The Yield and Diseases-Pest Performance of Breeding Materials for Tomatoes (Lycopersicon esculentum) Sourced from Different Exotic Sources

A study was conducted with 36 tomato germplasm [PGRC (19), The Netherlands (7), Japan (2), and Bangladesh (9)] with 3 check varieties in the research field of the Olericulture Division of Horticulture Research Centre (HRC), Bangladesh Agricultural Research Institute (BARI), Gazipur during the winter season of 2022-23 to identify promising tomato breeding germplasm. All the germplasm showed differences in most of the parameters studied. Considerable variation was observed for fruit yield per hectare varied from 39 to 144 tons, while the highest fruit yield per hectare was harvested from the germplasm viz., BD 7759B, BD 7757, BD 7751, BD 7301, QM, BD 7759A, BD 7762, QF, BD 7753, BD 8886, BD 10351, NL-1A, SLA-19. The number of locules, total soluble solids (TSS) and plant height at last harvest varied from 2 to 6.6, 2.6 to 5.9%, and 66 to 154cm, respectively. The TYLCV infection (%) and leaf-sucking pest infestation (%) were observed with a 1 to 20% range in the field condition in both cases. So, we can select that germplasm has zero per cent infestation. Considering the plant growth habit, earliness, different yield contributing horticultural traits, virus and pest infestation thirteen germplasm viz., BD 7759B, BD 7757, BD 7751, BD 7301, QM, BD 7759A, BD 7762, QF, BD 7753, BD 8886, BD 10351, NL-1A, SLA-19 were selected as breeding materials for further tomato improvement program.

Investigating the genetic diversity of several varieties of Iranian tomato (Solanum lycopersicum) using RAPD and ISSR molecular markers

Background:Numerous studies have demonstrated the existence of approximately 7,500 genetic tomato varieties worldwide.Hence,it is crucial to assess the genetic diversity among tomato cultivars.This study aimed to investigate the genetic diversity of selected Iranian tomato cultivars(Solanum lycopersicum)using RAPD and ISSR molecular markers.Method:Ten RAPD primers and ten ISSR primers were employed to assess the genetic diversity among 10 tomato cultivars:Matin,RFT 112,Hirad,Golsar,Raha,Hengam,Hedah,Fasa,JS12,and Emerald.Data analysis involved the UPGMA algorithm and NTYSYSpc software.Results:RAPD analysis revealed close genetic proximity between Fasa and JS12,as well as between Raha and Hadieh.Conversely,the RFT 112,Hengam,Hirad,and Emerald cultivars exhibited significant genetic diversity within this group.ISSR primer analysis identified Hengam as the most diverse variety,while Matin,Emerald,and Vibrid,as well as Raha and JS12,displayed genetic similarities with minimal observed diversity.Furthermore,the overall analysis of the cultivars using RAPD and ISSR markers indicated that Hengam exhibited the highest diversity among all the varieties.Notably,Raha and JS12 demonstrated limited diversity in this analysis.Conclusion:This research demonstrates substantial genetic diversity among the investigated tomato varieties,with Hengam displaying the highest diversity within this group.Furthermore,ISSR markers proved more effective in determining genetic diversity in tomato plants.

Microclimate modification using eco-friendly nets and floating row covers improves tomato (<i>Lycopersicon esculentum</i>) yield and quality for small holder farmers in East Africa

Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, minerals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmental variations especially under open field conditions. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya to evaluate the effects of agricultural nets (agronets) herein called eco-friendly nets (EFNs) and floating row covers (FRCs) on microclimate modification, yield, and quality of tomato. A randomized complete block design with five replications was used. Tomato plants were grown under fine mesh EFN (0.4-mm pore diameter) cover, large mesh EFN (0.9-mm pore diameter) cover or FRC. The EFN and FRC were maintained either permanently closed or opened thrice a week from 9 am to 3 pm. Two open control treatments were used: unsprayed (untreated control) or sprayed with chemicals (treated control). The use of EFN or FRC modified the microclimate with higher temperatures, lower diurnal temperature ranges, and higher volumetric water content recorded compared with the controls. On the other hand, light quantity and photosynthetic active radiation were reduced by the use of EFN and FRC compared with the controls. The use of FRC and EFN resulted in more fruit and higher percent in marketable yield compared with open field production. Fruit quality at harvest was also significantly improved by the use of EFN and FRC. Fruits with higher total soluble solids (TSS), lower titratable acidity (TA), and higher sugar acid ratio were obtained in EFN and FRC treatments compared with the controls. Fruits harvested from EFN and FRC were also firmer compared with control fruits. These findings demonstrate the potential of EFN and FRC in modifying microclimate conditions and improving yields and quality of tomato under tropical field conditions.

