The potato rot nematode (Ditylenchus destructor) is a very economically important nematode in agronomic and horticultural plants worldwide.  In this study, 43 populations of D. destructor were collected from different hosts across China, including 37 populations from Chinese herbal medicine plants.  Obtained sequences of ITS-rDNA and D2–D3 of 28S-rDNA genes of D. destructor were compared and analyzed.  Nine types of significant length variations in ITS sequences were observed among all populations.  The differences in ITS1 length were mainly caused by the presence of repetitive elements with substantial base substitutions.  Reconstructions of ITS1 secondary structures showed that the minisatellites formed a stem structure.  Ten haplotypes were observed in all populations based on mutations and variations of helix H9.  Among them, 3 known haplotypes (A–C) were found in 7 populations isolated from potato, sweet potato, and Codonopsis pilosula, and 7 unique haplotypes were found in other 36 populations collected from C. pilosula and Angelica sinensis compared with 7 haplotypes (A–G) according to Subbotin’ system.  These unique haplotypes were different from haplotypes A–G, and we named them as haplotypes H–N.  The present results showed that a total of 14 haplotypes (A–N) of ITS-rDNA have been found in D. destructor.  Phylogenetic analyses of ITS-rDNA and D2–D3 showed that all populations of D. destructor were clustered into two major clades: one clade only containing haplotype A from sweet potato and the other containing haplotypes B–N from other plants.  For further verification, PCR-ITS-RFLP profiles were conducted on 7 new haplotypes.  Collectively, our study suggests that D. destructor populations on Chinese medicinal materials are very different from those on other hosts and this work provides a paradigm for relevant researches.

A mixture of controlled-release urea and normal urea (CRUNU) is an efficient nitrogen (N) fertilizer type, but little is known about its effects on stem lodging resistance, grain yield, and yield stability of wheat.  In this study, a 4-year field experiment (from 2017 to 2021) was conducted to analyze the effects of N fertilizer types (CRUNU and normal urea (NU)) and application rates (low level (L), 135 kg ha^–1; medium level (M), 180 kg ha^–1; high level (H), 225 kg ha^–1) on population lodging resistance, basal internode strength, lignin content and synthetase activity, stem lodging resistance, grain yield, and yield stability of wheat.  Our results showed that the two N fertilizer types had the highest lodging rate under high N application rates, and the M-CRUNU treatment showed the lowest lodging rate.  Compared with NU, CRUNU improved the wheat population lodging resistance under the three N application rates, mainly related to improving wheat population characteristics and breaking the strength of the second basal internode.  Correlation analysis showed that the breaking strength of the second basal internode was related to the physical characteristics, chemical components, and micro-structure of the internode.  Compared with NU, CRUNU significantly increased wheat grain yield by 4.47, 14.62, and 3.12% under low, medium, and high N application rates, respectively.  In addition, CRUNU showed no significant difference in grain yield under medium and high N application rates, but it presented the highest yield stability under the medium N application rate.  In summary, CRUNU, combined with the medium N application rate, is an efficient agronomic management strategy for wheat production.

The cereal cyst nematode, Heterodera avenae, is one of the most economically important pathogens impacting the worldwide production of cereals and is widely distributed in more than 16 regions in China.  The present study used the numbers of nematodes inside the plant roots to evaluate the resistance/susceptibility of different subpopulations of barley Hordeum vulgare (QH2R, QH6R and TB2R) to H. avenae under field and pot conditions.  Nematode development in two highly resistant varieties was also evaluated by in vivo experiment and microscopic observation.  Analyses of 186 selected varieties showed the numbers of susceptible varieties identified with the number of females/cysts per plant (NFP) method were significantly higher than those identified with the Pf/Pi ratio (PPR) method, which indicated that the NFP method rather than the PPR method is more reliable to evaluate the resistance of barley.  The field and pot experiment results indicated that the QH2R subpopulation had lower females/cysts numbers than QH6R and TB2R subpopulations, and eight HR varieties (Sunong 7617, Sunong 7635, Dongyuan 87-14, Rudong 14-46, Rudong 87-57, Rudong 87-8-45, Rudong 88-14-2, and Rudong 88-67-1) were identified in QH2R, with the NFP numbers below 4.2.  Further microscopic observation of nematode development suggested that H. avenae often penetrated less into highly resistant varieties (Sunong 7635 and Dongyuan 87-14) and more frequently failed to develop into females than the susceptible barleys.  The promising resistant varieties identified in the present research might be helpful for breeders to develop CCN-resistant cultivars and control H. avenae populations effectively at low costs.

