Tomato Flowers Research Articles

A Role for APETALA1/FRUITFULL Transcription Factors in Tomato Leaf Development

Flexible maturation rates underlie part of the diversity of leaf shape, and tomato (Solanum lycopersicum) leaves are compound due to prolonged organogenic activity of the leaf margin. The CINCINNATA-teosinte branched1, cycloidea, PCF (CIN-TCP) transcription factor lanceolate (LA) restricts this organogenic activity and promotes maturation. Here, we show that tomato APETALA1/fruitfull (AP1/FUL) MADS box genes are involved in tomato leaf development and are repressed by LA. AP1/FUL expression is correlated negatively with LA activity and positively with the organogenic activity of the leaf margin. LA binds to the promoters of the AP1/FUL genes MBP20 and TM4. Overexpression of MBP20 suppressed the simple-leaf phenotype resulting from upregulation of LA activity or from downregulation of class I knotted like homeobox (KNOXI) activity. Overexpression of a dominant-negative form of MBP20 led to leaf simplification and partly suppressed the increased leaf complexity of plants with reduced LA activity or increased KNOXI activity. Tomato plants overexpressing miR319, a negative regulator of several CIN-TCP genes including LA, flower with fewer leaves via an SFT-dependent pathway, suggesting that miR319-sensitive CIN-TCPs delay flowering in tomato. These results identify a role for AP1/FUL genes in vegetative development and show that leaf and plant maturation are regulated via partially independent mechanisms.

Expression profiling of tomato pre-abscission pedicels provides insights into abscission zone properties including competence to respond to abscission signals

BackgroundDetachment of plant organs occurs in abscission zones (AZs). During plant growth, the AZ forms, but does not develop further until the cells perceive abscission-promoting signals and initiate detachment. Upon signal perception, abscission initiates immediately; if there is no signal, abscission is not induced and the organ remains attached to the plant. However, little attention has been paid to the genes that maintain competence to respond to the abscission signal in the pre-abscission AZ. Recently, we found that the tomato (Solanum lycopersicum) transcription factors BLIND (Bl), GOBLET (GOB), Lateral suppressor (Ls) and a tomato WUSCHEL homologue (LeWUS) are expressed specifically in pre-abscission tissue, the anthesis pedicel AZs. To advance our understanding of abscission, here we profiled genome-wide gene expression in tomato flower pedicels at the pre-abscission stage.ResultsWe examined the transcriptomes of three tomato flower pedicel regions, the AZ and flanking proximal- (Prox) and distal- (Dis) regions, and identified 89 genes that were preferentially expressed in the AZ compared to both Prox and Dis. These genes included several transcription factors that regulate apical or axillary shoot meristem activity. Also, genes associated with auxin activity were regulated in a Prox-Dis region-specific manner, suggesting that a gradient of auxin exists in the pedicel. A MADS-box gene affecting floral transition was preferentially expressed in the Prox region and other MADS-box genes for floral organ identification were preferentially expressed in Dis, implying that the morphologically similar Prox and Dis regions have distinct identities. We also analyzed the expression of known regulators; in anthesis pedicels, Bl, GOB, Ls and LeWUS were expressed in the vascular cells of the AZ region. However, after an abscission signal, Bl was up-regulated, but GOB, Ls and LeWUS were down-regulated, suggesting that Bl may be a positive regulator of abscission, but the others may be negative regulators.ConclusionsThis study reveals region-specific gene expression in tomato flower pedicels at anthesis and identifies factors that may determine the physiological properties of the pre-abscission pedicel. The region-specific transcriptional regulators and genes for auxin activity identified here may prevent flower abscission in the absence of signal or establish competence to respond to the abscission signal.

PREDICTION OF DAYS AFTER ANTHESIS OF DEVELOPING TOMATO (<i>SOLANUM LYCOPERSICUM</i>) FRUIT FROM BLOSSOM-END CHANGES IN COLOR

