In order to explore the functional gene information of transcriptome in bottle gourd, the transcriptome of Fuzhou bottle gourd was sequenced by high-throughput non-parametric sequencing technology and 664 252 268 reads fragments were obtained. The reads gave 87 518 Unigenes with the total length of 91 405 320 bp, and 76.03% of Unigenes were concentrated in 1-1 000 bp. The results of functional annotations showed that 55 725 Unigenes were annotated in Nr database, among which 26 354 Unigenes were annotated in cucurbitaceae, accounting for 47.29% of the total Unigenes. GO database annotated 18 278 Unigenes, which closely related to molecular function, cell structure function and biological process function with 55 subgroups. 41 635 Unigenes were annotated in COG database, which were divided into information storage and processing, cell process and signal transmission, metabolism and non-characteristic genes with a total of 25 functional groups and the number of genes involved in amino acid transport and metabolism was the largest. There are 24 770 Unigenes annotated in the KEGG database, involving 220 KEGG metabolic pathways. SSR locus retrieval results showed that there were 11 029 SSR loci in 8 617 Unigenes containing SSR sequences, with a frequency of 9.846%. The results of this study would lay a foundation for the further development of metabolic pathways and SSR molecular markers in bottle gourd.

In order to reveal the possible roles of MIR319 family (miR319, miR319a and miR319a-3p) under the CGMMV stress, mature sequences of MIR319 were blasted against the watermelon genome to obtain the precursor gene. MEGA was used to analyze the evolutional relationship of precursor genes for MIR319. PlantCARE was used to analyze the cis-acting regulatory elements of the precursor gene promoter. Degradome sequencing was used to identify target genes of MIR319, and transcriptome sequencing and qRT-PCR were used to obtain the expression of target genes. The common precursor gene of MIR319, Pre-MIR319 was obtained, which was 170 bp in length, able to form the stem-loop structure. Sequence alignment showed that mature sequences of MIR319 were highly conserved at the 2~14 bases of 5'-terminal. Phylogenetic analysis of watermelon Pre-MIR319 and 116 miR319 precursor sequences from 35 species divided these precursor sequences into four branches. Watermelon Pre-MIR319 was closest to potato precursor gene miR319 a (MI0025952). The promoter of Pre-MIR319 contain several cis-acting regulatory elements, such as light responsive element, gibberellin responsive element, ethylene responsive element, methyl jasmonate response element, MYB, MYC and etc. Five target genes of MIR319 family, Cla019567, Cla013523, Cla023342, Cla002428 and Cla013668, were predicted by degradome sequencing results. Among which, Cla019567, Cla013523, Cla023342 and Cla002428 are annotated as TCP transcription factor and Cla013668 is annotated as MYB transcription factor. The cleavage sites were located at the 10 ^th of MIR319 at the 5'-terminal end. The amino acids number, molecular weight and theoretical isoelectric point of target genes were 319~554 aa, 34.94~61.21 kDa and 5.29~7.80, respectively. These proteins do not contain transmembrane domains and was located in the nucleus/cytoplasm. Expression profiles of target genes using transcriptome and qRT-PCR analysis revealed that miR319a negatively regulated its target gene Cla013523 ( TCP). These results clarified the role of MIR319 family members in CGMMV stress response and revealed the regulation of MIR319 on their target genes.

