Environment control in biology 

About: Environment control in biology is an academic journal. The journal publishes majorly in the area(s): Light intensity & Transpiration. It has an ISSN identifier of 0582-4087. Over the lifetime, 933 publications have been published receiving 4180 citations. The journal is also known as: Environment control in biology.

Effects of Light Quality on Growth of Crop Plants under Artificial Lighting

Abstract: Major light factors affecting plant growth are light quality, light intensity, photoperiod, and the day/night cycle. These parameters can be controlled under greenhouse conditions using artificial light sources. Moreover, application of light pulses and shortterm changes of the spectral composition are effective ways to stimulate plants and to induce desired morphological developments. Controlling spectral qualities of the irradiation applied enables faster growth or higher yield at a given radiation energy, and the production of plants of optimized nutritional value. Recent developments of lighting technology have enabled not only researchers but also farmers to control spectral qualities by combinations of various light sources with different waveband emissions. This review summarizes previous papers and evaluates significant effects of the quality of artificial light on growth and development of higher plants, especially crops.

A Revised Experimental System of Root-Soil Interaction for Laboratory Workr

Abstract: A set of experimental system for the study on the root system-soil interaction for laboratory work was presented. This system consisted of the following apparatuses and associating techniques for operation; (1) a handy-type root box covered with a mirror sheet, (2) a pinboard which enabled sampling of the root system in the root box soil as it stood in the soil, (3) a piece of holed polyethylene sheet for handling during the sampling of the root system and preserving the root system without impairment and disarrangement after sampling, (4) a transmitted light box for taking photograph of the root system. Techniques associating with those apparatuses consisted of the soil filling up into the root box, supplying water to the root box, washing out the root system from soil, and staining the sampled root system.Distribution patterns of soil porosity and moisture, and daily changes of soil temperature in the root box soil, were determined. Our soil filling-up technique gave high reproducibility as well as uniform porosity distribution in the root box soil with small difference among the root boxes. No significant differences were found in the soil moisture content at a given depth of horizontal soil layer. When the root box was put into the trench, the soil temperature in the root box was closer to that of a natural soil profile than when it was placed on the ground. Upland rice and maize were grown in the root box placed in the trench. Root systems sampled showed considerably uniform profiles among triplicated plants for both species. These results demonstrate the significance of preparation and control techniques of soil environments for the study on root system-soil interaction.

Effects of the Number of Air Changes per Hour of the Closed Vessel and the Photosynthetic Photon Flux on the Carbon Dioxide Concentration Inside the Vessel and the Growth of Strawberry Plantlets in vitro

Abstract: Effects of the number of air changes per hour of the closed vessel (1.5 and 2.7 h-1) and the photosynthetic photon flux (PPF, 34.3 and 133 μmol m-2s-1) on the CO2concentration inside the vessel (Cin) and the growth of strawberry plantlets in vitro were investigated.Cin during the photoperiod was lower than CO2outside the vessel (Cout, inside the culture room) on 5 days after the start of experiments in all treatments. On 20 days after the start of experiments, Cinwas lower than Cout (350-400 ppm) by 100-300 ppm. The difference in CO2concentration between inside and outside was relatively larger in the higher PPF treatment and in the larger number of air changes per hour treatment.On 20 days after the start of experiments, the dry weight of the plantlet was larger in the higher PPF treatment than in the lower PPF treatment. However, the difference in the dry weight was not so large among the treatments, comparing with the large differences in Cinamong the treatments.Relative growth rate, chlorophyll content, net photosynthetic rate, dark respiration rate etc. were estimated to explain the relatively small difference in the dry weight among the treatments. Furthermore, suggestions were made to improve the environment in the vessel further for promoting the plantlet growth.

A Quantitative Analysis of the Relationships between SO2 or NO2 Sorption and Their Acute Effects on Plant Leaves Using Image Instrumentation

Abstract: We have reported on a method for evaluating the distributions of stomatal resistance to water vapor diffusion and SO2or NO2sorption on a leaf, using a thermal infrared image instrumentation system. In the present paper, we examined quantitatively the relation-ships between the acute effects, such as stomatal response and visible injury, of SO2or NO2on a leaf and gas sorption, using the image instrumentation method. The results obtained were as follows.1) There was a tendency for stomata to close during SO2or NO2exposure. However, the behavior varied randomly at different sites on a leaf. The differences in stomatal response at local sites were not dependent on those in integrated SO2or NO2sorption for 60 minutes exposure. These results suggest that there are differences in the stomatal sensitivity to SO2or NO2at local sites on a leaf.2) There was a tendency for visible injury to occur at sites where the integrated SO2or NO2sorption was over a threshold value. Injured leaves were generally separated into two areas, a healthy area and an injured one. It was seen that the characteristic visible injuries were caused by differences in boundary layer and stomatal resistances at local sites governing the gas sorption.

Regulatory Mechanism of Anthocyanin Biosynthesis in ‘Kyoho’ Grape Berries Grown under Different Temperature Conditions

Abstract: To clarify the mechanism regulating anthocyanin biosynthesis in ‘Kyoho’ grape berries grown under high temperature, we examined flavonoids accumulation and the activities of related enzymes as well as photoassimilates translocation on the berries. Anthocyanin content in the skin of berries of grape was lowered at 30 days after veraison when grown under high temperature condition (at consistently 30°C) as compared with berries at consistently 25°C or 30°C in the day and 15°C in the night concomitantly. Phenylalanine concentration in the skin and the photoassimilates partitioning to berry were also lower in those grown at 30°C than vines at 25°C or 30/15°C. While, phenylalanine ammonia lyase (PAL) activity in berries grown at 25°C was higher than that in berries grown at 30°C or 30/15°C. Berries grown at 30/15°C had the highest UDP-glucose : flavonoid 3-O-glucosyltransferase (UFGT) activity among three temperature conditions 30 days after veraison. These results suggest that grape berries grown at successive high temperature decrease anthocyanin accumulation in the skin by virtue of the decrease of the UFGT activities and the concentration of phenylalanine and photoassimilates partitioning to berry. On one hand, the grape berry grown under cool night temperature condition would result in high level of anthocyanin accumulation due possibly to great induction of UFGT activity and high phenylalanine accumulation.