The development of mathematical models to predict the physiological status of a developing fruit can b e a useful tool to reduce the variation in fruit respon se to postharvest treatments. The objective of this study was to develop a mathematical model to predict Days After Anthesis (DAA) in tomato fruit from changes in the blossom end color. Around 160 tomato flowers from 40 plants of a tomato cultivar ‘Rutgers’ and the nea rly isogenic line tomato ripening mutant rin were tagged after artificial pollination and allow ed to fruit set. The quantification of color was done from 5 to 85 DAA every 5 days in the tomato fruit blossom-end of both ‘Rutgers’ and mutant rin using a a Minolta chroma meter CR-300 set in the L*, a* and b* color space. The predictive model was developed using the stepwise procedure in forward selection with DAA as the respo nse variable and all the possible combinations between the next group of regressor: L*, a* and b*, square L*, a* and b*, chroma and Hue angle calculated from measured a* and b* values. It was used the F statistic, m ean square error, coefficient of determination, Mallows coefficient and distribution of residuals around z ero as indicators of model prediction’s efficiency. Correl ation coefficients between the different variables measured and the DAA were calculated. The reliability of the statistical analysis was tested by using the nearl y isogenic line of ‘Rutgers’: The non-ripening mutant rin as a comparative control. It was concluded that th e statistical procedure used is robust and sensitive enough to id entify data not suitable for developing a good pred ictive model. Also, it is possible to predict the days aft er anthesis of a developing tomato fruit from chang es in the blossom-end color with almost 80% of accuracy.

Transcriptome Analysis of Tomato Flower Pedicel Tissues Reveals Abscission Zone-Specific Modulation of Key Meristem Activity Genes

Tomato flower abscises at the anatomically distinct abscission zone that separates the pedicel into basal and apical portions. During abscission, cell separation occurs only at the abscission zone indicating distinctive molecular regulation in its cells. We conducted a transcriptome analysis of tomato pedicel tissues during ethylene promoted abscission. We found that the abscission zone was the most active site with the largest set of differentially expressed genes when compared with basal and apical portions. Gene Ontology analyses revealed enriched transcription regulation and hydrolase activities in the abscission zone. We also demonstrate coordinated responses of hormone and cell wall related genes. Besides, a number of ESTs representing homologs of key Arabidopsis shoot apical meristem activity genes were found to be preferentially expressed in the abscission zone, including WUSCHEL (WUS), KNAT6, LATERAL ORGAN BOUNDARIES DOMAIN PROTEIN 1(LBD1), and BELL-like homeodomain protein 1 (BLH1), as well as tomato axillary meristem genes BLIND (Bl) and LATERAL SUPPRESSOR (Ls). More interestingly, the homologs of WUS and the potential functional partner OVATE FAMILIY PROTEIN (OFP) were subsequently down regulated during abscission while Bl and AGL12 were continuously and specifically induced in the abscission zone. The expression patterns of meristem activity genes corroborate the idea that cells of the abscission zone confer meristem-like nature and coincide with the course of abscission and post-abscission cell differentiation. Our data therefore propose a possible regulatory scheme in tomato involving meristem genes that may be required not only for the abscission zone development, but also for abscission.

The behaviour of <i>Bombus impatiens</i> (Apidae, Bombini) on tomato (<i>Lycopersicon esculentum</i> Mill., Solanaceae) flowers: pollination and reward perception

The foraging behaviour of pollinators can influence their efficiency in pollinating certain plant species. Improving our understanding of this behaviour can contribute to an improvement of management techniques to avoid pollination deficits. We investigated the relationship between the number of visits of bumble bees (Bombus impatiens) to tomato flowers (Lycopersicon esculentum) and two variables related to the quality of the resulting fruits (weight, number of seeds), as well as the relationship between foragers’ thoracic weights, physical characteristics of thoracic vibrations (main frequency, velocity amplitude), amount of pollen removed from flowers, and the quality-related variables. In addition, we studied the capability of foragers to assess the availability of pollen in flowers. Tomato weight and seed number did not increase with the number of bee visits, neither were they correlated with the foragers’ thorax weight. Thorax weight also did not correlate with the amount of pollen removed from the flowers nor with the physical characteristics of vibration. Vibration characteristics did not change in response to the amount of pollen available on tomato flowers. Instead, foragers adjusted the time spent visiting the flowers, spending fewer time on flowers from which some pollen had already been removed on previous visits. The quantity and the production-related variables of tomatoes are not dependent on the number of bee visits (usually one visit suffices for full pollination); bigger foragers are not more efficient in pollinating tomato flowers than smaller ones; and B. impatiens foragers are capable of evaluating the amount of pollen on a flower while foraging and during pollination.

