警惕新发病毒番茄褐色皱果病毒Tomato brown rugose fruit virus对我国番茄产业的危害

番茄褐色皱果病毒Tomato brown rugose fruit virus(ToBRFV)于2014年首次在以色列发现,随后传播到欧洲、美洲以及亚洲等地。ToBRFV在番茄叶片上引起花叶,更重要的是在番茄果实上引起褐色皱缩斑,导致番茄完全失去商品价值,是番茄安全生产的重大威胁。为遏制ToBRFV的传播,多个国家已经将该病毒列入检疫对象。2019年,我们在山东番茄上检测到该病毒。本文综述了ToBRFV发生与危害、寄主范围和症状、传播方式、基因组结构、检测方法,并提出了防治建议,希望有助于防范该病毒在我国的扩散。

Difference in volatile profile between pericarp tissue and locular gel in tomato fruit

Aroma, a complex mixture of volatile compounds, plays an important role in the perception and acceptability of tomato products by consumers. Numerous studies have reported volatile profiles in tomatoes based on measurement of the whole fruit or pericarp tissue, however, little is understood regarding the volatile compositions in the inner tissues. The objective of this study was to investigate the differences in volatile profile between pericarp tissue and Iocular gel in tomato fruit. Based on HS-SPME-GC-MS analysis, totally 42 volatile compounds were detected in FL 47 and Tasti-Lee tomato fruits. Regardless of cultivars, a substantial higher concentration of total volatile compounds was observed in pericarp than that in/ocular gel, associated with higher levels of aldehydes, hydrocarbons, and nitrogen compounds. Pericarp tissue possessed higher levels of cis-3-hexenal, hexanal, heptanal, octanal, nonanal, cymene, terpinolene, undecane, dodecane, 2-phenylethanol, 6-methyl-5-hepten-2-one, 2-methylbutyl acetate, 1-nitro-pentane, and 1-nitro-2-phenylethane, while the abundances of 2-methylpropanal, butanal, 2-methylbutanal, 2-methyl-2-butenal, 2-methylpropanol, 3-methylbutanol, 2-methylbutanol, and 2-butanone were higher in Iocular gel. Principal component analysis （PCA） and cluster analysis using GC-MS and electronic nose （E-nose） data discriminated the two tissues.

Biological and molecular characterization of tomato brown rugose fruit virus and development of quadruplex RT-PCR detection

Tomato brown rugose fruit virus(ToBRFV) is a novel tobamovirus firstly reported in 2015 and poses a severe threat to the tomato industry. So far, it has spread to 10 countries in America, Asia, and Europe. In 2019, ToBRFV was identified in Shandong Province(ToBRFV-SD), China. In this study, it was shown that ToBRFV-SD induced mild to severe mosaic and blistering on leaves, necrosis on sepals and pedicles, and deformation, yellow spots, and brown rugose necrotic lesions on fruits. ToBRFV-SD induced distinct symptoms on plants of tomato, Capsicum annumm, and Nicotiana benthamiana, and caused latent infection on plants of Solanum tuberosum, Solanum melongena, and N. tabacum cv. Zhongyan 102. All the 50 tomato cultivars tested were highly sensitive to ToBRFV-SD. The complete genomic sequence of ToBRFV-SD shared the highest nucleotide and amino acid identities with isolate IL from Israel. In the phylogenetic tree constructed with the complete genomic sequence, all the ToBRFV isolates were clustered together and formed a sister branch with tobacco mosaic virus(TMV). Furthermore, a quadruplex RT-PCR system was developed that could differentiate ToBRFV from other economically important viruses affecting tomatoes, such as TMV, tomato mosaic virus, and tomato spotted wilt virus. The findings of this study enhance our understanding of the biological and molecular characteristics of ToBRFV and provide an efficient and effective detection method for multiple infections, which is helpful in the management of ToBRFV.