For exploring the effect mechanism of different nitrogen application amounts impact on potato tuber starch formation and yield in Ningxia arid areas, field trials were carried out in the mountainous areas of southern Ningxia in 2017(normal year) and 2019(wet year) respectively. The potato cultivar Qingshu No. 9 was used as the material and a single factor random Block experiment was designed, with no nitrogen fertilizer (N0) as the control, to study the effects of pure nitrogen application rate of 75 (N1), 150 (N2), 225 kg·hm ^-2 (N3) on potato starch content, key starch forming enzymes and yield. The results showed that with the increase of nitrogen application amount, the total starch and amylopectin content increased first and then decreased, with N2 being the highest, significantly increasing by 21.23, 26.42 percentage point (2017) and 19.74、24.93 percentage point(2019); while the amylose content increased with the increase of nitrogen application amount, reaching the highest at N3, which was 1.59 percentage point (2017) and 1.78 percentage point (2019) higher than N0. Both adenosine diphosphate glucose pyrophosphorylase (AGPP) and starch branching enzyme (SBE) had the highest N2, which increased by 57.38%, 36.83% (2017) and 67.19%, 29.01% (2019) compared with N0, respectively; while soluble starch synthase (SSS) and bound starch synthase (GBSS) were the highest with N3, which increased by 33.90%, 49.51% (2017) and 46.02%, 51.00% (2019) respectively compared with N0. Correlation and general analysis show that starch content and key enzymes in starch synthesis have a positive correlation, and AGPP, SSS, and GBSS have a greater direct contribution to the process of starch synthesis; Compared with N0, the potato output of N1~N3 increased by 10.72%~21.02% and 8.40%~16.30% in 2017 and 2019, respectively. The yield of N2 is the best; the best nitrogen application rate to achieve the highest yield is 150-184 (2017), 150-196 kg·hm ^-2 (2019). Therefore, it is suggested that the nitrogen application amount of 150-200 kg·hm ^-2 for potato in arid areas of Ningxia can effectively increase the activity of key enzymes in starch formation, accelerate starch formation and accumulation, and promote the increase of potato production, thereby increasing the economic benefits of local people.

In order to explore the function of mitogen-activated protein kinase (DsMAPK) in Dunaliella salina, the interacting proteins with MAPK in D.salina were screened by immunoprecipitation-mass spectrometry. The pGS-21a-MAPK plasmid was transfected into E. coli BL21 to express MAPK and prepare polyclonal antibodies. D. salina cells at logarithmic growth stage were treated with salt stress, then the total protein of D. salina was extracted and tested by SDS-PAGE and Western blotting. Using endogenous target protein as bait, total proteins of cell and MAPK’s antibody were co-incubated. The immunoprecipitation compound purified by protein A/G agarose beads were detected by mass spectrometry. The results showed that the prepared polyclonal antibody has good specificity and 165 specific differential proteins were screened out. Through GO and KEGG analysis, we found that these differentially expressed proteins are mainly involved in metabolism, genetic information transmission, signal transduction and other biological processes. Protein interaction network analysis revealed that 4 different proteins interact directly with MAPK. The results provide new information for further study on the molecular mechanism of D.salina responding to salt stress.

Soil salinization caused by soil sodium accumulation is becoming more and more serious,which is one of the important factors restricting rice yield and quality. Sodium ion is the main ion causing salt stress injury in rice. Study on the mechanisms of sodium ion uptake and transport in rice plants and the physiological and molecular mechanisms of rice in response to salt stress is very helpful to the selection and breeding of salt-resistant varieties and to the comprehensive management and utilization of saline-alkali land. This paper summarized the induction of salt signals and the characteristics of salt absorption and transport in rice, analyzed the effects of salt on rice morphology growth and development, and discussed the physiological mechanism of osmotic regulation, nutrient regulation, antioxidant system regulation and hormone regulation induced by rice in order to alleviate salt damage. The molecular regulation mechanisms of ion balance, membrane protection system and photosynthetic system in rice through differential expression of stress-resistant proteins and stress expression of salt-tolerant related genes are also discussed in present study. Besides, this paper proposed the exogenous application methods to improve salt tolerance of rice as well as the esearch prospects of this field.

In order to explore the specific content of bioactive ingredients in the broccoli leaves. Broccoli leaves were selected as the research material to analyze the bioactive ingredients contained. The contents of sulforaphane, total phenolics, total flavonoids, total proteins in broccoli leaves were 92.5 μg·g ^-1 (dry weight), 3.15 mg·g ^-1 (dry weight), 2.48 mg·g ^-1 (dry weight) and 89.38 mg·g ^-1 (dry weight). Ribulose-1,5-diphosphate carboxylase/oxygenase (Rubisco) occupied most of the proteins in broccoli leaves. This study clarified the specific contents of four bioactive components in broccoli leaves, which provided some data support for the further utilization of broccoli waste.

