The Experts below are selected from a list of 1500 Experts worldwide ranked by ideXlab platform
Donald L. Hendrix - One of the best experts on this subject based on the ideXlab platform.
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Effects of Aqueous Sprays of Silverleaf Whitefly Honeydew Sugars on Cotton Lint Stickiness
2000Co-Authors: Thomas J. Henneberry, L. Forlow Jech, Donald L. Hendrix, T. SteeleAbstract:Sprays of commercially-procured sugars that are also found in Silverleaf Whitefly Bemisia argentifolii Bellows and Perring [= B. tabaci (Gennadius) Strain B] honeydew were applied to clean cotton lint to determine the relationship between the sugars and cotton lint stickiness. Increasing concentrations of the sugars resulted in increasing thermodetector counts.
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Purification and properties of an unusual NADPH-dependent ketose reductase from the Silverleaf Whitefly
Insect Biochemistry and Molecular Biology, 1998Co-Authors: Michael E. Salvucci, Gregory R. Wolfe, Donald L. HendrixAbstract:Abstract Sorbitol accumulates in the Silverleaf Whitefly when this insect is exposed to elevated temperatures. Synthesis of sorbitol in the Silverleaf Whitefly is catalyzed by an unconventional enzyme that converts fructose to sorbitol using NADPH as the coenzyme. In the present study, the NADPH-dependent ketose reductase from adult whiteflies was purified to apparent homogeneity and characterized. The NADPH-dependent ketose reductase was tetrameric, composed of 38.7 kD subunits, and catalyzed both fructose reduction and sorbitol oxidation. The purified Whitefly enzyme exhibited an almost exclusive requirement for NADP(H) for ketose reduction/sorbitol oxidation. The pH and temperature optima for fructose reduction and sorbitol oxidation were 7°C and 45°C and >9°C and 50°C, respectively. The affinity of the enzyme for fructose was very low, but physiological considering the high concentrations of carbohydrate available to this phloem-feeding insect. Edman degradation analysis of three peptides from the enzyme showed that their amino acid sequences matched internal sequences of NAD + -dependent sorbitol dehydrogenases. Thus, the NADPH-dependent ketose reductase responsible for sorbitol synthesis in the Silverleaf Whitefly is structurally similar to the sorbitol catabolic enzyme NAD + -dependent sorbitol dehydrogenase, but differs in its coenzyme requirement. Antibodies directed against the purified Whitefly enzyme showed that this novel ketose reductase occurs in Whitefly eggs and nymphs, as well as in the adults.
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Silverleaf Whitefly and Cotton Lint Stickiness
1997Co-Authors: Thomas J. Henneberry, L. Forlow Jech, Donald L. Hendrix, H. H. Perkins, D. E. BrushwoodAbstract:Cotton plant densities of 10 or 40 thousand plants/acre had no effect on numbers of Silverleaf Whitefly, Bemisia argentifolii Bellows and Perring, adults, eggs, nymphs, extracted sugars from lint samples or thermodetector sticky cotton counts. Higher numbers of whitejlies occurred in early season in Pima S-7 cotton than in DPL 50 or DPL 5415 cotton. Seasonal averages for sugars, percentages of total reducing sugars and thermodetector counts were higher for DPL 50 compared with Pima S -7 but not DPL 5415. Insecticide treatments reduced thermodetector counts and associated sugars extracted from lint.
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Diglucomelezitose, a Novel Pentasaccharide in Silverleaf Whitefly Honeydew
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Yuan-an Wei, Donald L. Hendrix, Ronald NiemanAbstract:Honeydew excreted by the Silverleaf Whitefly (Bemisia argentifolii Bellows and Perring) feeding upon upland cotton (Gossypium hirsutum L.) was isolated from cotton lint and fractionated into various oligosaccharides using a charcoal column eluted with aqueous isopropyl alcohol. Two oligosaccharide fractions from the charcoal column, enriched in tetra- and pentasaccharides, were further fractionated on a Bio-Gel P2 column. A fraction from the later column was separated into individual oligosaccharides using high-performance anion-exchange chromatography. One of the sugars isolated in this procedure was found to be novel pentasaccharide. Analysis of this oligosaccharide by NMR showed it to contain sucrose and melezitose moieties. The results of these analyses are consistent with a pentasaccharide of the following structure: O-α-d-glucopyranosyl-(1→4)-O-α-d-glucopyranosyl-(1→3)-O-β-d-fructofuranosyl-(2↔1)-O-α-d-glucopyranosyl-(4←1)-α-d-glucopyranoside. A tetrasaccharide, maltosucrose [O-α-d-glucopyranosyl-(...
