PHYSIOLOGICAL CHANGES DURING MATURATION OF NEW MEXICAN-TYPE PEPPERS

New Mexican chile peppers were harvested at weekly intervals beginning 105 days after planting (DAP), and evaluated for ethylene (C2H4) production, respiration rates, chlorophyll content, beta-galactosidase activity, polygalacturonase (PG) activity, and fruit firmness. Physiological changes were most apparent in peppers harvested 139-154 DAP. Beta-galactosidase activity increased rapidly beginning 147 DAP, and reached a peak of 24.5 mmol·gfw-1 when peppers were harvested 160 DAP. Polygalacturonase was not detectable at any stage of maturation. Fruit firmness was greatest (35.8 N) at 139 DAP and decreased significantly at 160 DAP. Carbon dioxide production and chlorophyll content were highest in young pods harvested 105 DAP, and decreased steadily thereafter. Ethylene production peaked (0.185-0.202 nl·gfw-1·h-1) in peppers harvested between 146-154 DAP.

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Morphological and Physiological Changes during Maturation of New Mexican Type Peppers

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.4.476 ◽

1993 ◽

Vol 118 (4) ◽

pp. 476-480 ◽

Cited By ~ 19

Author(s):

Charles Lee Biles ◽

Marisa M. Wall ◽

Kevin Blackstone

Keyword(s):

Chlorophyll Content ◽

Developmental Stages ◽

Color Change ◽

Carbon Dioxide Production ◽

Fruit Firmness ◽

Physiological Changes ◽

New Mexican ◽

Pepper Fruit ◽

Chile Peppers ◽

Two Peaks

New Mexican Chile peppers (Capsicum annuum L. `New Mexico 6-4') were harvested at weekly intervals beginning 20 days after flowering (DAF), and were evaluated for ethylene (C2 H4) production, respiration rates, chlorophyll content, degradative enzyme activity (cellulase, polygalacturonase, ß-galactosidase), and fruit firmness. Morphological and physiological changes were most apparent in peppers harvested 54 to 69 DAF. ß-galactosidase activity increased rapidly beginning 54 DAF and reached a peak by 89 DAF. Fruit firmness was highest (36 newtons) at 54 DAF and had decreased significantly by 69 DAF. Carbon dioxide production and chlorophyll content were highest in young pods harvested 20 DAF and decreased steadily thereafter. A climacteric increase of CO, was absent. There were two peaks in C2 H4 production: one associated with rapid fruit growth and the other with color change (61 to 69 DAF). Fruit harvested on the same day but at different developmental stages (green to red) were similar to those observed in fruit harvested over the season for the physiological characteristics tested. Separation of pepper fruit soluble proteins on SDS-PAGE demonstrated increased intensity in protein bands at 27, 35, and 40 kDa and decreased intensity of 51 kDa band as the fruit matured. Several biochemical processes appeared to be enhanced in Chile pepper fruit from 47 to 69 DAF.

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Landscape heterogeneity influences carbon dioxide production in a young boreal reservoir

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2011-174 ◽

2012 ◽

Vol 69 (3) ◽

pp. 447-456 ◽

Cited By ~ 6

Author(s):

Soren M. Brothers ◽

Paul A. del Giorgio ◽

Cristian R. Teodoru ◽

Yves T. Prairie

Keyword(s):

Carbon Dioxide ◽

Water Column ◽

Landscape Heterogeneity ◽

Carbon Dioxide Production ◽

Respiration Rates ◽

Benthic Respiration ◽

Sediment Respiration ◽

Rate Of Decline ◽

The Individual ◽

Water Column Respiration

Surface carbon dioxide (CO2) emissions exhibit a high degree of spatial heterogeneity in the young boreal Eastmain-1 hydroelectric reservoir, located in northern Quebec, Canada. Estimates of the individual components of net CO2 production within the reservoir (benthic respiration, water column respiration, and primary production) furthermore provide a link between the heterogeneity in surface CO2 emissions and the flooded landscapes below. Specifically, the preflood carbon stock and soil–sediment respiration rates of flooded landscapes were found to influence benthic CO2 production, the rate of decline of hypolimnetic dissolved organic carbon (DOC), and the estimated rate at which flooded landscapes release DOC, further influencing water column respiration rates. Estimates of the individual components of net CO2 production in Eastmain-1 are supported by a positive relationship (t test, r2 = 0.64, P < 0.01) between measured surface CO2 emissions (mean ± SE = 1540 ± 145.4 mg C·m–2·day–1) and independently derived estimates of total net CO2 production (mean ± SE = 1230 ± 162.4 mg C·m–2·day–1). Our findings emphasize the utility of fundamental landscape characterization prior to construction in predicting reservoir greenhouse gas emissions.

