The alternative splicing of EAM8 contributes to early flowering and short-season adaptation in a landrace barley from the Qinghai-Tibetan Plateau.

KEY MESSAGE: The early flowering of Lalu was determined to be due to a novel spontaneous eam8 mutation, which resulted in intron retention and the formation of a putative truncated protein. Barley is a staple crop grown over an extensive area in the Qinghai-Tibetan Plateau. Understanding the genetic mechanism for its success in a high altitude is important for crop improvement in marginal environments. Early flowering is a critical adaptive trait that strongly influences reproductive fitness in a short growing season. Loss-of-function mutations at the circadian clock gene EARLY MATURITY 8 (EAM8) promote rapid flowering. In this study, we identified a novel, spontaneous recessive eam8 mutant with an early flowering phenotype in a Tibetan barley landrace Lalu, which is natively grown at a high altitude of approximately 4000 m asl. The co-segregation analysis in a F2 population derived from the cross Lalu (early flowering) × Diqing 1 (late flowering) confirmed that early flowering of Lalu was determined to be due to an allele at EAM8. The eam8 allele from Lalu carries an A/G alternative splicing mutation at position 3257 in intron 3, designated eam8.l; this alternative splicing event leads to intron retention and a putative truncated protein. Of the 134 sequenced barley accessions, which are primarily native to the Qinghai-Tibet Plateau, three accessions carried this mutation. The eam8.l mutation was likely to have originated in wild barley due to the presence of the Lalu haplotype in H. spontaneum from Tibet. Overall, alternative splicing has contributed to the evolution of the barley circadian clock and in the short-season adaptation of local barley germplasm. The study has also identified a novel donor of early-flowering barley which will be useful for barley improvement.

A rapid method for detecting bronopol in fresh fish, shrimp, crab, and shellfish samples using liquid chromatography-tandem mass spectrometry.

Fish farming plays a vital role in providing food, nutrition, and employment globally. However, this industry faces security challenges, necessitating the use of fungicides and preservatives, such as bronopol, to increase product yields. Bronopol (2­bromo-2-nitropropan-1,3-diol; CAS:52-51-7) is widely used in various fields, including food production, cosmetics, and, more recently, aquaculture. Currently, there is a limited number of techniques available for detecting bronopol in aquaculture products. This is primarily due to bronopol's instability, susceptibility to degradation, and tendency to form precipitates that pose challenges in extraction from aquaculture products. For this issue, this study presents a comprehensive method for detecting bronopol content in aquaculture tissues using liquid chromatography-tandem mass spectrometry (LC‒MS/MS). The methodology was optimized, involving extraction with Cu-Zn precipitant, cleanup using a small HLB column, separation on a T3 column, and gradient elution with water and acetonitrile mobile phases. The quantitative approach was employed without the use of an internal standard, following the external standard method. The spiked recoveries at 3 fortification levels (0.1, 0.2, and 1 mg/kg) ranged from 87.1 % to 108.1 % with relative standard deviations RSD ≤ 9.0 %. By applying this method to fresh fish, shrimp, crab, and shellfish samples from a local supermarket, no residues of bronopol were detected, ensuring the reliability of the results. The simplicity, rapidity, and high sensitivity of the method make it a suitable alternative to conventional techniques for bronopol detection. Moreover, the successful validation of the method's recovery and precision supports its potential application in monitoring and preventing the misuse of bronopol in aquaculture, thereby safeguarding aquaculture product quality and protecting public health.

Effects of Fertilizer on the Quality and Traceability of Tibet highland Barley (Hordeum vulgare L.): A Diagnosis Using Nutrients and Mineral Elements.

Production areas influence the quality of highland barley (Hordeum vulgare L.), and fertilization levels may be associated with the origin traceability of highland barley. As the main object of the study, a collection of highland barley was planted in different areas in Tibet, China, to explore the effect of fertilizer on the quality and traceability of highland barley. We carried out field experiments with and without fertilizer treatment (using urea and diamine phosphate). Highland barley was distinguished by nutrient and mineral element contents in combination with chemometric methods. The results indicated that fertilizer treatment significantly affected some mineral element contents in highland barley and improved the accuracy of highland barley traceability. The combination of nutrients and mineral elements could distinguish highland barley from those raised in other areas due to influence of growing environment. P, K, Fe, and Cu provided a great contribution to the classification of highland barley. Thus, the combination of nutrients and mineral elements can be used as a powerful tool to track highland barley, indicating that fertilization treatment should be considered when tracing highland barley.

Study on the dissipation pattern and risk assessment of metalaxyl-M in rice grains and paddy soil and water by liquid chromatography-tandem mass spectrometry.

Herein, field experiment trials were conducted at two different sites (Heilongjiang and Hubei Province) in China to determine the residual levels and dissipation kinetics of metalaxyl-M in rice grains, and paddy soil and water. A modified quick, easy, cheap, effective, rugged, and safe "QuEChES" method coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for determination of metalaxyl-M residual levels in different matrices. The method showed an excellent linear response (R2 > 0.99) over the concentration range of 0.01-0.50 mg kg-1 with satisfactory recovery rates in between 76.00 and 111.36%. The limits of quantification (LOQ) were estimated to be 0.010 mg kg-1 for all matrices. Half-lives of 0.27 to 10.83 days in rice plant, paddy soil, and water indicate that the analyte is easily degraded in the environment within a relatively short time. The terminal residues of metalaxyl-M in rice husks and rice grains were less than 0.05 mg kg-1. Dietary risk assessment showed that harvested rice treated with metalaxyl-M would not pose unreasonable risk to humans or the environment.

Stable isotopes verify geographical origin of Tibetan chicken.

Due to the particularity of origin area, the yield and price of Tibetan chicken are different from those in the plain areas, which leads to chickens from the plains being disguised as Tibetan chickens. In present study, Tibetan chicken and chicken from other four provinces in plain areas were distinguished by stable isotopes and chemometric methods. The cross-validation rate was 97.6%. Secondly, correlation between mean δ13C, δ15N, δ2H and δ18O values in chicken samples and environmentalparameters was investigated. These indicators are closely related to geographical environment. δ13C and δ15N values were positively correlated with longitude (R = 0.955) and altitude (R = 0.796), respectively. δ18O and δ2H values were negatively correlated with latitude (R = 0.903) and altitude (R = 0.938), respectively. At last, we used stable isotopes to trace Tibetan chicken from the different area of Tibet. When four stable isotope ratios were combined, we can distinguish them.

Study on the origin traceability of Tibet highland barley (Hordeum vulgare L.) based on its nutrients and mineral elements.

The potential of traceability by nutrients and mineral elements in highland barley (Hordeum vulgare L.) from five cities in Tibet were investigated. The results showed that there were significant differences in nutrients and mineral elements in highland barley from different regions (P < 0.05). The original classification accuracy of linear discriminant analysis (LDA) was 78.3%, and the discrimination accuracy of training set samples based on partial least-squares discriminant analysis (PLS-DA) model was over 65%. The results of correlation analysis show that five elements (Fe, Zn, K, Mn and P) in highland barley are related to the concentration of elements in soil, while three elements (Ca, Cu and Mg) in highland barley have no obvious correlation with soil, because the special natural environment in Tibet affecting the growth of highland barley. This indicates that the origin traceability of highland barley can be achieved by measuring its nutrients and mineral elements.