden buckwheat (F. cymosum)-and 20 wild species, the majority of which are concentrated in southwestern China. This region is not only the native habitat of the ancestral subspecies of common and tartary buckwheat (F. esculentum ssp. ancestrale and F. tataricum ssp. potanini), but also the area with the richest diversity of Fagopyrum, strongly indicating its status as the origin center. Furthermore, molecular markers and phylogenetic studies confirm close genetic relationships between wild and cultivated buckwheat species in this region, providing key evidence for reconstructing domestication pathways. With advancements in modern research, buckwheat has gained recognition not only for its short growth cycle, broad adaptability, and resilience to poor soils and cold climates, making it suitable for cultivation in remote and mountainous areas, but also for its grain's rich content of proteins, flavonoids, and functional sugar alcohols. As a highly promising functional coarse grain crop, buckwheat is particularly suited to the development of characteristic agriculture in central and western China. It holds significant potential for ecological sustainability, nutritional health, and high-value agricultural development, and is expected to play an important role in China’s national nutrition strategy and food diversity conservation. This study provides theoretical and empirical evidence to support the scientific designation of China as the center of origin and domestication of buckwheat, laying a solid foundation for future work in germplasm conservation, variety improvement, and industrial development.
【Objective】Adzuki bean (Vigna angularis) is an important legume crop in China, yet, its production is severely constrained by soil salinity. This study aimed to systematically identify and evaluate the salt tolerance of a large-scale adzuki bean germplasm collection to provide elite genetic resources and a theoretical basis for the genetic improvement of salt-tolerant adzuki bean cultivars. 【Method】A total of 398 adzuki bean accessions were evaluated in a hydroponic system under 100 mmol·L-1 NaCl stress a concentration determined as suitable for screening in preliminary experiments. The salt injury index and 10 root morphological traits of each accession were measured post-treatment. A comprehensive salt tolerance value (D-value) for each accession was calculated using a combination of principal component analysis (PCA) combined with the subordinate function method. Based on the D-value, all accessions were systematically evaluated and classified into different salt tolerance grades. Subsequently, differences in salt tolerance among three germplasm types (cultivars, landraces, and wild accessions) were compared. Finally, stepwise regression analysis was employed to identify key indicators for evaluating seedling salt tolerance and to construct a simplified evaluation model. 【Result】Salt stress significantly inhibited root growth in adzuki bean, but extensive genetic variation was observed among the accessions. PCA effectively reduced the 10 root traits to three independent principal components, accounting for a cumulative 88.76% of the total variation. According to the criteria of a comprehensive salt tolerance value (D-value) and salt tolerance grade, a group of highly tolerant accessions at the seedling stage, such as B552 and B533, were identified. Comparative analysis indicated that wild accessions and landraces exhibited stronger seedling stage salt tolerance potential than cultivars, with wild accessions showing particularly outstanding tolerance. Stepwise regression analysis identified the salt tolerance coefficients of five key traits, including root volume, root fresh weight, root dry weight, average root diameter, and number of root crossing as the key indicators. Based on these indicators, an optimal regression equation with a very high coefficient of determination was established. 【Conclusion】This study systematically evaluated the salt tolerance of a large-scale adzuki bean germplasm collection at the seedling stage. It not only identified a group of elite salt-tolerant accessions, but also established a simplified and efficient comprehensive evaluation system for seedling salt tolerance in adzuki bean based on five key root traits.
