Sucrose phosphate synthase (SPS) is a rate-limiting enzyme that works in conjunction with sucrose-6-phosphate phosphatase (SPP) for sucrose synthesis, and it plays an essential role in energy provisioning during growth and development in plants as well as improving fruit quality.  However, studies on the systematic analysis and evolutionary pattern of the SPS gene family in apple are still lacking.  In the present study, a total of seven MdSPS and four MdSPP genes were identified from the Malus domestica genome GDDH13 v1.1.  The gene structures and their promoter cis-elements, protein conserved motifs, subcellular localizations, physiological functions and biochemical properties were analyzed.  A chromosomal location and gene-duplication analysis demonstrated that whole-genome duplication (WGD) and segmental duplication played vital roles in MdSPS gene family expansion.  The Ka/Ks ratio of pairwise MdSPS genes indicated that the members of this family have undergone strong purifying selection during domestication.  Furthermore, three SPS gene subfamilies were classified based on phylogenetic relationships, and old gene duplications and significantly divergent evolutionary rates were observed among the SPS gene subfamilies.  In addition, a major gene related to sucrose accumulation (MdSPSA2.3) was identified according to the highly consistent trends in the changes of its expression in four apple varieties (‘Golden Delicious’, ‘Fuji’, ‘Qinguan’ and ‘Honeycrisp’) and the correlation between gene expression and soluble sugar content during fruit development.  Furthermore, the virus-induced silencing of MdSPSA2.3 confirmed its function in sucrose accumulation in apple fruit.  The present study lays a theoretical foundation for better clarifying the biological functions of the MdSPS genes during apple fruit development.

Laboratory mutants of Sclerotinia sclerotiorum (Lib) de Bary, resistant to boscalid, have been extensively characterized.  However, the resistance situation in the lettuce field remains largely elusive.  In this study, among the 172 S. sclerotiorum isolates collected from asparagus lettuce field in Jiangsu Province, China, 132 isolates (76.74%) exhibited low-level resistance to boscalid (Bos^LR), with a discriminatory dose of 5 μg mL^–1.  In comparison to the boscalid-sensitive (Bos^S) isolates, most Bos^LR isolates demonstrated a slightly superior biological fitness, as evidenced by data on mycelial growth, sclerotium production and pathogenicity.  Moreover, most Bos^LR isolates showed comparable levels of oxalic acid (OA) accumulation, increased exopolysaccharide (EPS) content and reduced membrane permeability when compared to the Bos^S isolates.  Nevertheless, their responses to distinct stress factors diverged significantly.  Furthermore, the effectiveness of boscalid in controlling Bos^LR isolates on radish was diminished compared to its efficacy on Bos^S isolates.  Genetic mutations were identified in the SDH genes of Bos^LR isolates, revealing the existence of three resistant genotypes: I (A11V at SDHB, SDHB^A11V), II (Q38R at SDHC, SDHC^Q38R) and III (SDHB^A11V+SDHC^Q38R).  Importantly, no cross-resistance was observed between boscalid and other fungicides such as thifluzamide, pydiflumetofen, fluazinam, or tebuconazole.  Our molecular docking analysis indicated that the docking total score (DTS) of the type I resistant isolates (1.3993) was lower than that of the sensitive isolates (1.7499), implying a reduced affinity between SDHB and boscalid as a potential mechanism underlying the boscalid resistance in S. sclerotiorum.  These findings contribute to an enhanced comprehension of boscalid’s mode of action and furnish valuable insights into the management of boscalid resistance.

DNA methylation plays an important role in plant growth and development, and in regulating the activity of transposable elements (TEs).  Research on DNA methylation-related (DMR) genes has been reported in Arabidopsis, but little research on DMR genes has been reported in Brassica rapa and Brassica oleracea, the genomes of which exhibit significant differences in TE content.  In this study, we identified 78 and 77 DMR genes in Brassica rapa and Brassica oleracea, respectively.  Detailed analysis revealed that the numbers of DMR genes in different DMR pathways varied in B. rapa and B. oleracea.  The evolutionary selection pressure of DMR genes in B. rapa and B. oleracea was compared, and the DMR genes showed differential evolution between these two species.  The nucleotide diversity (π) and selective sweep (Tajima’s D) revealed footprints of selection in the B. rapa and B. oleracea populations.  Transcriptome analysis showed that most DMR genes exhibited similar expression characteristics in B. rapa and B. oleracea.  This study dissects the evolutionary differences and genetic variations of the DMR genes in B. rapa and B. oleracea, and will provide valuable resources for future research on the divergent evolution of DNA methylation between B. rapa and B. oleracea.