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Effect of sucrose concentration on carbohydrate metabolism in Bemisia argentifolii : biochemical mechanism and physiological role for trehalulose synthesis in the Silverleaf Whitefly
Journal of Insect Physiology, 1997Co-Authors: Michael E. Salvucci, Gregory R. Wolfe, Donald L. HendrixAbstract:Uptake and metabolism of sucrose by adult Silverleaf whiteflies (Bemisia argentifolii) were investigated on defined diets containing sucrose concentrations from 3 to 30% (wv). At an optimal pH of 7, the volume of liquid ingested decreased with increasing dietary sucrose concentration, but the amount of sucrose ingested showed a net increase. Above a dietary sucrose concentration of about 10%, a greater amount of the ingested carbon was excreted by the whiteflies than was retained, and the proportion that was excreted increased progressively with increasing dietary sucrose concentration. Carbohydrate analysis showed that the composition of excreted honeydew changed from predominantly glucose and fructose at low dietary sucrose concentrations to predominantly trehalulose at high concentrations, with little change in the proportion of larger oligosaccharides. Measurements of Whitefly trehalulose synthase and sucrase activities revealed that the enzymatic potential for metabolizing sucrose shifted from favoring sucrose hydrolysis at low sucrose concentrations to sucrose isomerization at high sucrose concentrations. Thus, the amount of trehalulose synthesized by the Silverleaf Whitefly was directly related to the properties of trehalulose synthase and sucrase and the concentration of sucrose in the diet. We propose that trehalulose is synthesized for excretion when the carbon input from sucrose is in excess of metabolic needs.
S. Hanif-khan - One of the best experts on this subject based on the ideXlab platform.
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Effects of Silverleaf Whitefly feeding on tomato fruit ripening
Postharvest Biology and Technology, 2004Co-Authors: T. G. Mccollum, Charles A Powell, Peter J. Stoffella, Daniel J. Cantliffe, S. Hanif-khanAbstract:Silverleaf Whitefly (SLW) ( Bemisia argentifolii Bellows and Perring) feeding on tomato (Lycopersicon esculentumMill.) plants induces a disorder in the fruit known as irregular ripening. The effects of Silverleaf Whitefly feeding on ripening of tomato fruit both attached to and detached from the plant are described. ‘Florida Petite’ tomatoes free of SLW, attached to the plant, began an ethylene climacteric between 40 and 45 days after anthesis (DAA), coincident with a rapid increase in red color and loss of firmness. The ethylene climacteric began between 45 and 50 DAA in tomato fruit from plants infested with SLW, and the fruit developed less red color and softened less than did fruit from plants free of SLW. Fruit harvested 45 DAA from plants free of SLW reached the respiratory and ethylene climacteric peak 3 days after harvest, developed normal red color, and softened similar to fruit ripened on the plant. In contrast, fruit harvested 45, 50 or 55 DAA from SLW-infested plants showed no respiratory or ethylene climacteric, had poor color development, and did not soften to the same extent as did fruit from plants free of SLW. Published by Elsevier B.V.