MYB transcription factors play an important regulation role in the salt stress-responsive of plant. In order to characterize the biological function of a MYB transcription factor, RcWER-like, its'expression profile in diverse tissues under salt, hormone, and salt combined with hormore treatment were analyzed by real-time PCR. In this study, a MYB transcription factor gene of rose, RcWER-like was cloned from R. chinensis Old Blush based on the transcriptome and genome data. Bioinformatic analysis showed that the total length of RcWER-like gene was 882 bp, and the ORF of RcWER-like was 669 bp, which encode 223 amino acids. Multi-alignment of RcWER-like with other MYB type proteins revealed that RcWER-like had two conserved domains in the N-terminal. Phylogenic tree analysis showed that RcWER-like was clustered with PpWER-like in Prunus persica, PmWER-like in Prunus mume and MdWER-like in Malus domestica, and belonged to the R2R3-MYB type transcription factor. Real-time PCR results showed that the expression level of RcWER-like was significantly increased at 24 h under salt stress, and the SA and MeJA treatments could also induce the expression of RcWER-like. In addition, under salt stress, RcWER-like was significantly up-regulated by SA and MeJA, which was higher than that under salt stress and exogenous hormone treatment. Meanwhile, there were significant differences in the expression patterns of RcWER-like in different tissues at different time points under the treatment of salt and hormone. These evidences implied that the R2R3-MYB transcription factor RcWER-like in Rosa chinensis Old Blush could response to SA and MeJA, and might play an important role in response to salt stress. The results will provide candidate gene resources and theoretical basis for salt tolerance molecular breeding of rose.

To improve the potential of biochars removing nitrate through sorption, peanut shell biochars (BC) were prepared by pyrolysis at 600℃ and modified with FeCl ₃, MnCl ₂, MgCl ₂ solution (BC-Fe, BC-Mn, BC-Mg) by calcination at 300 ℃. The surface structure and adsorption properties of these modified biochars which were loaded the metal ions were detected by isothermal adsorption test, scanning electron microscope (SEM), Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD). The results showed that the modified biochars (BC-Fe, BC-Mn, BC-Mg) significantly increased specific surface area by 6.7~12.2 times, pore volume by 3.3~6.0 times, and significantly enhanced the adsorption capacity of nitrate nitrogen ($\text{NO}_{3}^{-}$-N) by 11.5%~17.1% in comparison with the BC control ( P<0.05). The maximum adsorption capacities of BC-Fe, BC-Mn and BC-Mg to $\text{NO}_{3}^{-}$-N were 41.58, 39.04 and 39.58 mg·g ^-1, respectively, as well as the best mass ratios of iron, manganese, magnesium ions to carbon were 0.8, 0.2 and 0.2, respectively. Therefore, BC-Fe showed the highest adsorption capacity for nitrate adsorption process. Acid condition was shown to improve the adsorption of modified biochars to $\text{NO}_{3}^{-}$-N. Langmuir equation was better fitted to describe nitrate isothermal adsorption of the above modified biochars ( R ²=0.935~0.961), and the quasi-first-order kinetics equation could describe nitrate kinetic adsorption well ( R ²=0.971~0.980). With higher specific surface area, well-developed pore structure, modified biochars optimize physical adsorption capacities and then enhanced the adsorption performance of nitrate. It also suggested that the oxygen-containing functional groups and metal ions on the surface of modified biochars would react with $\text{NO}_{3}^{-}$ by forming hydrogen bonds or electrostatic action, thereby enhancing the adsorption capacity of $\text{NO}_{3}^{-}$-N. The results of this study can provide a theoretical basis for the preparation and optimization of biochars to adsorb nitrate.

In order to explore the epigenetic mechanism of tolerance acquisition of the invasive plant Flaveria bidentis under heavy metal cadmium (Cd) stress, a pot experiment was conducted to simulate different concentrations of Cd contaminated habitats. Methylation sensitive amplification polymorphism (MSAP) technique was used to analyze the genomic DNA methylation variation characteristics of plant leaves under different Cd stress[0(CK)、2(Cd-1)、4(Cd-2)and 8(Cd-3) mg·kg ^-1]. The results showed that 726 methylation bands were amplified by 15 pairs of primers, and the percentage of primer polymorphism was 84.75%. With the increase of Cd stress concentration, the proportion of fully methylation and total methylation in leaves of Flaveria bidentis showed a gradual increase trend. The Cd-1, Cd-2 and Cd-3 was 1.51, 1.59 and 2.11 times the fully methylation level of the CK, respectively. Total methylation level of Cd-1, Cd-2 and Cd-3 increased by 39.28, 53.30 and 63.97 percentage point compared with the CK, respectively. The results of methylation analysis of Flaveria bidentis with different treatments showed that both remethylation and demethylation occured under Cd stress, but remethylation was the main transformative mode. Correlation analysis results showed that the levels of DNA fully methylation and total methylation levels were negatively correlated with phenotypic plasticity of growth and above-ground tolerance indexes, while positively correlated with antioxidant enzyme activity, Cd contents of different tissues, accumulation and transfer coefficient. The results of this study provide a new perspective for the prevention and control of invasive plant Flaveria bidentis from the aspect of epigenetics.

