Peanut varieties are diverse globally, with their characters and nutrition determining the product quality.  However, the comparative analysis and statistical analysis of key quality indicators for peanut kernels across the world remains relatively limited, impeding the comprehensive evaluation of peanut quality and hindering the industry development on a global scale.  This study aimed to compare and analyze the apparent morphology, microstructure, single-cell structure, engineering and mechanical properties, as well as major nutrient contents of peanut kernels from 10 different cultivars representing major peanut-producing countries.  The surface and cross-section microstructure of the peanut kernels exhibited a dense “blocky” appearance with a distinct cellular structure.  The lipid droplets were predominantly spherical with a regular distribution within the cells.  The single-cell structure of the kernels from these 10 peanut cultivars demonstrated varying morphologies and dimensions, which exhibited correlations with their mechanical and engineering properties.  Furthermore, the mass loss versus temperature profiles of the peanut kernels revealed five distinct stages, corresponding to moisture loss, volatile loss, protein denaturation, and the degradation of various biomacromolecules.  Variations were also observed in the lipid, protein, and sucrose contents, texture, bulk density, true density, porosity, geometric mean diameter, and sphericity among the different peanut varieties.  This study establishes relationships and correlations among microstructure, engineering properties, and nutritional composition of commonly grown peanut varieties in major peanut-processing countries.  The findings provide valuable insights into peanut quality evaluation, empowering the peanut industry to enhance their processing and product development efforts.

Nitrogen (N) is unevenly distributed throughout the soil and plant roots proliferate in N-rich soil patches.  However, the relationship between the root response to localized N supply and maize N uptake efficiency among different genotypes is unclear.  In this study, four maize varieties were evaluated to explore genotypic differences in the root response to local N application in relation to N uptake.  A split-root system was established for hydroponically-grown plants and two methods of local N application (local banding and local dotting) were examined in the field.  Genotypic differences in the root length response to N were highly correlated between the hydroponic and field conditions (r>0.99).  Genotypes showing high response to N, ZD958, XY335 and XF32D22, showed 50‒63% longer lateral root length and 36‒53% greater root biomass in N-rich regions under hydroponic conditions, while the LY13 genotype did not respond to N.  Under field conditions, the root length of the high-response genotypes was found to increase by 66‒75% at 40‒60 cm soil depth, while LY13 showed smaller changes in root length.  In addition, local N application increased N uptake at the post-silking stage by 16‒88% in the high-response genotypes and increased the grain yield of ZD958 by 10‒12%.  Moreover, yield was positively correlated with root length at 40‒60 cm soil depth (r=0.39).  We conclude that local fertilization should be used for high-response genotypes, which can be rapidly identified at the seedling stage, and selection for “local-N responsive roots” can be a promising trait in maize breeding for high nitrogen uptake efficiency.  

Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.  A high-density genetic map is a valuable tool for mapping quantitative trait loci (QTL) and marker-assisted breeding programs.   In this study, a single nucleotide polymorphism (SNP)-based high-density linkage map was constructed by a genotyping-by-sequencing (GBS) protocol using an F1 population of 178 progenies between two commercial litchi cultivars, ‘Ziniangxi’ (dwarf) and ‘Feizixiao’ (vigorous).  The genetic map consisted of 3 027 SNP markers with a total length of 1 711.97 cM in 15 linkage groups (LGs) and an average marker distance of 0.57 cM.  Based on this high-density linkage map and three years of phenotyping, a total of 37 QTLs were detected for eight dwarf-related traits, including length of new branch (LNB), diameter of new branch (DNB), length of common petiole (LCP), diameter of common petiole (DCP), length of internode (LI), length of single leaf (LSL), width of single leaf (WSL), and plant height (PH).  These QTLs could explain 8.0 to 14.7% (mean=9.7%) of the phenotypic variation.  Among them, several QTL clusters were observed, particularly on LG04 and LG11, which might show enrichment for genes regulating the dwarf-related traits in litchi.  There were 126 candidate genes identified within the QTL regions, 55 of which are differentially expressed genes by RNA-seq analysis between ‘Ziniangxi’ and ‘Feizixiao’.  These DEGs were found to participate in the regulation of cell development, material transportation, signal transduction, and plant morphogenesis, so they might play important roles in regulating plant dwarf-related traits.  The high-density genetic map and QTLs identification related to dwarf traits can provide a valuable genetic resource and a basis for marker-assisted selection and genomic studies of litchi.