Regulations of m^(6)A methylation on tomato fruit chilling injury

Tomato fruit are sensitive to chilling injury(CI)during cold storage.Several factors have been discovered to be involved in chilling injury of tomato fruit.Plant hormones play an important regulatory role,however,the relationship between chilling injury and N6-methyladenosine(m^(6)A)methylation of transcripts in plant hormone pathways has not been reported yet.In order to clarify the complex regulatory mechanism of m^(6)A methylation on chilling injury in tomato fruit,Nanopore direct RNA sequencing was employed.A large number of enzymes and transcription factors were found to be involved in the regulation process of fruit chilling injury,which were associated with plant hormone,such as 1-aminocyclopropane 1-carboxylate synthase(ACS),aspartate aminotransferase(AST),auxin response factor(ARF2),ethylene response factor 2(ERF2),gibberellin 20-oxidase-3(GA20ox)and jasmonic acid(JA).By conjoint analysis of the differential expression transcripts related to chilling injury andm^(6)Amethylation differential expression transcripts 41 differential expression transcripts were identified involved in chilling injury including 1-aminocyclopropane-1-carboxylate oxidase(ACO)and pectinesterase(PE)were down-regulated and heat shock cognate 70 kD protein 2(cpHSC70),HSP70-binding protein(HspBP)and salicylic acid-binding protein 2(SABP2)were up-regulated.Our results will provide a deeper understanding for chilling injury regulatory mechanism and post-harvest cold storage of tomato fruit.

Relationship Between Ca ^(2+)-CaM and Ethylene-Induced PG Activity in Tomato Fruit

Polygalacturonase (PG) was studied during ripening and senescence of postharvest tomato fruit at pink stage at low and normal temperature. The results showed that the PG activity increased, then decreased during ripening and senescence of tomato. Low temperature inhibited but ethylene enhanced PG activity. Ethylene also enhanced calmodulin content, which was dependent on Ca 2+concentration in cell. When EGTA(Ca 2+chelator), verapamil(Vp) and LaCl 3(Ca 2+channel blockers), trifluoperazine and chloropromaize (two CaM antagonisms) were used to treat tomato fruit at green mature stage with ethylene, they could reverse ethylene-induced increase in PG activity, but Vp, chloropromaize (CPZ), trifluoperazine (TFP) could not directly influence PG activity, which indirectly indicated that influx of Ca 2+ from the extracellular space including the cell wall via the Ca 2+ channel localized in plasma membrane and CaM were required for ethylene-induced PG activity increase and that ethylene signal transduction may be related to Ca 2+CaM messenger system.

Changes of Activities in NAD Kinase and NADP PhosphataseDuring Ripening and Senescence of Tomatoand Strawberry Fruits

Activities of NAD kinase(NADK)and NADP phosphatase and relationship between the two enzymes and temperature, respiration, ethylene production and trifluoperazine(TFP) were studied during ripening and senescence of strawberry and tomato fruits after harvest at 4℃ and 20℃. The activity of NAD kinase in strawberry decreased slowly during first four days, then increased gradually. The NADP phosphatase activity increased at the second day, decreased the next day,then increased again. In tomato fruit, the activities of NAD kinase and NADP phosphatase increased at the second day, decreased with the ripening and senescence of the fruit. The change trend of NAD kinase and respiration in the two fruits were similar, the same were NADP phosphatase and ethylene production. TFP enhanced the activity of NAD kinase and had little effect on NADP phosphatase. Low temperature(4℃) activated the NAD kinase and reduced the activity of NADP phosphatase. These results indicated that the NAD kinase and NADP phosphatase were related to the ripening and senescence of strawberry and tomato fruits. The activation of NAD kinase probably postponed the ripening and senescence of the fruits.