The potato cyst nematodes (PCN) Globodera rostochiensis (Wollenweber) Skarbilovich, 1959 is considered the most damaging nematode pest of potato worldwide that causes significant yield losses, and this nematode is recognized and listed as a quarantine nematode in many countries (EPPO 2017).  China is currently the largest producer of potato in the world, while the total production is also the highest (Guan and Cai 2019).  The survey for cyst nematodes on potato were conducted in Yunnan and Sichuan provinces of China during 2018–2020, numerous cysts were observed on potato roots in Huize County and Ludian County of Yunnan Province, Zhaojue County and Yuexi County of Sichuan Province.  Cysts and second-stage juveniles (J2s) were isolated from each soil sample using the Cobb decanting and sieving method.  The morphology of cysts and J2s and molecular analysis established the identity of this species as golden cyst nematode Globodera rostochiensis (Subbotin et al. 2010).  For morphological analysis, the cysts were characterized by smoothly rounded with a small projecting neck, brown and golden color, terminal cone was absent and circumfenestrate.  The key morphometrics of cysts (n=25) were: length excluding neck 705±24 (689–747) μm, width 698±28 (678–759) μm, number of cuticular ridges between anus and vulval fenestra 17.3±1.7 (14–19); fenestral diameter 13.6±1.1 (12.25–15.45) μm; distance from anus to the edge of fenestra 63.7±11.3 (48.23–79.14) μm; Granek’s ratio 4.7±0.7 (3.92–5.75).  The key morphometrics of J2s (n=25): body length 453.9±16.6 (440–496) μm, stylet length 21.9±1.0 (20.3–24.3) μm, tail length 51.1±3.2 (45.5–55.5) μm, and hyaline region length 24.4±2.5 (21.7–29.9) μm.  Morphology of the cysts and J2 were consistent with those of G. rostochiensis (Subbotin et al. 2010; EPPO 2017).  Moreover, the identification result was confirmed by PCR using universal primers TW81 (5´-GTTTCCGTAGGTGAACCTGC-3´) and AB28 (5´-ATATGCTTAAGTTCAGCGGGT-3´) for ITS region and D2A (5´-TTTTTTGGGCATCCTGAGGTTTAT-3´) D3B (5´-AGCACCTAAACTTAAAACATAATGAAAATG-3´) for rDNA-28S region, respectively.  The ITS rDNA sequences (GenBank accessions MZ042365, MZ042366, MZ042369, and MZ042370) exhibited 99.83% identity match to G. rostochiensis sequences available in the GenBank (GQ294513).  Sequence from the 28S region (GenBank accessions MZ057595, MZ057596, MZ057599, and MZ057600) was 99.33% similar to those of G. rostochiensis isolate from MF773722.  The species was also confirmed with species-specific primers ITS5 (5´-GGAAGTAAAAGTCGTAACAAGG-3´) and PITSr3 (5´-AGCGCAGACATGCCGCAA-3´) (Bulman and Marshall 1997), a single 434-bp fragment was obtained from Huize, Ludian, Zhaojue and Yuexi populations.  The pathog enicity testing of Huize, Ludian, Zhaojue and Yuexi, three weeks-old potato plants (cv. Qinshu 9)

were inoculated with 2 000 eggs, and cultured in an incubator at 23°C/20°C with a 16 h/8 h light/dark photoperiod.  After three months inoculation, 36±7.2 cysts and females were extracted from the infested potato roots, no females and cysts were observed on control plants.  

This is the first report of potato golden cyst nematode G. rostochiensis in China.  