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Plant Growth Regulators (GA3 and CCC) and Silverleaf Whitefly Effects on the Induction of Tomato Irregular Ripening in Dwarf Cherry Tomato
HortScience, 1997Co-Authors: S. Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:External and internal tomato irregular ripening (TIR) symptoms have been associated with the feeding of Silverleaf Whitefly (SLW), Bemisia argentifolii Bellows and Perring. Soil drench application of gibberellic acid (GA3) (100 ppm, Trial 1 and 2) and cycocel (CCC) (2000 ppm, Trial 1; 1000 ppm, Trial 2) were applied to dwarf cherry tomato (Lycopersicon esculentum) in the presence and absence of SLW to mimic the TIR disorder induced by the SLW. Application of GA3 induced external and internal TIR symptoms similar to the SLW-induced disorder in `Florida Petite'. There were essentially no TIR symptoms in fruit treated with CCC, an inhibitor of GA biosynthesis. In Trial 1, internal white tissue in GA3, SLW, and CCC treatments was expressed in 97%, 95%, and 4% of the total fruit, respectively. Incidence of external TIR symptom was highest (56%) in the GA3 plus SLW treatment. In Trial 2, GA3 application in the presence (83%) or absence (85%) of SLW resulted in the highest incidence of fruit with internal white tissue. External TIR symptoms induced by GA3 in the presence and absence of SLW were reduced with CCC application. These results suggest that the TIR disorder in tomato is induced by the SLW may be a GA3-regulated disorder.
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Possible Involvement of Altered Gibberellin Metabolism in the Induction of Tomato Irregular Ripening in Dwarf Cherry Tomato by Silverleaf Whitefly
Journal of Plant Growth Regulation, 1997Co-Authors: S. Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:External and internal tomato irregular ripening (TIR) symptoms were associated with the feeding of Silverleaf Whitefly (SLW), Bemisia argentifolii Bellows and Perring. Four experiments consisting of various soil drench applications of GA3 (100 ppm) and cycocel (CCC, an inhibitor of GA biosynthesis; 1,000 and 2,000 ppm) were applied to dwarf cherry tomato cv. Florida Petite in the presence and absence of SLW in an attempt to mimic the disorders induced by the SLW. The application of GA3 induced external and internal TIR symptoms similar to the SLW-induced disorder. Minimal TIR-like symptoms also occurred in the control and CCC treatments. Internal TIR symptoms in GA3, GA3 plus SLW, and GA3 plus CCC treatments ranged from 66% to 97% throughout the experiments. The incidence of external TIR symptoms was highest in the GA3 plus SLW treatment compared with the other treatments. CCC reduced the incidence of external TIR symptoms induced by GA3 or GA3 plus SLW treatments. However, CCC-treated plants also attracted more oviposition and higher populations of SLW and consequently induced a greater incidence of TIR symptoms than SLW treatment alone. Furthermore, although low SLW populations may be associated with low external TIR symptoms, internal TIR symptoms almost always remained high in infested plants. The results suggest that the TIR disorder in dwarf cherry tomato which is induced by the SLW may be a gibberellin-regulated disorder.
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Symptom Development and Susceptibility of Dwarf Cherry Tomato to Tomato Irregular Ripening, A Fruit Disorder Induced by Silverleaf Whitefly
HortScience, 1996Co-Authors: S. Hanif-khan, Charles A Powell, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, Heather J. McauslaneAbstract:Silverleaf Whitefly (SLW) (Bemisia argentifolii Bellows and Perring) feeding has been associated with development of tomato irregular ripening (TIR) symptoms. Four dwarf cultivars of cherry tomato (Lycopersicon esculentum L.) were infested with adult SLW to observe oviposition preference, tolerance and TIR symptom development. Oviposition preference was observed at low SLW population. Florida Petite was the most preferred and Micro-Tom the least preferred cultivar, with Florida Lanai and Florida Basket intermediate. Each cultivar exhibited TIR symptoms associated with feeding by the SLW. TIR fruit symptoms were expressed as longitudinal red streaks with yellow, green, pink or red blotches externally, and white, yellow or green tissue internally. External TIR symptoms ranged from 32% (Micro-Tom) to 82% (Florida Basket). However, external symptoms disappeared from 34% (Florida Lanai) to 56% (Micro-Tom) of the fruits during ripening. SLW infested plants had 82% (Florida Lanai) to 99% (Florida Basket) of fruits with internal white tissue regardless of external symptoms. Tomatoes with TIR symptoms rarely ripened to a mature red, and sometimes had empty locules, were smaller in size and were seedless.
