Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a potentially devastating fungal disease of wheat worldwide.  The present study was to evaluate the resistance of 42 wheat monogenic lines with known stem rust resistance (Sr) genes and 69 wheat cultivars to three new Pgt races (34C0MRGQM, 34C3MKGQM, and 34C6MTGSM) identified from aeciospores at the seedling and adult-plant stages.  The phenotyping results revealed that monogenic lines harboring resistance genes Sr9e, Sr17, Sr21, Sr22, Sr26, Sr30, Sr31, Sr33, Sr35, Sr36, Sr37, Sr38, Sr47, SrTmp, and SrTt3 were effectively resistant to all three Pgt races at the seedling and adult-plant stages.  In contrast, monogenic lines containing Sr5, Sr6, Sr7b, Sr9a, Sr9d, Sr9f, Sr9g, Sr9b, Sr16, Sr24, Sr28, and Sr39 were highly susceptible to these races at both seedling and adult-plant stages.  The other lines with Sr8a, Sr10, Sr11, Sr13, Sr14, Sr15, Sr18, Sr20, Sr19, Sr23, Sr25, Sr27, Sr29, Sr32, and Sr34, displayed variable levels of resistance to one or two of the tested races.  Seedling infection types (ITs) and adult-plant infection responses (IRs) indicated that 41 (59.4%) of the wheat cultivars showed high resistance to all the three races.  Molecular marker analysis showed that four wheat culitvars likely carried Sr2, 20 wheat culitvars likely carried Sr31, 9 wheat culitvars likely carried Sr38, and none of the cultivars carried Sr24, Sr25, and Sr26.  Our results provide a scientific basis for rational utilization of the tested Sr genes and wheat cultivars against these novel Pgt races. 

The red imported fire ant, Solenopsis invicta Buren, poses a significant threat to biodiversity, agriculture, and public health in its introduced ranges.  While chemicals such as toxic baits and dust are the main methods for S. invicta control, toxic baits are slow, requiring approximately one or two weeks, but dust can eliminate the colony of fire ants rapidly in just three to five days.  To explore more active ingredients for fire ant control using dusts, the toxicity of bifenthrin and dimefluthrin, the horizontal transfer of bifenthrin and dimefluthrin dust and their efficacy in the field were tested.  The results showed that the LD₅₀ (lethal dose) values of bifenthrin and dimefluthrin were 3.40 and 1.57 ng/ant, respectively.  The KT₅₀ (median knockdown time) and KT₉₅ (95% knockdown time) values of a 20 μg mL^–1 bifenthrin dose were 7.179 and 16.611 min, respectively.  The KT₅₀ and KT₉₅ of a 5 μg mL^–1 dimefluthrin dose were 1.538 and 2.825 min, respectively.  The horizontal transfers of bifenthrin and dimefluthrin among workers were effective.  The mortality of recipients (secondary mortality) and secondary recipients (tertiary mortality) were both over 80% at 48 h after 0.25, 0.50 and 1.00% bifenthrin dust treatments.  The secondary mortality of recipients was over 99% at 48 h after 0.25, 0.50 and 1.00% dimefluthrin dust treatments, but the tertiary mortality was below 20%.  The field trial results showed that both bifenthrin and dimefluthrin exhibited excellent fire ant control effects, and the comprehensive control effects of 1.00% bifenthrin and dimefluthrin dusts at 14 d post-treatment were 95.87 and 85.70%, respectively.

Passion fruit (Passiflora edulis Sims) is a vine of the Passiflora genus in the Passifloraceae family.  The extracted components include flavonoids and terpenoids, which have good anti-anxiety and anti-inflammatory effects in humans.  In this study, we analyzed the transcriptomes of four tissues of the ‘Zixiang’ cultivar using RNA-Seq, which provided a dataset for functional gene mining.  The de novo assembly of these reads generated 96 883 unigenes, among which 61 022 unigenes were annotated (62.99% yield).  In addition to its edible value, another important application of passion fruit is its medicinal value.  The flavonoids and terpenoids are mainly derivatives of luteolin, apigenin, cycloartane triterpenoid saponins and other active substances in leaf extracts.  A series of candidate unigenes in the transcriptome data that are potentially involved in the flavonoid and terpenoid synthesis pathways were screened using homology-based BLAST and phylogenetic analysis.  The results showed that the biosynthesis of triterpenoids in passion fruit comes from the branches of the mevalonate (MVA) and 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathways, which is different from the MVA pathway that is used in other fruit trees.  Most of the candidate genes were found to be highly expressed in the leaves and/or flowers.  Quantitative real-time PCR (qRT-PCR) verification was carried out and confirmed the reliability of the RNA-Seq data.  Further amplification and functional analysis of these putative unigenes will provide additional insight into the biosynthesis of flavonoids and terpenoids in passion fruit.