Mining Heat Stress Associated Genes in Tomato Fruit (Solanum lycopersicum L.) Through RNA-seq

Tomato(Solanum lycopersicum L.)is a thermophilic vegetable crop,but sensitive to high temperature stress,especially under the greenhouse conditions.Due to global climate changes,heat stress has now become a great threat to tomato production and fruit quality.Many studies have been conducted to determine the functions of genes in tomato responsive to abiotic and biotic stresses,but transcriptomic information on heat stress responses of tomato fruit is still limited.To investigate heat stress associated genes in tomato fruit,a cDNA library was constructed using fruit harvested from tomato cv.P19-9 plants grown under 42℃for 0,1,2 and4 h and the expression profiles of heat stress responsive genes in tomato fruit were analyzed through RNA-seq.A total of 632224558 clean high quality paired-end reads were obtained and then mapped to reference genome for RNA-seq analysis.After quality control analysis,alignment analysis and transcript assembly,a total of 55457 RNA transcripts were obtained with functional annotations.Overall,6869 differentially expressed genes(DEGs)were identified with a significant response to one or more of the three heat stress treatment times.Based on GO enrichment analysis,22 genes potentially involved in tomato thermo-tolerance were selected and validated for their expressions through qPCR.The expression profile of tomato fruit genes obtained in this study could shed light on the mechanism and gene editing breeding projects for tomato thermo-tolerance.These findings could also benefit improvement of harvest and storage of tomato in greenhouse.

Evaluation of Genetic Diversity and Genetic Relationship of Large Fruited Tomato Core Germplasms Based on Genotypic Value

[Objective] The paper aimed to analyze genetic diversity and genetic relationship of large fruited tomato core germplasms based on genotypic value.[Method] Taking 55 large fruited tomato core germplasms as tested materials, the genetic diversity of seven agronomic traits was analyzed, and the correlation between traits and genetic relationship between germplasms were analyzed based on genotypic effect value.[Result] The diversity indexes of seven agronomic traits were 3.98, 3.97, 3.99, 3.99, 3.97, 3.98 and 3.87, respectively, indicating there were rich genetic diversities in large fruited tomato core germplasms. Correlation analysis of traits was conducted based on genotypic effect value. The results showed that there was extremely significant positive correlation between leaf length and leaf width, and the correlation coefficient was 0.66. There was extremely significant positive correlation between fruit length and fruit width, with a correlation coefficient of 0.49. There was extremely significant positive correlation between weight per fruit and fruit width, with a correlation coefficient of 0.46. The genetic distance between large fruited tomato core germplasms was calculated based on the phenotypic value of traits. When the distance was 5, 55 large fruited tomato core germplasms were divided into three groups. The genetic distance between large fruited core germplasms tomato was calculated based on genotypic predictive value of traits. When the distance was 10, 55 large fruited tomato core germplasms were divided into six groups. Comparing the results of two clustering analysis, it was found that the clustering analysis based on genotypic value could better explain the genetic relationship between germplasms.[Conclusion] The results could provide some basis for understanding the population variation of large fruited tomato and genetic improvement of tomato cultivars.

Over-expression of GhDWF4 gene improved tomato fruit quality and accelerated fruit ripening

Brassinosteroids（BRs）, a class of steroidal phytohormones are essential for many biological processes in plant. However, little is known about their roles in fruit development. Tomato is a highly valuable vegetable and has been adopted as the model species for studying fruit growth, development, and ripening. To understand the role of endogenous BRs in the development of tomato fruit, the expression patterns of three homologues of DWF4 gene were investigated and the transgenic tomato plants were generated in which the Gh DWF4 gene from upland cotton（Gossypium hirsutum L.） was ectopically expressed. The contents of main quality components were analyzed in fruits of transgenic tomato line and non-transgenic line（control plant, CP） when the fruit was mature. Sl CYP90B3 that possesses high homology with Gh DWF4 preferentially expressed in mature fruit. Significantly higher contents of soluble sugar, soluble proteins, and vitamin C were obtained in fruit of transgenic tomato lines compared with those in the CP. Furthermore, overexpressing Gh DWF4 promoted fruit growth and ripening. The weight per fruit was increased by about 23% in transgenic lines. In addition, overexpressing Gh DWF4 promoted the germination of transgenic tomato seeds and hypocotyl elongation of seedlings. These results indicated that overexpressing Gh DWF4 gene in tomato could increase the contents of many nutrients in fruit and accelerate fruit ripening. It is suggested that increased endogenous BRs in fruit affect the growth and development of tomato fruit and therefore improved the nutrient quality of tomato.

