Low levels of ozone increase bean leaf maintenance respiration

1988 ◽  
Vol 66 (4) ◽  
pp. 724-726 ◽  
Author(s):  
Jeffrey S. Amthor ◽  
Jonathan R. Cumming
Keyword(s):  
Phaseolus Vulgaris ◽  
Dark Respiration ◽  
Relative Increase ◽  
Maintenance Respiration ◽  
Metabolic Intermediates ◽  
Pinto Bean ◽  
Growth Respiration ◽  
Low Levels ◽  
Growth Respiration Coefficient ◽  
Maintenance Respiration Coefficient

Pinto bean (Phaseolus vulgaris) plants were exposed to charcoal-filtered air with or without added low levels of ozone (90 nL∙L−1). Dark respiration (CO2 efflux) by expanding primary leaves of the plants was measured and mathematically partitioned into growth and maintenance components. The growth respiration coefficient was unaffected by ozone, whereas the maintenance respiration coefficient increased 15%. Such a relative increase in maintenance respiration results in a diversion of energy and metabolic intermediates from growth processes.

scholarly journals Respiratory Q10 of Lettuce Increases with Increasing Plant Size

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 854D-855
Author(s):  
Marc W. van Iersel*
Keyword(s):  
Growth Rate ◽  
Exchange Rate ◽  
Plant Growth ◽  
Plant Size ◽  
Maintenance Respiration ◽  
Relative Growth ◽  
Growth Respiration ◽  
Increasing Temperature ◽  
Growth Respiration Coefficient ◽  
Maintenance Respiration Coefficient

Literature reports on the Q10 for respiration vary widely, both within and among species. Plant size and metabolic activity may be responsible for some of this variation. To test this, respiration of whole lettuce plants was measured at temperatures ranging from 6 to 31 °C during a 24-h period. Subsequently, plant growth rate (in moles of carbon per day) was determined by measuring the CO2 exchange rate of the same plants during a 24-h period. Environmental conditions during this 24-h period resembled those that the plants were exposed to in the greenhouse. The measured growth rate was then used to estimate the relative growth rate (RGR) of the plants. The respiratory Q10 ranged from 1.4 for small plants to 1.75 for large plants. The increase in Q10 with increasing plant size was highly significant, as was the decrease in Q10 with increasing RGR. However, growth rate had little or no effect on the respiratory Q10. One possible explanation for these findings is that the Q10 depends on the ratio of growth to maintenance respiration (which is directly related to RGR). The growth respiration coefficient generally is considered to be temperature-insensitive, while the maintenance respiration coefficient normally increases with increasing temperature. Based on this concept, the Q10 for the maintenance respiration coefficient can be estimated as the estimated Q10 at a RGR of zero (i.e. no growth and thus no growth respiration), which was 1.65 in this experiment. Although the concept of dividing respiration into growth and maintenance fractions remains controversial, it is useful for explaining changes in respiratory Q10 during plant development.

Latitudinal trends in the responses of growth respiration and maintenance respiration to temperature in the beach pea, Lathyrus japonicus

1980 ◽  
Vol 58 (14) ◽  
pp. 1521-1524 ◽  
Author(s):  
M. J. Lechowicz ◽  
L. E. Hellens ◽  
J.-P. Simon
Keyword(s):  
Respiratory Activity ◽  
Dark Respiration ◽  
Adaptive Significance ◽  
Carbon Loss ◽  
Maintenance Respiration ◽  
Growth Respiration ◽  
Beach Pea ◽  
Respiratory Responses

The response of dark respiration to temperature was measured for populations of Lathyrus japonicus collected from 39–56° N latitude. Carbon loss in dark respiration increases with latitude at all temperatures. This increased respiratory activity is attributable to concomitant increases in both the growth and maintenance components of total dark respiration. The possible adaptive significance of these respiratory responses is discussed.

Weed Control Efficacy and Pinto Bean (Phaseolus vulgaris) Tolerance to Early Season Mechanical Weeding

1995 ◽  
Vol 9 (3) ◽  
pp. 531-534 ◽  
Author(s):  
Mark J. Vangessel ◽  
Lori J. Wiles ◽  
Edward E. Schweizer ◽  
Phil Westra
Keyword(s):  
Phaseolus Vulgaris ◽  
Weed Control ◽  
Weed Management ◽  
Seed Weight ◽  
Growth Stage ◽  
Integrated Approach ◽  
Growth Stages ◽  
Weed Species ◽  
Control Efficacy ◽  
Pinto Bean

An integrated approach to weed management in pinto bean is needed since available herbicides seldom adequately control all weed species present in a field. A two-year study was conducted to assess weed control efficacy and pinto bean tolerance to mechanical weeding from a rotary hoe or flex-tine harrow at crook, unifoliolate, and trifoliolate stages of bean development. Weed control was similar for both implements and all timings in 1993. In 1994, mechanical weeding at trifoliolate and both crook and trifoliolate stages controlled more weeds than at other growth stages, regardless of type of implement. Using the flex-tine harrow reduced pinto bean stand, but results based on growth stage were not consistent each year. Damage to pinto bean hypocotyls and stems was observed with the flex-tine harrow used at both crook and trifoliolate stages in 1994. Rotary hoeing did not reduce pinto bean stand or cause injury. Yield and seed weight did not differ among treatments in either year.

