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Abstract

A procedure for carotenoid analysis which has practical application to genetic and breeding research is outlined. It includes extraction, separation of total carotenoids by partition on a silica column into carotene and xanthophylls, and the separation of the carotene fraction into specific pigments using thin-layer chromatography. The relative concn of specific pigments in the carotene fraction was measured using a semi-quantitative technique: Four genetic lines of carrot and four tomato cultivars were analyzed. Wide differences between carrot lines were detected in total carotenoids and the relative concn of the various pigments. The tomato cultivars differed considerably in total carotenoids. The ratios of pigments (pigment pattern) of red tomato were almost identical to that of the red carrot cultivar, Kintoki.

Open Access

Tomatoes have been associated with numerous outbreaks of salmonellosis in recent years. Trace-backs suggest tomato fruits may become contaminated during preharvest. The objective of this study was to determine the potential for Salmonella enterica serotype Newport to be internalized into the roots, stems, leaves, and fruit of red round tomato plants through contaminated irrigation water at various stages of plant development. Tomato plants were irrigated with 250 or 350 mL (depending on growth stage) of 7 log CFU·mL−1 S. Newport-contaminated irrigation water every 7 days. Roots, stems, leaves, and two tomato fruit from plants irrigated with S. Newport or water (negative control) were sampled for contamination at five stages of growth. Twenty-five of the 92 total samples taken from plants irrigated with S. Newport were confirmed positive (serovar specificity was not evaluated). Sixty-five percent of confirmed samples were roots, 40% were stems, 10% were leaves, and 6% were fruit. There was a significant difference in the presence of S. enterica according to tissue sampled (roots > stems > leaves, and fruit) (P < 0.05) and no association between growth stage and contamination (P > 0.05). Contamination of tomato fruit with S. Newport introduced through irrigation water is low because a high level of persistent contamination of a plant in the agricultural setting is unlikely.

Free access

accession LA1777 was highly resistant to B. tabaci , resulting in fewer numbers of immature life-stages per unit area of leaflet relative to S. lycopersicum ( Muigai et al., 2003 ). The whitefly resistance in S. habrochaites was related to naturally

Free access

greenhouses in northern China Nutr. Cycl. Agroecosyst. 94 63 72 He, F.F. Chen, Q. Jiang, R.F. Chen, X.P. 2007 Yield and nitrogen balance of greenhouse tomato ( Lycopersicum esculentum Mill.) with conventional and site-specific nitrogen management in northern

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Abstract

‘Earlirouge’ tomato (Lycopersicum esculentum Mill.) was developed to replace ‘Starfire’, the common cultivar grown in eastern Ontario, Canada, in the 1960s. It was named for its earliness and bright red color of the fruit. It is now grown for the handpick fresh market tomato in Ontario and Quebec provinces of Canada and northeastern United States.

Open Access

Abstract

‘Quinte’ (ST-19) is a midseason, large, firm, crimson-colored tomato (Lycopersicum esculentum Mill.). It was developed in the early 1970s to replace ‘Moira’. Named after the Bay of Qunite, it is now extensively grown in eastern Ontario, Canada, and the northeastern United States, especially in areas where Verticillium wilt (Verticillium alboatrum Reinke & Berth, and V. dahliae Kleb.) is a problem. The fruit is suitable to the fresh-market and processed-juice industries.

Open Access

Abstract

‘Bellestar’ (ST-50) is a tomato (Lycopersicum esculentum Mill.) developed for the sandy loam to clay loam soils (pH 6.0 to 7.5) of the cool regions of eastern Ontario. The cultivar satisifies the need for an early hand harvest, processing tomato with a concentrated maturity. It also can be used for the fresh market as a pick-your-own pastetype tomato. Commercial growers in the northeastern United States have received this cultivar quite well and used it in a limited planting in 1983.

Open Access

`Solar Fire' is a heat-tolerant hybrid tomato (Solanum lycopersicum L. formerly Lycopersicon esculentum Mill.) with resistance to all three races of Fusarium wilt incited by Fusarium oxysporum f. sp. lycopersici Sacc. Snyder & Hansen. It has superior fruit-setting ability in comparison with most existing cultivars under high temperatures (>32 °C day/>21 °C night), and the fruit crack less under the rainy field conditions often present in the early fall Florida production season. Fla. 7776 is the pollen parent in `Solar Fire', providing much of the heat tolerance in this hybrid. It has large fruit-providing breeders with a parent to produce heat-tolerant hybrids with two heat-tolerant parents.

Free access

Late blight [caused by Phytophthora infestans (Mont.) de Bary] causes severe loss of tomato [Solanum lycopersicum L. (formerly Lycopersicon esculentum Mill.)] production in environments favorable to the pathogen. Researchers at the Asia Vegetable Research Development Center (AVRDC) identified resistance to late blight in an accession of S. pimpinellifolium [formerly L. pimpinellifolium (L.) Mill.] that they named accession L3708. This resistance has now been transferred to processing tomato lines, which are resistant to multiple P. infestans isolates. Lab trials, inoculated field trials in New York, and naturally infested field trials in Mexico all indicate that these processing tomato lines are fixed for late blight resistance. Segregation data obtained for resistance in the breeding populations were dependent on the pathogen isolate used for the disease screen. Segregation data do not support the hypothesis of single gene control of the full resistance trait, but instead suggest that more than one gene is involved, and that these genes interact in an epistatic manner.

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Abstract

The leaf homogenate (LH) most toxic in soil to Pratylenchus penetrans (Cobb) Chitwood & Oteifa was of white pine (Pinus strobus L.). Other toxic LH were of dogwood (Cornus florida L.), red oak (Quercus borealis Michx. f. maxima (Marsh) Ashe, tobacco (Nicotiana tabacum L.), sunflower (Helianthus annuus L.), pachysandra (Pachysandra terminalis Sreb. & Zucc.), tomato (Lycopersicum esculentum Mill.), geranium (Geranium maculatum L.) and bluegrass (Poa pratensis L.). Sodium nitrate at 100 mg/kg of soil increased the toxicity of new pine needles and new oak leaves. Some LH were toxic in water but not in soil. Acetone powders of some tree leaves were toxic. Some products of decay or organic matter or closely related and easily available compounds were toxic to another nematode, Tylenchorhynchus dubius (Bütschl:) or stylet nematode.

Open Access