Blotchy Ripening Research Articles

Molecular Methods for the Simultaneous Detection of Tomato Fruit Blotch Virus and Identification of Tomato Russet Mite, a New Potential Virus–Vector System Threatening Solanaceous Crops Worldwide

Tomato fruit blotch virus (ToFBV) (Blunervirus solani, family Kitaviridae) was firstly identified in Italy in 2018 in tomato plants that showed the uneven, blotchy ripening and dimpling of fruits. Subsequent High-Throughput Sequencing (HTS) analysis allowed ToFBV to be identified in samples collected in Australia, Brazil, and several European countries, and its presence in tomato crops was dated back to 2012. In 2023, the virus was found to be associated with two outbreaks in Italy and Belgium, and it was included in the EPPO Alert list as a potential new threat for tomato fruit production. Many epidemiologic features of ToFBV need to be still clarified, including transmission. Aculops lycopersici Massee (Acariformes: Eriophyoidea), the tomato russet mite (TRM), is a likely candidate vector, since high population densities were found in most of the ToFBV-infected tomato cultivations worldwide. Real-time RT-PCR tests for ToFBV detection and TRM identification were developed, also as a duplex assay. The optimized tests were then transferred to an RT-ddPCR assay and validated according to the EPPO Standard PM 7/98 (5). Such sensitive, reliable, and validated tests provide an important diagnostic tool in view of the probable threat posed by this virus–vector system to solanaceous crops worldwide and can contribute to epidemiological studies by simplifying the efficiency of research. To our knowledge, these are the first molecular methods developed for the simultaneous detection and identification of ToFBV and TRM.

Modifying Walk-In Tunnels through Solar Energy, Fogging, and Evaporative Cooling to Mitigate Heat Stress on Tomato

Global warming is by far the most significant issue caused by climate change. Over the past few decades, heat stress has intensified into a serious issue that has a negative impact on crop production. Hence, it is crucial to modify cultivation systems to cope with this kind of stress, particularly in arid dry regions. In comparison to open-field cultivation, tomato production under protected cultivation techniques in walk-in tunnels that are suited for different farmers’ financial abilities was evaluated during the late summer season. The studied tunnels included a shaded net tunnel with natural ventilation, net tunnel with a fogging system and plastic tunnel with evaporative cooling (wet pad and fans). For the operation of fogging and evaporative cooling systems, solar energy was used as a sustainable, eco-friendly energy source. The results indicated that the solar energy system successfully operated the studied cooling systems. All studied protective cultivation techniques mitigated heat stress on tomato plant and improved the microclimate under walk-in tunnels. Moreover, evaporative cooling and fogging systems significantly increased plant leaf area, cell membrane efficiency and the contents of chlorophyll, relative water and proline compared to the net tunnel with natural ventilation. Furthermore, a marked reduction in physiological disorders was noticed. Improved physiological and biochemical parameters and limited physiological diseases led to higher fruit set, marketable fruit yield and total productivity. The percentage of marketable fruit yield increased by around 31.5% with an evaporative cooling system, 28.8% with a fogging system and 17% with a shaded net tunnel with no positive cooling as compared to an open field. However, the plants grown in open-field cultivation without protection significantly deteriorated from heat stress and had a high incidence of physiological disorders. The most incident physiological disorders were blossom-end rot, cracking, internal white tissues, sunscald, puffiness, blotchy ripening, cat face and exserted stigma. It is recommended to use a solar energy system to modify microclimate conditions through fogging or evaporative cooling under walk-in tunnels to ameliorate heat stress on grown tomato in the late summer season for higher fruit yield and fewer physiological disorders.

Effect of ICM Practices on Yield and Economics in Tomato (Lycopersicon esculentum Mill.)

