The red coloring of pear fruits is mainly caused by anthocyanin accumulation.  Red sport, represented by the green pear cultivar ‘Bartlett’ (BL) and the red-skinned derivative ‘Max Red Bartlett’ (MRB), is an ideal material for studying the molecular mechanism of anthocyanin accumulation in pear.  Genetic analysis has previously revealed a quantitative trait locus (QTL) associated with red skin color in MRB.  However, the key gene in the QTL and the associated regulatory mechanism remain unknown.  In the present study, transcriptomic and methylomic analyses were performed using pear skin for comparisons between BL and MRB.  These analyses revealed differential PcHY5 DNA methylation levels between the two cultivars; MRB had lower PcHY5 methylation than BL during fruit development, and PcHY5 was more highly expressed in MRB than in BL.  These results indicated that PcHY5 is involved in the variations in skin color between BL and MRB.  We further used dual luciferase assays to verify that PcHY5 activates the promoters of the anthocyanin biosynthesis and transport genes PcUFGT, PcGST, PcMYB10 and PcMYB114, confirming that PcHY5 not only regulates anthocyanin biosynthesis but also anthocyanin transport.  Furthermore, we analyzed a key differentially methylated site between MRB and BL, and found that it was located in an intronic region of PcHY5.  The lower methylation levels in this PcHY5 intron in MRB were associated with red fruit color during development, whereas the higher methylation levels at the same site in BL were associated with green fruit color.  Based on the differential expression and methylation patterns in PcHY5 and gene functional verification, we hypothesize that PcHY5, which is regulated by methylation levels, affects anthocyanin biosynthesis and transport to cause the variations in skin color between BL and MRB.

The cotton direct seeding after wheat (rape) harvested is under trial and would be the future direction at the Yangtze River Valley region of China.  The objective of this study was to quantify the effects of branch and stem architecture on cotton yield and identify the optimal cotton architecture to compensate the yield loss due to the reduction of individual production capacity under high planting density in the direst seeding after wheat harvested cropping system.  The characteristics of the stem and branch architecture and the relationships between architecture of the stem and branch with yield formation were studied on eight short season cotton cultivars during 2015 and 2016 cotton growth seasons.  Based on the two years results, three cultivars with different architectures of stem and branch were selected to investigate the effect of mepiquat chloride (MC) application on the architecture of the stem and branch, boll retention, and the yield in 2017.  Significant differences were observed on plant height, all fruiting nodes to branches ratio (NBR) in the cotton plant, and the curvature of the fruiting branch (CFB) among the studied cultivars.  There were three types of stem and fruiting branch structures: Zhong425 with stable and suitable plant height and NBR (about 90 cm and 2.5, respectively), high CFB (more than 10.0), and high boll retention speed and seed cotton yield; Siyang 822 with excessive plant height and NBR, low CFB, and low boll retention speed and seed cotton yield; and other studied cultivars with unstable structure of stem and branch, boll retention speed, and seed cotton yield across years.  And MC application could promote the appropriate plant height and NBR and high CFB and thus resulted in high boll retention speed and the yield.  The results suggested that the suitable plant height and NBR (about 90 cm and 2.5 respectively), and high CFB (more than 10.0), which was related to both genotype and cultural practice, could promote the higher boll retention speed and seed cotton yield.

Genome dynamics of pathogenic organisms are driven by plant host and pathogenic organism co-evolution, in which pathogen genomes are used to overcome stresses imposed by hosts with various genetic backgrounds through generation of a range of field isolates.  This model also applies to the rice host and its fungal pathogen Magnaporthe oryzae.  To better understand genetic variation of M. oryzae in nature, the field isolate V86010 from the Philippines was sequenced and analyzed.  Genome annotation found that the assembled V86010 genome was composed of 1 931 scaffolds with a combined length of 38.9 Mb.  The average GC ratio is 51.3% and repetitive elements constitute 5.1% of the genome.  A total of 11 857 genes including 616 effector protein genes were predicted using a combined analysis pipeline.  All predicted genes and effector protein genes of isolate V86010 distribute on the eight chromosomes when aligned with the assembled genome of isolate 70-15.  Effector protein genes are located disproportionately at several chromosomal ends.  The Pot2 elements are abundant in V86010.  Seven V86010-specific effector proteins were found to suppress programmed cell death induced by BAX in tobacco leaves using an Agrobacterium-mediated transient assay.  Our results may provide useful information for further study of the molecular and genomic dynamics in the evolution of M. oryzae and rice host interactions, and for characterizing novel effectors and AVR genes in the rice blast pathogen.  

