Sugar contents of six generation populations (P₁, P₂, F₁, F₂, B₁ and B₂) derived from the cross between low sugar content inbred line ‘Huapicaigua’ (Cucumis melo var. conmmon Makino) and high sugar content inbred line ‘XLH’ (Cucumis melo var. saccharinus Naud.) were determined by high performance liquid chromatography (HPLC) method. Fruit sugar related traits in melon were analyzed using the joint segregation analysis method of a mixed major gene plus polygene genetic model. The results showed that the genetic model E-0, incorporating two pairs of additive-dominance-epitasis major genes plus an additive-dominance-epitasis polygene, was the best-fitting genetic model for fruit fructose content; and the genetic model E-1, incorporating two pairs of additive-dominance-epistasis major genes plus an additive-dominant polygene, was the optimal genetic model for fruit glucose, sucrose and total sugar contents. The fructose, glucose, sucrose, and total sugar contents were all controlled by two pairs of major genes and polygenes; the additive effect of major genes was mainly negative, and the interaction between the major genes was in common. Among them, the dominant and dominant interaction effect of the major genes for fructose, glucose and total sugar contents were the strongest, while the dominant and additive interaction effect of the major genes for sucrose content was the strongest. The negative additive effect of polygenes for sucrose and total sugar contents was relatively obvious. The heritabilities of major genes in the F₂ populations conferring the fructose, glucose, sucrose and total sugar contents were 85.7%, 86.2%, 92.7% and 85.0%, respectively; and the environment showed very little effect for fruit sugar content. Thus, in melon breeding, selection for high sugar content in early generation melon is desirable.

Core germplasm construction is one of the important means to utilize and manage plant germplasm resources. In present study, 180 germplasms of vegetable pea (Pisum sativum) were collected to study the construction strategy of core germplasm. The agronomic and yield characters were investigated, including the number of pod per plant, number of seed per pod, pod length, pod width, pod thickness, fresh mass of 100-pod, fresh mass of 100-seed, and yield. The results revealed an abundant genetic diversity in these vegetable pea germplasms. Using these data, the construction strategies of core germplasm were studied by using the minimum distance stepwise sampling (LDSS) method with four genetic distances and eight sampling ratios. Then, the construction strategies were evaluated by using the coincidence rate of range (CR) and variable rate of coefficient of variation (VR). The principal component analysis and cluster analysis were conducted to validate the representativeness of core germplasms. The results showed that Euclidean distance (ED) combining 25% sampling ratio was the best construction strategy in core germplasm construction of vegetable pea based on LDSS method. This study will lay a foundation for the core germplasm construction and efficient utilization of vegetable pea.

Verticilliumwilt of eggplant occurs seriously in some areas of Zhejiang Province. To control the disease effectively, the disease observation and pathogenicity tests of pathogen were carried out, and the pathotype and physiological races of pathogen were identified. Furthermore, inhibitory activity of Paenibacillus polymyxa strains against hypha growth and conidial germination of pathogen were determined, and inoculation assays for controlling Verticillium wilt of eggplant and plant growth promotion were conducted, and volatile metabolites and lipopeptides produced by P. polymyxa strains were analyzed. Results of disease observation and pathogenicity tests indicated that Verticillium wilt of eggplant in greenhouse occurred usually in mid-January, and it was caused by Verticillium dahliae Kleb. Identification results of pathotype and physiological races of pathogen with the representative strains demonstrated that seven isolates from Zhejiang Province all belonged to the defoliation pathotype and physiological race-2, respectively. In vitro experiments showed that the strain ShX301 had a highest inhibitory activity against hypha growth and conidial germination of pathogens isolated the diseased eggplant plants among five P. polymyxa strains. The in vivo experiments for controlling Verticillium wilt of eggplant and plant growth promotion displayed that the strain ShX301 had a highest inhibitory activity. Inoculation by the strain ShX301 reduced disease incidence and severity by 30% and 20.02%, respectively, and promoted eggplant plant growth with enhancing aboveground seedling stem length and biomass by 59.24% and 69.41%, as well as underground biomass by 54.11%, respectively. The determination of volatile metabolites showed that the five strains of P. polymyxa were able to produce volatile metabolites, which inhibited hypha growth of pathogen, but there were no significant differences among the strains. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) analysis revealed that the fusaricidins were main activity compounds of antagonistic pathogen. Therefore, this study provides a scientific theory basis for development of the strain ShX301 as a biocontrol or plant growth promotion agent.