Food allergy is one of the serious food safety problems threatening human health. Food irradiation can reduce the allergenicity of food allergens and is a potential physical desensitization technology. In this review, the characteristics, principle and development history of irradiation desensitization technology were introduced, and the research progresses on reducing the allergenicity of animal foods(e.g. milk, eggs, shrimp and fish) and plant foods (peanut, soybean, wheat and nuts) by irradiation were summarized. In addition, the reducing effects and impact factors of irradiation on food allergens were analyzed, and the future research direction of irradiation desensitization technology was discussed. The purpose is to provide reference for the research and application of reducing the allergenicity of food allergens by irradiation technology.

In order to establish a irrigation system for the standardized cultivation of perilla [ Perilla frutescens (L.) Britt], effects of drought stress (mild drought, moderate drought and severe drought) on the growth and quality of perilla was studied by using the seedling as the material and the normal water supply as the control (CK). The results showed that the mild and the moderate drought stress significantly increased malondialdehyde (MDA) content and relative electrical conductance (REC) of perilla leaves, and it maintained antioxidant enzyme activity, proline, soluble sugar and soluble protein content at a high level. The treatment of severe drought stress also significantly increased the MDA content and the REC of perilla leaves, but its antioxidant enzyme activity, proline, soluble sugar and soluble protein content were significantly lower than CK. With the prolongation of stress treatment time, under the condition of serve drought, the MDA content and REC of the leaves increased gradually, while the antioxidant enzymes activities, proline, soluble sugar and soluble protein were decreased. With the increase of drought stress, the biomass of the upper part of the perilla significantly decreased, and the total volatile oil content in the leaves increased first and then decreased. The result indicated that the drought stress treatment was not conducive to the growth of perilla, but proper drought stress treatment can promote the synthesis of volatile oil in perilla leaves, thus significantly improve the medicinal quality of perilla leaves. The study provided a theoretical basis for cultivation of perilla.

To better understand the physiological mechanism behind the phenomenon of decreased photosynthetic rate when foxtail millet seedlings are treated with Sigma Broad, different concentrations (0, 7.5, 15.0, 30.0, 60.0 mg·L ^-1) of 3.6% Sigma Broad were sprayed at the five-leaf stage of Zhangzagu 5 and Jingu 21, and gas exchange parameters, photosynthetic key enzyme activities and soluble matter content were determined and analyzed after 7 days later. The results showed that the net photosynthetic rate (Pn), ETR, the activities of phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), NADP-malate dehydrogenase (NADP-MDH), were reduced with the increasing of Sigma Broad at 15 mg·L ^-1. The NAD-malic enzyme (NAD-ME), Ribulose-1, 5-bisphosphate carboxylase oxygenase (Rubisco) activities and soluble substances content increased first and then decreased with the increased concentration of Sigma Broad in the two varieties, and the maximum values of NAD-ME, reducing sugar, sucrose and soluble protein were all appeared at the treatment of 15 mg·L ^-1 for both varieties. In summary, Sigma Broad making the obvious damages to the net photosynthetic rate in leaves of foxtail millet is partially due to that the activities of PSⅡ photochemical, PEPC, NADP-MDH, and PPDK were reduced, and the activities of Rubisco and NAD-ME and the metabolism of sugar were affected.