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Thermoregulatory, metabolic, and cardiovascular response of rats to microwaves

Journal of Applied Physiology ◽

10.1152/jappl.1975.38.4.630 ◽

1975 ◽

Vol 38 (4) ◽

pp. 630-635 ◽

Cited By ~ 48

Author(s):

R. D. Phillips ◽

E. L. Hunt ◽

R. D. Castro ◽

N. W. King

Keyword(s):

Carbon Dioxide ◽

Heart Block ◽

Cardiovascular Response ◽

Absorbed Dose ◽

Carbon Dioxide Production ◽

Physiological Changes ◽

Dose Rates ◽

Colonic Temperature ◽

Skin Temperatures ◽

Exposure Measurements

This study was undertaken to determine the effects of 2,450-MHz microwave irradiation on thermoregulation, metabolism, and cardiovascular function of rats. Young adult male animals (430 g) were exposed for 30 min to 2,450-MHz microwaves in a cavity at absorbed dose rates of 0, 4.5, 6.5, or 11.1 mW/G. For animals of the size used in this study, these dose rates represent absorption of energy at the rate of 27.7, 40.1, and 68.2 cal/min, respectively. For a period of 5 h following exposure, measurements were made of colonic temperature, skin temperature, oxygen consumption, carbon dioxide production, respiratory quotient, and heart rate. Rats that received 27.7 cal/min for 30 min exhibited an initial transient increase in colonic and skin temperatures but no alterations in other functions. The group irradiated at 40.1 cal/min had greater elevations in colonic and skin temperatures immediately after exposure, followed by overcompensation and lower than normal colonic temperatures for about 3 h. The metabolic rate was depressed in this group for 3 h. Bradycardia developed within 20 min after exposure and persisted for about 3 h. The group of rats that received 68.2 cal/min for 30 min had responses similar to those of the 40.1 cal/min group, but the changes were more severe and lasted longer. In addition, a number of transient abnormalities were noted in the ECG tracings of rats that had received the highest dose, including irregular rhythms and incomplete heart block. The physiological changes observed in this study can be attributed to the heating induced by irradiation.

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Ethylene and Carbon Dioxide Production in Detached Fruit of Selected Pepper Cultivars

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.124.4.402 ◽

1999 ◽

Vol 124 (4) ◽

pp. 402-406 ◽

Cited By ~ 26

Author(s):

Lucia Villavicencio ◽

Sylvia M. Blankenship ◽

Douglas C. Sanders ◽

William H. Swallow

Keyword(s):

Carbon Dioxide ◽

Ethylene Production ◽

Carbon Dioxide Production ◽

King Arthur ◽

Ethylene Evolution ◽

Green Fruit ◽

Respiration Rates ◽

Maturity Stages ◽

Hot Peppers ◽

Bell Peppers

Bell peppers (Capsicum annuum L.) are classified as nonclimacteric fruits while some hot peppers have been reported as climacteric. Responses of peppers to exogenously applied ethylene-releasing compounds suggest ethylene involvement in the ripening process. Ethylene production and respiration rates in 13 cultivars of pepper: `Camelot', `Cherry Bomb', `Chiltepin', `Cubanelle', `Banana Supreme', `Habanero', `Hungarian Wax', `Mesilla', `Mitla', `Savory', `Sure Fire', `Tabasco', and `King Arthur' were studied under greenhouse and field conditions. Fruit from each cultivar were harvested at different maturity stages determined by color, ranging from mature-green to full red-ripe. Carbon dioxide and ethylene production were measured by gas chromatography. Both variables were significantly different among maturity stages for all cultivars. Respiration rates were between 16.5 and 440.3 mg·kg-1·h-1 CO2. Ethylene production ranged from 0.002 to 1.1 μL·kg-1·h-1. Two patterns of CO2 production were identified: higher CO2 production for mature-green fruit with successive decreases for the rest of the maturity stages or lower respiration rates for mature-green fruit with an increase in CO2 production either when fruit were changing color or once fruit were almost totally red. A rise in CO2 production was present for most cultivars. Ethylene evolution increased significantly at maturity or before maturity in all cultivars except `Cubanelle' and `Hungarian Wax'. Respiration rates and ethylene production were significantly different among cultivars at the mature-green and red stages.

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