Label-free based phosphoproteomics technology was used to study the phosphoproteome change of disease-susceptible strawberry cultivar ‘Benihopp’ and resistant cultivar ‘Sweet Charlie’ infected with Colletotrichum gloeosporioides. There were 154 and 173 phosphoproteins showing more than 1.5-fold change in ‘Benihopp’ and ‘Sweet Charlie’, respectively. The differentially expressed phosphoproteins were analyzed by gene ontology annotation and bioinformatics, and we found that, most differentially expressed phosphoproteins were involved in macromolecule complexe formation, and the biological processes of structural localization, stimulus response and signal transduction. Compared with ‘Benihopp’, ‘Sweet Charlie’ may specifically own two motif types of S*Y and T*F of differentially expressed phosphorylated peptides, and its plant hormone signal transduction pathway and carbon fixation pathway had higher levels of phosphorylation. The result is of great benefit to further deeply reveal the molecular mechanisms of plant-pathogen interactions and the breeding of pathogen-resistant strawberry cultivars.

Cephalcia chuxiongica Xiao (Hymenoptera: Pamphiliidae) is one of the most dangerous defoliators of Pinus yunnanensis Franch. and other pine species in Yunnan Province, resulting in serious losses. Its damage characteristics are the females’ aggregation of oviposition and larvae’s aggregation of feeding. In order to explore the chemical mechanism of the aggregation of oviposition, olfactory responses of the females to odors of pine needles and insect ovipositors were tested by means of Y-olfactory meter. In one-way choice tests, unmated females tended to the extracts of fresh needles with or without fresh eggs, but they did not tend to the eluents of fresh needles with or without fresh eggs, and the eluents both of unmated and mated female ovipositors. The mated females tended neither to the eluent of fresh needles nor to the eluent of unmated female ovipositors, but could be attracted by the crude extracts of fresh needles with or without fresh eggs, the eluent of fresh needles with fresh eggs and the eluent of mated female ovipositors. In two-way choice tests, the mated females showed tendency to the eluent of fresh needles with fresh eggs and the eluent of mated female ovipositors, neither to the eluent of fresh needles nor to the eluent of unmated female ovipositors. Based on the results, we conclude: 1) The volatiles in host needles play an important role in the females’ host search and selection; 2) the critical factor that attracts the mated females to aggregate to one pine shoot for oviposition is the volatile from the accessory genital glands of the pioneer egg-laying female.

This study aimed to improve the withering process of the white tea manufacturing and to achieve the stability and controllability of white tea quality. Fresh leaves plucked from tea (Camellia sinensis) bushes of 15 cultivars were used to explore the effects of withering temperatures (30, 25, 20 ℃) on the dehydration rate, sensory quality and biochemical compositions of white tea. The contents of biochemical compositions were compared among the samples based on the two-dimensional point set distribution and principal component analysis. The results showed that the water loss rates of all tea shoots tended to decelerate gradually under the different withering temperatures, the higher the withering temperature, the faster the water loss rate. Dehydration rate equation was consistent with the hyperbolic function. Compared with the natural withering, the average withering time at 25 ℃ was significantly shortened by 13.6 h. The sensory evaluation suggested that the white tea prepared under the withering condition of 25 ℃ had the highest quality, which was equivalent to the quality under the natural withering. The analysis of biochemical composition found that there was no difference between withering at 25 ℃ and natural withering. In conclusion, the time of the white tea withering at 25 ℃ was greatly shorten and the quality of the prepared white tea was superior, which could further improve the production efficiency of the white tea, and provide effective references for the improvement of the white tea process.