Stunt nematodes (Tylenchorhynchus spp.) are obligate migratory root ecto-parasitic nematodes found in the fields of many cultivated crops.  These nematodes, with phyto-sanitary potential, are frequently ignored or misdiagnosed as pests, and this may pose a threat to food security.  The accuracy of its identification based on a morphological approach has been challenged recently, due to the overlapping of the morphological and morphometric characters of the species.  Consequently, the objective of this study is to identify and characterize stunt nematodes present in 54 fields cultivated with cereal crops (wheat, maize and rice) in the savannahs of northern Nigeria, using integrative taxonomy and molecular approaches.  The molecular and morphological studies identified and confirmed the presence of T. annulatus as the occurring specie in the savannahs of northern Nigeria.  The phylogenetic analysis was carried out using the internal transcribed spacer (ITS) and 28S genes of ribosomal DNA further confirmed the presence of T. annulatus.  The first molecular characterization and sequences of the ITS and 28S rDNA gene for T. annulatus from Nigeria were provided by this research.  Also, according to our literature search, this is the first report on T. annulatus in wheat, maize and rice in the savannahs of northern Nigeria.  Further study to test the pathogenicity of the parasitic nematode species found in this survey is recommended for the prioritization and development of efficient management strategies.

Potassium (K), an important nutrient element, can improve the stress resistance/tolerance of crops.  The application of K in resisting plant-parasitic nematodes shows that the K treatment can reduce the occurrence of nematode diseases and increase crop yield.  However, data on K₂SO₄ induced rice resistance against the root-knot nematode Meloidogyne graminicola are still lacking.  In this work, K₂SO₄ treatment reduced galls and nematodes in rice plants and delayed the development of nematodes.  Rather than affecting the attractiveness of roots to nematodes and the morphological phenotype of giant cells at feeding sites, such an effect is achieved by rapidly priming hydrogen peroxide (H₂O₂) accumulation and increasing callose deposition.  Meanwhile, galls and nematodes in rice roots were more in the potassium channel OsAKT1 and transporter OsHAK5 gene-deficient plants than in wild-type, while the K₂SO₄-induced resistance showed weaker in the defective plants.  In addition, during the process of nematode infection, the expression of jasmonic acid (JA)/ethylene (ET)/brassinolide (BR) signaling pathway-related genes and pathogenesis-related (PR) genes OsPR1a/OsPR1b was up-regulated in rice after K₂SO₄ treatment.  In conclusion, K₂SO₄ induced rice resistance against M. graminicola.  The mechanism of inducing resistance was to prime the basal defense and required the participation of the K⁺ channel and transporter in rice.  These laid a foundation for further study on the mechanism of rice defense against nematodes and the rational use of potassium fertilizer on improving rice resistance against nematodes in the field.

Soybean cyst nematode (SCN) Heterodera glycines is considered as the major constraint to soybean production.  GmSHMT08 at Rhg4 locus on chromosome 08, encoding a serine hydroxylmethyltransferase, is a major gene underlying resistance against H. glycines in Peking-type soybeans.  However, the molecular mechanism underpinning this resistance is less well characterized, and whether GmSHMT08 could interact with proteins in H. glycines remains unclear.  In this study, yeast two-hybrid screening was conducted using GmSHMT08 as a bait protein, and a fragment of a 70-kDa heat shock protein (HgHSP70) was screened from H. glycines that exhibited interaction with GmSHMT08.  This interaction was verified by both GST pull-down and bimolecular fluorescence complementation assays.  Our finding reveals HgHSP70 could be applied as a potential candidate gene for further exploring the mechanism on GmSHMT08-mediated resistance against SCN H. glycines.

Synthetic hexaploid wheat (SHW), possesses numerous genes for drought that can help breeding for drought-tolerant wheat varieties.  We evaluated 10 root traits at seedling stage in 111 F₉ recombinant inbred lines derived from a F₂ population of a SHW line (SHW-L1) and a common wheat line, under normal (NC) and polyethylene glycol-simulated drought stress conditions (DC).  We mapped quantitative trait loci (QTLs) for root traits using an enriched high-density genetic map containing 120 370 single nucleotide polymorphisms (SNPs), 733 diversity arrays technology markers (DArT) and 119 simple sequence repeats (SSRs).  With four replicates per treatment, we identified 19 QTLs for root traits under NC and DC, and 12 of them could be consistently detected with three or four replicates.  Two novel QTLs for root fresh weight and root diameter under NC explained 9 and 15.7% of the phenotypic variation respectively, and six novel QTLs for root fresh weight, the ratio of root water loss, total root surface area, number of root tips, and number of root forks under DC explained 8.5–14% of the phenotypic variation.  Here seven of eight novel QTLs could be consistently detected with more than three replicates.  Results provide essential information for fine-mapping QTLs related to drought tolerance that will facilitate breeding drought-tolerant wheat cultivars.