Native bees pollinate tomato flowers and increase fruit production

The tomato plant has a specific relationship with native pollinators because the form of its flowers is adapted to buzz pollination carried out by some pollen-gatherer bees that vibrate their indirect flight muscles to obtain that floral resource. The absence and the low density of these bees in tomato fields can lead to pollination deficits for crop. The aim of this study is to demonstrate that open tomato flowers, probably visited by native pollinator, have greater pollen load on their stigma than unvisited flowers. Another objective is to show that this great pollen load increases fruit production. We selected crops of the Italian tomato cultivar in areas of the State of Goiás, Brazil. Thirty seven plants of three crops each had one inflorescence bagged in the field. Bagged and non-bagged flowers had their stigmas collected and the amount of pollen on their surfaces was quantified. For the comparison of fruit production, we monitored bagged and not-bagged inflorescences and after 40 days, their fruits were counted, weighed, measured and had their seeds counted. The amount of pollen grains on the stigma of flowers available to pollinators was higher than that on the stigma of bagged flowers. On average, fruit production was larger in not-bagged inflorescences than in bagged inflorescences. In addition, not-bagged flowers produced heavier fruits than did bagged flowers. There was a significant difference in the number of seeds between treatments, with significantly more seeds in the non-bagged fruit. Our results show that native bees buzz-pollinate tomato flowers, increasing the pollen load on their stigma and consequently fruit production and quality.

Alteration of tomato microRNAs expression during fruit development upon Cucumber mosaic virus and Tomato aspermy virus infection

The economic importance of Solanaceae plant species is well documented, and tomato has become a model for fleshy fruit development and ripening studies. Plant microRNAs (miRNAs) are small endogenous RNAs that are involved in a variety of activities including plant development, signal transduction and protein degradation, as well as response to environment stress and pathogen invasion. Here in this study, we aimed at quantifying the expression alterations of nine miRNAs and target mRNAs in tomato flower and fruit development upon Cucumber mosaic virus (CMV) and Tomato aspermy virus infections. Three different CMV strains CMV-Fny, CMV-FnyΔ2b and CMV-Fny-satT1 were used in our investigation, and the miRNA/mRNA expression alterations were analyzed by real-time quantitative RT-PCR. The results shown the levels of several miRNA/mRNA pairs were increased upon virus infections. However, the increased level of individual miRNA differed for different virus strains, reflecting differences in severity of symptom phenotypes. The altered expression patterns of these miRNA/mRNA pairs and their predicted functions indicate the possible roles in flower and fruit development, and provide experimental data for understanding the miRNA-mediated phenotype alterations in tomato fruit.

Application of β-naphthoxyacetic acid ( β-NOA) improves fruit yield and marketable quality in out-of-season cherry tomatoes (Solanum lycopersicum L. var. cerasiforme (Dunal) D. M. Spooner, G. J. Anderson and R. K. Jansen) cultivated in unheated greenhouses in the Mediterranean Basin

SummaryThe effects of truss vibration, and the application of β-naphthoxyacetic acid ( β-NOA) to flowers, on fruit-set, total and marketable yields, and fruit quality were studied in two cherry tomato [Solanum lycopersicum L. var. cerasiforme (Dunal) D. M. Spooner, G. J. Anderson and R. K. Jansen] hybrids ‘Conchita F1’ and ‘Cherelino F1’, grown in an unheated plastic greenhouse during the Winter/Spring and Spring seasons in Southern Greece. Fruit-set was high in the Winter/Spring crop but, due to unfavourable conditions (i.e., night-time temperatures below 10ºC, which impaired microsporogenesis, pollination, and fertilisation), most fruit contained few seeds, were small and unmarketable. Although both truss vibration and β-NOA significantly increased mean fruit weights, and total yields, in both cultivars, the application of β-NOA gave the greatest increase in mean fruit weight and percentage of marketable fruit. In contrast, in the Spring crop, neither treatment affected the number or weight of fruit per plant because the climatic conditions were more favourable for pollination and fertilisation. The application of β-NOA did not adversely affect fruit quality, as previously reported in large-fruiting tomato cultivars. β-NOA did not induce any malformation or puffiness in the fruit and, while these seedless fruit showed higher dry mass percentages, higher total soluble solids contents, and lower titratable acidity levels than seeded tomato fruit, their colour, firmness, sugar, and phenolics contents were not affected. Conditions that are unfavourable for fruit set frequently occur in unheated greenhouses in the Mediterranean Basin during the Winter and early Spring; therefore, we conclude that the application of β-NOA to the flowers of cherry tomato at that time will ensure higher yields, better market quality, and higher market returns.