Maria Jesus P. De Castro - One of the best experts on this subject based on the ideXlab platform.
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Characterization of antibiosis to the Silverleaf Whitefly Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in cowpea entries
Journal of Pest Science, 2014Co-Authors: Patrícia L. Cruz, Edson L. L. Baldin, Maria Jesus P. De CastroAbstract:The Silverleaf Whitefly, Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae), is considered one of the most important pests of cowpea ( Vigna unguiculata L. Walp.), limiting the productivity of this crop worldwide. Chemical control is still the main strategy for the management of populations of this insect. However, due to the harmful effects of pesticides on the environment and to humans, less injurious alternatives have been investigated. Along this line, the use of resistant genotypes can be a valuable tool for the control of the Silverleaf Whitefly. In this paper, we investigate some biological aspects of B. tabaci biotype B confined on 14 genotypes of cowpea. We evaluated the incubation period, egg viability, duration of nymphal stages, total duration of the juvenile phase, instar mortality and total mortality of the immature stage. The genotype MNC 99-541 F21 exhibited antibiosis against the Whitefly, prolonging the lifecycle of the insect. The genotypes Canapu, BRS-Urubuquara and TE97-304 G-4 also exhibited antibiosis, causing high nymphal mortality. These results may help in breeding programmes to develop cowpea lines with resistance to B. tabaci biotype B.
Charles A Powell - One of the best experts on this subject based on the ideXlab platform.
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Effects of Silverleaf Whitefly feeding on tomato fruit ripening
Postharvest Biology and Technology, 2004Co-Authors: T. G. Mccollum, Charles A Powell, Peter J. Stoffella, Daniel J. Cantliffe, S. Hanif-khanAbstract:Silverleaf Whitefly (SLW) ( Bemisia argentifolii Bellows and Perring) feeding on tomato (Lycopersicon esculentumMill.) plants induces a disorder in the fruit known as irregular ripening. The effects of Silverleaf Whitefly feeding on ripening of tomato fruit both attached to and detached from the plant are described. ‘Florida Petite’ tomatoes free of SLW, attached to the plant, began an ethylene climacteric between 40 and 45 days after anthesis (DAA), coincident with a rapid increase in red color and loss of firmness. The ethylene climacteric began between 45 and 50 DAA in tomato fruit from plants infested with SLW, and the fruit developed less red color and softened less than did fruit from plants free of SLW. Fruit harvested 45 DAA from plants free of SLW reached the respiratory and ethylene climacteric peak 3 days after harvest, developed normal red color, and softened similar to fruit ripened on the plant. In contrast, fruit harvested 45, 50 or 55 DAA from SLW-infested plants showed no respiratory or ethylene climacteric, had poor color development, and did not soften to the same extent as did fruit from plants free of SLW. Published by Elsevier B.V.
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Multitrophic interactions of the Silverleaf Whitefly, host plants, competing herbivores, and phytopathogens.