Genotype imputation has become an indispensable part of genomic data analysis.  In recent years, imputation based on a multi-breed reference population has received more attention, but the relevant studies are scarce in pigs.  In this study, we used the Illumina PorcineSNP50 Bead Chip to investigate the variations of imputation accuracy with various influencing factors and compared the imputation performance of four commonly used imputation software programs.  The results indicated that imputation accuracy increased as either the validation population marker density, reference population sample size, or minor allele frequency (MAF) increased.  However, the imputation accuracy would have a certain extent of decrease when the pig reference population was a mixed group of multiple breeds or lines.  Considering both imputation accuracy and running time, Beagle 4.1 and FImpute are excellent choices among the four software packages tested.  This work visually presents the impacts of these influencing factors on imputation and provides a reference for formulating reasonable imputation strategies in actual pig breeding.

Marek’s disease (MD), a highly cell-associated and contagious disease of chickens caused by Marek’s disease virus (MDV) can result in neural lesions, immunosuppression and neoplasia in chicken.  The Meq gene is an important oncogene in the MDV genome, and it is expressed highly in MD tumor tissues and MD T-lymphoblastoid cell lines.  An experiment was conducted to elucidate the role of Meq in MD tumor transformation.  RNA interference technology was used to block its expression, and then analyzed the biological effects of Meq knockdown on the MD tumor cell line MSB1.  A small interfering RNA with an interference efficiency of 70% (P<0.01) was transfected into MSB1 cells to knock down the expression of Meq gene.  The cell proliferation, cycle and apoptosis were detected post-Meq knockdown.  The results showed that MSB1 cell proliferation was downregulated remarkably at 48 h (P<0.01), 60 h (P<0.05) and 72 h (P<0.01) post-Meq knockdown.  The cell cycle was unaffected (P>0.05).  B-cell lymphoma 2 gene (BCL2) was anti-apoptotic and caspase-6 was the effector in the apoptosis pathway.  The activity of caspase-6 was upregulated (P<0.05) significantly and BCL2 gene expression was downregulated (P<0.05) significantly post-Meq knockdown, suggesting cell apoptosis might be induced.  MSB1 cell migration did not exhibit any obvious change (P>0.05) post-Meq knockdown, but the expression of two genes (matrix metalloproteinase 2 (MMP2) and MMP9) that are correlated closely to cell invasion was downregulated (P<0.05) remarkably post-Meq knockdown.  The Meq knockdown might affect the main features of tumorous cells, including proliferation, apoptosis, and invasion, suggesting that the Meq gene might play a crucial role in interfering with lymphomatous cell transformation.

In order to clarify the main pathogens of tomato Fusarium wilt in Shanxi Province, China, morphological identification, elongation factor 1 alpha (EF-1α) sequence analysis, specific primer amplification and pathogenicity tests were applied to study the isolates which were recovered from diseased plants collected from 17 different districts of Shanxi Province.  The results were as follows: 1) Through morphological and molecular identification, the following 7 species of Fusarium were identified: F. oxysporum, F. solani, F. verticillioides, F. subglutinans, F. chlamydosporum, F. sporotrichioides, and F. semitectum; 2) 56 isolates of F. oxysporum were identified using specific primer amplification, among which, 29, 5 and 6 isolates were respectively identified as F. oxysporum f. sp. lycopersici physiological race 1, race 2, and race 3; 3) pathogenicity test indicated the significant pathogenicity of F. oxysporum, F. solani, F. verticillioides, and F. subglutinans to tomato plant.  Therefore, among these 4 species confirmed as pathogenic to tomato in Shanxi, the highest isolation rate (53.3%) corresponded to F. oxysporum.  Three physiological species, race 1, race 2, and race 3 of F. oxysporum f. sp. lycopersici are detected in Shanxi, among which race 1 is the most widespread pathogen and is also considered as the predominant race.