The application of fertilizer in agricultural production has become universally common for achieving high crop yields and economic benefits, but it has potential impacts on food safety, energy crisis and environmental pollution.  Optimal management of fertilization is thus necessary for maintaining sustainable agriculture.  Two-year (2013–2015) field experiment was conducted, in Yangling (108°24´E, 34°20´N, and 521 m a.s.l.), Shaanxi Province, China, to explore the effects of different nitrogen (N) applications on biomass accumulation, crop N uptake, nitrate N (NO₃^–-N) distribution, yield, and N use with a winter wheat/summer maize rotation system.  The N applications consisted of conventional urea (U) (at 80 (U80), 160 (U160), and 240 (U240) kg N ha–1; 40% applied as a basal fertilizer and 60% top-dressed at jointing stage) and controlled-release urea (CRU) (at 60 (C60), 120 (C120), 180 (C180), and 240 (C240) kg N ha^–1; all applied as a basal fertilizer) with no N application as a control (CK).  The continuous release of N from CRU matched well with the N demands of crop throughout entire growing stages.  Soil NO₃^–-N content varied less and peaked shallower in CRU than that in urea treatments.  The differences, however, were smaller in winter wheat than that in summer maize seasons.  The average yield of summer maize was the highest in C120 in CRU treatments and in U160 in urea treatments, and apparent N use efficiency (NUE) and N agronomic efficiency (NAE) were higher in C120 than in U160 by averages of 22.67 and 41.91%, respectively.  The average yield of winter wheat was the highest in C180 in CRU treatments and in U240 in urea treatments with C180 increasing NUE and NAE by averages of 14.89 and 35.62% over U240, respectively.  The annual yields under the two N fertilizers were the highest in C120 and U160.  The results suggested that CRU as a basal fertilizer once could be a promising alternative of urea as split application in semiarid areas. 

Agricultural application studies, including field experiments and acute toxicity tests, were conducted for lipopeptides secreted by marine-derived Bacillus marinus B-9987.  Benefiting from commercially available scaled-up lipopeptide purification, the sample of impurities (isolated from target lipopeptides), raw extracted sample (purity: 9.08%), partially purified sample (purity: 20.86%), and highly purified sample (purity: 87.51%) were prepared from B. marinus B-9987 fermentation broth, and used in lab-scale antagonism tests, field experiments, swarming motility tests, and acute toxicity tests.  Operations and conditions in field experiments were consistent with the Pesticide-Guidelines for the Field Efficacy Trials (GB/T 17980.28-2000), and acute toxicity tests were executed according to Toxicological Test Methods of Pesticides for Registration (GB 15670-1995).  In agar diffusion tests in vitro and pot tests in vivo, all lipopeptide samples with different purities significantly inhibited Botrytis cinerea; meanwhile the sample of impurities isolated from target lipopeptides were not effective against B. cinerea.  Results of lab-scale tests showed that the target lipopeptides were effective substances against B. cinerea.  Thus, partially purified and raw extracted samples were used in field experiments instead of the highly purified sample for cost saving.  In the field experiments against rose grey mold, biological control efficacy of 500 mg L^–1 lipopeptides reached 67.53%, slightly lower than 74.05% reached by the agrochemical pyrimethanil.  However, pyrimethanil severely suppressed B. marinus B-9987, whereas the lipopeptides promoted swarming motility and biocontrol efficacy of Bacillus biomass.  Lipopeptides at 87.51% purity were tested for systemic acute toxicity and confirmed as low-toxicity substances.  In conclusion, low-toxicity lipopeptides were potential alternatives to agrochemicals, and they also performed good promotion when combined with homologous biological control microorganism.  There were 2 breakthroughs in this research: (1) marine-derived bacterial lipopeptides inhibited grey mold caused by B. cinerea in field experiments; and (2) purified bacterial lipopeptides (sample purity: >87.51%) were determined to be low-toxicity substances by systemic acute toxicity tests, satisfying the strict requirement of pesticide registration in China (required purity: >85%).  This study provides support for using extracellular Bacillus-derived lipopeptides commercially similar to Bacillus-based biological control agents.  