The taste quality of yellow tea and the contribution of taste-chemical compositions to yellow tea taste were explored by sensory evaluation, taste-compound detection, chemometrics analysis and dose-over-threshold factors (DoT), based on Zhejiang partial main cultivated cultivars and an improved process in north Zhejiang yellow tea production area. The results showed that the yellow tea, which was processed from Yingshuang, Baiyeyihao and Zhenong 113 tea cultivars and different yellowing process, presented varying degrees of sweet, mellow, umami, astringency and stewed taste. There were significant differences on the most of taste-chemical compositions among yellow teas from three tea cultivars, while there was a small difference among yellow teas from the same tea cultivar. The content analysis and partial least square discriminant analysis (PLS-DA) indicated that the taste quality of yellow tea was influenced remarkably by tea cultivars. The catechins like (-)-epigallocatechin-3-gallate (EGCG), (-)-gallocatechin-3-gallate (GCG), (-)-epigallocatechin (EGC), flavonol glycosides like myricetin-3-O-galactoside (Myr-gal), quercetin-3-O-glucoside (Que-glu), kaempferol-3-O-rutinoside (Kae-rut), amino acids like glutamic (Glu), theanine (Thea), arginine (Arg), aspartic acid (Asp), asparagine (Asn), et al., had great contribution to yellow tea taste characteristic under the experimental conditions. The further research of DoT value indicated that the specific taste of single compound in the aqueous solution would change in the complex tea liquor, which may be due to the interaction among different compounds.

With the rapid urbanization and industrialization process in recent decades, soil heavy metal pollution has been a serious threat to the development of society and human health in China. Mapping the spatial heavy metal distribution is an efficient way to identify high pollution areas, facilitate pollution source apportionment, and formulate prevention and control strategies. Selecting Hangzhou City as a case study, the spatial distribution of heavy metals was predicted by Bayesian maximum entropy (BME) method using the soil parent material as auxiliary information, and the estimation accuracy was compared with the traditional Kriging technique. The results showed that BME method has higher prediction accuracy than Kriging method, which was supported by narrower error distribution, smaller mean absolute error and root mean square error. Although the pollution risk of heavy metals in the study area was relatively low (their mean values were lower than the corresponding secondary soil environmental quality standard values), the contents of cadmium (Cd) and arsenium (As) were significantly higher than their local background values, which were 1.59 and 1.31 times of their corresponding background values, respectively. The contents of lead (Pb) and mercury (Hg) were high in the northeastern urban areas, implying that urbanization, industrialization and transportation may be the pollution sources; Cd and As were relatively high in the southwestern and mid-western rural areas, implying that agricultural activities may be responsible for the pollution source. In addition, Cd also showed some high content areas in the mid-eastern part of the city, which could be attributed to local mining activities. Chromium was mainly affected by natural sources.

The aim of this study was to provide a theoretical and technical basis for the selection and utilization of native grass by discussing the water use efficiency of dominant plants, and the vegetative characteristics of the Agropyron mongolicum, Glycyrrhiza uralensis and Stipa breviflora communities responding to different precipitation amounts in desert steppe of Ningxia. The field investigation and experiment were carried out; and carbon stable isotopic composition (δ¹³C) value, proline content and relative water content (RWC) of plant leaves were measured. The results showed that A. mongolicum, G. uralensis, S. breviflora and Lespedeza potaninii were the dominant species in the community with a large number of Artemisia scoparia, and they were all C₃ plants. With the increase of precipitation amount during the rainy season, the species richness, diversity indexes of these three communities and the soil water content increased significantly. There were significant effects on the leaf δ¹³C value, proline content and relative water content due to different precipitation amounts, and had significant interaction with different species, indicating that there were significant differences among these five species. In comparison, the water-use efficiency of G. uralensis was the highest; the anti-dehydration ability of A. mongolicum was the stronger than that of the others; the osmotic regulation ability of L. potaninii and A. scoparia was strong; and the water-use efficiency of S. breviflora was stable. The δ¹³C value of dominant plants was with significantly negative correlation to the soil water content, and with significantly positive correlation to the proline content, as well as the relative water content of leaves. Overall, precipitation significantly affected the community species composition, structure, and water use efficiency of dominant plants. Glycyrrhiza uralensis had a more water-saving trait, while S. breviflora and A. scoparia exhibited a more ‘conservative’ water use pattern,and A. mongolicum and L. potaninii had a flexible water use pattern.

