Environmental Control in Biology
Online ISSN : 1883-0986
Print ISSN : 1880-554X
ISSN-L : 1880-554X
Volume 51 , Issue 1
Environmental Control in Biology
Showing 1-9 articles out of 9 articles from the selected issue
Review
Original Paper
  • Teruo WADA, Hideo IKEDA, Hiroaki HIRAI, Yoshifumi NISHIURA
    2013 Volume 51 Issue 1 Pages 11-16
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    This study was carried out to make a simulation model for predicting the fruit yield of tomatoes in summer. Tomato seeds were sown monthly from February to September. Plants were grown hydroponically on a single-truss system in 0, 30, 55, and 83% shade. Total fruit yield per plant increased linearly with increasing integrated solar radiation from the first flower anthesis to the first fruit harvest. When all data from all crops were pooled, the regression line did not have as high a coefficient of determination (r2=0.73) as it did with the unpooled data. Most of the regression lines fitted to the data from each crop individually had higher coefficients of determination, except for lines plotted for the June and July crops. The slope (r2=0.929) and the x intercept (r2=0.860) of the regression lines, except for the June crop, were correlated with averaged air temperature during fruit development linearly and quadratically, respectively. From these results, the simulation model for predicting fruit yield from both integrated solar radiation and averaged air temperature was constructed. The model could be applied at 19 to 27°C of averaged air temperature. Standard error of cross-validation (SECV) of the data excluding the June crop was lower (92.1) in the model modified with air temperature, compared with the model with only integrated solar radiation (111.4).
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  • Yoshinori UENO, Megumi EGI, Naoto IWASAKI
    2013 Volume 51 Issue 1 Pages 17-21
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    This study was conducted to ascertain the relation between the degree of reduced pressure in flesh intercellular space and water absorption of sweet cherry fruit, which changes with fruit growth, as well as susceptibility to cracking. Results show that the differential pressure between the intercellular space and atmospheric pressure (DPIA) was around −2.2 to −2.3 Pa during fruit growth by 39 days after bloom (DAB). The DPIA on 54 DAB became 6.0 Pa lower than ambient air pressure. The water-absorbing capability (WAC) of the fruit tended to increase concomitantly with decreasing DPIA. Their correlation coefficient was −0.9622**. When the DPIA was −6.0 Pa, the WAC, as estimated as the ratio of volume of inert fluid absorbed to fruit under atmospheric pressure (V inert) against the intercellular space capacity (V int), was around 73%. The WAC fluctuated between 24.4% on 44 DAB and 73.3% on 54 DAB. The cracking index (CI), which was 5.8 in the fruit at the yellow to pink stage (ca. 35 DAB), increased with fruit growth, becoming 64.4 in the fruit at the maturing stage (ca. 45 DAB). However, it decreased to 30.4 in the overripe fruit (ca. 53 DAB). Therefore, results suggest that the water on the fruit surface was sucked into flesh intercellular space resulting from reduction of the flesh intercellular space pressure caused by respiration.
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  • Akira TANI
    2013 Volume 51 Issue 1 Pages 23-29
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    Monoterpenes and oxygenated monoterpenes emitted by plants are involved in producing photochemical oxidants and secondary organic aerosols in the atmosphere. In the present study, the fragment patterns and the reaction rate constants of some of these compounds have been determined by proton transfer reaction-mass spectrometry (PTR-MS). Five monoterpenes (myrcene, camphene, α-phellandrene, α- and γ-terpinene) and two monoterpene alcohols (linalool and cineole) were observed to produce dominant ions of m/z 81 and 137 along with some minor m/z 67 and 95 ions. Myrcene, which is a straight-chained compound, produced an m/z 69 ion along with the above mentioned ions. A monoterpene ketone, thujone, has been found to produce a fragment ion, m/z 93. Since the m/z 69 and 93 ions are the protonated molecular ions of ubiquitous isoprene and toluene, respectively, these respective fragment ions may interfere with the quantification of both isoprene and toluene. We have also revealed that the proton transfer reaction rate is faster in the oxygenated monoterpenes (rate constant: 2.6–3.5×10−9 cm3 s−1) than in the common monoterpenes (2.2–2.4×10−9 cm3 s−1). This suggests that the calibration equation obtained from the relationship between the concentration and the produced ion count (m/z 81+137) of selected monoterpenes may underestimate the total concentration of monoterpene alcohols and monoterpenes.
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  • Shoko HIKOSAKA, Hideo YOSHIDA, Eiji GOTO, Noriko TABAYASHI, Takeshi MA ...
