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through the plastic mulch for transplanting after 14 d of methyl bromide applied as the MC33 treatment. Bell pepper ( Capsicum annuum , cv. Cascade) seedlings were transplanted between October and November in two rows per bed separated by 40 cm with an in
Accessions of Capsicum annuum L., a susceptible host, and C. pubescens (R. & P.), a resistant host, were grown in a replicated greenhouse study to test whether antixenosis (nonpreference), antibiosis, or both was the mechanism for resistance to green peach aphid [Myzus persicae (Sulzer)]. A plant choice experiment established that aphids preferred C. annuum to C. pubescens. A no-plant choice test was not undertaken; nevertheless, the aphid's reproductive rates were measured in leaf containment cages and were similar on both hosts. The mechanism of antibiosis was not indicated because fecundity was not reduced in the containment cages; however, other measures of antibiosis were not studied. These observations suggest that antixenosis may be functioning in C. pubescens.
To test the effectiveness of different bioregulators in enhancing bell pepper (Capsicum annuum L.) yield and fruit quality, the commercial bioregulators CCC, NAA, GA3, and Biozyme® were sprayed on plants at flower initiation, followed by two additional applications at 30-day intervals. Biozyme produced a significant increase in total yield but ≈40% of the fruit were not marketable. Treatment with NAA produced the highest yield of marketable fruit. Treatments did not affect fruit firmness compared to the control. Gibberellic acid increased fruit ascorbic acid and citric acid concentrations and Biozyme, GA3, and CCC increased fruit soluble solids content. Biozyme treatment increased fruit fructose, sucrose, carotenoid, and lycopene concentration. Treatments had no effect on fruit calcium concentration or pH. Chemical names used: chlormequat chloride (CCC); naphthaleneacetic acid (NAA), gibberellic acid (GA3); GA3 + IAA (indoIe-3-acetic acid) + zeatine + micronutrients (Biozyme®).
Anthers from more than 17000 flowers of 19 bell pepper Capsicum annuum L. hybrids (provided by `Semillas Fitó S.A.') were cultured in a double layer modified H medium (Nitsch and Nitsch, 1969) supplemented with 0.5 % activated charcoal and 0.26 % Gelrite in the solid phase. Significant differences between genotypes were observed on embryogenesis (472.3 to 9.7 embryos / 100 flowers) and number of plants rescued (4.0 to 0.3 plants / 100 flowers). Trying out maltose, malt extract, and sucrose. as carbohydrates, at 20, 40, 60 or 80 g/l, gave significantly better results for maltose (20 or 40 g/l). In addition, maintaining the anther cultures in an atmosphere enriched with 600 ppm CO2 was beneficial for embryo number, embryo development and number of rescued plants. Isocitrate dehydrogenase zymograms from leaf extracts indicate the microspore origin of the acclimated plants. Flow citometry of nuclei was used to determined an early diploidization of 70 % of the acclimated plants.
Research at Padova Univ., Italy, during Summer 2003, was carried out to determine the effect on nitrogen fertilization on yield and canopy reflectance of sweet bell pepper (Capsicum annuum). Pepper var. Tolomeo LRP 4993 (Syngenta) was transplanted into plots (24 m2) on 20 May, maintaining 40 cm between plants and 75 cm between rows (3.3 plant per m2). The experimental design was a randomized block with four replicates. Treatments were 6 nitrogen fertilization rates ranging from 0 to 300 kg·ha-1. Nitrogen was distributed at planting and as top dressing, 44 days after planting. All other production techniques were typical of pepper production in the Veneto region. Beginning the second week after transplanting, canopy reflectance was measured weekly using a multispectral radiometer MSR 87 (Cropscan Rochester, Minn.). Fruits were harvested at breaking color stage starting from 21 July to 9 Oct. (8 harvests). At harvest, total and marketable yield, fruit averaged weight and nitrogen content were determined. Maximum yield was recorded at the 120 kg·ha-1 nitrogen treatment, while higher rates proved ineffective at increasing production. Nitrogen rates positively affected fruit weight. The nitrate content of fruits also increased with the nitrogen rates although it remained below the level dangerous for human health. Canopy reflectance was able to detect the different nitrogen treatments only during the late stages of the growth cycle making difficult its use as a tool to drive nitrogen fertilization.