Effects on Sucrose Metabolism,Dry Matter Distribution and Fruit Quality of Tomato Under Water Deficit

Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.

Evaluation of Tomato Lines against Septoria Leaf Spot under Field Conditions and Its Effect on Fruit Yield

Field studies were conducted at Hazara Agriculture Research Station, Abbottabad to evaluate thirteen AVRDC lines along with one commercial check (Roma) for potential of fruit yield against septoria leaf spot during summer season 2014. The disease established itself by natural infection and disease severity was estimated with the help of 0 - 5 disease rating scale after 15 days interval from the onset of symptoms. The lines showed significant difference in % septoria leaf spot infection. The disease severity % increased up to 100% in line AVTO1314 whereas the lowest % severity was recorded in AVTO1173 which showed the highest yield (468.1 g) with average fruit weight 122.22 g while the significantly lowest mean yield/plant (35.05 g) was calculated in line AVTO1314 with fruit weight 47.92 g. It was concluded that the line AVTO1173 could be useful in genetic programs for incorporating resistant genes in local tomato germplasm against septoria leaf spot disease.

果型和抗性基因协同对番茄黄化曲叶病毒带毒量的影响

以12份番茄种质为试材,其具有2类果实大小和3种不同抗性基因,通过检测番茄黄化曲叶病毒病田间抗性和带毒量指标,探索果实大小、抗病基因与田间抗性、带毒量之间的关系。结果显示,在自然传毒情况下,所有番茄材料都能检测到病毒感染。在番茄定植后28 d,小果型番茄M8(I)、M5(I)、M3(I)、M7(I)、M9(I)和M11(HR)带毒量均较低,大果型番茄M6(S)、M10(S)、M4(S)和M2(S)带毒量均较高,且小果型番茄田间发病率明显低于大果型番茄。除了Ty-1/ty-1单基因抗性不受番茄果实大小影响外,携带其他单基因或聚合基因抗性的番茄种质均与果实大小有关。在此节点上,带毒量越高抗性越弱,带毒量越低抗性越强。总体来说,在遭受番茄黄化曲叶病毒侵染时,小果型番茄田间抗性强于大果型番茄。

叶面喷施硅肥和钙肥对北京市设施春茬番茄生产与裂果预防效果的影响

京郊设施春茬番茄栽培后期裂果比较常见,为筛选出减少番茄裂果的发生的不同的肥料配施方式,开展了喷施硅肥和钙肥对番茄生长、产量、预防裂果的影响研究。结果表明:喷施2 mmol·L^(-1)硅酸钠水溶液+30 g·L^(-1)氨基酸钙液的处理(T4),不仅促进了番茄生长,株高和茎粗都较对照显著提高,而且对提升番茄产量和防治裂果的效果显著,其中产量较对照提高22.39%,番茄裂果率较对照降低4.58%。T4处理的番茄可溶性固形物含量显著提高,硬度有所提升,果实钙含量显著增加。综上,喷施2 mmol·L^(-1)硅酸钠水溶液+30 g·L^(-1)氨基酸钙的处理,不仅能够促进番茄生长,而且可以提高番茄产量,改善番茄品质,增加果实硬度,降低果实裂果率,可作为北京市设施春茬番茄防治裂果的选择途径。

果实发育期盐胁迫对番茄生长发育的影响

植物抗盐性指标是研究植物抗盐机理和盐能力的基础,本试验利用营养土模拟土壤盐渍化的方式,研究了不同浓度NaCl处理对番茄生长发育的影响,以求为进一步研究盐胁迫条件下番茄生长发育和品质的调控提供理论依据。结果表明:0.04 mol/LNaCl、0.08 mol/L NaCl、0.16 mol/L NaCl 3个盐胁迫处理均显著抑制番茄植株高度和茎粗的生长。在整个处理期间,NaCl盐浓度越大,对番茄植株高度生长的抑制越大。盐胁迫明显降低番茄的单株产量和单果重,随着NaCl盐浓度的增加,这种作用越强。盐胁迫对番茄单株产量的影响主要是单果重量减小造成的,而不是由番茄每株的果数造成。