Evaluation of the expression of internal control transcripts by real-time RT-PCR analysis during tomato flower abscission

Many investigations of the abscission mechanisms in plants are based on gene expression studies. Quantitative real-time RT-PCR (qRT-PCR) is widely and increasingly used for mRNA quantification, and the results are typically referenced to an internal control gene to avoid bias. We investigated the suitability of twelve tomato (Lycopersicon esculentum Mill. var. Liaoyuanduoli) housekeeping genes during hormone, high salt and temperature-induced abscission. The free software-based applications NormFinder and qBase PLUS were used to statistically identify the best internal controls for a given set of biological samples. The expression stability of a number of housekeeping genes were validated during tomato abscission. The two most suitable reference genes for the commonly used treatments of the major hormones related to abscission are TBP and RPL8. In some cases, more than three reference genes may be required, depending on the type of samples being compared. Four suitable reference genes (TBP/DNAj/RPL8/EXPRESSION) are recommended for more complex analysis, such as hormone and bio-stress induced abscission samples.

Genome-wide analysis of SAUR gene family in Solanaceae species

The plant hormone auxin plays a vital role in regulating many aspects of plant growth and development. Small auxin up-regulated RNAs (SAURs) are primary auxin response genes hypothesized to be involved in auxin signaling pathway, but their functions remain unclear. Here, a genome-wide search for SAUR gene homologues in Solanaceae species identified 99 and 134 members of SAUR gene family from tomato and potato, respectively. Phylogenetic analysis indicated that the SAUR proteins from Arabidopsis, rice, sorghum, tomato and potato were divided into four major groups with 16 subgroups. Among them, 25 histidine-rich SAURs genes with metal-binding characteristics were found in Arabidopsis, sorghum and Solanaceae species, but not in rice. Using tomato as a model, a comprehensive overview of SAUR gene family is presented, including the gene structures, phylogeny and chromosome locations. Quantitative real-time PCR analysis indicated that 11 randomly selected SlSAUR genes in tomato could be expressed at least in one of the tomato organs/tissues tested. However, different SlSAUR genes displayed distinctive expression levels. SlSAUR16 and SlSAUR71 exhibited highly tissue-specific expression patterns. Almost all of the detected SlSAURs showed an accumulating pattern of mRNA along tomato flower and fruit development. Some of them displayed differential response to exogenous IAA treatment. The abiotic (cold, salt and drought) stresses significantly modified transcript levels of SlSAURs genes. Most of them were down-regulated in response to abiotic stresses (drought, heat and salinity), but SlSAUR58, as a histidine-rich SAUR gene, was up-regulated after salt treatment, indicating that it may play a specific role in the salt signaling transduction pathway. Our comparative analysis provides some basic genomic information for the SAUR genes in the Solanaceae species and will pave the way for deciphering their function during plant development.

Characterization of Tomato Transcription Factor WUSCHEL and Functional Study in Arabidopsis

AbstractThe homeobox transcription factor WUSCHEL (WUS) plays a critical role in keeping the balance between the maintenance and differentiation of stem cell population in shoot and floral meristems of Arabidopsis thaliana. The corresponding gene SlWUS is yet to be characterized in tomato. In order to characterize SlWUS gene and its biological function, we cloned it from tomato and analyzed its structure. Tissue expression showed that the SlWUS highly expressed in tomato flower abscission zone. The overexpression of SlWUS in Arabidopsis could trigger undifferentiation of plant flower organ and indeterminacy of flower identity, suggesting that SlWUS maybe involved in flower structure development as well as flower organ identity. Taken together, our results indicated that the SlWUS plays an important role in flower abscission zone and plant organ shedding.

The Impact of Greenhouse Tomato (Solanales: Solanaceae) Floral Volatiles on Bumble Bee (Hymenoptera: Apidae) Pollination

ABSTRACT Greenhouse tomato (Lycopersicon esculentum Mill) production relies on pollination by commercially-produced bumble bee (Bombus impatiens Cresson) colonies. Inadequate pollination by bumble bees has been a problem for growers at certain times of year; however, its cause has yet to be determined. Bumble bees have been shown to exit tomato greenhouses to forage on flowers of other plants. This study investigates tomato's floral characteristics and their affect on bumble bee pollination by 1) observing foraging preferences for bumble bees on greenhouse tomato, 2) determining if the plant's floral advertisements could be used by the bees to estimate pollen availability, and 3) identifying temporal changes in floral display which correspond to peak bumble bee activity. Flower size (petal length, anther cone width, and anther cone length) and floral scent (release of β-phellandrene, 2-carene, α-pinene, and p-cymene) were evaluated to identify the pollinator-important characteristics of tomato flowers. Ou...