Organic phosphorus (P) is an important component of the soil P pool, and it has been proven to be a potential source of P for plants.  The phosphorus utilization efficiency (PUE) and PUE related traits (tiller number (TN), shoot dry weight (DW), and root dry weight) under different phytate-P conditions (low phytate-P, 0.05 mmol L^–1 and normal phytate-P, 0.5 mmol L^–1) were investigated using a population consisting of 128 recombinant inbred lines (RILs) at the vegetative stage in barley.  The population was derived from a cross between a P-inefficient genotype (Baudin) and a P-efficient genotype (CN4027, a Hordeum spontaneum accession).  A major locus (designated Qpue.sau-3H) conferring PUE was detected in shoots and roots from the RIL population.  The quantitative trait locus (QTL) was mapped on chromosome 3H and the allele from CN4027 confers high PUE.  This locus explained up to 30.3 and 28.4% of the phenotypic variance in shoots under low and normal phytate-P conditions, respectively.  It also explains 28.3 and 30.7% of the phenotypic variation in root under the low and normal phytate-P conditions, respectively.  Results from this study also showed that TN was not correlated with PUE, and a QTL controlling TN was detected on chromosome 5H.  However, dry weight (DW) was significantly and positively correlated with PUE, and a QTL controlling DW was detected near the Qpue.sau-3H locus.  Based on a covariance analysis, existing data indicated that, although DW may affect PUE, different genes at this locus are likely involved in controlling these two traits.

The root-knot nematode Meloidogyne graminicola, which is distributed worldwide, is considered a major constraint on rice production in Asia.  The present study used the root gall index and number of nematodes inside the roots to evaluate resistance/susceptibility to M. graminicola in different subpopulations of Oryza sativa (aus, hybrid aus, indica, hybrid indica, temperate japonica, tropical japonica).  Nematode development in highly resistant varieties was also evaluated.  Analyses of randomly selected 35 varieties showed the number of M. graminicola nematodes inside the roots correlated very strongly (r=0.87, P≤0.05) with the nematode gall index, and the results from pot and field experiments revealed similar rankings of the varieties for resistance/susceptibility.  Among the 136 tested varieties, temperate japonica displayed the highest gall index, followed by tropical japonica, indica, hybrid indica, aus, and hybrid aus. Zhonghua 11 (aus), Shenliangyou 1 (hybrid aus) and Cliangyou 4418 (hybrid indica) were highly resistant to M. graminicola under both pot and field conditions.  Further examination of nematode development suggested that compared to susceptible rice, M. graminicola penetrated less often into highly resistant varieties and more frequently failed to develop into females.  The promising varieties found in the present research might be useful for the breeding of hybrid rice in China and for the further development of practical nematode management measures.   

Plant-parasitic nematodes are very common on cereal crops and cause economic losses via reduction in grain quality and quantity. During 2014, 83 soil samples were collected from wheat and barley fields in 21 districts of 13 provinces across five regions (Central Anatolia, Marmara, Aegean, Southeast Anatolia, and Black Sea Region) of Turkey. Cyst-forming nematodes were found in 66 samples (80%), and the internal transcribed spacer (ITS) sequencing and species-specific PCR identified the species in 64 samples as Heterodera filipjevi, Heterodera latipons, and Heterodera avenae. The predominant pathogenic cereal cyst nematode was H. filipjevi, which was found in all five regions surveyed. H. avenae was only detected in Southeast Anatolia whereas H. latipons was detected in Southeast Anatolia and Central Anatolia. ITS-rDNA phylogenetic analyses showed that H. avenae isolates from China clustered with H. australis, and Turkish isolates were closely related to European and USA isolates of this species. H. filipjevi from Turkey and China were clustered closely with those from the UK, Germany, Russia, and the USA. The density of many of these populations exceeded or approached the maximum threshold level for economic loss. To our knowledge, this is the first report of H. filipjevi in Diyarbakir, Edirne, and Kutahya provinces, and the first report of H. avenae in Diyarbakir Province. These results exhibit the most rigorous analysis to date on the occurrence and distribution of Heterodera spp. in Turkey’s major wheat-producing areas, thus providing a basis for more specific resistance breeding, as well as other management practices.