Effects of Solanum lycopersicum Rootstock Grafting on Tomato Resistance and Quality

[Objectives] This experiment was carried out to explore the effects of Solanum lycopersicum rootstock grafting on tomato resistance and quality. [Methods] 6 different S. lycopersicum rootstocks were used to graft ＇Guihong 2＇ tomato. The grafting affinity was better and the resistance to bacterial wilt was higher. [Results] S. lycopersicum rootstock grafting may reduce the tomato, but it can improve the taste and endogenous quality of tomato. Besides, soluble solids, soluble sugars, Vc content, and sugar-acid ratio were all significantly higher than that of the control group. [Conclusions] S. lycopersicum rootstock y11, 53, and 177 grafting can increase Vc, soluble solids, and sugar-acid ratio of tomato fruit, so they are optimal rootstocks for tomato grafting.

The Effect of Water Hyacinth (<i>Eichhornia crassipes</i>) Compost on Tomato (<i>Lycopersicon esculentum</i>) Growth Attributes, Yield Potential and Heavy Metal Levels

The potential of different water hyacinth compost application rates in influencing growth attributes, yield and heavy metal accumulation of lead (Pb), copper (Cu), nickel (Ni) and zinc (Zn) in tomato fruit was studied in Masvingo. Four treatments of water hyacinth compost rates of 0, 37, 55.6 and 74.1 t·ha-1 were each replicated three times and applied in a randomized complete block design set up. Results showed that water hyacinth compost application rates significantly affected plant height, days to maturity and yield but had no influence on the number of tomato fruits per plant. The plant height at application rate of 74.1 t·ha-1 was 25%, 56% and 63% higher than the control at week 6, 9 and 12, respectively. At application rates of 56.6 t·ha-1, plant heights were 11%, 13% and 12% higher than the control whilst marginal plant height differences of -4%, 6% and 4% were recorded between application rate of 34.7 t·ha-1 and the control at week 6, 9 and 12, respectively. Tomato plants under compost rates of 34.7, 56.6 and 74.1 t·ha-1 in comparison to the control delayed maturity by 10, 17 and 20 days, respectively. Yields of 52, 55, 60 and 68 t·ha-1 were realized from hyacinth compost rates of 0, 34.7, 56.6 and 74.1 t·ha-1, respectively. Heavy metal concentrations increased with increase in the water hyacinth compost rate but at all application rates, the average concentrations were 85%, 93% and 86% lower than the Codex Alimentarious Commission permissible levels for Pb, Cu and Zn. Water hyacinth compost at a rate of 74 t·ha-1 therefore can be used for increased tomato yield without exposing consumers to heavy metal toxicity.

Genetic Diversity and Population Structure of Tomato (<i>Solanum lycopersicum</i>) Germplasm Developed by Texas A&M Breeding Programs

Genetic variation developed in plant breeding programs is fundamental to creating new combinations that result in cultivars with enhanced characteristics. Over the years, tomato (Solanum lycopersicum) breeding programs associated with the Texas A&M University system have developed morphologically diverse lines of tomatoes selected for heat tolerance, fruit quality, and disease resistance to adapt them to Texas growing conditions. Here we explored the intraspecific genetic variations of 322 cultivated tomato genotypes, including 300 breeding lines developed by three Texas A&M breeding programs, as an initial step toward implementing molecular breeding approaches. Genotyping by sequencing using low coverage whole-genome sequencing (SkimGBS) identified 10,236 high-quality single-nucleotide polymorphisms (SNPs) that were used to assess genetic diversity, population structure, and phylogenetic relationship between genotypes and breeding programs. Model-based population structure analysis, phylogenetic tree construction, and principal component analysis indicated that the genotypes were grouped into two main clusters. Genetic distance analysis revealed greater genetic diversity? among the products of the three breeding programs. The germplasm developed at Texas A&M programs at Weslaco, College Station, and by Dr. Paul Leeper exhibited genetic diversity ranges of 0.175 - 0.434, 0.099 - 0.392, and 0.183 - 0.347, respectively, suggesting that there is enough variation within and between the lines from the three programs to perform selection for cultivar development. The SNPs identified here could be used to develop molecular tools for selecting various traits of interest and to select parents for future tomato breeding.