This study investigated the influence of activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase-B (LDH-B) on the colour stability of mutton.  From 60 sheep (Bayannur mutton sheep), 15 longissimus dorsi (LD) muscles were selected on the basis of colour stability (R630/580 and a* value) during the storage and classified into three groups (5 for each group) as high colour stability (HCS), intermediate colour stability (ICS) and low colour stability (LCS).  The activities of GAPDH and LDH-B, muscle colour attributes, nicotinamide adenine dinucleuotide (NADH) concentration and lactate concentration were measured.  The samples in HCS had higher activities of GAPDH and LDH-B than the samples in the LCS, and the samples in the HCS group also possessed higher NADH and lower lactate concentration.  The higher activity of dehydrogenase enzyme may result in higher NADH concentrations and colour stability in muscle tissue.  The results suggest that the activity of GAPDH and LDH-B may also play a role in maintaining colour stability.

    Bovine mastitis caused by Staphylococcus aureus is difficult to treat because of increasing resistance against antibiotics, especially penicillin. β-Lactamase and biofilm are responsible for penicillin resistance of S. aureus. The aim of this study was to investigate the β-lactamase activity and biofilm formation capacity of 37 penicillin-resistant S. aureus strains (35 were blaZ positive and 2 were blaZ negative) from bovine mastitis in Gansu Province, China, as well as to measure the intercellular adhesion genes icaA and icaD of these strains. β-Lactamase Test Kit was used to determine the β-lactamase activity, biofilm formation was tested by semi-quantitative adherence assay method. Moreover, the presence of icaA and icaD were measured by PCR. A total of 32 penicillin-resistant S. aureus strains, including the two blaZ-negative strains, were identified as β-lactamase producers. All tested S. aureus isolates produced biofilm in the microtiter plate assay. Meanwhile, all these strains were PCR-positive for the ica locus, icaA and icaD. The study indicated high prevalence of β-lactamase activity, biofilm-forming capacity, and the ica genes among the penicillin-resistant S. aureus isolates, and implied that S. aureus resistant to penicillin was attributed to multiple mechanisms.

To dissect the genetic control of the sensory and textural quality traits of Chinese white noodles, a population of recombinant inbred lines (RILs), derived from the cross of waxy wheat Nuomai 1 (NM1) and Gaocheng 8901 (Gc8901), was used.  The RILs were tested in three different environments to determine the role of environmental effects on quantitative trait loci (QTL) analysis.  A total of 45 QTLs with additive effects for 17 noodle sensory and textural properties under three environments were mapped on 15 chromosomes.  These QTLs showed 4.23–42.68% of the phenotypic variance explained (PVE).  Nineteen major QTLs were distributed on chromosomes 1B, 1D, 2A, 3B, 3D, 4A, and 6A, explaining more than 10% of the phenotypic variance (PV).  Clusters were detected on chromosomes 2B (3 QTLs), 3B (11 QTLs) and 4A (5 QTLs).  The cluster detected on chromosome 4A was close to the Wx-B1 marker.  Five co-located QTLs with additive effects were identified on chromosomes 2B, 3D, 4A, 6A, and 7B.  The two major QTLs, Qadh.sdau-3B.1 and Qspr.sdau-3B.1, in cluster wPt666008–wPt5870 on chromosome 3B were detected in three different environments, which perhaps can be directly applied to improve the textural properties of noodles.  These findings could offer evidence for the selection or development of new wheat varieties with noodle quality using molecular marker-assisted selection (MAS).

    Staphylococcus aureus is the most common etiological pathogen of bovine mastitis. The resistant strains make the disease difficult to cure. The aim of this study was to characterize the genetic nature of the antimicrobial resistance in S. aureus cultured from bovine mastitis in Northwest China in 2014. A total of 44 S. aureus were isolated for antimicrobial resistance and resistance-related genes. Antimicrobial resistance was determined by disc diffusion and the corresponding resistance genes were detected by PCR. Phenotype indicated that S. aureus isolates were resistant to penicillin (84.09%), erythromycin (20.45%), tetracycline (15.91%), gentamicin (9.09%), tobramycin (6.82%), kanamycin (6.82%) and methicillin (2.27%). 9.09% of the S. aureus isolates were classified as multidrug resistant. In addition, genotypes showed that the isolates were resistant to rifampicin (100%, rpoB), penicillin (95.45%, blaZ), tetracycline (22.73%, tetK, tetM, alone or in combination), erythromycin (22.73%, ermB or ermC), gentamicin/tobramycin/kanamycin (2.27%, aacA-aphD), methicillin (2.27%, mecA) and vancomycin (2.27%, vanA). Resistance to tetracycline was attributed to the genes tetK and tetM (r=0.558, P<0.001). This study noted high-level geno- and phenotypic antimicrobial resistance in S. aureus isolates from bovine mastitis cases in Northwest China.