The present investigation was carried out to study the effect of integrated crop management practices on yield and economics of tomato at farmer’s field of Mancherial district, Telangana state during the year from 2019-20, 2020-21 and 2021-22. The farming area available for the production of tomato across India during the financial year 2022 is estimated to have amounted to 841 thousand hectares. The treatments consist of farmer practice (T1) with application of RDF (180: 100: 60 kg NPK ha-1) and direct sowing in the field and T2 consists of raising of seedlings by nursery, installation of yellow sticky traps @ 25 ha-1, staking of plants, marigold grown as trap crop (tomato 16 rows: marigold 1 row) and spraying of need-based chemicals along with application of RDF (180: 100: 60 kg NPK ha-1). The results revealed that the total percent yield gap between potential yield and actual yield of tomato was 52.94 percent, in which 10.38 percent of yield gap between demonstration plot and actual farmers plot yield and 42.56 percent of technological gap. The data (T2) showed that highest yield recorded (34.46 t ha-1) in comparison to farmer practice (25.54 t ha-1) (T1), high net prot (T2) over (T1) with BC Ratio 1.56 (T2) and 1.42 (T1). The experiment showed that the number of fruits, fruit weight and marketable yield were highest in T2 (ICM practices) over T1 (application of RDF: 180: 100: 60 kg NPK ha-1). The adoption of ICM practices shows positive impact on yield (34.46 t ha-1) and economics of tomato through adoption of ICM practices and also decreased the incidence of physiological disorders (blotchy ripening, sun-scalding) and pest-disease incidence (fruit borer and blight infestation).

AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process.

Comparative Genetic Variability and Heritability in Some Tomato Varieties against Fruit Borer, Shape Disorders and Their Correlation

Present study was carried out to determine the breeding potential ten tomato (Lycopersicon esculentum) varieties to develop resistant varieties for fruit borer, fruit cracking, blossom end rot, cat face, sunscald and blotchy ripening. Coefficients of variation, heritability and correlation coefficients were determined for this purpose. Significant varietal difference for all the resistant measured was observed. The coefficients of variability for phenotype were always greater then genotypic and environmental coefficients of variation for under study characters. High heritability for fruit borer resistant, cracked resist fruit, blossom end rot resist fruit, cat face resist fruit was observed. The positive significant relationships were obtain for Cracked resist fruit-Cat face resist fruit, Blossom end rot resist fruit-Sunscald resist fruit and Cracked resist fruit-Blotchy ripened resist fruit pairs.

Effect of Pepino mosaic virus on the yield and quality of glasshouse‐grown tomatoes in the UK

Two fully replicated trials were conducted with glasshouse‐grown tomatoes, under conditions similar to commercial production, to define the impact of Pepino mosaic virus (PepMV). PepMV was not found to reduce bulk yields in these trials, but the quality of tomato fruits harvested was reduced significantly. Compared with uninoculated, PepMV‐free control plants, 6·5% of fruits of PepMV‐affected cv. Espero were downgraded from class 1 in trial 1. In trial 2, an average 38% of class 1 fruits from PepMV‐affected cvs Espero and Encore were lost as a result of downgrading. Loss of quality was mainly a result of blotchy ripening, gold marbling, gold spot, and symptoms directly attributed to PepMV infection. PepMV infection also affected fruit size. The results are discussed in relation to the demands of multiple retailers in the UK for class 1 tomatoes only.

(183) Quality and Shelf Life of Greenhouse Tomatoes Exposed to 1-Methylcyclopropene

The objectives of this research were to determine if 1-methylcyclopropene (1-MCP) improves fruit quality and extends shelf life of Ontario greenhouse tomatoes. `Beefsteak' tomatoes between breaker and turning maturity stages were harvested from commercial growers in Leamington, Ontario, and randomly sorted into uniform lots for 1-MCP treatment. Application of 1-MCP concentrations from 0 to 1200 nL/L was done at 22 °C for 12 hours in sealed bags. After treatment, fruit were held at 22 °C. Color change, fruit firmness, and production rates of CO2 and ethylene were followed for a period of 2 weeks. Significant differences (P ≤ 0.05) were found in color, ethylene, and CO2 production rates between treatments. However, there were few significant differences among cultivars and growers. This suggests that different tomato cultivars respond similarly to 1-MCP, and that commercial growing conditions and practices may not affect its efficacy. Over the 2-week ripening period, fruit from treatments of less than 300 nL/L 1-MCP exhibited similar color changes while treatments of more than 600 nL/L resulted in blotchy ripening, causing fruit to be unmarketable. 1-MCP treatment led to an increase in the rates of ethylene and CO2 production, two processes correlated with the onset of fruit ripening. This increase was unexpected and other studies showed that 1-MCP delayed the onset of these processes in tomatoes, and inhibited them in other fruits. Tomatoes treated at a maturity between breaker and turning did not respond well to 1-MCP, perhaps due to the ripening process having already begun. This implies that maturity stages earlier than breaker to turning may respond better to 1-MCP, and it may be more beneficial to target greenhouse tomatoes at an earlier maturity.