The objective of this study was to investigate the effects of applying different amounts of water and nitrogen on yield, fruit quality, water use efficiency (WUE), irrigation water use efficiency (IWUE) and nitrogen use efficiency (NUE) of drip-irrigated greenhouse tomatoes in northwestern China.  The plants were irrigated every seven days at various proportions of 20-cm pan evaporation (E_p).  The experiment consisted of three irrigation levels (I1, 50% E_p; I2, 75% E_p; and I3, 100% E_p) and three N application levels (N1, 150 kg N ha^–1; N2, 250 kg N ha^–1; and N3, 350 kg N ha^–1).  Tomato yield increased with the amount of applied irrigation water in I2 and then decreased in I3.  WUE and IWUE were the highest in I1.  WUE was 16.5% lower in I2 than that in I1, but yield was 26.6% higher in I2 than that in I1.  Tomato yield, WUE, and IWUE were significantly higher in N2 than that in N1 and N3.  NUE decreased with increasing N levels but NUE increased with increase the amount of water applied.  Increasing both water and N levels increased the foliar net photosynthetic rate.  I1 and I2 treatments significantly increased the contents of total soluble solids (TSS), vitamin C (VC), lycopene, soluble sugars (SS), and organic acids (OA) and the sugar:acid ratio in the fruit and decreased the nitrate content.  TSS, VC, lycopene, and SS contents were the highest in N2.  The harvest index (HI) was the highest in I2N2.  I2N2 provided the optimal combination of tomato yield, fruit quality, and WUE.  The irrigation and fertilisation regime of 75% E_p and 250 kg N ha^–1 was the best strategy of water and N management for the production of drip-irrigated greenhouse tomato.

A hydroponic study was conducted to determine the effects of selenium (Se: 0, 3, 6 μmol L−1) on senescence-related oxidative stress in garlic plants grown under two sulfur (S) levels. We evaluated the yields of plants harvested at 160 and 200 days after sowing. Plants grown under a low Se dose (0.3 μmol L−1) at low S level showed higher yields (12.0% increase in fresh weight yield, 13.7% increase in dry weight yield) than the controls, despite a decrease in chlorophyll concentration. Compared with control plants, the Se-treated plants showed lower levels of lipid peroxidation. The Se-treated plants also showed higher activities of glutathione peroxidase and catalase, but lower superoxide dismutase activities. Changes in Fv/Fm values and proline contents were affected more strongly by S than by Se. On the basis of our results, we can conclude that Se plays a key role in the antioxidant systems in garlic seedlings. It delays senescence by alleviating the peroxide stress, but it can be toxic at high levels. A high S level may increase tolerance to high Se concentrations through reducing Se accumulation in plants.

This study investigated the effects of the degree of unsaturation (unsaturity) of long-chain fatty acids on microbial protein content and the activities of transaminases and dehydrogenase in vitro using goat rumen fluid as the cultural medium. Six types of fatty acids, stearic acid (C18:0, group A, control group), oleic acid (C18:1, n-9, group B), linoleic acid (C18:2, n-6, group C), α-linolenic acid (C18:3, n-3, group D), arachidonic acid (C20:4, n-6, group E), and eicosapentaenoic acid (C20:5, n-3, group F), were tested, and the inclusion ratio of each fatty acid was 3% (w/w) in total of culture substrate. Samples were taken at 0, 3, 6, 9, 12, 18 and 24 h, respectively, during culture for analyses. Compared with stearic acid, linoleic acid, α-linolenic acid, and arachidonic acid increased the bacterial protein content, while oleic acid and eicosapentaenoic acid had no significant effects; the protozoal protein content was reduced for all the unsaturated fatty acids, and the magnitude of the reduction appeared to be associated with the degree of unsaturity of fatty acids. The total microbial protein content was dominantly accounted by the protozoal protein content (about 4–9 folds of the bacterial protein), and only increased by linoleic acid, but reduced by oleic acid, arachidonic acid and eicosapentaenoic acid. There were no significant effects in the activities of both glutamic oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) for all the other fatty acids, except for arachidonic acid which enhanced GOT activity and oleic acid which enhanced GPT activity. The total dehydrogenase activity was positively correlated with the degree of unsaturation of fatty acids. In conclusion, the inclusion of 3% of long-chain unsaturated fatty acids increased bacterial protein content, whereas reduced protozoal protein content and enhanced dehydrogenase activity. The fatty acids with more than three double bonds had detrimental effects on the microbial protein content. This work demonstrates for the first time the effect rule of the unsaturation degree of long-chain fatty acids on the rumen microbial protein in vitro.