By simulating the way of rain-fog leaching under natural conditions, a laboratory experiment was conducted to investigate the allelopathic effect of growth, physiology and biochemistry of I. indigotica exposed to leaf litter extracts of Camellia sinensis (LLEC) (CK: 0 mg·mL ^-1,T1: 6.25 mg·mL ^-1, T2: 12.5mg·mL ^-1, T3: 25 mg·mL ^-1, T4: 50 mg·mL ^-1). The changes of growth, antioxidant enzyme activity, gene expression, cell membrane damage rate, malondialdehyde, hydrogen peroxide, osmotic regulators and secondary metabolites were measured. The results showed a dose-dependent effect, namely promoting effect at low concentration and suppressing effect at high concentration on the growth of Ⅰ. indigotica. Compared to CK, the growth of Ⅰ. indigotica was enhanced by T1 treatment. However, it was not conducive to its growth when the concentration of LLEC exceeded the tolerance threshold of Ⅰ. indigotica. With increasing the concentration of LLEC, the content of soluble sugar and soluble protein increased first and then decreased, but proline content continued to increase. There were no significant differences between the malondialdehyde content, the cell membrane damage rate and hydrogen peroxide content and CK by T1 treatment. These indicators increased significantly under T3 and T4 treatments. The activities and gene expressions of antioxidant enzymes were affected to different degrees by LLEC. The activity of peroxidase and ascorbate peroxidase by T1 treatment, the activity of catalase by T2 treatment were the highest, but the activities of four antioxidant enzymes by T4 treatment were significantly lower than those of CK. A significant positive correlation was found between the activities of peroxidase and related gene expression level, but the correlation between enzyme activities and related gene expression levels of superoxide dismutase,catalase and ascorbate peroxidase were not significant. Remarkable difference was observed in the accumulation of secondary metabolites in Ⅰ. indigotica under different concentrations of LLEC. The contents of indigo and indirubin were the highest under T1 treatment, and the contents of total flavonoids were the highest under T4 treatment. In conclusion, low concentration of LLEC could promote the growth and accumulation of indigo and indirubin of Ⅰ. indigotica, while high concentration of LLEC could promote the accumulation of total flavonoids. The research provides a theoretical reference for intercropping model of C. sinensis and Ⅰ. indigotica in the young tea field.

In order to explore the effects of selenium-sulfur interaction on the physiology and sulforaphane metabolism of broccoli sprouts under high temperature stress, broccoli seeds were sprayed with ZnSO ₄ or Na ₂SeO ₃ alone or combined with ZnSO ₄ or Na ₂SeO ₃ or both under high temperature stress. The main physiological and biochemical indexes of broccoli sprouts during germination were analyzed and the changes of gene expression of key enzymes in sulforaphane metabolism were analyzed by fluorescence quantitative PCR. The results showed that the application of Na ₂SeO ₃ alone could significantly increase the sprouts length and the fresh weight per plant ( P<0.05), and effectively alleviate the inhibition of high temperature and ZnSO ₄ on the growth and development of broccoli sprouts. During germination, compared with spraying ZnSO ₄ alone, the selenium content, total antioxidant capacity, glucosinolates content, mesonase activity, isothiocyanate content and sulforaphane content of broccoli sprouts sprayed with ZnSO ₄ and Na ₂SeO ₃ after high temperature were significantly increased ( P<0.05). The content of sulforaphane was 39% higher than that of spraying ZnSO ₄ alone. The expressions of MYB28, UGT74 B1 and ST5b in sprouts treated with high temperature combined with ZnSO ₄ and Na ₂SeO ₃ for 4 days were significantly up-regulated compared with the control, while BoHMT1 was significantly down-regulated ( P<0.05). To sum up, broccoli sprouts treated with high temperature combined with selenium and sulfur is an effective way to enrich sulforaphane. The results of this study provide a theoretical basis and technical support for the production of functional sprouts rich in sulforaphane.