Combined use of chloropicrin (Pic) and 1,3-dicloropropene (1,3-D) is as effective as methyl bromide (MB) at controlling soilborne diseases in many trials and commercial uses. However, Pic and 1,3-D are both highly volatile and may pose strong exposure risks to humans and the environment. A gelatin capsule formulation containing Pic and 1,3-D has been developed to reduce exposure risks to workers and bystanders and improved application safety. We conducted two experiments in tomato and cucumber greenhouses located in Beijing and Qingdao, China, to study the efficacy of Pic plus 1,3-D gelatin capsules applied at different dosages and soil depths. Results indicated that both injection and gelatin capsules of Pic plus 1,3-D provided good control of soil nematodes and reduced disease index of Fusarium wilt and root-knot nematode. Plant yield of tomato and cucumber treated with gelatin capsules was similar to MB treatment. Based on our results, gelatin capsules applied at a soil depth of 15 cm provided better control of soilborne diseases and led to higher fruit yield compared to an application depth of 5 cm. In conclusion, a gelatin capsule of Pic plus 1,3-D is a promising and novel formulation, which not only shows good efficacy in controlling soilborne diseases, but also reduces potential exposure risks of fumigants.

Cotton cultivars with brown (Xiangcaimian 2), green (Wanmian 39) and white (Sumian 9) fiber were investigated to study fiber developmental characteristics of natural-colored cotton and the effect of hormones on fiber quality at different stages after anthesis. Fiber lengths of both natural-colored cottons were lower than the white-fibered control, with brown-fibered cotton longer than green. Fiber strength, micronaire and maturation of natural-colored cotton were also lower than the control. The shorter fiber of the green cultivar was due to slower growth during 10 to 30 days post-anthesis (DPA). Likewise, the lower fiber strength, micronaire and maturation of natured-colored cotton were also due to slower growth during this pivotal stage. Indole-3-acetic acid (IAA) content at 10 DPA, and abscisic acid (ABA) content at 30 to 40 DPA were lower in the fibers of the natural-colored than that of the white-fibered cotton. After applying 20 mg L^–1 gibberellic acid (GA3), the IAA content at 20 DPA in the brown and green-fibered cottons increased by 51.07 and 64.33%, fiber ABA content increased by 38.96 and 24.40%, and fiber length increased by 8.13 and 13.96%, respectively. Fiber strength, micronaire and maturation were also enhanced at boll opening stage. Those results suggest that the level of endogenous hormones affect fiber quality. Application of external hormones can increase hormone content in natural-colored cotton fiber, improving its quality.

Ridge-furrow rainwater harvesting (RFRH) planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in arid and semiarid areas.  Supplemental irrigation would still be needed to achieve a higher production.  Field experiments were conducted for two growing seasons (2012–2013 and 2013–2014) to determine an appropriate amount of supplemental irrigation to be applied to winter oilseed rape at the stem-elongation stage with RFRH planting pattern.  Four treatments, including supplemental irrigation amount of 0 (I1), 60 mm (I2) and 120 mm (I3) with RFRH planting pattern and a control (CK) irrigated with 120 mm with flat planting pattern, were set up to evaluate the effects of supplemental irrigation on aboveground dry matter (ADM), nitrogen nutrition index (NNI), radiation use efficiency (RUE), water use efficiency (WUE), and seed yield and oil content of the oilseed rape.  Results showed that supplemental irrigation improved NNI, RUE, seed yield and oil content, and WUE.  However, the NNI, RUE, seed yield and oil content, and WUE did not increase significantly or even showed a downward trend with excessive irrigation.  Seed yield was the highest in I3 for both growing seasons.  Seed yield and WUE in I3 averaged 3 235 kg ha^–1 and 8.85 kg ha^–1 mm^–1, respectively.  The highest WUE was occurred in I2 for both growing seasons.  Seed yield and WUE in I2 averaged 3 089 kg ha^–1 and 9.63 kg ha^–1 mm^–1, respectively.  Compared to I3, I2 used 60 mm less irrigation amount, had an 8.9% higher WUE, but only 4.5 and 0.4% lower seed yield and oil content, respectively.  I2 saved water without substantially sacrificing yield or oil content, so it is recommended as an appropriate cultivation and irrigation schedule for winter oilseed rape at the stem-elongation stage.