Down-regulation of DR12, an auxin-response-factor homolog, in the tomato results in a pleiotropic phenotype including dark green and blotchy ripening fruit.

Following differential screening of gene expression during tomato fruit development, we isolated developmentally regulated (DR) clones, including several putative transcription factors. Based on sequence homology, DR1, DR3, DR4 and DR8 are members of the Aux/IAA family, and DR12 belongs to the auxin response factor (ARF) family of transcription factors. Importantly, mRNA accumulation for the Aux/IAA-like genes was regulated by ethylene in tomato fruit but not in the leaves, indicating that these putative auxin response components also participate to the ethylene-dependent regulation of gene expression in a tissue-specific manner. The functional significance of DR12, the ARF-like gene, was investigated by cellular biology and reverse genetics approaches. Heterologous protein targeting studies, carried out using a DR12-GFP gene fusion construct, revealed specific nuclear localization of the DR12-encoded protein, in accordance with its putative function as a transcriptional regulator. Transgenic plants over- and under-expressing DR12 were generated in order to explore the physiological role of the gene. Both antisense and sense co-suppressed DR12-inhibited lines displayed a pleiotropic phenotype that included dark-green immature fruit, unusual cell division in the fruit pericarp, blotchy ripening, enhanced fruit firmness, upward curling leaves and increased hypocotyl and cotyledon growth. While a perturbation of the response to auxin may explain some of the phenotypes, surprisingly, the expression of members of four classes of early auxin-regulated genes was unaffected in the DR12-inhibited plants. The involvement of this ARF-like encoded protein in mediating the auxin response is discussed along with the possibility that it might affect responsiveness to other phytohormones in the tomato.

Fruit Maturity and Timing of Ethylene Treatment Affect Storage Performance of Green Tomatoes at Chilling and Nonchilling Temperatures

Green tomato (Lycopersicon esculentum `Sunny') fruit were stored at 2.5, 5, 7.5, 10, or 12.5 °C (36.5, 41, 45.5, 50, or 54.5 °F) for 1, 3, 5, or 7 days to determine their sensitivity to chilling injury. In subsequent experiments, fruit were treated with ethylene at 20 °C (68 °F) until the breaker stage was reached, either before or after storage at 12.5 °C for 0, 1, 3, 5, or 7 days, or 2.5 °C for 3, 5, 7, or 9 days. Number of days to reach the breaker stage was used as an indicator of initial maturity. The chilling threshold temperature for green `Sunny' tomatoes was near 7.5 °C, with delayed ripening occurring in fruit stored for ≥5 days. Longer exposure times at chilling temperatures resulted in reduced marketable life, dull color, flaccidity, and delayed, uneven (blotchy) and nonuniform ripening. Chemical composition was generally unaffected by chilling, while loss of firmness as a result of chilling exposure time rather than chilling temperatures per se was observed. Increased storage time at either 2.5 or 12.5 °C accentuated the initial differences in fruit maturity and thus resulted in less uniform ripening, especially for tomatoes stored before ethylene treatment, but the effect was much greater following 2.5 °C storage. Exposure to 2.5 °C for as little as 3 days before ethylene treatment caused blotchy ripening and decay, and reduced the marketable life of tomatoes by half compared to storage at nonchilling temperature. Treatment with ethylene before storage prevented chilling injury for up to 5 days at 2.5 °C and prolonged the marketable life of tomatoes stored at either chilling or nonchilling temperature. Tomatoes became less responsive to poststorage ethylene treatment with increased storage time at either 2.5 or 12.5 °C. More mature tomatoes and those treated with ethylene before 12.5 °C storage lost less weight. Vitamin C content was lower in more mature tomatoes, but ethylene treatment resulted in better maintenance of vitamin C by shortening the time to reach the red stage. No other significant differences in color, firmness or chemical composition at the red stage were found between fruit with different initial maturities or fruit treated with ethylene before or after 2.5 or 12.5 °C storage. Treating green tomatoes with ethylene before storage or transport is preferable to poststorage treatment because of faster and more uniform ripening, and also increased marketable life and reduced risk of injury in the event of exposure to chilling temperatures.