We amplified and characterized the BmDaxx gene of the silkworm (Bombyx mori) by real-time quantitative polymerase chain reaction (RT-qPCR). The expression levels of BmDaxx and its downstream genes BmFadd and BmDredd showed significant increases after overexpression of BmDaxx. However, the expression levels of BmDaxx and BmFadd decreased significantly after siRNA interference of BmDaxx. Overexpression of BmDaxx increased the activity of the cystein-asparate protease-3/7 (caspase-3/7), while siRNA interference decreased the activity. When BmN cells were treated by caspase-3/7 inhibitor, the transcriptional levels of BmDaxx, BmFadd and BmDredd decreased as compared with controls. The expression level of BmDaxx was significantly higher in silk glands than in other organs at the silking stage, consistent with the silk gland degeneration at this stage. After injecting of the caspase inhibitor, the expression levels of the apoptosis-related genes BmDaxx, BmFadd and BmDredd showed significant decreases. It is concluded that there are direct relationships between BmDaxx and its predicted downstream genes BmFadd and BmDredd, which play critical roles both in BmN cells and in silk gland apoptosis.

Zika rabbit (N strain) was selected as the experimental material, and the expression levels of leptin gene (leptin) in leg muscle, perirenal fat and subcutaneous fat at four different days of age (35, 70, 84, 91) of Zika rabbits were determined by quantitative real-time fluorescence polymerase chain reaction (qRT-PCR). The pH value of leg muscle, cooked meat rate, drip loss and intramuscular fat were also measured. The correlation between leptin gene expression level and meat quality index in above the three tissues of Zika rabbits was analyzed. The results showed that leptin gene expression in perirenal fat and leg muscle of female rabbits was higher than that of male rabbits, and the leptin gene expression in subcutaneous fat of male rabbits was higher than that of female rabbits. The correlation coefficients between the expression level of leptin gene in subcutaneous fat and intramuscular fat content, cooked meat rate, pH value of 24 h after slaughter in the 84 day-old female rabbits were 0.95 (P＜0.01), 0.83 (P＜0.05) and 0.67 (P＜0.05), respectively; and the correlation coefficient between pH value of 24 h after slaughter and the expression level of leptin gene in the leg muscle in the 84 day-old male rabbits was －0.85 (P＜0.01). According to the analysis result, the expression level of leptin gene in the tissues of Zika rabbits is significantly correlated with meat quality, and it can be used as a candidate gene for studying meat quality of rabbits, and provide a reference for using molecular genetic marker technology and genetic improvement of meat rabbits.