    Sesquiterpenes in Eupatorium adenophorum are abundant in leaves and have great development potential as biopesticides. The toxicity of sesquiterpenes in immune cells and their corresponding immune functions are not fully understood. We evaluated the immunotoxicity of two cadinene sesquiterpenes 2-deoxo-2-(acetyloxy)-9-oxoageraphorone (DAOA) and 9-oxo-10,11-dehydro-agerophorone (ODA) by using histopathology and toxicology methods in vitro and in vivo in lymphocytes and natural killer cells in Kunming mice. The mice were given single doses of 75, 150 and 300 mg kg⁻¹ body weight (BW) of DAOA/ODA every day for a week. Serious damage to the thymus and spleen was found in tissue images with clear lysis reduction numbers and a loosened arrangement of splenocytes and thymocytes to the mice treated with 150–300 mg kg⁻¹ DAOA/ODA. Mice cytology was also affected with significant cellular alterations, increased splenocytes apoptosis rates (P<0.01), proliferation reduction (P<0.05) and natural killer cells activities reduction (P<0.05) when given 150–300 mg kg⁻¹ DAOA/ODA, the severities of which were dose-dependent. However, a 75 mg kg⁻¹ dose of DAOA/ODA showed no change in tissue or cytology after the 7 day treatment, and therefore was considered to be within acceptable safety parameters. Taken together, cadinene sesquiterpenes, as a type of toxic botanical component, have low environmental risks in small doses and should be further studied for their use as biopesticides.

The combination of 1,3-dichloropropene+dimethyl disulfide (1,3-D+DMDS), which forms a pre-plant soil fumigant, can provide a substitute for the environmentally unfriendly methyl bromide (MB). Three greenhouse trials were performed to evaluate the root-knot nematode and soilborne fungi control efficacy in the suburbs of Beijing in China in 2010-2014. Randomized blocks with three replicates were designed in each trial. The combination of 1,3-D+DMDS (10+30 g m−2) significantly controlled Meloidogyne incognita, effectively suppressed the infestation of Fusarium oxysporum and Phytophthora spp., and successfully provided high commercial fruit yields (equal to MB but higher than 1,3-D or DMDS). The fumigant soil treatments were significantly better than the untreated controls. These results indicate that 1,3-D+DMDS soil treatments can be applied by soil injection or chemigation as a promising MB alternative against soilborne pests in cucumber in China.

Higher boll worm survival rates were detected after high temperature presented during square period in Bt cotton. The objective of this study was to investigate the effects of high temperature level on the Bt efficacy of two different types of Bt cotton cultivars at squaring stage. During the 2011 to 2013 cotton growth seasons, high temperature treatments ranged from 34 to 44°C in climate chambers, and field experiments under high temperature weather with various temperature levels were conducted to investigate the effects of the high temperature level on square Bt protein concentration and nitrogen metabolism. The climate chamber experiments showed that the square insecticidal protein contents reduced after 24 h elevated temperature treatments for both cultivars, whereas significant declines of the square insecticidal protein contents were detected at temperature >38°C, and only slightly numerical reductions were observed when temperature below 38°C. Similar high temperature responses were also observed at the two field experimental sites in 2013. Correspondingly, high temperature below 38°C seems have little effect on the square amino acid concentrations, soluble protein contents, glutamic- pyruvic transaminase (GPT) and glutamic-oxalacetic transaminase (GOT) activities as well as protease and peptidase activities; however, when the temperature was above 38°C, reduced soluble protein contents, enhanced amino acid concentrations, decreased GPT and GOT activities, bolstered protease and peptidase activities in square were detected. In general, the higher the temperature is (>38°C), the larger the changes for the above compound contents and key enzymes activities of the square protein cycle. The findings indicated that the unstable insect resistance of the square was related to high temperature level during square stage.