Seasonal soil freeze-thaw events may enhance soil nitrogen transformation and thus stimulate nitrous oxide (N₂O) emissions in cold regions.  However, the mechanisms of soil N₂O emission during the freeze-thaw cycling in the field remain unclear.  We evaluated N₂O emissions and soil biotic and abiotic factors in maize and paddy fields over 20 months in Northeast China, and the structural equation model (SEM) was used to determine which factors affected N₂O production during non-growing season.  Our results verified that the seasonal freeze-thaw cycles mitigated the available soil nitrogen and carbon limitation during spring thawing period, but simultaneously increased the gaseous N₂O-N losses at the annual time scale under field condition.  The N₂O-N cumulative losses during the non-growing season amounted to 0.71 and 0.55 kg N ha^–1 for the paddy and maize fields, respectively, and contributed to 66 and 18% of the annual total.  The highest emission rates (199.2–257.4 μg m^–2 h^–1) were observed during soil thawing for both fields, but we did not observe an emission peak during soil freezing in early winter.  Although the pulses of N₂O emission in spring were short-lived (18 d), it resulted in approximately 80% of the non-growing season N₂O-N loss.  The N₂O burst during the spring thawing was triggered by the combined impact of high soil moisture, flush available nitrogen and carbon, and rapid recovery of microbial biomass.  SEM analysis indicated that the soil moisture, available substrates including NH₄⁺ and dissolved organic carbon (DOC), and microbial biomass nitrogen (MBN) explained 32, 36, 16 and 51% of the N₂O flux variation, respectively, during the non-growing season.  Our results suggested that N₂O emission during the spring thawing make a vital contribution of the annual nitrogen budget, and the vast seasonally frozen and snow-covered croplands will have high potential to exert a positive feedback on climate change considering the sensitive response of nitrogen biogeochemical cycling to the freeze-thaw disturbance.   

    Tassel branch number (TBN) is the principal component of maize tassel inflorescence architecture and is a typical quantitative trait controlled by multiple genes. The main objective of this research was to detect quantitative trait loci (QTLs) for TBN. The maize inbred line SICAU1212 was used as the common parent to develop BC₁S₁ and recombinant inbred line (RIL) populations with inbred lines 3237 and B73, respectively. The two related populations consisted of 123 and 238 lines, respectively. Each population was grown and phenotyped for TBN in two environments. Eleven QTLs were detected in the BC₁S₁ population, located on chromosomes 2, 3, 5, and 7, accounted for 4.45–26.58% of the phenotypic variation. Two QTLs (qB11Jtbn2-1, qB12Ctbn2-1, qBJtbn2-1; q11JBtbn5-1, qB12Ctbn5-1, qBJtbn5-1) that accounted for more than 10% of the phenotypic variation were identified. Three QTLs located on chromosomes 2, 3 and 5, exhibited stable expression in the two environments. Ten QTLs were detected in the RIL population, located on chromosomes 2, 3, 5, 8, and 10, accounted for 2.69–13.58% of the TBN variation. One QTL (qR14Dtbn2-2) explained >10% of the phenotypic variation. One common QTL (qB12Ctbn2-2, qR14Dtbn2-2, qRJtbn2-2) was detected between the two related populations. Three pairs of epistatic effects were identified between two loci with or without additive effects and accounted for 1.19–4.26% of the phenotypic variance. These results demonstrated that TBN variation was mainly caused by major effects, minor effects and slightly modified by epistatic effects. Thus, identification of QTL for TBN may help elucidate the genetic basis of TBN and also facilitate map-based cloning and marker-assisted selection (MAS) in maize breeding programs.

Aphid-borne Zucchini yellow mosaic virus (ZYMV) is one of the most economically important viruses of cucurbitaceous plants.  To survey and control this virus, it is necessary to develop an efficient detection technique.  Using purified ZYMV virion and the conventional hybridoma technology, three hybridoma cell lines (16A11, 5A7 and 3B8) secreting monoclonal antibodies (MAbs) against ZYMV Zhejiang isolate were obtained.  The working titers of the ascitic fluids secreted by the three hybridoma cell lines were up to 10^–7 by indirect enzyme-linked immunosorbent assay (ELISA).  All MAbs were isotyped as IgG1, kappa light chain.  Western blot analysis indicated that the MAb 3B8 could specifically react with the coat protein of ZYMV while MAbs 5A7 and 16A11 reacted strongly with a protein of approximately 51 kDa from the ZYMV-infected leaf tissues.  According to this molecular weight, we consider this reactive protein is likely to be the HC-Pro protein.  Using these three MAbs, we have now developed five detection assays, i.e., antigen-coated-plate ELISA (ACP-ELISA), dot-ELISA, tissue blot-ELISA, double-antibody sandwich ELISA (DAS-ELISA), and immunocapture-RT-PCR (IC-RT-PCR), for the sensitive, specific, and easy detection of ZYMV.  The sensitivity test revealed that ZYMV could be readily detected respectively by ACP-ELISA, dot-ELISA, DAS-ELISA and IC-RT-PCR in 1:163 840, 1:2 560, 1:327 680 and 1:1 310 720 (w/v, g mL^–1) diluted crude extracts from the ZYMV-infected plants.  We demonstrated in this study that the dot-ELISA could also be used to detect ZYMV in individual viruliferous aphids.  A total of 275 cucurbitaceous plant samples collected from the Zhejiang, Jiangsu, Shandong and Hainan provinces, China, were screened for the presence of ZYMV with the described assays.  Our results showed that 163 of the 275 samples (59%) were infected with ZYMV.  This finding indicates that ZYMV is now widely present in cucurbitaceous crops in China.  RT-PCR followed by DNA sequencing and sequence analyses confirmed the accuracy of the five assays.  We consider that these detection assays can significantly benefit the control of ZYMV in China.  