Archives of insect biochemistry and physiology, 2002Co-Authors: Richard T. Mayer, Cindy L Mckenzie, Charles A Powell, Robert G Shatters, Moshe Inbar, Victoria A. Borowicz, Ute Albrecht, Hamed DoostdarAbstract:Our laboratory found that Silverleaf Whitefly (SLW; Bemisia argentifolii Bellows & Perring) feeding alters host plant physiology and chemistry. The SLW induces a number of host plant defenses, including pathogenesis-related (PR) protein accumulation (e.g., chitinases, b-1,3-glucanases, peroxidases, chitosanases, etc.). Induction of the PR proteins by SLW feeding occurs in various plant species and varieties. The extent and type of induction is dependent on a number of factors that include host plant growing conditions, the length of time the host plant is exposed to SLW feeding, the plant variety, and SLW population densities. The appearance of PR proteins correlates well with reduced infestations of conspecific insect herbivore competitors. Greenhouse and field experiments in which herbivore competitors (cabbage looper, Trichoplusia ni; leaf miner, Liromyza trifolii) were placed on plants previously exposed to SLW feeding demonstrated behavioral differences (oviposition, feeding preferences) and reduced survival rates and development times of these insects. The interaction was asymmetrical, i.e., SLW infestations of plants previously exposed to leaf miners had little or no effect on SLW behavior (oviposition). Induction of plant-defensive proteins by SLW feeding was both local (at the feeding site) and systemic (uninfested leaves distant to the feeding site). There are interactions between diseases such as tomato mottle virus (ToMoV; a geminivirus) and the host plant and SLW. PR proteins were induced in tomato plants infected with ToMoV much as they were via non-viruliferous SLW feeding. The presence of ToMoV in tomato plants significantly increased the number of eggs produced by SLW females. Experiments using tomato plants, powdery mildew (PM), and tobacco mosaic virus (TMV) show that Whitefly infestations can affect plant pathogen relationships but the effects vary among pathogen types. Enzyme analyses prior to pathogen inoculation showed that Whitefly treatment significantly increased the activities of foliar chitinase and peroxidase. Evaluation of pathogen growth 3 weeks after inoculation showed that Whitefly feeding significantly reduced the incidence of PM. However, TMV levels evaluated by ELISA were not significantly affected by Whitefly feeding. Six weeks after inoculation with pathogens, the chitinase and peroxidase activities were still elevated in plants initially fed on by whiteflies but continuing pathogen infection had no effect on these enzymes. The possibility that geminivirus infection and/or SLW infestations isolate the host plant for the selected reproduction of the virus and the insect is discussed. Multitrophic cascade effects may contribute to the successful eruptive appearance of SLW on various crops, ranking them as a major pest. They may explain the general observation that when SLW infest a host plant there are few if any competing insect herbivores and pathogens found in the host. However, the results indicate that certain SLW-virus relationships could be mutualistic. Arch. Insect Biochem. Physiol. 51:151-169, 2002. Published 2002 Wiley-Liss, Inc. †
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Ethylene Levels and Fruit Quality of Silverleaf Whitefly-Infested Dwarf Cherry Tomato
1999Co-Authors: Shahab Hanif-khan, Charles A Powell, Jeffrey K. Brecht, Peter J. StoffellaAbstract:Tomato ( Lycopersicon esculentum Mill.) irregular ripening (TIR) is a disorder of fruit pigmentation induced by the infestation of Silverleaf Whitefly (SLW), { Bemisia argentifolii Bellows and Peering). Experiments were conducted to differentiate the postharvest characteristics of the SLW-infested and control fruit. Ethylene production by SLW-infested fruit was 2-fold higher than control fruit on day 1 of measurement and declined thereafter. In general, the SLW-infested fruit were slightly lighter in color than the control fruit. The control fruit developed normal red color while the SLW-infested fruit developed blotchy and streaky symptoms and were overall more of an orange-red color. SLW-infested fruit were firmer than control fruit. Total soluble solids contents were not significantly different between the treatments. However, titratable acidity and pH measurements indicated that the SLW-infested fruit were more acidic than control fruit. SLW-infested fruit exhibited a high incidence of TIR symptoms, both externally (i.e., blotches and streaks) and internally (i.e., white tissues), as well as a star formation color pattern at the blossom end of the fruit while control fruit had no TIR symptoms. The ripening process in the SLW-infested fruit appeared slower compared with the control fruit.