番茄褐色皱纹果病毒分子检测与基因组部分序列分析

为了确定张家口及银川番茄产区是否发生番茄褐色皱纹果病毒病(ToBRFV),探究番茄ToBRFV的遗传信息和演化,为番茄褐色皱纹果病毒的诊断和防治及番茄抗病毒病基因工程提供重要的科学依据,采用张家口和银川两地区疑似病果进行分子检测,并利用相关分子生物学软件对该病毒基因进行序列分析及全基因组的系统进化分析。结果表明,张家口及银川果实病毒分离物与GenBank中大部分ToBRFV分离物的基因组结构相似性在99%以上,确定两地区番茄果实病毒为番茄褐色皱纹果病毒。ToBRFV分离物的地域性很强,中国不同地区的ToBRFV病毒,与来自欧洲和亚洲的多个国家地区都有关联,张家口分离物与中国分离物(MT018320.1)亲缘关系最近,银川分离物与秘鲁分离物聚类到一起,说明银川分离物可能来自南美洲。张家口分离物与中国分离物(MT018320.1)的4个ORF氨基酸相似性最高,而银川分离物与张家口分离物相似性较低。另外,研究结果首次发现,银川分离物CP蛋白的第444位碱基由A突变成G,从而导致CP蛋白的氨基酸第131位由V(缬氨酸)突变为A(丙氨酸),CP蛋白发生了有义突变。综上所述,张家口及银川番茄产区发生了番茄褐色皱纹果病毒病,且两地区的病毒来自不同的地方。

超微粉碎对水果番茄粉理化性质与结构特性的影响

为研究超微粉碎技术对水果番茄粉品质的影响,对水果番茄干进行粉碎处理得到粗粉(40目)、细粉(100目)、超微粉(200目)3种粉体,运用粒度分析、扫描电镜、X射线衍射图谱、傅里叶红外光谱、差式量热扫描等技术测定粒度、比表面积、微观结构、热性质等物理、化学和结构特性。结果表明,水果番茄超微粉的粒径达11μm且流动性较好,其亮度较粗粉和细粉显著提高(P<0.05),水溶性、持水力、膨胀度、乳化性、稳定性、持油力、休止角和滑角显著高于细粉与粗粉(P<0.05),润湿性、复水性、堆积密度、振实密度显著低于细粉和粗粉(P<0.05);超微粉的总酸含量较粗粉显著提高(P<0.05),番茄红素含量较粗粉显著降低(P<0.05),粗脂肪、蛋白质、维生素C含量显著高于细粉与粗粉(P<0.05);3种粉体的灰分含量无显著差异;在粒径减小的同时,超微粉的形状变得规则均匀,超微粉碎未破坏水果番茄的官能团结构、热性质以及分子结构。本研究对水果番茄深加工有一定的指导意义。

不同外源硒对番茄的硒生物强化效果

【目的】比较土壤中施用不同量硒肥(亚硒酸盐和硒酸盐)对番茄生物量、不同部位硒含量及果实品质的影响,为生产优质的富硒番茄和开发其他富硒蔬菜品种提供参考。【方法】供试番茄品种为金美丽娜,采用盆栽试验,通过在土壤中拌施0.5,1,2和5 mg/kg亚硒酸钠和硒酸钠溶液对番茄进行硒生物强化,以不施用硒肥处理作为对照,测定不同处理成熟番茄的果实生物量、不同部位(果实、茎下部、茎上部、叶下部、叶上部和根)硒含量,以及果实品质参数(有机酸、可溶性糖组成及其含量,维生素C含量等),比较2种硒肥对番茄的硒生物强化效果。【结果】与对照相比,土壤中施用2种外源硒均增加了番茄果实生物量。与对照相比,0.5~5 mg/kg外源硒均显著增加了番茄果实的硒含量(P<0.05),且当土壤中施用硒肥量相同时,硒酸钠处理番茄果实的硒含量极显著高于亚硒酸钠处理(P<0.01)。各施硒处理番茄茎下部、茎上部、叶下部、叶上部和根中硒含量均显著高于对照(P<0.05),且这5个部位的硒含量均随外源施硒量的增加而显著增高(P<0.05)。外源施用硒肥番茄果实中有机酸的组成(草酸、酒石酸、苹果酸、柠檬酸、琥珀酸)几乎没有变化,各处理番茄果实均以苹果酸和柠檬酸为主,但各有机酸组分含量变化较大。与对照相比,外源施0.5~2 mg/kg硒均可显著提高番茄果实中的果糖和葡萄糖含量。与对照相比,土壤中施用0.5~2 mg/kg亚硒酸钠和硒酸钠后,番茄果实总有机酸、总可溶性糖、维生素C含量及糖酸比均显著升高(P<0.05)。【结论】土壤中施入0.5~2 mg/kg硒酸钠既可确保硒富集效果,又能提高果实品质。基于人体健康的考虑,推荐以在土壤中施用0.5 mg/kg硒酸钠的方式进行番茄的硒生物强化。