Locating of important agronomic genes onto chromosome is helpful for efficient development of new wheat varieties. Wheat chromosome substitution lines between two varieties have been widely used for locating genes because of their distinctive advantages in genetic analysis, compared with the aneuploid genetic materials. Apart from the substituted chromosome, the other chromosomes between the substitution lines and their recipient parent should be identical, which eases the gene locating practice. In this study, a set of chromosome substitution lines with cv. Wichita (WI) as the recipient parent and cv. Cheyenne (CNN) as the donor parent were studied for the composition of high molecular weight glutenin subunits (HMW-GS) as well as a range of agronomic important traits. Results revealed that the substitution lines of WI(CNN5D), WI(CNN6A) and WI(CNN7B) had higher plant heights than the two parents of WI and CNN, and WI(CNN3D) had later maturity than the parents. By sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis, a substitution line WI(CNN5B) was found to contain different HMW-GS patterns from its two parents, in which 1By9 was replaced by 1By8 on chromosome 1BL. Simple sequence repeat (SSR) analysis confirmed that the variation on 1BL in WI(CNN5B) was originated from Chinese Spring (CS). It is concluded that chromosomal fragments from bridge material and donor parent were quite often retained in intracultivaral chromosome substitution lines except the substituting chromosomes.

   Homeobox A10 (HOXA10) is a well-known transcription factor that plays an important role in directing endometrial differentiation and establishing the conditions required for implantation. Interestingly, the expression level of HOXA10 may be associated with litter size. To study the effects of the porcine HOXA10 promoter fragment on the expression of HOXA10 gene in vivo, we generated a transgenic mouse model using pronuclear microinjection, and measured the expression of HOXA10 in the endometrium. There was no difference in the expression level of HOXA10 between transgenic and wild-type mice in the absence of hormone stimulation. However, following treatment with progesterone and estradiol benzoate, the expression level of HOXA10 was significantly increased in transgenic mice compared with that of wild-type mice. Furthermore, the litter size of transgenic females was larger than that of wild-type females (7.02±1.73 vs. 6.48±1.85; P=0.14). Moreover, the difference of litter size was greater in the later parities (7.33±1.62 vs. 6.37±2.02; P=0.08) compared with the first parity (6.76±1.81 vs. 6.61±1.67; P=0.77) between transgenic and wild-type mice. Therefore, our transgenic mouse model provides exciting insights regarding the actions of HOXA10 and its hormone-inducible promoter in vivo. The present study offers valuable proof of principle to develop transgenic pigs with a hormone-inducible promoter regulating HOXA10 to alter litter size.

To improve Mixograph testing effect, Farinograph measurements were adopted as a quality standard and changes in water absorption and parameter conversion in Mixograph test were explored. Comparative study showed that increasing water absorption to about 73% and converting original parameters to compound parameters in Mixograph tests significantly increased their predictive power for flour quality. These efforts also enabled the adoption of fixed water addition level in Mixograph test and simplified the test procedure significantly. With the success in parameter conversions, Mixograph test results were successfully described by Farinograph parameters, which allow breeders to compare and exchange test results easily. All these changes optimized the official method of Mixograph test with simplified procedure and enhanced reliability and made the Mixograph being the superior tool for quality assessment in wheat-breeding programs.

The Chinese wheat line Yu 356-9 exhibits a high level of resistance to leaf rust. In order to decipher the genetic base of resistance in Yu 356-9, gene postulation, inheritance analyses, and chromosome linkage mapping were carried out. Gene postulation completed using 15 leaf rust pathotypes and 36 isogenic lines indicated that Yu 356-9 was resistant to all pathotypes tested. F1 and F2 plants from the cross Yu 356-9 (resistant)/Zhengzhou 5389 (susceptible) were tested with leaf rust pathotype “FHNQ” in the greenhouse. Results indicated a 3:1 segregation ratio, indicative of the presence of a single dominant leaf rust resistance gene in Yu 356-9 which was temporarily designated as LrYu. Bulk segregant analysis and molecular marker assays were used to map LrYu. Five simple sequence repeat (SSR) markers on chromosome 2BS were found closely linked to LrYu. Among these markers, Xwmc770 is the most closely linked, with a genetic distance of 5.7 cM.