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Tomato Irregular-ripening Symptom Development and Ripening of Silverleaf Whitefly-infested Dwarf Cherry Tomatoes
Journal of the American Society for Horticultural Science, 1998Co-Authors: Shahab Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:Silverleaf Whitefly (SLW) (Bemisia argentifolii Bellows and Perring) feeding was associated with development of tomato irregular ripening (TIR) symptoms. `Micro-Tom', `Florida Basket', `Florida Lanai', and `Florida Petite' dwarf cherry tomatoes (Lycopersicon esculentum Mill.) were infested with adult SLW to observe oviposition preference, plant tolerance, and TIR symptom development in two experiments. There was no oviposition preference among the cultivars in either of the trials. TIR fruit symptoms were expressed as longitudinal red streaks with yellow, green, pink, or red blotches externally and white tissue internally. External TIR symptoms at the pink stage of ripening ranged from 32% (`Micro-Tom') to 82% (`Florida Basket') in Expt. 1 and 44% (`Micro-Tom') to 93% (`Florida Petite') in Expt. 2. In Expt. 1, external TIR symptoms disappeared from 18% (`Florida Lanai') to 37% (`Micro-Tom') and, in Expt. 2, 16% (`Micro-Tom') to 39% (`Florida Basket') of the fruit during ripening. SLW-infested plants exhibited 82% (`Florida Lanai') to 99% (`Florida Basket') and 76% (`Micro-Tom') to 90% (`Florida Petite') of fruit with internal white tissue regardless of external symptoms in Expts. 1 and 2, respectively. Tomatoes with severe TIR symptoms rarely ripened to full red. Postharvest characteristics of ripening SLW-infested and control fruit were evaluated (Expts. 3 and 4). Generally, the SLW-infested fruit were lighter in color than the control fruit. The control fruit developed normal red color while the SLW-infested fruit developed a blotchy, streaky color that was overall more of an orange-red. SLW-infested fruit were firmer than the control fruit in both experiments. Ethylene production was higher in SLW-infested fruit. While the total soluble solids contents were not significantly different between the treatments, the SLW-infested fruit were more acidic than the control fruit. Each cultivar was susceptible to oviposition by SLW and induction of TIR symptoms. However, TIR symptom expression differed among the cultivars. Despite higher ethylene levels, the ripening process in the SLW-infested fruit appeared slower or may have been inhibited by factors induced by the SLW compared with the control fruit, which ripened normally.
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Plant Growth Regulators (GA3 and CCC) and Silverleaf Whitefly Effects on the Induction of Tomato Irregular Ripening in Dwarf Cherry Tomato
HortScience, 1997Co-Authors: S. Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:External and internal tomato irregular ripening (TIR) symptoms have been associated with the feeding of Silverleaf Whitefly (SLW), Bemisia argentifolii Bellows and Perring. Soil drench application of gibberellic acid (GA3) (100 ppm, Trial 1 and 2) and cycocel (CCC) (2000 ppm, Trial 1; 1000 ppm, Trial 2) were applied to dwarf cherry tomato (Lycopersicon esculentum) in the presence and absence of SLW to mimic the TIR disorder induced by the SLW. Application of GA3 induced external and internal TIR symptoms similar to the SLW-induced disorder in `Florida Petite'. There were essentially no TIR symptoms in fruit treated with CCC, an inhibitor of GA biosynthesis. In Trial 1, internal white tissue in GA3, SLW, and CCC treatments was expressed in 97%, 95%, and 4% of the total fruit, respectively. Incidence of external TIR symptom was highest (56%) in the GA3 plus SLW treatment. In Trial 2, GA3 application in the presence (83%) or absence (85%) of SLW resulted in the highest incidence of fruit with internal white tissue. External TIR symptoms induced by GA3 in the presence and absence of SLW were reduced with CCC application. These results suggest that the TIR disorder in tomato is induced by the SLW may be a GA3-regulated disorder.
Peter J. Stoffella - One of the best experts on this subject based on the ideXlab platform.