Perennial waterlogged soil (PWS) is induced by the high level of groundwater, and has a persistent impact on natural ecosystems and agricultural production. Traditionally, distribution information regarding PWS is mainly collected from in situ measurements through groundwater level surveys and physicochemical property analyses. However, in situ measurements of PWS are costly and time-consuming, only rough estimates of PWS areas are available in some regions. In this paper, we developed a method to monitor the perennial waterlogged cropland using time-series moderate resolution imaging spectroradiometer (MODIS) data. The Jianghan Plain, a floodplain located in the middle reaches of the Yangtze River, was selected as the study area. Temporal variations of the enhanced vegetation index (EVI), night land surface temperature (LST), diurnal LST differences (ΔLST), albedo, and the apparent thermal inertia (ATI) were used to analyze the ecological and thermodynamic characteristics of the waterlogged croplands. To obtain pure remote sensing signatures of the waterlogged cropland from mixed pixels, the croplands were classified into different types according to soil and land cover types in this paper, and a linear mixing model was developed by fitting the signatures using the multiple linear regression approach. Afterwards, another linear spectral mixing model was used to get the proportions of waterlogged croplands in each 1 km×1 km pixel. The result showed an acceptable accuracy with a root-mean-square error of 0.093. As a tentative method, the procedure described in this paper works efficiently as a method to monitor the spatial patterns of perennial sub-surface waterlogged croplands at a wide scale.

Apple replant disease (ARD) causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured: yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed: hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components, (E)-2-hexenal, hexanal and 1-hexanol, significantly increased. Eight characteristic aroma components were found in the rotational cropping fruits: hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, 2-methyl- butyl butyrate, hexyl acetate and hexyl propionate. There were four characteristic ester components (hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate) and two characteristic aldehyde aroma components ((E)-2-hexenal and hexanal) in the continuous cropping fruits. Compared with the rotational cropping fruits, four characteristic ester components were declined and two characteristic aldehyde aroma components were increased. Compared with the control, replanted apple plant ground diameter, plant height increment and the total length of the current-year shoots were reduced by 27.6, 40.6 and 72.2%, respectively.

The variation among Chinese genotypes of Brassica napus L. for seed tocopherols content and their analysis using gas chromatography has not been comprehensively reported till to date. In the present study, the tocopherol contents of four Chinese genotypes of Brassica napus L., namely, Gaoyou 605, Zhejiang 619, Zheshuang 758, and Zheshuang 72, were evaluated using three modified sample preparation protocols (P1, P2, and P3) for tocopherol extraction. These methods were distinguished as follows. Protocol one (P1) included the evaporation of solvent after extraction without silylation. Protocol two (P2) followed the direct supernatant collection after overnight extraction without drying and silylation. Protocol three (P3) included trimethylsilylation with N,O-bis(trimethylsilyl) trifluoroacetamide. Genotypic comparison of tocopherol and its isoforms revealed that Gaoyou 605 was dominant over the other genotypes with (140.5±10.5), (316.2± 9.2), and (559.1± 24.3) μg g-1 of seed meal α-, γ-, and total (T-) tocopherol, respectively, and a 0.44±0.04 α- to γ-tocopherol ratio. The comparison of the sample preparation protocols, on the other hand, suggests that P3 is the most suitable method for the tocopherol extraction from Brassica oilseeds and for the analysis of tocopherols using gas chromatography flame ionization detector (GC-FID). Trimethylsilylation is the key step differentiating P3 from P1 and P2. Variations detected in tocopherol contents among the Chinese rapeseed (B. napus) genotypes signify the need to quantify a wide range of rapeseed germplasm for seed tocopherol dynamics in short and crop improvement in long.