Effects of low oxygen and high carbon dioxide on tomato cultivar ‘Bermuda’ fruit physiology and composition

Breaker stage tomatoes ( Lycopersicon esculentum Mill., cultivar ‘Bermuda’) were treated in air, 0.5% or 1.0% oxygen (O 2) in nitrogen (N 2) or 80% carbon dioxide (CO 2) in air for 1, 3, 5 or 7 days at 22 °C. A 1 day low O 2 treatment delayed ripening after treatment by 1–2 days compared to a ripening period of 4 days for the control; elevated CO 2 for 1 day had no effect on ripening after treatment. Low O 2 increased production of ethanol and acetaldehyde compared to the control and high CO 2. Fruit treated for 3 or more days in low O 2 or high CO 2 showed skin injury and blotchy ripening. Disease incidence increased with treatment time, but could be controlled in 1 day treatments by reducing relative humidity to about 70%. Firmness, total soluble solids, titratable acidity and pH of pericarp and gel of 1 day treated fruit were not different from the control.

Effects of root pruning and N-NO 3 solution concentration on tomato plant growth and fruit yield

Confining and air pruning roots of tomato plants during growth in containers of limited volume occur often in protected horticulture and may reduce tomato yield and fruit quality. The objective of the present work was to determine if a high nitrate (NO 3) concentration in the solution can compensate for pruned roots in relation to shoot growth, fruit mean weight, total yield and the occurrence of blotchy ripening of tomato (cultivar F 121). Treatments included intact roots and mildly and severely pruned roots (leaving two-thirds and one-third of the roots, respectively) which were factorially combined with 1.5 mM or 9 mM N-NO 3 complete culture solution. Although root pruning reduced shoot growth, fruit yield and average fruit weight, it increased the percentage of fruits lacking internal and external blotchy ripening. There were no significant interactions between root pruning and NO 3 solution concentration in terms of vegetative growth or fruit yield. The lower NO 3 solution concentration significantly reduced dry weights of the vegetative organs, but had no significant effect on fruit yield and quality. Thus high NO 3 solution concentration could not compensate for the pruned roots regarding tomato yield and did not affect the occurrence of blotchy ripening.

VIBRATION OF TOMATO FRUIT CAUSES ABNORMAL RIPENING.

Previous investigations have shown that severe injury and bruising result from impacts, compression, and vibration scuffing during transport. Work specifically on vibration has focused on damage caused by “micro impact” and not true vibration. Our study looked at true vibration-imparted energy and analyzed the effects of force and frequency. Mature green tomato fruit were secured to a platform and energized with a vibration cell at different frequencies and force for 0, 10, 20, 30, 40, 50 and 60 minutes. The fruit were then allowed to ripen at 20C. Ethylene and respiration rates were determined along with general condition for two weeks. Ethylene production and respiration rate increased initially and remained high with increasing force and length of treatment. Fruit vibrated for 40, 50, and 60 m developed an uneven ripening pattern. When the control fruit were red, the vibrated fruit showed blotchy ripening. In addition, the ripening rate was slower, although respiration and ethylene production were higher. However, when the control fruit were full red to overripe, the blotchy ripening disappeared in the treatments, but they never developed as deep a red as the controls. We are continuing to investigate vibrational effects on gel breakdown and membrane integrity