Effect of Grafting on Growth and Shelf Life of Tomatoes (Solanum lycopersicum L.) Grafted on Two Local Solanum Species

The Rio Grande variety of tomato is widely grown because of its high productivity during the cold and dry seasons, and its resistance to Verticillium wilt (caused by Fusarium oxysporium) and to stem canker (Alternaria). Grafting tomato onto compatible rootstocks resistant to these diseases offers a better potential to overcome soil-borne diseases, abiotic stresses, improve growth, yield and fruit quality. However, in Cameroon, there is little or no information on grafting between Rio Grande tomato and selected eggplant rootstocks. The objectives of this study were: 1) To determine the compatibility between Rio tomato grafting and a popular local eggplant (Nkeya) rootstock;2) To verify the effect of grafting on flowering time;3) To evaluate the effect of eggplant rootstocks on growth, fruit shelf life and fruit quality of Rio tomatoes. The trial was conducted in a randomized complete block design with 3 replications. Rio Grande (To) was the ungrafted treatment used as a control. To/Ko, To/To and To/Nk were the grafted treatments eventually transplanted to the field. Growth data were subjected to analysis of variance using SPSS software. Descriptive analyses were performed for the other parameters. The results revealed that, 1) The cleft grafting method used was successful with success rate varying between 90 and 100%;2) Grafting influenced flowering date (DAT, p = 0.05) as well as tomato growth parameters including stem height (H, 1.49 × 10-10 p 0.00014) and collar diameter (SD, 4 × 10-14 p 0.009). The To/To treatment was significantly different from the ungrafted cultivar To, which had no significant difference in stem diameter. A significant difference in plant height was also observed between the ungrafted treatment To and the To/Ko and To/Nk treatments. In addition, only the collar diameter of To/Nk was different from To. Also, there was no significant difference between To/To and To, but a significant difference between To/Ko and To/Nk compared to To. Conversely, grafting improved the lifespan of To/Ko. Ultimately, the grafting method used was successful, but further studies are needed to overcome the problem of graft incompatibility in order to improve the agronomic performance of grafted plants.

Yield and Pest Performance of High-Temperature Tolerant Tomato (Lycopersicon esculentum) Lines for Year-Round Tomato Production in Bangladesh

The study was conducted at Olericulture Division, Bangladesh Agricultural Research Institute, Gazipur, Bangladesh during summer season of 2021 to see the performances of yield and yield-related components of twelve heat tolerant tomato hybrids. Significant variation was expressed for days to first harvest (101.0 - 108.0 days), while maximum number of fruits per plant was calculated in F1 2101 and F1 2201 (9.5), followed by F1 203, F1 2001, F1 2303, F1 2401 (9.0). The highest single fruit weight was estimated in F1 2501 (195.5 g), followed by F1 2101 (119.0 g), F1 2201 (113.8 g), while the range was 33.1 - 195.5 g. The range of fruit yield was 7.9 - 38.7 t/ha, while higher-yielding hybrids were viz., F1 203 (27.7 t/ha), F1 2101 (35.5 t/ha), F1 2201 (33.9 t/ha) and F1 2501 (28.7 t/ha). Maximum TSS was produced by F1 2501 (5.9%), followed by BARI Hybrid Tomato-8 (5.1%), F1 1101, F1 1903 (5.0%), with a range of 4.0% - 5.9%, while TYLCV infection and leaf sucking pest infestation varied from 0.0% - 10.0% and 3.3% - 16.7%, respectively. Thus, based on the performances of different yield and yield contributing traits, the hybrids, viz., F1 2101, F1 2201, F1 2501 may be selected to develop heat tolerant tomato hybrid varieties for the farmers of sub-tropical regions.