The excessive nitrogen (N) fertilizer input coupled with flood irrigation might result in higher N leaching and lower nitrogen recovery efficiency (NRE). Under an intensive rice system in the Ningxia irrigation region, China, environmental friendly N management practices are heavily needed to balance the amount of N input for optimum crop production while minimize the nitrogen loss. The objective of this study was to determine the influences of side-dressing (SD) technique in mechanical transplanting systems on the NRE, N leaching losses and rice yield in anthropogenic-alluvial soil during two rice growing seasons (2010-2011). Four fertilizer N treatments were established, including conventional urea rate (CU, 300 kg ha–1 yr–1); higher SD of controlled-release N fertilizer rate (SD1, 176 kg ha–1 yr–1); lower SD of controlled-release N fertilizer rate (SD2, 125 kg ha–1 yr–1); and control (CK, no N fertilizer). Field lysimeters were used to quantify drainage from undisturbed soil during six rice growing stages. Meanwhile, the temporal variations of total nitrigen (TN), NO3 –-N, and NH4 +-N concentrations in percolation water were examined. The results showed that SD1 substantially improved NRE and reduced N leaching losses while maintaining rice yields. Across two years, the averaged NRE under SD1 treatment increased by 25.5% as relative to CU, but yet the rice yield was similar between two treatments. On average, the nitrogen loss defined as TN, NH4 +-N, and NO3 –-N under the SD1 treatment reduced by 27.4, 37.2 and 24.1%, respectively, when compared with CU during the study periods. Although the SD2 treatment could further reduce N leaching loss to some extent, this technique would sharply decline rice yield, with the magnitude of as high as 21.0% relative to CU treatment. Additionally, the average NRE under SD2 was 11.2% lower than that under SD1 treatment. Overall, the present study concluded that the SD technique is an effective strategy to reduce N leaching and increase NRE, thus potentially mitigate local environmental threat. We propose SD1 as a novel alternative fertilizer technique under an irrigated rice-based system in Ningxia irrigation region when higher yields are under consideration.

Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in this study. CHA induced programmed cell death (PCD) as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) and DNA laddering analysis. In the early phase, CHA-SQ-1 triggered organelle changes and PCD in wheat leaves accompanied by excess production of reactive oxygen species (O2 -. and H2O2) and down-regulation of the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD). Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-1-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.

Domain I of the activated Crystal protein from Bacillus thuringiensis has a seven α-helix bundle structure, which is responsible for membrane channel formation in its insecticidal mechanism. Cry1Ie is toxic to Asian corn borer, Ostrinia furnacalis (Guenée), and plays important roles in insect biological control. The domain I from Cry1Ie has been expressed and purified in its normal conformation, as embedded in the full length homologous toxin structure. The membrane insertion ability of this single domain was compared with the full length homologous toxin using a monolayer insertion experiment. The results indicated that the Cry1Ie-domain I had the ability to insert into the lipid monolayer, and this ability is greater than that of the IE648 toxin. However, the state of insertion is not stable and remains for only a short period of time. The Cry1Ie-domain I plays no role in receptor binding as it had a nonspecific binding with the brush border membrane vesicles of the Asian corn borer.

An experiment was conducted in a singly factorial design to study the effect of glycyl-glutamine dipeptide on enzymeactivity, cell proliferation and apoptosis of jejunal tissues from weaned piglets at different glycyl-glutamine concentrationlevels of 2, 4, 10, 20, and 30 mmol L-1, respectively. The glutaminase activity, diamine oxidase (DAO) activity, cellpeoliferation, apoptosis, and perotein metabolism were measured by the tissue culture method in vitro using jejunaltissues. The immunohistochemical method was used to study the cell proliferation and apoptosis of jejunal tissues. Theresults showed that compared to the blank control, the percentage and MOD value of BrdU-positicve cells incubated withglycyl-glutamine dipeptide solution were significantly (P<0.05) increased. Accordingly, the percentage and MOD valueof caspase-3-positive cells from tissue incubated with glycyl-glutamine dipeptide were notably lower (P<0.05) than thatfrom the control treatment. The glycyl-glutamine dipeptide increased the glutaminase activity, DAO activity and proteincontent of jejunal tissues, as the dipeptide concentration was on the rise (P<0.05). These results indicated that glycylglutaminedipeptide affected the jejunum development and adaptation of weaned piglets, and the function might befulfilled by enhancing the glutamine-related enzyme activity, thereby increasing the consumption of glutamine, and thenimproving the jejunal cell proliferation and suppressing cell apoptosis. The effects of glycyl-glutamine dipeptide relied ina dose-dependent manner, and the maximum effect was achieved at 20-30 mmol L-1 glycyl-glutamine dipeptide.