External and Internal Blotchy Ripening and Fruit Elemental Content of Trickle-irrigated Tomatoes as Affected by N and K Application Time

Tomatoes (Lycopersicon esculentum Mill.) were grown on polyethylene-mulched beds of an Arrendondo fine sand during two seasons to evaluate the effects of trickle irrigation-applied N and/or K, percentages of trickle-applied nutrient(s) (50%, 75%, and 100%), and schedules of nutrient application (variable, 2% to 12.5% of total amount weekly, or constant, 8.3% of the total amount weekly) on the occurrence of fruit external and internal blotchy ripening and fruit mineral nutrient concentration. Trickle-applied fertilizer was injected into the irrigation water weekly during the first 12 weeks of each season. External and internal blotchy ripening were less severe with trickle-applied N supplied as N + K or N than with preplant-applied N. Trickle-applied N + K or N resulted in higher fruit concentrations of N, P, K, Ca, and Mg than with all preplant-applied N. Internal fruit quality improved slightly as the trickle-applied percentage of N and/or K increased from 50% to 100%, but significant differences in exterior quality were not obtained. Internal fruit quality was higher early in the season than late in the season during both years, but this response was not associated with fruit elemental concentration. The weekly schedule of nutrient injection had no significant effect on fruit quality or fruit elemental concentration. Highest yields of high-quality fruit were obtained with 50% trickle-applied N + K.

Inheritance of Resistance to Blotchy Ripening in Processing Tomatoes

Inheritance of resistance to blotchy ripening In tomato (Lycopersicon esculentum Mill.) cultivars intended for machine harvest was studied in two diallel crosses using the Hayman and Griffing analyses. Additive effects were most important as indicated by the high level of general combining ability compared with specific combining ability. Some hybrids performed better than the mid-parent mean; however, heterosis for resistance to blotch above the best inbred line was not evident. Epistasis occurred between recessive genes in two parents, resulting in reduced blotch. No significant interaction between the expression of blotch in diallel progeny and K availability was evident. Genotype-environment Interaction was significant, but relative variation in blotch between experiments only occurred in cultivars with an intermediate level of resistance.

INFLUENCE OF POTASSIUM FERTILIZATION ON BLOTCHY RIPENING IN PROCESSING TOMATOES

The effect of potassium fertilization on blotchy ripening in processing tomatoes (Lycopersicon esculentum Mill.) was investigated. Potassium treatments up to 624 and 590 kg ha−1 in 1983 and 1984 decreased the incidence of blotchy fruit. Differences in blotch susceptibility occurred among commercial cultivars. Potassium fertilization and cultivar are factors influencing pericarp color in processing tomatoes.Key words: Tomato, blotchy ripening, potassium

Resistance to Tobacco Mosaic Virus-induced Blotchy Ripening in Greenhouse Tomato Hybrids1

Abstract Germplasm sources for resistance to tobacco mosaic virus-induced blotchy ripening of greenhouse tomato (Lycopersicon esculentum Mill.) were tested in hybrid combinations using a virus strain belonging to Pelham Group I. Breeding lines possessing Tm-2 or Tm-2a genes contributed high tolerance against TMV infection based on both leaf and fruit symptoms. ‘Perou 2’ (Tm-2), Ohio MR-13 (Tm-2a), and Ohio MR-12 (Tm-2a) and hybrids involving these lines were tolerant to the virus. Significant dominance for tolerance was observed in most hybrids heterozygous at the Tm-2 or Tm-2a locus. Tm-1 gene sources were not very effective in controlling blotchiness.