外源NO与蔗糖对盐胁迫下番茄(Lycopersicon esculentum Mill)幼苗氧化损伤的保护效应

选取长至6～8片真叶的健康番茄（Lycopersicon esculentum Mill）幼苗,分别进行蔗糖、硝普钠（sodium nitropresside,SNP,作为外源NO供体）及其体积比例组合（1∶1）处理;36h后施以NaCl胁迫,并分别于0h（胁迫前）、24h、48h和72h取样,进行相关生理生化指标测定。具体5个实验处理如下：A.蒸馏水（CK）;B.100 mmol/L NaCl;C.0.1 mmol/L SNP＋100 mmol/L NaCl;D.0.1 mmol/L SNP＋1.0mmol/L蔗糖＋100 mmol/L NaCl;E.1.0 mmol/L蔗糖＋100 mmol/L NaCl。结果表明：与SNP和蔗糖单独处理相比,二者组合处理对缓解盐胁迫下番茄幼苗的氧化损伤存在正协同效应,主要表现在进一步增强了番茄幼苗超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）的活性;提高了脯氨酸（Pro）的含量,同时膜脂过氧化产物丙二醛（MDA）含量显著降低（P〈0.05）。采用聚丙烯酰胺浓度梯度凝胶电泳对盐胁迫24 h和48 h材料的POD同功酶检测表明,当NaCl单独处理时,番茄幼苗叶片POD同功酶第V条带缺失,其它谱带酶量减少,抑制了POD同功酶的表达;SNP和蔗糖单独处理能够保护盐胁迫（24、48h）所导致的POD同功酶条带的完整;而组合处理既保证了POD同功酶条带的完整,又加强了酶量的表达。随着盐胁迫时间的延长,其氧化损伤程度愈烈,SNP和蔗糖组合处理能够更有效地缓解盐胁迫对番茄幼苗植株造成的氧化损伤。

花青苷对低温弱光处理的番茄(L.esculentum Mill.)幼苗光合机构的保护作用

【目的】探索幼苗叶片花青苷对低温弱光处理的番茄幼苗的光合作用是否具有保护作用。【方法】利用硫灯和氙灯下生长的番茄幼苗真叶之间以及野生型(WT)和光敏素双突变体(phyB1phyB2)幼苗真叶之间花青苷含量的差异,以叶绿素荧光为指标,研究花青苷对低温弱光处理的番茄幼苗叶片光合荧光变化的影响。【结果】低温弱光(2oC,100μmol photons·m-2·s-1)对番茄幼苗叶片PSⅡ具有显著的抑制作用,但是对PSI活性影响不大。低温弱光处理硫灯和氙灯下的番茄幼苗及硫灯下的WT和突变体番茄幼苗3h后,硫灯下富含花青苷的番茄PSⅡ光化学效率Fv/Fm降低到处理前的76.3%,氙灯下的降低到63.3%;能合成花青苷的WT的Fv/Fm降低到处理前的64.3%左右,而不能合成花青苷的phyB1phyB2降低到处理前的53.7%;下降程度显著高于WT。在番茄幼苗叶片不能合成花青苷后,分别生长在硫灯和氙灯下的番茄植株叶片在经过低温弱光处理3h后,叶片的PSⅡ光化学效率Fv/Fm的变化幅度没有显著的差别;同样,硫灯下WT和phyB1phyB2植株之间也没有显著差别。【结论】花青苷对低温弱光逆境处理的番茄叶片的光合机构具有保护作用,这种保护作用极可能与花青素对可见光和紫外光的吸收和屏蔽作用有关。

Study on Inheritance Mechanism of Tomato Fruit Firmness

[Objective] This study aimed to investigate the inheritance mechanism of tomato fruit firmness.[Method] Two tomato cultivars significantly different in fruit firmness were selected for investigation of the inheritance mechanism of tomato fruit firmness using combination analysis of six generations （P1,P2,F1,F2,B1 and B2）.[Result] The results indicated that the heredity of tomato fruit firmness was consistent with the additive-dominant model controlled by one pair of major genes; the additive effect （d）,dominant effect （h） and degree of dominance （h/d） of major genes were 17.37,-7.96 and-0.46,respectively,showing positive additive effect and incompletely dominant-negative effect; the hereditability of major gene effect in B1,B2 and F2 generation was 88.59％,45.81％ and 85.62％,respectively.[Conclusion] The heredity of fruit firmness was controlled by one pair of major gene,showing significant additive effect and dominant effect.

Effect of Low Night Temperature Treatment on Sucrose Synthesis Ability of Tomato Leaves in Seedling Stage

[Objective] The aim was to explore the effects of low night temperature treatment on sucrose synthesis ability of tomato leaves in seedling stage.[Method] Effects of low night temperature of 6 ℃（with 15 ℃ as control）on the sucrose synthesis ability of tomato leaves were studied after 1,3,5,7 d of treatment.[Result] The contents of fructose,glucose and sucrose in tomato leaves were higher than control at 6：00 during the treatment of low night temperature,but in contrast at 11：00.The contents of fructose,glucose and sucrose in tomato leaves of low night temperature treatment and control group at 6：00 were lower than that at 11：00.The content of starch in tomato leaves was higher than control at 6：00 and 11：00 during the treatment.And the activities of sugar metabolism enzymes of tomato were changed by the treatment of low night temperature.The activities of acid invertase（AI）and neutral invertase（NI）were higher than those of control,while the activities of sucrose synthase（SS）and sucrose phosphate synthase（SPS）were lower than control at 6：00 and 11：00 during the treatment.The activity of all the enzymes at 11：00 of low night temperature treatment plants treated for 1,3,5,7 d was higher than that at 6：00.Compared to 6：00,the invertase activity of the control plant decreased,while the synthetase activity increased.The activity of sucrose synthase（SS）was decreased for treated plants,and the increase amount of sucrose content in leaves was lower than that of control at 11：00 during the treatment,indicating that the sucrose synthesis ability of tomato leaves was decreased by the treatment of low night temperature.[Conclusion] The results in this study had provided theoretical basis for the environmental control of high-yield cultivation 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.