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Effects of Silverleaf Whitefly feeding on tomato fruit ripening
Postharvest Biology and Technology, 2004Co-Authors: T. G. Mccollum, Charles A Powell, Peter J. Stoffella, Daniel J. Cantliffe, S. Hanif-khanAbstract:Silverleaf Whitefly (SLW) ( Bemisia argentifolii Bellows and Perring) feeding on tomato (Lycopersicon esculentumMill.) plants induces a disorder in the fruit known as irregular ripening. The effects of Silverleaf Whitefly feeding on ripening of tomato fruit both attached to and detached from the plant are described. ‘Florida Petite’ tomatoes free of SLW, attached to the plant, began an ethylene climacteric between 40 and 45 days after anthesis (DAA), coincident with a rapid increase in red color and loss of firmness. The ethylene climacteric began between 45 and 50 DAA in tomato fruit from plants infested with SLW, and the fruit developed less red color and softened less than did fruit from plants free of SLW. Fruit harvested 45 DAA from plants free of SLW reached the respiratory and ethylene climacteric peak 3 days after harvest, developed normal red color, and softened similar to fruit ripened on the plant. In contrast, fruit harvested 45, 50 or 55 DAA from SLW-infested plants showed no respiratory or ethylene climacteric, had poor color development, and did not soften to the same extent as did fruit from plants free of SLW. Published by Elsevier B.V.
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Ethylene Levels and Fruit Quality of Silverleaf Whitefly-Infested Dwarf Cherry Tomato
1999Co-Authors: Shahab Hanif-khan, Charles A Powell, Jeffrey K. Brecht, Peter J. StoffellaAbstract:Tomato ( Lycopersicon esculentum Mill.) irregular ripening (TIR) is a disorder of fruit pigmentation induced by the infestation of Silverleaf Whitefly (SLW), { Bemisia argentifolii Bellows and Peering). Experiments were conducted to differentiate the postharvest characteristics of the SLW-infested and control fruit. Ethylene production by SLW-infested fruit was 2-fold higher than control fruit on day 1 of measurement and declined thereafter. In general, the SLW-infested fruit were slightly lighter in color than the control fruit. The control fruit developed normal red color while the SLW-infested fruit developed blotchy and streaky symptoms and were overall more of an orange-red color. SLW-infested fruit were firmer than control fruit. Total soluble solids contents were not significantly different between the treatments. However, titratable acidity and pH measurements indicated that the SLW-infested fruit were more acidic than control fruit. SLW-infested fruit exhibited a high incidence of TIR symptoms, both externally (i.e., blotches and streaks) and internally (i.e., white tissues), as well as a star formation color pattern at the blossom end of the fruit while control fruit had no TIR symptoms. The ripening process in the SLW-infested fruit appeared slower compared with the control fruit.
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Tomato Irregular-ripening Symptom Development and Ripening of Silverleaf Whitefly-infested Dwarf Cherry Tomatoes
Journal of the American Society for Horticultural Science, 1998Co-Authors: Shahab Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:Silverleaf Whitefly (SLW) (Bemisia argentifolii Bellows and Perring) feeding was associated with development of tomato irregular ripening (TIR) symptoms. `Micro-Tom', `Florida Basket', `Florida Lanai', and `Florida Petite' dwarf cherry tomatoes (Lycopersicon esculentum Mill.) were infested with adult SLW to observe oviposition preference, plant tolerance, and TIR symptom development in two experiments. There was no oviposition preference among the cultivars in either of the trials. TIR fruit symptoms were expressed as longitudinal red streaks with yellow, green, pink, or red blotches externally and white tissue internally. External TIR symptoms at the pink stage of ripening ranged from 32% (`Micro-Tom') to 82% (`Florida Basket') in Expt. 1 and 44% (`Micro-Tom') to 93% (`Florida Petite') in Expt. 2. In Expt. 1, external TIR symptoms disappeared from 18% (`Florida Lanai') to 37% (`Micro-Tom') and, in Expt. 2, 16% (`Micro-Tom') to 39% (`Florida Basket') of the fruit during ripening. SLW-infested plants exhibited 82% (`Florida Lanai') to 99% (`Florida Basket') and 76% (`Micro-Tom') to 90% (`Florida Petite') of fruit with internal white tissue regardless of external symptoms in Expts. 1 and 2, respectively. Tomatoes with severe TIR symptoms rarely ripened to full red. Postharvest characteristics of ripening SLW-infested and control fruit were evaluated (Expts. 3 and 4). Generally, the SLW-infested fruit were lighter in color than the control fruit. The control fruit developed normal red color while the SLW-infested fruit developed a blotchy, streaky color that was overall more of an orange-red. SLW-infested fruit were firmer than the control fruit in both experiments. Ethylene production was higher in SLW-infested fruit. While the total soluble solids contents were not significantly different between the treatments, the SLW-infested fruit were more acidic than the control fruit. Each cultivar was susceptible to oviposition by SLW and induction of TIR symptoms. However, TIR symptom expression differed among the cultivars. Despite higher ethylene levels, the ripening process in the SLW-infested fruit appeared slower or may have been inhibited by factors induced by the SLW compared with the control fruit, which ripened normally.