Twelve fluorescence-labeled microsatellite markers were used to analyze the genetic diversity of 12 domestic duck breeds and 2 wild duck breeds to determine the relationship and origin of Chinese domestic duck breeds. Gene frequency, effective number of alleles (Ne), expected heterozygosity (He), polymorphism information contents (PIC), inbreeding coefficient in population (Fis), standard genetic distance (DS), and genetic distance (DA) were calculated by FSTAT and distance and phylogenetic analysis after the dates which were output from the Microsatellite-Toolkit software. Genetic distances between 12 domestic duck breeds and 2 wild duck breeds were analyzed by variance analysis. Unweighted pair group method with arithmetic mean (UPGMA) and phylogenetic trees used for cluster analysis were structured. The results indicated that 11 loci had medium- or high-level genetic diversity among the 12 loci, which could be efficiently used in the detection of the genetic parameters of each population. The values of He were 0.5414 to 0.7343, those of PIC proved similar, and those of Fis were 0.1101 to 0.3381 among all populations. All breeds were clustered into three groups by UPGMA phylogenetic trees. Banzui duck was clustered into a separate group. Differences of the DA were analysed by t-test. The results showed that difference in DA between the 12 domestic duck breeds and Lvtou duck and the Banzui duck were very significant (P<0.01), indicating that these 12 domestic duck breeds originated from Lvtou wild duck, but not Banzui duck.

A segregating population with 410 F2 individuals from the cross MERCIA (Rht-B1a) × Dwarf 123 was made to identify a new major dwarfing gene carrying by novel wheat germplasm Dwarf 123. Combination of bulk segerant analysis method was used. A total of 145 SSR markers were tested for polymorphisms among parental lines and DNA bulks of F2 population. Out of 145 primer pairs only three markers revealed corresponding polymorphism among parental lines and F2 DNA bulks. The marker Barc20 was close to the dwarfing gene with a genetic distance of 1.8 cM, and markers Gwm513 and Gwm495 were linked to the gene with genetic distance of 6.7 and 13 cM, respectively. Linkage analysis mapped the dwarfing gene to the long arm of chromosome 4B with the order of Barc20-dwarfing gene-Gwm513-Gwm495. The Comparision between the new gene and the known Rht-B1 alleles showed that dwarfing gene Rht-Ai123 was different from the others. The identification of the new dwarfing gene and its linked markers will greatly facilitate its utilization in wheat high yield breeding for reducing plant height.

This study was conducted at three rivers of the Chaohu Lake watershed during the summer season of 2008, aiming to investigate the diurnal variations of dissolved CH4 concentrations and emissions, as well as the dynamics of CH4 accumulation emission rates over consecutive 72 h. The results showed that CH4 concentrations in the Fengle, Hangbu, and Nanfei rivers ranged from 56.33-124.79, 160.82-341.03, and 213.49-716.81 nmol L-1, respectively, over a daily cycle; while the saturation of CH4 ranged from 188.72-418.07, 538.74-1 142.46, and 715.23-2 401.38%, respectively, which indicated that surface waters were in all cases oversaturated with respect to the atmosphere. An obvious diurnal variation pattern of the dissolved CH4 concentrations demonstrated a higher value during daytime but a lower value for night time. Additionally, the highest dissolved CH4 concentrations were detected in the Nanfei River which received substantial urban wastewater discharges. CH4 emissions measured with floating chambers ranged from 5.82-15.46, 5.77-8.41, and 13.51-49.25 mg C m-2 h-1 for the Fengle, Hangbu, and Nanfei rivers, respectively, over a daily cycle. Significantly higher CH4 emissions were also observed from the Nanfei River. The accumulative CH4 emissions for each river increased with time, while a decline trend on the accumulation rates was investigated over the consecutive 72 h.