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.

番茄(Lycoqersicon esculentum Mill)小孢子发生及其雄配子体发育的细胞学观察

番茄小孢子的发生从孢原细胞开始,经过造孢细胞,小孢子母细胞、四分体、小孢子、雄配子体等发育阶段,最后形成二核花粉.番茄的绒毡层细胞是由初生壁细胞衍生的同型的双核细胞,正常情况下在减数分裂时期至四分体时期同步溶解.番茄的绒毡层为"变形绒毡层"类型,即溶解后的绒毡层要形成周原质团流入药室.番茄小孢子母细胞的减数分裂为同时型,在减数第一次分裂后不立即形成细胞壁,而是形成一个双核细胞;第二次分裂中,两个核同时进行分裂,其方向互为垂直,当分裂完成时,在四个核之间产生细胞壁,分隔成一个呈正四面体形的四分体.新形成的小孢子有浓厚细胞质和一个位于中央的细胞核.小孢子进一步发育形成明显的细胞壁,增大体积,细胞核被挤向一侧,在贴近细胞壁的位置上细胞核进行有丝分裂.分裂的结果形成两个子核:生殖核和营养核,两核之间最初由一弧形细胞板分隔成两个不等的细胞.番茄小孢子的发育基本是同步的,大多数小孢子都能发育成正常的成熟花粉.

Effects of Nitrogen Forms on Carbon and Nitrogen Accumulation in Tomato Seedling

Utilization of organic nitrogen （N） is an important aspect of plant N assimilation and has potential application in sustainable agriculture. The aim of this study was to investigate the plant growth, C and N accumulation in leaves and roots of tomato seedlings in response to inorganic （NH4^＋-N, NO3^-N） and organic nitrogen （Gly-N）. Different forms of nitrogen （NH4^＋-N, NO3^--N, Gly-N） were supplied to two tomato cultivars （Shenfen 918 and Huying 932） using a hydroponics system. The plant dry biomass, chlorophyll content, root activity, total carbon and nitrogen content in roots and leaves, and total N absorption, etc. were assayed during the cultivation. Our results showed that no significant differences in plant height, dry biomass, and total N content were found within the first 16 d among three treatments; however, significant differences in treatments on 24 d and 32 d were observed, and the order was NO3^--N 〉 Gly-N 〉 NH4^＋-N. Significant differences were also observed between the two tomato cultivars. Chlorophyll contents in the two cultivars were significantly increased by the Gly-N treatment, and root activity showed a significant decrease in NHa^＋-N treatment. Tomato leaf total carbon content was slightly affected by different N forms; however, total carbon in root and total nitrogen in root and leaf were promoted significantly by inorganic and organic N. Among the applied N forms, the increasing effects of the NH4^＋-N treatment were larger than that of the Gly-N. In a word, different N resources resulted in different physiological effects in tomatoes. Organic nitrogen （e.g., Gly-N） can be a proper resource of plant N nutrition. Tomatoes of different genotypes had different responses under organic nitrogen （e.g., Gly-N） supplies.

Response of Tomato Plants to a New Application Method of Polyolefin-Coated Fertilizer

The response of tomato （Lycopersicon esculentum） plants basically fertilized with 0.3 g N per plant of compound fertilizer with a N：P2O5：K2O ratio of 20：10：20 to sticks of polyolefin-coated fertilizer （POCF） （LongT0 with a N：P2Os：K2O ratio of 14：12：14） applied 23 d after transplanting was investigated using rooting boxes in the greenhouse. The results at 26 and 40 d after stick fertilizer treatment showed that the use of the stick fertilizer greatly increased the production of many new fine roots from the tomato plants. Compared to the unfertilized control, root length and root length density in the stick fertilizer treatment increased by 3.6-6.7 fold. In the soil zones near the stick fertilizer, root weight and root mass density were also significantly higher for the stick fertilizer treatment. Additionally, the use of the stick fertilizer increased the N, P and K concentrations in the leaves and stems of the tomato plants. The new fine roots growing near the stick fertilizer not only absorbed more nutrients and translocated them to the shoots, but also contained more nutrients within themselves. The soil ammonium and nitrate N data showed that N released from the stick fertilizer played a major role in inducing the production of new fine roots. These results indicated that stick fertilizer could be used as an alternative to the co-situs application technique to change and control the root distribution of crops as well as to increase the potential capacity of roots for water and nutrient absorption.