“串番茄”(Truss tomato)果实主要数量性状的遗传

02S02和02S18是“串番茄”育种的好材料,02S35×02S45、02S15×02S51是综合性状优良的组合。单花序果实个数和果实横径性状狭义遗传力较高,在早期世代选择效果明显,单果质量、小区产量等性状遗传力较低,宜在高世代进行选择。相关分析表明,单果质量是串番茄最重要的产量组成因子,单果质量与单花序果实数呈极显著的负相关关系。

1-甲基环丙烯缓释贴纸对模拟运输期间完熟期番茄果实品质的影响

完熟期番茄果实的成熟度高,生理代谢旺盛,不耐贮运。为了减轻高成熟度番茄果实运输过程中的损耗问题,将果实装入纸箱或泡沫箱,并添加1-甲基环丙烯(1-methylcyclopropene,1-MCP)缓释贴纸作为处理,于(30±5)℃条件下进行3 d的模拟运输试验(包含2 h的模拟振动)。以番茄果实的生理代谢、采后品质和相关酶活性为评价指标,分析1-MCP缓释贴纸和包装材料对番茄果实模拟运输期间品质的影响。结果表明,随着模拟运输时间延长,果实品质劣变加剧,包括硬度下降,形成瘀伤、伤呼吸、伤乙烯以及色泽变化。1-MCP缓释贴纸能降低果实的损伤指数、呼吸强度、乙烯生成速率、红色指数a^(*)、丙二醛含量和脂氧合酶活力,保持较高的硬度、亮度L^(*)、抗坏血酸含量,并诱导过氧化物酶和过氧化氢酶活力。此外,主成分分析表明纸箱包装更适合于贮藏环节,泡沫箱包装更适合于运输环节。综上,使用1-MCP缓释贴纸处理以及泡沫箱外包装可以更好地维持完熟期番茄果实运输期间的采后品质,为高成熟度番茄果实的物流配送及品质调控提供了技术参考。

日光温室番茄果实膨大期温光需求特性研究

为研究果实膨大期番茄对温、光环境因子的需求特性,本文以‘凯德雅丽1832’番茄为试材,分12批次定植,利用日光温室的自然条件为番茄生长创造不同温、光环境,研究了其对番茄果实膨大前期和后期生长的影响。结果表明,通过构建基于生长天数的番茄果实横径logistic模型,可以把番茄果实膨大期分为前期(包括渐增期和线性增长期)和后期(缓慢增长期);基于主成分分析综合评价果实膨大前期和后期的长势因子,获得各时期的温光需求参数,果实膨大前期适宜的日均温为19.73±2.26℃、昼均温为25.39±2.51℃、夜均温为16.80±2.04℃、光合有效辐射为543.03±153.40μmol·m^(-2)·s^(-1)、日照时数为11.31±0.60 h·d^(-1);果实膨大后期适宜的日均温为19.27±2.30℃、昼均温为26.13±2.90℃、夜均温为15.43±1.15℃、光合有效辐射为542.51±155.11μmol·m^(-2)·s^(-1)、日照时数为10.52±0.79 h·d^(-1),研究结果为番茄优质高效生产温、光环境精准调控提供了理论依据。