Impatiens balsamina L. (Balsaminaceae), an annual herb found throughout China, has been extensively used in traditional Chinese medicine (TCM). However, our knowledge regarding the adverse effects of I. balsamina in vivo is very limited. In this present study, the nematode Caenorhabditis elegans model was employed to fully assess the adverse effects of hydroalcoholic (EtOH 55%) extracts of I. balsamina stems (HAEIBS) in vivo. After exposure to 10 mg/mL HAEIBS, the major organism-level endpoints of C. elegans of percent survival, frequency of head thrash and body bends, and reproduction had decreased by 24%, 30%, and 25%, respectively. The lifespan of C. elegans was also greatly reduced after HAEIBS exposure compared to the controls. The active compounds in HAEIBS were separated using high speed countercurrent chromatograph (HSCCC) and characterized by high performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Two compounds, lawsone and 2-methoxy-1,4-naphthoquinone (MNQ), and their adverse effects were then more thoroughly detailed in this study. It was found that lawsone is the major toxin in HAEIBS with a higher toxicity than MNQ in terms of negative impact on C. elegans mortality, locomotion, reproduction, and lifespan. Our data also suggests that the C. elegans model may be useful for assessing the possible toxicity of other Chinese medicines, plant extracts, and/or compounds.

Soil salinity and alkalinity are key abiotic stresses that limit crop growth and yield worldwide. Balanced N fertilization is important for improving rice (Oryza sativa L.) yield via efficient utilization of P and K under saline and alkaline soil conditions. In this study, a japonica rice cultivar, Kenjing 8, was used to investigate the effects of N fertilizer on rice yield, as well as N, P, and K status, in a 2‐yr field experiment in saline‐alkaline soil in Heilongjiang Province, northeast China. The plants were assigned to the following five treatment groups: no N fertilizer, or conventional, balanced, reduced, and postponed N fertilizer management. Compared with conventional N management practice, balanced and reduced N management practices increased the concentrations of N, P, and K in the leaves, stem‐sheaths, and panicles at full heading (FH) and maturity; however, postponed N management led to the opposite results. Balanced N management increased N, P, and K mobilization to the leaves (from FH to maturity) by 49, 43, and 67%, respectively, resulting in the highest crop yields among all the N management practices studied. Furthermore, rice yield was positively correlated with N, P, and K accumulation and rates of nutrient mobilization to the leaves, stem‐sheaths, and panicles at maturity. The application of 150 or 135 kg N ha−1, and the proportion of 4:3:1:2 in the pre‐transplanting, mid‐tillering, panicle initiation, and panicle differentiation stages, may increase rice yield and facilitate efficient utilization of nutrients in saline‐alkaline soil.

Integrated crop management practices can improve rice (Oryza sativa L.) grain yield, but the effects of such practices on dry matter accumulation and photosynthetic productivity are inconsistent and not well understood. The primary objective of this study was to investigate the effects of integrated crop management practices on dry matter accumulation and redistribution, photosynthetic production, and yield of rice in northeast China. Medium‐ and high‐yielding potential japonica rice cultivars were grown using four crop management practices, including no N application (N0), local farmers’ cultivation practice (FP), high‐yield cultivation practice (HYP), and super‐high‐yield cultivation practice (SHYP). The increases in average yield with the HYP and SHYP treatments were 16.87 and 36.70%, respectively, in 2017 and 14.70 and 31.05%, respectively, in 2018, compared with FP. Increases in effective panicle number and spikelet number per panicle were the main reason for the increase in yield under the integrated crop management treatments. Compared with FP, the HYP and SHYP treatments significantly increased the population dry matter by 26.40 and 56.64%, respectively, before the heading stage. Relative to N0 and FP, HYP and SHYP significantly increased the dry matter export, export rate, and translocation rate in the leaves, stems, and sheaths and significantly increased the photosynthetic potential throughout the growth stage and the net assimilation rate after the tillering stage. These increases were critical for improving the quality of rice and achieving higher yields. Our study provides a theoretical basis for the development of high‐yield cultivation methods for rice in northeast China.

Seeds of Cassia obtusifolia L. are known as homology of medicine and food material, which is a commonly consumed beverage in China. One new compound, 8-hydroxy-1,7-dimethoxy-3-methylanthracene-9,10-dione-2-O-β-d-glucoside (1), together with 11 known compounds, including seven anthraquinones (2-8), was isolated from the seeds. The 2D NMR data of compound 2 are reported for the first time. The structures of the compounds were established on the basis of 1D and 2D NMR, IR and HR-ESI-MS spectra. The cytotoxic activities of all the compounds against five cell lines (LO2, HCT-116, A549, HepG2 and SGC7901) were evaluated by using CCK8 methods. Compounds 1, 3 and 7 show moderate cytotoxicity towards HCT-116 cells compared with oxaliplatin.

Applying appropriate agronomic practices instead of conventional farming practices might improve rice yield. However, few studies have focused on how integrated agronomic practices affect N, P, and K accumulation and allocation in rice (Oryza sativa L.). Therefore, this study was conducted to investigate grain yield, N, P, and K accumulation, and allocation under different agronomic practices. A japonica rice cultivar was grown in the field, with four agronomic practice treatments: no N application (N0), local farmers' practice (FP), high-yield practice (HYP), and super-high-yield (SHY) practice. The results showed that the latter two practices significantly increased grain yield by 11.0% and 26.4%, respectively, compared with that under FP, mainly as a result of an increase in mean number of panicles m −2 and spikelets panicle −1 . Mean aboveground N, P, and K accumulation significantly increased by 24.9, 15.3, and 79.1%, in HYP and 42.0, 38.8, and 219.7% in SHY, respectively, compared with that under FP. In particular, K accumulation was higher than N and P accumulation in HYP and SHY plants than those in FP plants. However, N, P, and K grain productivity was lower by 7. 5, 9.5, and 20.3% under HYP, and 20.3, 17.2 and 62.7% under SHY treatments than that of FP, respectively, and N, P, and K grain productivity were negatively correlated with yield. Our results suggest that an increase in N, P, and K accumulation from the full-heading stage (FH) to the maturity stage (MS) may assist with improving rice yields under HYP and SHY treatments. 1238wileyonlinelibrary.com/journal/agj2