Down-regulation of a single auxin efflux transport protein in tomato induces precocious fruit development

The PIN-FORMED (PIN) auxin efflux transport protein family has been well characterized in the model plant Arabidopsis thaliana, where these proteins are crucial for auxin regulation of various aspects of plant development. Recent evidence indicates that PIN proteins may play a role in fruit set and early fruit development in tomato (Solanum lycopersicum), but functional analyses of PIN-silenced plants failed to corroborate this hypothesis. Here it is demonstrated that silencing specifically the tomato SlPIN4 gene, which is predominantly expressed in tomato flower bud and young developing fruit, leads to parthenocarpic fruits due to precocious fruit development before fertilization. This phenotype was associated with only slight modifications of auxin homeostasis at early stages of flower bud development and with minor alterations of ARF and Aux/IAA gene expression. However, microarray transcriptome analysis and large-scale quantitative RT-PCR profiling of transcription factors in developing flower bud and fruit highlighted differentially expressed regulatory genes, which are potential targets for auxin control of fruit set and development in tomato. In conclusion, this work provides clear evidence that the tomato PIN protein SlPIN4 plays a major role in auxin regulation of tomato fruit set, possibly by preventing precocious fruit development in the absence of pollination, and further gives new insights into the target genes involved in fruit set.

Role of calcium in the expression of MAP kinase kinases (MKKs) and MAP kinases in tomato flower abscission

The mitogen activated protein kinase (MAPK) cascade is an important intracellular signaling module that functions as a convergent point for crosstalk during stress signaling. In this study, we constructed a phylogenetic tree for MAP kinase kinases (MKKs) and MAP kinases (MPKs) in Arabidopsis and Lycopersicon esculentum (tomato) and found that abscission-related AtMKK4 and AtMKK5, and AtMPK3 and AtMPK6 clustered with LeMKK2, and LeMPK1,and LeMPK2 and LeMPK3, respectively. To investigate whether there was a link between homology and abscission, we studied all the LeMKKs at the messenger ribonucleic acid (mRNA) transcript level. LeMKK2 and its homologue AtMKK4/5 both have roles in regulating abscission. Quantitative real time polymerase chain recation (qRT-PCR) of LeMPK1 and LeMPK2, which are highly homologous to AtMPK3 and AtMPK6, most probably mediate abscission downstream through LeMKK2. Calcium depressed the expression of these genes in the early stages of abscission. Treatment with W7 (a calmodulin inhibitor) indicated that the expression of LeMKKs and LeMPKs depended on calmodulin during tomato flower explant abscission.

Abundance ofFrankliniella schultzei(Thysanoptera: Thripidae) in Flowers on Major Vegetable Crops of South Florida

The flower thrips, Frankliniella schultzei (Trybom), has only recently been recognized as a pest of vegetable crops in south Florida. Little is known about its abundance and impact on vegetable crops in this region. Therefore, a field experiment was conducted comparing F. schultzei abundance in blooms of the 5 key fruiting vegetable crops grown in south Florida, i.e., cucumber, pepper, snap bean, squash and tomato. Mean number of F schultzei larvae was highest in cucumber flowers (78.1 larvae/5 flowers) and lowest in bean flowers (5.1 larvae/5 flowers). However, adults of F schultzei were most numerous in tomato flowers (27.5 adults/5 flowers) and least numerous in snap bean flowers (3.5 adults/ 5 flowers). Neither larvae nor adults of F. schultzei were found in pepper flowers in the present study. The flower samples collected from 5 vegetable crops were also found to be infested with 3 other thrips species. Amongst these, Thrips palmi Karny was the second most abundant thrips species. Frankliniella occidentalis (Pergande) was found in low numbers on all crops except pepper, and Frankliniella fusca (Hinds) was found only on tomato. The above information should be useful in the development of monitoring programs, design of pest management strategies and in the timely application of preventive or suppressive measures in south Florida.