Three commercial planting media (Sunshine Mix#1, Sunshine Mix#5, and Metro Mix 360) were compared with the standard soil mixture prepared at New Mexico State Univ. for their effectiveness in differentiating Verticillium wilt—resistant and susceptible accessions of chile (Capsicum annuum L.) Each medium was infested with Verticillium dahliae Kleb. microsclerotia and planted with the resistant and susceptible accessions. When susceptible populations exhibited severe symptoms, individual plants were rated for disease severity (1 = no symptoms to 9 = death). Mean disease severities of populations differed among planting media, and, regardless of medium, resistant and susceptible populations were readily differentiated. Mean disease severities of plants grown in Sunshine Mix #1 and Sunshine Mix #5 differed from those grown in the standard University soil mix, but all media provided reliable screening tests. Mean disease severities of plants grown in Metro Mix 360 were most similar to those of plants grown in the University mix. Furthermore, greater differentiation was apparent between resistant and susceptible accessions in Metro Mix 360 than in accessions grown in the University medium.
Adventitious shoots and viable plants were regenerated from bell pepper (Capsicum annuum L.) cultivars and dihaploid lines (DHLs) obtained from F1 hybrids via androgenesis (Dolcet-Sanjuan et al., in press). Hypocotil and cotyledon sections from in vitro-germinated seeds were used as explants. A modified MS medium (Murashige and Skoog, 1962) supplemented with IAA (0 to 3.2 μM) and BAP (0 to 100 μM) was used in a 3-week-long shoot primordia induction phase. Shoot elongation was best performed in the same basal medium, but supplemented with silver thiosulfate and GA3. Shoots were regenerated from eight selected DHLs (`C213', `C215', `C218', `C2123', `C2125', `C3111', `C3113', and `P493') and two cultivars (`Padrón' and `Yolo Wonder'). The percentage of cotyledon sections with shoot primordia after the induction phase was not genotype-dependent and always higher than with hypocotil sections (93.4% and 17.9%, respectively). The number of shoot primordia per responsive cotyledon section was also higher than with hypocotil sections (3.3 and 1.7, respectively). The genotype had a significant effect on the number of shoots regenerated per responsive cotyledon (1.1 to 5.5) or hypocotil (0.5 to 3.5) section. All adventitiously regenerated plants were fertile. This adventitious shoot regeneration protocol is being used to obtain transgenic plants from sweet bell pepper genotypes.
Reduction of floral number in Capsicum annuum has been observed during growth at high temperature. To determine whether decreased flower production or increased flower abscission is a direct response to high temperatures or a response to water stress induced by high temperatures, we compared flowers and fruit produced and flowers aborted to leaf growth rate, osmotic potential, stomatal conductance, and chlorophyll fluorescence of two cultivars. To determine the stage(s) of floral development that are most sensitive to high temperatures, flower buds were wax-embedded and examined at each stage of development during heat treatment. Rate of floral development also was examined. At first visible floral bud initiation, plants were transferred to each of three controlled environment growth chambers with set temperatures and vapor pressure deficits (VPD) of 25°C, 1.1 kPa; 33°C, 1.1 kPa; and 33°C, 2.1 kPa. Flower bud production and leaf growth rate were not significantly affected by high temperatures. Pepper fruit set, however, was inhibited at 33°C at either VPD. Preliminary water relations data suggested that water potentials were more negative under high temperature conditions. Differences in leaf fluorescence were statistically significant for temperature treatments, but not for VPD. Temperature is the primary factor in the decrease of fruit production in pepper. Decreased production is due to flower abortion and not to decreased flower initiation or plant growth.
Abstract
Bighart, an improved Pimiento pepper (Capsicum annuum L.) variety (Fig. 1), was developed at the Agricultural Experiment Station, Auburn University, Auburn, Alabama, and released to the Associated Pimiento Canners in February 1969. Bighart averaged 74% more yield than the commercial Truhart variety in 2 years’ trials at the North Alabama Horticulture Substation, Cullman, Alabama. Bighart fruits were 37% heavier, had 13% thicker walls and gave a 10% higher recovery of canned product than those of Truhart. In addition, the concentrated fruit set and fruit maturity of Bighart promises suitability for machine harvest.
Germplasm release 509-45-1 is a small-fruited Capsicum annuum L. pepper released in 2013 by the Agricultural Research Service (ARS) of the U.S. Department of Agriculture (USDA). Fruit of 509-45-1 contain high concentrations of capsiate [(4-hydroxy