In order to further explore the higher density of maize in Hexi Oasis Irrigation Area, whether high yield can be obtained under the condition of water and nitrogen reduction, the photosynthetic potential, dry matter accumulation, grain yield and yield composition of maize during growth period were determined. The field experiment designed traditional irrigation (W ₁) and growth period reduction 20% irrigation (W ₂), high nitrogen application (450 kg·hm ^-2, N ₁), reduction of 30% nitrogen application (300 kg·hm ^-2, N ₂) and three planting density of 75,000 plants·hm ^-2 (D ₁), 97,500 plants·hm ^-2 (D ₂) and 120,000 plants·hm ^-2 (D ₃). The results indicated that no significant difference was found in the photosynthetic potential of W ₂N ₂ and W ₁N ₁ corn in the late growth stage. Under the W ₂N ₂ treatments, the photosynthetic potential of D ₂ increased by 8.7% compared with D ₁ during the whole growth period of the maize. There was no significant difference between D ₂ and D ₃. The dry matter accumulation of W ₂N ₂ was eventually equal to W ₁N ₁ at a low amount of water and nitrogen conditions. The dry matter accumulation of D ₂ increased by 21.1% compared with D ₁ during the whole growth period of maize and no significant difference was found between D ₂ and D ₃. The grain yield of W ₂N ₂D ₂ was the same with that of W ₁N ₁D ₂. The dry matter accumulation of D ₂ increased by 9.0%~33.7% compared to that of D ₁ treatment. Irrigation and nitrogen applications had no significant effect on the grain number per ear and 1000-grain weight of maize. Under the same water and nitrogen conditions, the grain number of D ₃ corn compared with D ₁ decreased by 5.9%~26.1%, and the 1000-grain weight of corn decreased by 9.2%~12.3%. In conclusion, W ₂N ₂D ₂ still maintained a large photosynthetic potential of maize under reduced irrigation and nitrogen application at the later stage of growth, which provides material guarantee for the formation of corn yield, thus obtaining high yield. Therefore, maize planting with plant density of 97,500 plants per hm ^-2 in a condition of reduced 20% irrigation and 30% nitrogen application can be recommended as a technical reference.

In order to investigate curing characteristics of upper tobacco leaves, the difference of water loss rate, yellowing and browning characteristics, chlorophyll relative content (SPAD), color values, polyphenol oxidase (PPO) activity and chemical composition content of the different maturity leaves of K326, Bi’na1, Zunyan6, Guiyan1, Guiyan4 and Honghuadajinyuan (Hongda) were studied during curing or during drawer testing. The results showed that Bi’na1 had smaller water loss rates while Hongda and Guiyan1 had larger water loss rates; Bi’na1 and K326 had shorter yellowing time while Hongda had a longer yellowing time during curing and drawer testing. The average PPO activity of Bi’na1 was less than 0.4 U and that of Guiyan1 was larger than 0.5 U during curing. As for chlorophyll relative content, Hongda had larger SPAD values, then were Zunyan6 and Guiyan1, and the last were Bi’na1, Guiyan4 and K326 during drawer testing. Hongda and Zunyan6 showed a relatively poor color values, and Guiyan1 showed a more serious browning. However, Bi’na1 had a lighter browning during drawer testing. Moreover, flue-cured tobacco leaves of Bi’na1, Guiyan4 and Zunyan6 had a relatively suitable chemical composition content. Following progressive improvement of tobacco leaves maturity levels, the yellowing time of fresh tobacco leaves was shortened and the activity of PPO increased during curing, the total content plant alkaloid and nitrogen decreased, and the content of water-soluble total sugar and reducing sugar increased. In addition, the yellowing time and browning time of tobacco leaves were shortened, the SPAD value was reduced, and the color showed better before the leaf became browning with the improvement of tobacco leaf maturity levels during drawer testing. Variety and maturity not only affected the leaf phenotype, but also had a significant impact on its intrinsic physiology. The curing characteristics of different flue-cured tobacco varieties were not only closely related to the chemical composition, but also the genotypes. As for drawer testing, SPAD value could be used as a phenotypic indicator for judging the easy curing portential, and the color parameters could be used as a phenotypic indicator for judging the easy and endurable curing portential. Taken together, K326, Bi’na1, Guiyan1 and Guiyan4 had a better easy curing portential, then was Zunyan6, and Hongda showed the worst performance. In addition, Bi’na1 had a better endurable curing portential, then were K326, Guiyan4, Hongda and Zunyan6, and Guiyan1 showed the worst performance. According to the difference of curing characteristics of different flue-cured tobacco varieties, we have put forward some specific measures for different tobacco varieties curing, which lay the theoretical foundation for different flue-cured tobacco varieties curing and the improvement of upper tobacco quality.

In order to explore the feasibility of pre-harvest oxalic acid treatment in postharvest preservation of broccoli, broccoli was sprayed with 20 mmol·L ^-1 oxalic acid aqueous solution 5 days before harvest (pure water spraying as control), and the harvest broccoli heads was stored for 15 days at 2℃ followed by 20℃ for 4 days. During storage time, physiological and quality parameters were periodically determined. The results indicated that pre-harvest application of oxalic acid on broccoli significantly inhibited the ethylene production and respiration rate( P<0.05), delayed the increase of weight loss, restrained the L ^* value increase and H value decrease and maintained the appearance color, and delayed the decline of vitamin C, chlorophyll content and firmness. Overall, pre-harvest treatment of oxalic acid significantly increased the storage quality of broccoli head, which provided the theoretical foundation of oxalic acid application on broccoli storage.

