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Cucurbit leaf crumple geminivirus (CuLCrV) is transmitted by sweet-potato whitefly (Bemisia tabaci) biotype B (SPWF-B) and occurs on cucurbits in Arizona, California, Texas, and Mexico. This virus is identical to Cucurbit leaf curl virus, and their symptoms are similar to Squash leaf curl virus on squash (Cucurbita sp.) and Melonleaf curl virus on melon (Cucumis melo L.). Melon has been reported to be either susceptible to CuLCrV, or to have the ability to recover from infection. Twenty-three melon cultigens were inoculated with CuLCrV in greenhouse tests using SPWF-B. Eighteen of the cultigens tested were highly susceptible to CuLCrV (≥60% infected plants) and generally exhibited pronounced CuLCrV symptoms: `Amarillo', `Edisto 47', `Esteem', `Fuyu 3', `Impac', `Moscatel Grande', `Negro', `Perlita', PI 234607, PI 236355, PI 414723, `PMR 5', `Seminole', `Sol Dorado', `Sol Real', `Top Mark', `Vedrantais', and WMR 29. Five cultigens were resistant to CuLCrV (<40% infected plants that exhibited restricted, mild symptoms): MR-1, PI 124111, PI 124112, PI 179901, and PI 313970. Symptoms abated with time in both groups although infected plants remained positive for the virus. Ten of the cultigens (`Edisto 47', `Fuyu 3', `Impac', MR-1, PI 124112, PI 313970, PI 414723, `PMR 5', `Top Mark', and WMR 29) were included in field tests in 2003 and 2004 that were naturally infected with CuLCrV. With the exception of PI 414723, the greenhouse and field data were consistent for reaction to CuLCrV.

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Pansy cultivars were evaluated for number of days to flower, flower size, flower color, plant habit, plant dimensions, weather tolerance, floriferousness, uniformity, and overall appearance during the winters of 1994–95 and 1995–96. In 1994–95, the number of days from sowing of seed to first flower among 122 cultigens ranged from 68 days for `Allegro Beaconsfield' to 94 days for `Springtime New Red'. Flower diameter ranged from 4.1 cm for `Allegro Pure Yellow' to 6.5 cm for `Bingo Yellow with Blotch'. Plant height after 114 to 122 days from seed sowing ranged from 11.4 cm for `Allegro Pure Orange' to 19.7 cm for `Fama See-Me'. Subjective ratings showed few differences among the cultigens in plant uniformity and floriferousness, but differences with respect to overall appearance. In 1995–96, the number of days from seed sowing to first flower for 113 cultigens ranged from 75 days for `Rally Light Blue with Blotch' to 97 days for `Happy Face White'. Flower diameter ranged from 4.8 cm for `Sprite Beaconsfield' and `Sprite Yellow' to 7.5 cm for `Bingo Yellow with Blotch'. Plant height at 140 to 143 days after seed sowing ranged from 12.4 cm for `Maxim Chiffon' to 26.5 cm for `Universal Plus White'. Subjective ratings showed no differences among the cultigens in plant uniformity or overall appearance and few differences in floriferousness or flower display.

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Significant loss in yield of cucumber (Cucumis sativus L.) due to fruit rotting caused by Rhizoctonia solani (Kuhn) is frequently observed in the Southeastern United States. Chemical controls are costly and provide only partial control. Currently there are no resistant cultivars. The objective of this study was to identify potential sources of resistance and develop efficient screening methods for use in a breeding program. In the summer of 1991, 105 cucumber cultigens representing a range from resistant to susceptible were grown in Clinton, NC. Those cultigens were screened using field and detached fruit methods. Resistant cultigens chosen for further study were PI 165509, PI 197086 and PI 197088, with 2 to 4 % of the fruit surface damaged. Susceptible cultigens were PI 419108, PI 178886 and PI 432855, with 13 to 16 % of the fruit surface damaged. Five methods were then evaluated on greenhouse grown cucumber seedlings to identify an efficient screening method. The methods evaluated were a soil drench, a leaf dip using a mycelium suspension, syringe inoculation, and potato dextrose agar disks of R. solani placed on the third true leaf or against the hypocotyl at the soil line.

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Within a program determining the response of melon plants when grown at suboptimal cold temperatures, fruit quality was examined in 20 cultigens grown under two temperature regimes. The cultigens included open pollinated and hybrid cantaloupes and honey dews. The two temperature regimes were: (i) heated greenhouse, at minimum and maximum temperatures close to commercial cultivation requirements, and (ii) unheated greenhouse, at a temperature 7-8°C lower than the former, representing a major cold stress. The parameters examined included fruit appearance and marketability (weight, size, netting) as well as fruit constituents (sucrose, glucose, reducing sugars, TSS, pH, EC, titratable acidity). Cold stress was found to improve some parameters, but impair others. The low temperatures significantly reduced fruit weight and size, but increased fruit number per plant, sucrose and TSS in most but not all cultigens. Significant interaction was found between the temperature regimes and cultigens in these parameters. The results strongly indicate that genetic variation exists in melons for response to low temperature, and therefore that potential for breeding melons for cold stress is present.

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Thirty-seven species within Cucurbitaceae representing the genera Citrullus, Cucumis, Cucurbita, Lagenaria, and Luffa were evaluated for disease reaction to an Acremonium cucurbitacearum A. Alfaro-Garcia, W. Gams, and Garcia-Jimenez, isolate (TX 941022) from the Lower Rio Grande Valley of Texas. After 28 days in the greenhouse, seedling disease ratings were made on the hypocotyl, stem-root junction, primary root, and secondary roots. An additional disease measure was derived by averaging the four root disease ratings to establish a disease severity index (DSI). Vine and root dry weight were poor measures of plant damage caused by A. cucurbitacearum. According to the DSI, all species within Cucurbita, Lagenaria, Luffa, and three Cucumis sativus L. cultigens were rated as highly resistant to A. cucurbitacearum. Cucumis melo L. and Citrullus lanatus (Thunb.) Matsum. & Nakai cultigens were the only cucurbits receiving DSI ratings of moderately resistant to susceptible.

