Photoinhibition of Photosynthesis Causes a Reduction in Vegetative Growth Rates of Dwarf Bean (Phaseolus vulgaris) Plants

1995 ◽  
Vol 22 (4) ◽  
pp. 511 ◽  
Author(s):  
WA Laing ◽  
DH Greer ◽  
TA Schnell
Keyword(s):  
Phaseolus Vulgaris ◽  
Growth Rates ◽  
Causal Link ◽  
Photon Flux ◽  
O2 Evolution ◽  
Similar Amount ◽  
Photoinhibition Of Photosynthesis ◽  
Relative Growth Rates ◽  
Inhibition Of Growth ◽  
Dwarf Bean

Effects of photoinhibition of photosynthesis were assessed on growth rates of dwarf bean (Phaseolus vulgaris L.). Plants were grown at four photon flux densities (PFDs) ranging from 300 to 1000 pmol m-2 s-1 and at 25/20�C and 17.5/17.5�C. Plants were also grown and transferred from 25 to 17.5�C either at 500 and 1300 μmol m-2 s-1 or from 500 to 1300 μmol m-2 s-1. Relative growth rates (RGRs) were determined by destructive harvests and photoinhibition was assessed by fluorescence and photon yields of O2 evolution. Carotenoid pigments were analysed by HPLC. The RGRs were PFD-dependent, increasing to a maximum at 430 μmol mm-2 s-1 at 17.5�C and at 650 μmol m-2 s-1 at 25�C. At 25�C, growth rates at 1300 μmol m-2 s-1 were inhibited about 25% over that at light saturation. Transferring the plants from 25 to 17.5�C at constant PFD reduced RGR by a similar amount. Concurrently increasing the PFD resulted in a further 9% reduction in RGR. These changes were consistent with photoinhibition-induced limitations on photosynthesis. Correlated with growth rate reductions were marked changes in both photon yield and FvFm, revealing a causal link between photoinhibition of photosynthesis and inhibition of growth rates. However, acclimation occurred via zeaxanthin-mediated photoprotection during exposure to the photoinhibitory conditions, ameliorating the longer term effects of photoinhibition on growth.

Stage-dependent sensitivity to ultraviolet radiation in zygotes of the brown alga Fucus serratus

Zygote ◽  
2003 ◽  
Vol 11 (2) ◽  
pp. 101-106 ◽  
Author(s):  
María Altamirano ◽  
Antonio Flores-Moya ◽  
Ralph Kuhlenkamp ◽  
Félix L. Figueroa
Keyword(s):  
Growth Rate ◽  
Uv Radiation ◽  
Growth Rates ◽  
Brown Alga ◽  
Radiation Condition ◽  
The Other ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Inhibition Of Growth ◽  
Fucus Serratus

Sensitivity to ultraviolet (UV) radiation (UV-A, λ = 315-400 nm; plus UV-B, λ = 280-315 nm) of zygotes of the brown alga Fucus serratus L. (Phaeophyta) has been assessed through effects on growth of developing germlings. Different stages of development were distinguished by considering 5 h periods of time after fertilisation. Both the stage of the zygote and the UV radiation condition significantly affected growth of developing germlings. The negative response of growth rate of early stages of the zygotes to UV radiation seemed to be caused by UV-B rather than UV-A radiation, as the lowest relative growth rates were always estimated for germlings developed from zygotes irradiated with UV-B radiation. As regards the stage of the zygote, those germlings that developed from zygotes irradiated at 5-10 h after fertilisation showed the strongest inhibition of growth compared with the other stages. These results point to polarisation as the most UV-sensitive process during the first 24 h of the development of the zygote. A non-linear relationship between the developmental stage of the zygote and the sensitivity to UV radiation is suggested.

Selection for biomass production based on respiration parameters in eucalypts: effects of origin and growth climates on growth rates

1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca
Keyword(s):  
Temperature Dependence ◽  
Growth Rates ◽  
Heat Rate ◽  
Eucalyptus Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Metabolic Heat ◽  
Respiratory Parameters ◽  
Metabolic Heat Rate ◽  
Different Climates

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.

Studies on the sowing dates of cotton in the Sudan Gezira: I. The influence of date of sowing on plant growth and development

1967 ◽  
Vol 69 (3) ◽  
pp. 305-315 ◽  
Author(s):  
J. E. Jackson
Keyword(s):  
Growth Rates ◽  
Slow Growth ◽  
Seasonal Pattern ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Research Division ◽  
Sowing Dates ◽  
Net Assimilation ◽  
State Growth ◽  
Sudan Gezira

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.

Sign in / Sign up

Export Citation Format

Share Document