An eight-week feeding experiment was conducted to evaluate the effects of dietary administration of Bacillus subtilis and yeast culture on growth performance, whole body composition and farming water quality of juvenile hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂). Nine isonitrogenous and isoenergetic diets were formulated that contained three levels of B. subtilis [0 (control), 0.5% and 1.0%] and three yeast culture levels [0 (control), 0.5% and 1.0%] at each B. subtilis level; the Y0B0 was taken as control group. The results showed that the interaction between B. subtilis and yeast culture had no significant effect on specific growth rate (SGR) of grouper (P＞0.05). The SGR of Y1B1 and Y1B2 groups were significantly higher than the control and Y2B2 groups (P＜0.05). The feed efficiency (FE) and protein efficiency ratio (PER) of grouper had a similar trend with SGR. The whole fish body composition showed no significant difference between treatment groups (P＞0.05). Meanwhile, the results showed that the interaction between B. subtilis and yeast culture had no significant effect on the whole body composition of juveniles (P＞0.05). The monitoring results of farming water quality for 12 d showed that the interaction between B. subtilis and yeast culture had a significant effect on the ammonia, nitrite and chemical oxygen demand (COD) contents in water starting from the sixth day; and the farming water quality of Y1B1 and Y1B2 groups had a significant improvement, compared with the control group. In conclusion, 0.5% yeast culture+0.5% B. subtilis and 0.5% yeast culture+1.0% B. subtilis in diets could promote growth performance and PER of juvenile hybrid grouper, and the farming water quality could be also obviously improved.

Temperature is an important factor affecting the postembryonic development duration of Chinese mitten crab (Eriocheir sinensis). Biological zero temperature and effective accumulated temperature reflect the intrinsic relationship between temperature and developmental duration. In this experiment, the larvae of Jianghai 21, an improved species of E. sinensis bred in Sheyang area of Yancheng City, Jiangsu Province, were used as experimental objects. A single factor, three treatments and three repetitive constant temperature test (constant temperature was set at 20, 22 and 24 ℃, respectively) was designed to monitor the development temperature and duration of E. sinensis at regular intervals. The biological zero and effective accumulated temperatures were calculated and validated by the effective accumulated temperature formula. The experimental data and the local five-year historical monitoring data were analyzed by single factor variance analysis. The test results showed that: 1) There was no statistically significant difference between the experimental data of biological zero temperature, effective accumulated temperature and the historical data (P＞0.05). It was confirmed that the biological zero and effective accumulated temperatures of E. sinensis were separately 6.91 ℃ and 274.18 ℃?d at the postembryonic stage. 2) Among the experimental temperature range, the larval development period of E. sinensis decreased with the increase of temperature. The above results can provide a scientific and theoretical basis for the study of postembryonic development of E. sinensis.

In order to investigate the structure of infectious bursal disease virus (IBDV) and how the double-stranded RNA (dsRNA) segments of IBDV are organized inside its capsid and how the genome segments are transcribed and assembled, we first obtained IBDV particles by infecting DF-1 cell with IBDV and purified the virus particles; we then determined the three-dimensional structure of IBDV using a single-particle cryo-electron microscopy (cryo-EM) at ≈6.6 ? resolution. The results showed that IBDV possessed a T＝13 single shell with 260 VP2 trimers. Unexpectedly no characteristic densities of dsRNA and RNA-dependent RNA polymerase were observed inside the IBDV capsid, which was in contrast to the structures of cytoplasmic polyhedrosis virus (CPV), bluetongue virus (BTV) and rotavirus (RV). These facts implicate that IBDV might adopt different mechanisms to organize, transcribe and assemble its genome segments, and that IBDV might originate and evolve differently from other dsRNA viruses.

The applicability of ISO 8178 C1 eight steady-state emission test cycle to small-scale agricultural machinery diesel engines with huge reserves remains to be discussed, so a diesel engine working condition recorder based on a single chip microcomputer was designed to collect and record the actual working condition information of small-scale agricultural machinery diesel engines. Through data analysis and extraction, a six-condition steady-state emission test cycle suitable for domestic small-scale agricultural machinery diesel engine was proposed and verified by bench test. The results of data analysis showed that the typical working conditions of domestic small-scale agricultural machinery diesel engine were quite different from those of the ISO 8178 C1 eight operating cycle. The results of bench emission test showed that the comprehensive emission level of pollutants of small-scale agricultural machinery diesel engine under the six working conditions was obviously different from that under the ISO 8178 C1 eight working conditions, and in most cases, the emission level under the six working conditions was worse than that under the eight working conditions. The above results can provide some references for the formulation and revision of relevant emission standards and the research on emission control technology of small-scale agricultural machinery diesel engine.