Molecular Markers for Tm-2 Alleles of Tomato Mosaic Virus Resistance in Tomato

Tomato mosaic virus (ToMV) is one of the most infectious virus diseases in tomato (Solanum lycopersicum L). The practical and effective method of controlling this disease is through genetic control by using major resistance genes. So far, three genes Tm-1, Tm-2 and Tm-22 conferring resistance to ToMV have been reported and utilized in tomato culti-var development. Marker assisted selection (MAS) has become very important and useful tool in selection of ToMV re-sistant tomato lines or hybrids. The objective of this research was to identify allele-specific PCR-based, cleaved ampli-fied polymorphic sequence (CAPS), and allele-derived single nucleotide polymorphism (SNP) markers for Tm-2 loci. Four allele-specific PCR-based markers were identified: one for Tm-2, one for Tm-22, and two for the susceptible allele tm-2. Three allele-derived CAPS markers were identified, which can identify and distinguish three alleles, tm-2, Tm-2 and Tm-22 in tomato germplasm. Three SNP markers were developed specific for Tm-2 locus. These markers will pro-vide breeders with a tool in selection of Tm-2 and Tm-22 resistance genes in tomato breeding program.

Epiphytic and Endophytic Fungal Communities of Tomato Plants

Plants harbor diverse fungal communities both on their surfaces(epiphytic)and inside of plant tissues(endophytic),and these fungi play important roles in plant health and vigor.However,comparisons of epiphytes and endophytes have rarely been performed.In this study,the soil,epiphytic and endophytic fungal assemblages of greenhouse-grown tomato plants were extensively examined and compared by Illumina sequencing of 18S rRNA amplicons.The fungal communities differed in both size and composition.The soil communities were the richest and most abundant,while the endophytes showed the lowest richness and diversity.The diversity of endophytes also differed in different tissues,with the highest diversity occurring in the roots.In both the epiphytic and endophytic samples,the majority of fungi corresponded to ascomycetes,amongwhich Sordariomycetes,Dothideomycetes and Eurotiomyceteswere the most frequent classes.Themajor non-ascomycete fungi were associated only with the class Exobasidiomycetes(Basidiomycota).At the order level,the epiphytes showed similar distribution patterns in the stems and leaves,but among the endophytes,distinct fungal orders were enriched in different tissues.Capnodialeswas recorded as amajor fungal group in the stems,leaves and seeds,and Saccharomycetales was specifically enriched in the pericarp and jelly around seeds.The present data suggested that different drivers shaped epiphytic and endophytic fungi communities and deepened our knowledge of the complex plant-fungus interaction in tomato.

Tomato SlPti5 plays a regulative role in the plant immune response against Botrytis cinerea through modulation of ROS system and hormone pathways

While SlPti5 has been shown to play a crucial role in the regulation of antagonistic genes in Solanum lycopersicum and Arabidopsis against pathogen infection,there have been no comprehensive studies on the effects of SlPti5 on the regulatory response mechanism of reactive oxygen species(ROS) system and hormone pathways during growth and disease resistance of tomato plants.Here,we investigated the function of SlPti5 in the defense response of tomato against Botrytis cinerea utilizing a virus-induced gene silencing(VIGS)-based system.Expression profile analysis showed that SlPti5 was significantly induced upon B.cinerea infection,with high expression levels in the leaves and fruit of tomato.VIGS-based silencing of SlPti5 inhibited early vegetative growth,increased the plant’s susceptibility to infection,promoted the development of ROS,affected the expression of genes involved in the ROS scavenging system,and attenuated the expression of genes associated with pathogenesis and the ethylene/jasmonic acid signaling pathways.In sum,our data demonstrated that SlPti5 stimulates the immune response of tomato plant to Botrytis cinerea infection by involving the ethylene(ET)-and jasmonic acid(JA)-mediated pathways and modulating the expression of some key pathogenesis-related(PR) genes.