Pinto Bean (Phaseolus vulgaris) Varietal Tolerance to Imazethapyr

Weed Science ◽  
1995 ◽  
Vol 43 (3) ◽  
pp. 417-424 ◽  
Author(s):  
Troy A. Bauer ◽  
Karen A. Renner ◽  
Donald Penner ◽  
James D. Kelly
Keyword(s):  
Phaseolus Vulgaris ◽  
Acetolactate Synthase ◽  
Differential Sensitivity ◽  
Laboratory Studies ◽  
Physiological Maturity ◽  
Pinto Bean ◽  
Number Of Genes ◽  
Varietal Response ◽  
Varietal Tolerance ◽  
Seed Yields

Field and laboratory studies were conducted to determine if differences existed in pinto bean varietal tolerance to postemergence application of imazethapyr under field conditions; if differences in tolerance were due to differential acetolactate synthase enzyme sensitivity or differences in14C-imazethapyr absorption, translocation, and metabolism; and the heritability of imazethapyr tolerance in pinto bean. All rates of imazethapyr injured Olathe, Sierra, UI-114, P89405, Aztec, and P90570 pinto bean varieties 7 d after treatment in 1991 and 1992, except 53 g ai ha−1of imazethapyr applied to Sierra pinto bean in 1991. Olathe was injured more than other varieties in 1991, and physiological maturity of Olathe was delayed more than Sierra in 1991 and 1992. Seed yields of all varieties were not reduced in 1991, and only P90570 had reduced seed yields from 53 g ha−1of imazethapyr in 1992. Differential sensitivity of the acetolactate synthase enzyme to imazethapyr was not the mechanism of differential varietal response. Olathe pinto bean absorbed and translocated 1.4 and 1.3 times more14C-imazethapyr, respectively, than Sierra pinto bean 24 h after application. No differences in14C-imazethapyr metabolism were detected between Olathe and Sierra pinto bean. Broad heritability of imazethapyr tolerance in pinto bean was calculated to be 0.85. The number of genes controlling the inheritance of imazethapyr tolerance in pinto bean was greater than one.

Bioassay for Screening Plant Accessions for Resistance to Fall Armyworm (Lepidoptera: Noctuidae) Using Artificial Diets

1991 ◽  
Vol 26 (3) ◽  
pp. 367-374 ◽  
Author(s):  
M. M. Diawara ◽  
B. R. Wiseman ◽  
D. J. Isenhour
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Plant Introductions ◽  
Resistance To Insects ◽  
Pinto Bean ◽  
Low Levels ◽  
Sorghum Genotypes ◽  
Lepidoptera Noctuidae ◽  
Sorghum Bicolor L ◽  
Laboratory Bioassays

Laboratory bioassays demonstrated that formulation of artificial insect diet influenced the expression of antibiosis to fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), in grain sorghum, Sorghum bicolor (L.) Moench. Larvae of FAW were reared on a diet formulated with pinto bean and a diet formulated with no pinto bean, both supplemented with dried milk stage florets of resistant and susceptible sorghum genotypes. The sorghum lines showed a significantly higher antibiosis to FAW when mixed in the diet formulated with no pinto bean than when mixed in the diet containing the bean. Larvae that were fed the no-bean diet supplemented with resistant sorghum genotypes weighed one-half to one-third less, required longer to pupate, and resulted in lighter pupae than larvae reared on mixtures containing the bean. The results obtained when the larvae were reared on the bean diet were significantly correlated (P = 0.0001, r > 0.80, n = 18) with those recorded when the no-bean diet was used for the FAW variables measured. Because a higher expression of antibiosis is obtained with the no-bean diet, this formulation should be recommended for bioassays designed to study lines with low levels of resistance to insects or to screen plant introductions in which the level of resistance is not known.

The Effect of Palm Age and Planting Density on the Partitioning of Assimilates in Oil Palm (Elaeis guineensis)

1988 ◽  
Vol 24 (1) ◽  
pp. 53-66 ◽  
Author(s):  
C. J. Breure
Keyword(s):  
Leaf Area ◽  
Oil Palm ◽  
Light Transmission ◽  
Elaeis Guineensis ◽  
Light Response ◽  
Planting Density ◽  
Maintenance Respiration ◽  
Area Index ◽  
Growth Respiration ◽  
Photosynthetic Assimilation

SUMMARYYield and growth records from an oil palm planting density experiment, comparing 56, 110, 148 and 186 palms ha−1, and a progeny experiment, planted at 115 and 143 palms ha−1, were used to estimate the partitioning of assimilates into those used for structural dry matter (DM) production, and those used for growth and maintenance respiration.Gross photosynthetic assimilation (A) for closed canopies was estimated from absorbed photosynthetically active radiation (PAR), derived from actual sunshine hours, and the assimilation-light response curve, to be 128 t CH2O ha−1 year−1. A for non-closed canopies was calculated by correcting for the degree of light transmission, which in turn was estimated from recorded leaf area index values (L), i.e. the total leaf area per unit ground area.Forty-eight percent of gross assimilation was used for DM production, about half of this being lost in growth respiration. The remaining 52% was lost in maintenance respiration. These losses appeared to level off before crown expansion was completed, and since trunk biomass continued to increase, maintenance respiration per unit biomass (R) decreased with age.An increase in planting density reduced the assimilates available for bunch DM, had little effect on those for vegetative growth, but strongly reduced maintenance respiration and, since biomass was little affected, reduced R. Assimilates for bunch DM ha−1 reached a maximum at L = 5.6.The observed trends in R as a function of palm age and planting density merit further study.

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