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Plant Growth Regulators (GA3 and CCC) and Silverleaf Whitefly Effects on the Induction of Tomato Irregular Ripening in Dwarf Cherry Tomato
HortScience, 1997Co-Authors: S. Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:External and internal tomato irregular ripening (TIR) symptoms have been associated with the feeding of Silverleaf Whitefly (SLW), Bemisia argentifolii Bellows and Perring. Soil drench application of gibberellic acid (GA3) (100 ppm, Trial 1 and 2) and cycocel (CCC) (2000 ppm, Trial 1; 1000 ppm, Trial 2) were applied to dwarf cherry tomato (Lycopersicon esculentum) in the presence and absence of SLW to mimic the TIR disorder induced by the SLW. Application of GA3 induced external and internal TIR symptoms similar to the SLW-induced disorder in `Florida Petite'. There were essentially no TIR symptoms in fruit treated with CCC, an inhibitor of GA biosynthesis. In Trial 1, internal white tissue in GA3, SLW, and CCC treatments was expressed in 97%, 95%, and 4% of the total fruit, respectively. Incidence of external TIR symptom was highest (56%) in the GA3 plus SLW treatment. In Trial 2, GA3 application in the presence (83%) or absence (85%) of SLW resulted in the highest incidence of fruit with internal white tissue. External TIR symptoms induced by GA3 in the presence and absence of SLW were reduced with CCC application. These results suggest that the TIR disorder in tomato is induced by the SLW may be a GA3-regulated disorder.
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Possible Involvement of Altered Gibberellin Metabolism in the Induction of Tomato Irregular Ripening in Dwarf Cherry Tomato by Silverleaf Whitefly
Journal of Plant Growth Regulation, 1997Co-Authors: S. Hanif-khan, Charles A Powell, Heather J. Mcauslane, Peter J. Stoffella, Jeffrey K. Brecht, Robert C. Bullock, R. YokomiAbstract:External and internal tomato irregular ripening (TIR) symptoms were associated with the feeding of Silverleaf Whitefly (SLW), Bemisia argentifolii Bellows and Perring. Four experiments consisting of various soil drench applications of GA3 (100 ppm) and cycocel (CCC, an inhibitor of GA biosynthesis; 1,000 and 2,000 ppm) were applied to dwarf cherry tomato cv. Florida Petite in the presence and absence of SLW in an attempt to mimic the disorders induced by the SLW. The application of GA3 induced external and internal TIR symptoms similar to the SLW-induced disorder. Minimal TIR-like symptoms also occurred in the control and CCC treatments. Internal TIR symptoms in GA3, GA3 plus SLW, and GA3 plus CCC treatments ranged from 66% to 97% throughout the experiments. The incidence of external TIR symptoms was highest in the GA3 plus SLW treatment compared with the other treatments. CCC reduced the incidence of external TIR symptoms induced by GA3 or GA3 plus SLW treatments. However, CCC-treated plants also attracted more oviposition and higher populations of SLW and consequently induced a greater incidence of TIR symptoms than SLW treatment alone. Furthermore, although low SLW populations may be associated with low external TIR symptoms, internal TIR symptoms almost always remained high in infested plants. The results suggest that the TIR disorder in dwarf cherry tomato which is induced by the SLW may be a gibberellin-regulated disorder.