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Three randomly amplified polymorphic DNA (RAPD) markers (E07, G17, and 596) linked to the Fom-2 gene, which confers resistance to race 0 and 1 of Fusarium oxysporum f. sp. melonis, were evaluated by RAPD-polymerase chain reaction for their linkage to Fusarium wilt resistance/susceptibility in diverse melon cultigens (48 resistant, 41 susceptible). Primer 596 was identified in the multiple disease-resistant breeding line MR-1, whereas E07 and G17 were identified in the susceptible `Vedrantais'. The RAPD markers E07 (1.25 kb) and G17 (1.05 kb) correctly matched phenotypes in 88% and 81% of the cultigens. The validity of the RAPD scores was verified by Southern hybridization analysis for sequence homology and bulked segregant analysis of a selected cross population for the linkage. These results will facilitate the introgression of resistance genes into susceptible lines from multiple sources in marker-assisted selection.

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Various species and cultivars of citrus were studied to determine the relationship between texture and cell wall polysaccharide content of fruit flesh. Among those tested cultivars, navel orange (Citrus sinensis Osbeck) and hassaku (C. hassaku Hort. ex Tanaka) were firmest, `Fukuhara orange' (C. sinensis Osbeck) was intermediate, and satsuma mandarin (C. unshiu Marc.) was softest. There was a 3-fold difference in firmness among the 12 citrus cultigens measured. Cohesiveness values ranged from 0.30 to 0.49 and were not correlated with fruit firmness. Sugar content in each cell wall fraction was highest in the water and EDTA fractions, followed by the hemicellulose fraction, and was lowest in the cellulose fraction. Correlation coefficients between firmness and sugar content ranged from 0.69 to 0.88 and were highest in the cellulose fraction. This study suggests that firmness of fruit flesh among the cultigens is influenced by cell wall polysaccharide composition. Chemical name used: ethylenediaminetetraacetic acid (EDTA).

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Twenty-six muscadine cultigens were evaluated for fruit size, color, soluble solids, and other horticultural characteristics pertaining to fresh market use. Seventeen cultigens were evaluated for 7 years and 9 were evaluated for 2 years. Entries with the largest fruit size were `Granny Vale', `GA 33-1-4', `Sweet Jenny', and `Black Fry' with fruit weights averaging over 10.5 grams each. `Summit', `GA 33-1-4' `Sweet Jenny', `Fry', `Dixieland', and `GA 9-4-1' were consistently over 17% soluble solids during the years of this study. The yield per vine was highest on `Watergate', `Carlos', `Summit', `Higgins', and `Redgate'. The highest average yield was 30.0 kg per vine on `Watergate'. Recently released cultivars `Black Fry', `Black Beauty', and `Granny Vale' exhibited extremely good characteristics for the fresh market industry.

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Genetic control of cuticle cracking (CC) in tomatoes (Lycopersicon esculentum Mill.) was studied using half-diallel analyses and reciprocal hybrid comparisons of five parents and reciprocal F1 hybrids over 3 years in Bradenton, Fla. Maternal effects were usually not significant, but in general, CC incidence in hybrids with a resistant cultigen as the female parent was lower than if the resistant cultigen was the male parent. General combining ability (GCA) was significant at all harvests, with specific combining ability (SCA) becoming significant under high environmental stress. Narrow-sense and broad-sense heritabilities for CC incidence ranged from 0.45 to 0.69 and 0.62 to 0.89, respectively, increasing directly with environmental stress.

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Demand for triploid watermelons has outpaced the demand for diploid watermelons in the United States in recent years. The size of most triploid watermelons sold in U.S. markets is from 6 to 9 kg. Recently, a new produce item, seedless watermelons weighing about 1.8 to 3.6 kg, have been introduced and created excitement in the produce industry. Several vegetable seed companies have developed proprietary miniwatermelon hybrids. Syngenta Seeds and Seminis Vegetable Seeds have received the most publicity, with the PureHeart and Bambino brands being featured in the 15 June 2003 New York Times. The 2003 season was the first year that cultigens (cultivars and advanced lines) were generally available. At least four trials were conducted in the southeastern United States to evaluate yields and quality of mini-watermelons; Bradenton, Fla., Ediston, S.C., Charleston, S.C., and Kinston, N.C. Cultural practices and the number of cultigens varied among locations (9 to 17). Fruit less than 3.6 kg that yielded best in all locations were `Petite Perfection' (Syngenta) and RWT 8149 (Syngenta). Other cultigens that yielded well in at least one location were; `Precious Petite' (Syngenta), `Vanessa' (Sunseeds), ZG 8905 (Zeraim Gedera), SR 8103 WM (Sunseeds), SW 8002 (Southwestern), and HA 5130 (Hazera). Rind thickness varied from 6 to 25 mm and soluble solids ranged from 10 to 13%, depending on location and cultigen. New cultivars will be made available in 2004. Key characteristics that seem important to overall success in the market of the triploid miniwatermelon is consistent quality. This includes high yields of uniform sized fruit from about 1.6 to 3.8 kg; high soluble sugars (11% to 13%); and fruit with bright red, crisp flesh with a thin rind that endures shipping.

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