Influences of Potassium, Cultivar, and Season on Tomato Graywall and Blotchy Ripening1

Abstract ‘Healani’, ‘Homestead-24’, ‘Walter’, and ‘Flora-Dade’ tomatoes (Lycopersicon esculentum Mill.) were grown with 0, 93, 186, 372, or 744 kg K/ha during spring and fall to determine the influence of K rate, cultivar, and season on the separate fruit disorders of graywall (GW) and blotchy ripening (BR). Susceptibility to GW was determined by inoculating a GW-inducing type of bacteria, Erwinia herbicola (Dye), into the outer pericarp of immature green fruit. All 4 cultivars developed more GW without added K than with it during the spring season. In both field and greenhouse conditions, ‘Flora-Dade’ and ‘Homestead-24’ were more resistant to GW than ‘Healani’ and ‘Walter’. Natural GW, contrasted to bacterially induced GW, occurred in ‘Healani’ and ‘Homestead-24’ fruit grown with low K concentrations in a sand culture experiment. Both cultivars were free of natural GW with the high-K treatment. ‘Flora-Dade’ was resistant to natural GW under all K treatments. Fruit from all cultivars had significantly less BR with K fertilization in both seasons. External blotchy ripening (EBR) and internal blotchy ripening (IBR) were more severe in the spring than in the fall. ‘Healani’ showed resistance to yellow shoulder, the primary EBR symptom, which was severe during the spring in all other culti vars. ‘Healani’ was generally the most BR-resistant cultivar and ‘Flora-Dade’ the most BR-susceptible. Pericarp K concentration increased with K rate in all cultivars during both seasons, but differences in susceptibility to BR between cultivars were not associated with differences in pericarp K, Ca, Mg, or P content.

Multicompartmental Analysis on the Metabolism of ^<14>C-Glucose in Tomato Fruit in the Inducing Condition of Blotchy Ripening

Multicompartmental Analysis on the Metabolism of ^<14>C-Glucose in Tomato Fruit in the Inducing Condition of Blotchy Ripening

Protein and enzyme changes in tomato fruit in relation to blotchy ripening and potassium nutrition

AbstractThe effects of potasium deficiency and blotchy ripening in tomato fruit on some nitrogenous constituents, especially the proteins, have been investigated. The distribution of nitrogen in normal and potassium‐deficient fruit of the cherry tomato Lycopersicon pimpinellifolium was examined and compared with that from potassiumdeficient and blotchy ripened fruit of a cultivated variety (L. esculentum, cv. Moneymaker). The protein fraction from cv. Amberley Cross was analysed in detail using disc gel electrophoresis. Changes induced by potassium deficiency in the general protein pattern and on a wide range of enzymes active in ripening were compared with the effects brought about by blotchy ripening. The distribution of protein components and isoenzymes in low potassium fruit was to a large extent similar to that of normal tissue at an earlier stage of development, whereas the alterations in blotchy tissue appeared to be of a random nature.

ASSOCIATION OF WEATHER DATA AND THE INCIDENCE OF BLOTCHY RIPENING OF GREENHOUSE TOMATOES IN BRITISH COLUMBIA

Blotchy ripening (BR) of greenhouse tomatoes (Lycopersicon esculentum Mill.) appears irregularly in the spring crop in British Columbia. Variation in BR incidence among seasons and also within a season does not appear correlated with any changes in cultural conditions; therefore, an examination of meteorological data for an association with incidence of BR was undertaken. Light as hours of bright sunshine was studied in the cases where BR was reported in the commercial crop. Daily meteorological records were examined for weekly periods, and the correlation of BR with conditions at week of harvest and each of the 7 wk preceding harvest, and combinations of 2–8 of those weeks studied. Some 180 models were examined, and the highest r2 value occurred in the regression equation of Y = 1.51 − 0.0167 X, where Y is the severity rating (0–3) of the BR incidence, and X is the total hours of bright sunshine from the combination in which these hours were the difference between the sums for alternate weeks from harvest and the remaining weeks of the 8-wk period. In other words, the incidence of BR will be severe when the total hours of bright sunshine of even-numbered weeks were smaller than that of odd-numbered weeks, or when even-numbered weeks were cloudy and odd-numbered weeks were sunny. The emphasis is placed on a cumulative, cyclical effect that previous workers appear to have overlooked. The hypothesis is being used to plan regimes in controlled environment to study blotchy ripening.