The cereal cyst nematode (CCN, Heteroder aavenae) causes serious yield loss on cereal crops, especially wheat, worldwide. Daxing population in Beijing City and Huangyuan population in Qinghai Province, China, are two CCN populations. In this study, the CCN pathotypes of Daxing and Huangyuan populations were characterized by tests on 23 standard “International Test Assortment” with the local species Wenmai 19 as the susceptible control. Tested materials were grouped by three nematode populations’ virulence on resistant genes (Rha1, Rha2, Rha3, Cre1) and nonresistant genes, varieties and lines. Both Daxing and Huangyuan populations were avirulent to Ortolan (Ha1). Barley cvs. Ortolan, Siri, Morocco, Bajo Aragon 1-1, and Martin 403-2 were all resistant to both populations. Cultivars Herta, Harlan 43 and wheat Iskamish-K-2-light were all susceptible to Huangyuan population, all of them, however, were resistant to Daxing population. The other five oats were all resistant to the two tested CCN populations. Except Iskamisch K-2-light, all the other wheat cultivars (Capa, Loros×Koga, AUS 10894, and Psathias) were susceptible to Daxing population. Because the pathotypes of the two tested CCN populations in Beijing and Qinghai were not identical to any of the 13 pathotypes previously characterized by the test assortment, we classified Daxing and Huangyuan populations as the new pathotypes, named Ha91.

The purpose of the present study was to survey contents of trace elements of Cu, Mn, Fe, and Zn in the surface layer (0-20 cm) in the soil, pasture and serum of sheep in Huangcheng area of Qilian mountain grassland, China. Also the soil-plant- animal continuum was analyzed. Soil (n=300), pasture (n=60), and blood serum samples from sheep (n=480) were collected from Huangcheng area of Qilian mountain grassland, China. The contents of trace element in the samples were analyzed by atomic absorption spectrophotometer after digestion. The soil trace elements density distribution shows a ladder-like pattern distribution. Equations developed in the present study for prediction of Fe (R2=0.943) and Zn (R2=0.882) had significant R2 values.

A greenhouse experiment was carried out to determine plant growth, reactive oxygen species (ROS) metabolism in roots and functions of plasma membrane (PM) and tonoplast in cucumber seedlings (Cucumis sativus L. cv. Xintaimici) treated with 40 μmol L-1 CuSO4·5H2O, which were either ungrafted or grafted onto the rootstock (Cucurbita ficifolia). Cu treatment inhibited growth, induced significant accumulation of H2O2 and led to serious lipid peroxidation in cucumber roots, and the ROS-scavenging enzymes activities in grafted seedlings roots were significantly higher than that of ungrafted plants, thus less accumulation in grafted cucumber roots induced by Cu. As a result, lipid peroxidation in roots decreased. Furthermore, the activities of H+-ATPase, H+-PPase and Ca2+-ATPase in PM and/or tonoplast in grafted cucumber seedlings under Cu stress were obviously higher than that in ungrafted plants, resulting into higher ability in grafted plants to expulse the excess H+, promote the cytoplasm alkalinization, regulate the intracellular Ca2+ concentration and brought the cytoplasma concentration of free Ca2+ to extremely low level under Cu stress.

The computer swine disease diagnosis is an important tool for swine farming industry, but the traditional expert system cannot meet the requirement of practical application. To improve the situation, a swine disease ontology is constructed, which can model the knowledge of swine disease diagnosis into a concept system, and a mechanism that can save the ontology into relational database is established, further more a computer system is developed to implement ontologybased swine disease diagnosis, so make the diagnosis results extended and more precise.

This study aimed to compare the effects of two types of drip irrigation line design on cotton yield, water use, and net returns. The experiments were carried out in the arid region of Xinjiang, Northwest China, during 2009-2010 growing years. The two types of lateral placement are commonly used by the local farmers in the area: double lines (two laterals controlling four rows) and single line designs (one lateral controlling four rows). The results indicated that less irrigation water was applied by single line compared with double lines design. This implies that more irrigation water could be saved using single line, by reducing the water consumption of cotton. The emergence rates for double lines were 2 and 6% higher than those for single line design in 2009 and 2010. The seed cotton yields for double lines design were 5.76 and 6.41 Mg ha-1 which were 13 and 9% higher than for single line design in 2009 and 2010, respectively. Single lines could however lower the investment cost compared to double lines, which produced 10 and 7% more net income in 2009 and 2010, respectively. By contrast, the double lines was more profitable and suitable for the farmers in Northwest China than single line design.