【Objective】Rapeseed (Brassica napus L.) is the first major oil-bearing crop in China. Enhancing rapeseed yield per unit area is the key to increase its effective supply and economic benefits. Under the condition of mechanical direct seeding, further clarifying the impacts of major technical factors, such as variety selection, overwintering regulation, and disease and pest control, on the yield per unit area could provide a theoretical basis for the improvement of rapeseed yield per unit area in China. 【Method】Nine high-yield and high-quality rapeseed varieties were selected, and mechanical direct-seeding experiments were conducted at 22 experimental sites (major rapeseed-producing counties) over 2 years from 2021 to 2023. A systematic study was carried out to investigate the impacts of factors such as rapeseed variety, seed treatment, overwintering regulation, and Sclerotinia sclerotiorum control on the yield per unit area under the condition of reduced topdressing application of nitrogen fertilizer. 【Result】The application of three combined treatment techniques, namely seed treatment (Maishuping coating for pest prevention, D1), overwintering regulation (D2), and novel Sclerotinia sclerotiorum control (fluxapyroxad, D3), all significantly increased the yield per unit area of rapeseed under reduced nitrogen topdressing (urea 45 kg·hm-2). Compared with the traditional loss-reduction technology mode (uncoated seeds+no overwintering regulation and prochloraz for Sclerotinia sclerotiorum control+urea topdressing, CK), with a yield of 112.5 kg·hm-2, the yields under D1, D2 and D3 treatments increased significantly by 6.2%, 6.4%, and 10.9%, respectively, while the corresponding yields reached 2 594.2, 2 600.4 and 2 708.9 kg·hm-2, respectively. However, only the incidence of Sclerotinia sclerotiorum was extremely significantly reduced by 49.1% under the D3 treatment. Different technical combinations exhibited significant interaction effects on yield per unit area improvement. When seed treatment and overwintering regulation were combined with the novel Sclerotinia sclerotiorum control technology respectively, the yields were significantly 15.7% and 16.1% higher than those under the traditional technology, respectively, reaching 2 820.0 and 2 834.2 kg·hm-2, respectively, while the incidence of Sclerotinia sclerotiorum decreased by 55.6% and 55.3%, respectively. Additionally, there was a significant interaction effect between rapeseed variety genotypes and technology. The application of new technologies could exceed the national regional trial yields of the corresponding varieties. For instance, the regional trial yields of Yangguang 131, Dadi 199 and Zhongyouza 39 were 2 341.2, 3 085.5, and 2 982.0 kg·hm-2, respectively. Under optimized combinations of regulatory technology, the yields were 11.7%, 5.0% and 3.5% higher than their respective regional trial yields, respectively. A multiple stepwise regression analysis was conducted between the experimental yield and factors including the regional trial yield, disease resistance of rapeseed varieties, as well as different technological combinations, and the results revealed that the critical factors determining yield levels were the 1000-seed weight in regional trials, regional trial yield of varieties, novel Sclerotinia sclerotiorum control, and reduced winter urea topdressing rate. Canonical correlation analysis further confirmed that the regional trial yield, regional trial 1000-seed weight, and regional trial silique number of varieties determined the yield levels. Meanwhile, fluxapyroxad and Maishuping played a very important role in enhancing yield increase rates. Additionally, the novel Sclerotinia sclerotiorum control technology and overwintering stress resistance regulation were related to reducing the incidence of Sclerotinia sclerotiorum. 【Conclusion】In the mechanical production of rapeseed, the regional trial yield of varieties was a key factor affecting the rapeseed yield levels. The use of fluxapyroxad to control Sclerotinia sclerotiorum was an effective factor for reducing the yield loss caused by Sclerotinia sclerotiorum at present. The combination of seed treatment, overwintering regulation and the novel Sclerotinia sclerotiorum control technology could further exert the yield potential of rapeseed varieties. It was suggested that in practical production, high-yield and high-quality varieties should be selected, and loss-reduction technologies, such as supporting seed treatment, overwintering regulation and fluxapyroxad, should be matched to achieve a significant improvement in rapeseed yield per unit area.
【Objective】Field experiments were conducted to examine the effects of nitrogen fertilization on the biomass yields of alfalfa and oat by measuring the plant’s 13C fixation and the 13C abundance in different plant organs, aiming to shed light on the transport and distribution of photosynthetic carbon in the plant-soil system and to explore effective means of soil carbon sequestration and soil quality improvement. 【Method】The 13C pulse labeling method was adopted in the field experiment. Two treatments were incorporated for alfalfa and oat crops, including nitrogen fertilization at 75 kg·hm-2 in addition to a control experiment (no nitrogen). Plant aboveground and belowground biomass were measured. 13C abundances in different plant organs were also measured. 【Result】Nitrogen fertilization increased soil organic carbon (SOC) content in oat plots, while no significant SOC effects were observed in alfalfa plots. However, nitrogen fertilization increased the leaf, stem, and root biomass in alfalfa by 117.5% for leaf and stem and 97.8% for roots. The biomass increases in oat under nitrogen fertilization were smaller than that in alfalfa. The aboveground and belowground biomass under nitrogen fertilization in oat was increased by 19.1% and 9.6%, respectively, compared with the control experiment. Moreover, nitrogen fertilization also increased 13C abundance in alfalfa and oat by 54.36‰ and 28.6‰, respectively. Additionally, more carbon was allocated to roots in alfalfa under nitrogen fertilization than the control experiment (11.5% versus 5%). No significant differences in carbon allocation were observed in oat, despite slight increases in root carbon allocation in oat. 【Conclusion】Nitrogen fertilization increased soil organic carbon content of alfalfa and oat, increased alfalfa biomass yield, and stimulated carbon allocation to roots in alfalfa. Nevertheless, nitrogen fertilization showed no significant effects on both carbon fixation and allocation in oat.