In January 2022, we received ant specimens collected from three field colonies from Shantou City, Guangdong Province, China.  They were identified as the little fire ant, Wasmannia auropunctata, through morphological and molecular analyses.  Wasmannia auropunctata is listed as one of the 100 most dangerous invasive species by the International Union for Conservation of Nature (IUCN) and has spread from its native range in South America to every continent except Antarctica.  DNA analysis of mitochondrial cytochrome c oxidase subunit I (COI) in nine specimens of W. auropunctata found that they had a close genetic relationship with specimens from Argentina.  This study represents the first formal record of the establishment of W. auropunctata outdoor in Chinese mainland.  However, the invasion stage and occurrence degree of W. auropunctata in China are not clear to date.  The implementation of quarantine measures, investigation of the occurrence and distribution, and development of monitoring and control strategies are needed to actively respond to the threat posed by this highly invasive ant.

Frequent international trade has accelerated alien species invasion.  However, data on the distribution of invasive species after their introduction and research on the factors that determine their geographical distribution are lacking.  This study analyzed the distributional trends of invasive species in China and the drivers for such trends, by identifying the effect of international trade from a dynamic analysis of 13 main invasive insect pests in three time periods – before China’s reform and opening up in 1978, from 1979 to 2001, and after China’s accession to the World Trade Organization in 2001.  The results showed that the abundance of invasive species gradually decreased from south to north and from southeast coast to inland.  Guangdong (442 species) and Yunnan (404 species) provinces have the highest abundance of invasive species.  Among the 13 key invasive insects investigated, 3, 10 and 13 occurred chronologically in the three periods, and invaded 7, 28 and 34 provinces, respectively.  Alien pests are found to invade China through Xinjiang, the Bohai Rim and the southeast.  Value of imports was a strong predictor of the number of invasive species in China, and followed by temperature heterogeneity, in explaining the richness pattern of invasive animal, plants and insects, but not that of microorganisms.  This study provides a scientific basis for furthering international quarantine and effective invasive species control.

Contract farming has been increasingly found to benefit smallholders in developing countries, yet much less is known about its role in the poultry industry where economies of scale could be more prominent.  This study aims to narrow this gap by analysing the choice of contract farming among Chinese broiler producers using a nationally representative survey.  Simply cost-benefit analysis and multinomial logit regression modelling are jointly employed to explain contract farming decision making especially among small producers.  In contrast to many recent studies, we find that small producers, though not passively excluded, usually opt out of contract farming due to limited profitability when large producers are coexistent.  Such relationship is appropriately identified through a control function approach to correct for possible endogeneity.  Therefore, contract farming may not help achieve higher welfare goals for small broiler producers who actually instead seek alternative market opportunities that better realise their comparative advantages. 

    Alcohol dehydrogenase (ADH) catalyzes the interconversion of aldehydes and their corresponding alcohols, and is a key enzyme in volatile ester biosynthesis. However, little is known regarding ADH and ADH encoding genes (ADHs) in pear. We identified 8 ADHs in the pear’s genome (PbrADHs) by multiple sequences alignment. The PbrADHs were highly homologous in their coding regions, while were diversiform in structure. 9 introns were predicted in PbrADH₃–PbrADH₈, while 8 introns, generated through exon fusion and intron loss, were predicted in PbrADH₁ and PbrADH₂. To study the genetic regulation underlying aroma biogenesis in pear fruit, we determined the PbrADH transcripts, ADH activities and volatile contents of fruits during ripening stage for Nanguoli and Dangshansuli, two cultivars having different aroma characteristics. ADH activity was strongly associated with the transcription of ADH6 in the two cultivars during fruit ripening stage. The higher ester content paralleling to a higher ADH activity was detected in Nanguoli than in Dangshansuli, so it is induced that the lower ester content in Dangshansuli fruit may be the result of weak ADH activity. The present study revealed that total ADH activity and volatile ester production correlated with increased PbrADH₆ transcript levels. PbrADH6 may contribute to ADH activity catalyzing aldehyde reduction and ester formation in pear fruit.

With consecutive occurrences of drought disasters in China in recent years, it is important to estimate their potential impacts on regional crop production. In this study, we detect the impacts of drought on wheat and maize yield and their changes at a 0.5°×0.5° grid scale in the wheat-maize rotation planting area in the North China Plain under the A1B climate change scenario using the Decision Support System for Agrotechnology Transfer (DSSAT) model and the outputs of the regional climate modeling system - Providing Regional Climates for Impacts Studies (PRECIS). Self-calibrating palmer drought severity index was used as drought recognition indicator. Two time slices used for the study were the baseline (1961-1990) and 40 years of 2011-2050. The results indicate that the potential planting region for double crop system of wheat-maize would expend northward. The statistic conclusions of crop simulations varied considerably between wheat and maize. In disaster-affected seasons, wheat yield would increase in the future compared with baseline yields, whereas in opposite for maize yield. Potential crop yield reductions caused by drought would be lower for wheat and higher for maize, with a similar trend found for the ratio of potential crop yield reductions for both crops. It appears that the negative impact of drought on maize was larger than that on wheat under climate change A1B scenario.