The paper aimed to reveal the antifungal activity and possible mechanism of plant essential oil on dominant pathogens of postharvest sweet cherries. Hongdeng, the main varietiy in Taian, Shandong Province, was chosen as the raw material, traditional morphological identification method combined ITS analysis was performed to separate dominant pathogens from rotten sweet cherries, and antifungal activity of clove essential oil on three pathogenic fungal strains was assessed by in vitro fumigation and contact. The results showed that these strains were identified as Botrytis cinerea, Alternaria alternate and Colletotrichum gloeosporioides. Clove oil at certain concentrations exhibited obvious antifungal effects by inhibiting mycelial growth and spore germination of the three strains, and fumigation was better than contact. For B. cinerea, A. alternate and C. gloeosporioides, the minimal inhibitory concentrations (MIC) of clove oil in air phase were 120, 100 and 100 μL·L ^-1 in vitro testing, respectively. Moreover, the possible mechanisms of fumgitoxic action were related to the hydrophobicity of essential oils which enabled them to disrupt membrane structure of microorganism, and lead to loss of cell contents. In conclusion, clove essential oil was proved to be a promising candidate as effective antifungal agent for postharvest decay of sweet cherries.

Rice yield depends on size and coordination of the sink and source-related traits. To study effect of pyramiding of different sink-source genes on yield and its related traits, near-isogenic lines of four cloned sink-source genes including NAL1 ^LT, GNP1 ^TQ, Ghd7 ^{MH 63} and Ghd8 ⁹³¹¹ in different genetic backgrounds were used as materials to develop F ₂ populations for pyramiding different genes, and homozygous single and two-gene pyramiding individuals were selected by marker-assisted selection using their respective linkage markers for further evaluation of yield and its related traits in F ₃ lines. The results showed that individuals with NAL1 ^LT + Ghd7 ^{MH 63}, NAL1 ^LT + Ghd8 ⁹³¹¹ and Ghd7 ^{MH 63}+ Ghd8 ⁹³¹¹ had significant yield-increased effect with 26.45%, 45.47% and 48.03% higher than their respective high-value parents, suggesting the three types of pyramiding had synergistic effect on sink-, source- and yield-related traits in their progenies. Oppositely, another three pyramiding types of NAL1 ^LT + GNP1 ^TQ, GNP1 ^TQ + Ghd7 ^{MH 63} and GNP1 ^TQ + Ghd8 ⁹³¹¹ had no significant effects on yield, some yield-related traits increased but other decreased or maintained the same levels as parents. For pyramiding breeding of complicated quantitative traits, we think it should firstly, study pyramiding effect of different genes on yield traits to ascertain pyramiding effectiveness among them, which will give us twofold results with half the effort in breeding. Our results will provide a theoretical basis of molecular pyramiding improvement of rice sink and source traits.

In this work, experiments were explored to prepare the cross-linked enzyme aggregates (CLEAs) of β-glucosidase from black plum seeds and evaluate their stability. After determination of the optimal preparation parameters, including the optimum precipitation agent, volume ratio of precipitant to enzyme liquid and glutaraldehyde concentration, then the shape and surface morphology of the CLEAs were examined using scanning electron microscopy. Moreover, the salidroside synthesis catalyzed by CLEAs was chosen as a model reaction to investigate the thermal and operational stabilities. The optimum precipitation agent, volume ratio of precipitant to enzyme liquid, glutaraldehyde concentration and crossing-linking time were found to be 95% ethanol, 1:3 (v:v), 30 mmol·L ^-1 and 1.0 h, under which the activity recovery of CLEAs recorded 91.4%. Compared to free enzyme, the surface morphology of CLEAs displayed a very high specific surface area, abundant pores and dense channels. Experimental data of the thermal stability indicated that CLEAs retained 75.1% of their original activity after incubation for 2.0 h at 60℃, which was 6.1 times high than that of the free enzyme. For the operational stability, 73.5% of the initial activity of CLEAs was still maintained after eight successive cycles of reuse. This study proves CLEAs of β-glucosidase from black plum seeds exhibited good activity, thermal stability and operational stability, which was advantageous to the synthesis of the glycosides.