Dose Response of Glyphosate and Dicamba on Tomato (Lycopersicon esculentum) Injury

Field studies were conducted to determine the response of sublethal glyphosate and dicamba doses to processing tomato flowering loss and marketable yield. Dose–response studies for both herbicides were conducted on four commercial processing tomato lines (two different lines within each study) and plants were sprayed at either the vegetative stage or the early bloom stage. Both glyphosate and dicamba caused higher yield losses when sprayed at the early bloom stage. A 25% yield loss was observed with 8.5 and 7.5 g ae ha−1for glyphosate and dicamba, respectively, at the early bloom stage and 43.9 and 11.9 g ae ha−1for glyphosate and dicamba, respectively, at the early vegetative stage. Overall, these tomato cultivars were more sensitive to dicamba than to glyphosate. We conclude that glyphosate and dicamba drift could have serious implications on tomato yields especially if the drift occurs during flowering.

Effect of moisture stress at different growth stages of tomato plant (<i>Lycopersicon esculentum</i> Mill.) on yield and quality of fruits

There is a need to utilize the water efficiently and effectively because water availability is scarce in the dry zone of Sri Lanka. An experiment was conducted to determine the changes in fruit quality of tomato cv. KC-1 with moisture stress viz., determine the vitamin C, total soluble solids (TSS) and acid contents of tomato fruits during fruit ripening stage. Also, investigated in the present study was to find out the most critical stage/s of the plant growth to moisture stress in order to sustain the yield by efficient water management. Experiment was conducted at the agronomy farm of the Faculty of Agriculture, Eastern University, Sri Lanka. The experimental design was randomized complete block design with five treatments and four replications. Moisture stress was imposed during vegetative, flowering, early fruiting and fruit ripening stages of tomato for a period of four days in each growth stages. The control plants were watered daily to the field capacity. The stress cycle was single in which water was withheld completely at once. The result showed that moisture stress at fruit ripening stage reduced the vitamin C contents of fruits. The TSS and acid contents of the fruits were slightly affected by moisture stress when the stress was imposed during the fruit ripening stage but they were not significant. Vitamin C, TSS and acid contents of fruits were unaffected by moisture stress given during vegetative, flowering and early fruiting stages. Moisture stress reduced the yield of tomato and the stress during the flowering stage showed the highest yield reduction compared to the other growth stages. Hence, the flowering stage is the most critical stage of growth of tomato to moisture stress for the fruit yield.Keywords: Tomato, Growth stages, Moisture stress, Fruit quality, Yield.DOI: http://dx.doi.org/10.4038/josuk.v5i0.4086 J Sci.Univ.Kelaniya 5 (2010): 1-11

Diversidade de visitantes florais e potenciais polinizadores de Solanum lycopersicum (Linnaeus) (Solanales: Solanaceae) em cultivos orgânicos e convencionais

Studies on the impacts of agricultural activities are important for the conservation of insect. Little is known about these impacts in the state of Sergipe. The objective was tosurvey the insect visitors in organic and conventional tomato crops pollinators identifying and verifying possible differences between these forms of cultivation. The species collected were identified and classified. We found six orders, with emphasis on Hymenoptera, the order of pollinating the flowers of tomato. The number of individuals was 76% higher in organic fields, which shows that the products used in conventional crops arelikely to affect the diversity of insect.Key words: pollinators, buzz pollination, agroecosystems

Sunlight Fluctuation Compensation for Tomato Flower Detection Using Web Camera

As basic research to develop a machine vision system to detect tomato flowers, a robust color and brightness compensation approach against the sunlight fluctuation was proposed. This approach used the scanning strategy to obtain an uniform condition for precise color and brightness measurement even under changing sunlight illumination. According to the relations between color differences and camera properties, adaptive camera parameter adjustment was calibrated to generate the best possible color correction. Experimental results showed that this method could not only measure tomato flower colors, but also meet the requirements of automatic flower recognition under varying illumination conditions.

Influence of fruit ripening acceleration measures on flowering and fruiting of small-sized tomato

The investigations were carried out in 2001-2003 at the Horticulture Experimental Station, University of Agriculture in Szczecin. The influence of truss cutting and application of Ethrel preparation on the flowering and acceleration of ripening of small-sized tomato fruit was studied. The experiment focused on the following factors: methods of acceleration of tomato fruit ripening (truss cutting, Ethrel preparation, truss cutting + Ethrel preparation) and tomato cultivars ('Cheresita F1', 'Favorita F1'). The applied methods had no influence on the number of flowers and germs of the small-sized tomato. The truss cutting increased the percentage of set fruits compared to the number of flowers. The application of Ethrel preparation along with truss cutting significantly increased the early yield of tomato fruits. The Ethrel and truss cutting accelerated the small-sized tomato harvesting by 12 days. Cv. 'Cheresita F1' produced a larger number of flowers, germs and fruits than 'Favorita F1'.