Sewage sludge amendment (SSA) is an alternative waste disposal technique and a potential way to increase fertility of mudflats for crop growth. The present study aimed to assess the suitability of SSA by assessing the nitrogen (N) and phosphorous (P) uptakes, heavy metal accumulation, growth, biomass, and yield response of ryegrass (Lolium perenne L.) at 0, 30, 75, 150, and 300 t ha-1 SSA rates at various growth stages. The results showed that the highest biomass of ryegrass at seedling and vegetative stages were at 300 and 150 t ha-1 SSA rate, respectively. The increments of ryegrass yield at reproductive stage at 30, 75, 150, and 300 t ha-1 SSA rates were 98.0, 122.6, 88.1, and 61.2%, compared to unamended soil. N and P concentrations in ryegrass increased with increasing SSA rates at all stages except N and P in roots dropped significantly at 300 t ha-1 rate at vegetative stage. The metal concentration for Mn, Cu, Zn, Ni, Cd, Cr, and Pb in shoot of ryegrass at 300 t ha-1 SSA rate increased by 0.63-, 2.34-, 15.02-, 0.97-, 10.00-, 0.01- and 1.13-fold, respectively, compared to unamended soil. However, heavy metal concentrations in shoot of ryegrass were lower than the standard for forage products in China. The study suggested that sewage sludge amendment in mudflat soils might be feasible. However, the impacts of sludge application on edible crop plants and soil environment need further investigations.

Alternative splicing is a cellular mechanism in eukaryotes that results in considerable diversity of gene products. It plays an important role in several diseases and cellular signal regulation. Heat stress is a major factor that induces immunosuppression in pigs. Little is known about the correlation between alternative splicing and heat stress in pigs. Therefore, this study aimed to clone, sequence and quantify the alternative splicing variant of toll-like receptor 4 (TLR4) in Bama miniature pigs (Sus scrofa domestica) following exposure to heat stress. The results showed that the second exon of TLR4 was spliced and 167 bp shorter in the alternative splicing variant, and the protein was putatively identified as a type of truncated membrane protein consisting of extramembrane, transmembrane and intramembrane regions lacking a signal peptide. Further, it was not a nonclassical secretory protein. Five potential reference genes were screened for their potential as reliable standards to quantify the expression of TLR4 alternative spliced variants by real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). The stability of these reference genes was ranked using the geNorm and NormFinder programs, and ribosomal protein L4 (RPL4) and TATA box-binding protein (TBP) were found to be the two genes showing the most stable expression in the in vitro cultured peripheral blood mononuclear cells (PBMCs) during heat shock. The mRNA level of the TLR4 gene (both classical and spliced) in stressed pigs increased significantly (P<0.05). Further, the expression levels of the alternative spliced variant of TLR4 (TLR4-ASV) showed a 2-3 folds increase in heat-stressed PBMCs as compared to control pigs. The results of the present study suggested that heat shock might modulate the host immune response by regulating the expressions of TLR4 and its alternative splicing variant.

The plasmid pGPDGFP under the control of pgpdA promotor was used together with vector pAN7-1 containing the hygromycin resistance cassette to co-transform protoplasts of HG1, Fusarium graminearum from Hubei Province, China. Twelve out of 14 hygromycin-resistant transformants showed green signal under the UV light and contained one or several copies of gfp, as indicated by Southern analysis of genomic DNA digested with different restriction enzymes and hybridized to the gfp probe. A single gfp copy transformant (HG1C5) was selected for further evaluation of 80 Chinese wheat cultivars or advanced lines. The results showed different resistance type to F. graminearum were observed. GFP signals observed in the rachis and adjacent spikes of 70 Chinese wheat lines such as Chuanchongzu 104 indicated both type I (host resistance to the initial infection by the fungus) and type II (resistance to the spread of FHB symptoms within an infected spike) were not observed. While other 10 lines showed type II resistance to F. graminearum with GFP signals only in inoculated spikelets. Development of the mycelium can be intuitively observed and the resistance of wheat to F. graminearum can be identified at 7 days post inoculation (dpi) in this way. The results showed no differences were evaluated between the transformed HG1C5 and the non-transgene artificial inoculation by SAS paired chi-square test and McNemar’s test (P=0.0625).