    2013 Volume 51 Issue 1 Pages 31-33
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    The transgenic everbearing strawberry (Fragaria×ananassa Duch. ‘HS 138’) can be cultivated in a closed plant production system to produce functional proteins that enhance human immune functions. In this study, we investigated the effects of light quality on fruit growth and the concentration of human adiponectin (hAdi) at three mature stages in transgenic strawberry. hAdi plants were exposed to 3 different light qualities (white [W], blue [B], and red [R]) for a 16-h light period under fluorescent lamps during the flowering and harvest stage; fruits were then harvested at three different mature stages (small green, turning white, and mature red). hAdi concentration increased with fruit maturation, and the mature red stage fruit from the R light treatment group had a significantly greater concentration of hAdi on a fresh-weight basis than all other treatments. There was no relationship between hAdi concentration and fruit fresh weight and the number of days from anthesis to harvest. Although the factors that promoted the production of the functional hAdi proteins were not clear in this study, the results suggest that the fruit growth stages of the transgenic strawberry differed in their response to light quality. For hAdi plants, exposure to red light resulted in the greatest level of functional protein production under the tested treatments.
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  • Mohammad A. MOJID, Taposh K. ACHARJEE
    2013 Volume 51 Issue 1 Pages 35-39
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    Characteristics of rainfall-induced salt leaching was investigated in a field after wheat (Triticum aestivum L.) cultivation under irrigation by synthetic saline water, which was prepared by mixing sodium chloride (NaCl) with fresh water pumped from a borehole well. The treatments of the experiment — I1: root zone soil with salinity 0.12 dS m −1, and I2, I3, I4 and I5: root zone soils with salinity 0.39, 0.51, 0.69 and 0.86 dS m −1, respectively — had three replications. The soil salinities were developed due to irrigation by fresh water (of 0.385-dS m −1 background salinity) for I1 and by saline water of 4, 7, 10 and 13 dS m −1 salinity for I2, I3, I4 and I5, respectively. Soil samples were collected from each plot from 0–20, 20–40 and 40–60 cm soil layers at 15 (in a few cases at 30) days interval during rainy season (April–September 2011) after harvesting of the crop. By measuring electrical conductivity (EC) on saturation extracts of the samples salt dynamics at the three soil layers under the five irrigation treatments were characterized. Variation of soil pH due to the leaching process was also evaluated by measuring pH of the soil extracts. At the end of rainy season, the salt that accumulated in the soil due to irrigation by saline water leached almost completely out of the top 0–20-cm soil layer in all treatments. The salt from the upper layer leached down and initially elevated salinity of the lower layers. Salinity in the bottom layer of I2–I5 treatments did not reduce to pre-irrigation non-saline level, implying that rainfall, although a substantial amount (1673 mm) could not wash out the imposed salinity from the root zone soil. At the early period of leaching, both the frequency and quantity of rainfall were relatively small, but the rate of reduction of EC in the soil profile was quite substantial and rapid, especially in the soil with high salinities (e.g., I4 and I5). At the later period, on the other hand, the rate of EC reduction slowed down although the frequency and quantity of rainfall were higher than at the early period of leaching. The salt removal rate was thus inversely related to its concentration in the soil. It is concluded that, irrigation by saline water of EC 4, 7, 10 and 13 dS m −1 caused accumulation of salt in the soil in excess of that washed out by the monsoon rainfall.
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  • Kota HIDAKA, Kazuhiro DAN, Hitoshi IMAMURA, Yuta MIYOSHI, Tomohiko TAK ...
    2013 Volume 51 Issue 1 Pages 41-47
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    Although supplemental lighting has been successfully used to boost greenhouse vegetable production, it has not found wide application in forced strawberry cultivation. In this study, we examined the effect of supplemental lighting from two different light sources on strawberry growth and yield. Strawberry plants were exposed to LED or fluorescent lamp illumination for 12 h (6:00–18:00) daily from January to April. Under LED illumination, PPFD values greater than 400 μmol m −2 s −1 were recorded at leaf heights of 10–30 cm, and leaf photosynthetic rates in plants exposed to LED supplemental lighting were much higher than in controls and plants exposed to fluorescent light. This accelerated photosynthesis promoted plant growth, as manifested by increases in leaf dry matter production, leaf area, and specific leaf weight, leading in turn to significant increases in average fruit weight, number of fruits, and marketable yield. The higher yields observed in LED-exposed plants compared with those under fluorescent lamp illumination were due to comparatively higher LED light intensities. Fruit soluble solids content, an index of sweetness, also increased under LED lighting. These results suggest that supplemental lighting using higher irradiance LED is an effective method for high yield production during forced strawberry cultivation.
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  • Taku YANO, Makoto OHARA, Kimiaki MATSUBARA, Akira TAMANOI, Takuya ARAK ...
    2013 Volume 51 Issue 1 Pages 49-56
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    Light condition is a fundamental environmental factor for high-quality plant production. In this paper, we discuss how light condition affects fruit development in the long and short term, and attempt to clarify management methods for active fruit development under conditions of low solar radiation, by using quantitative research on fruit water and carbon balance during greenhouse cultivation of Satsuma mandarin (Citrus unshiu Marc.). A significant decrease in yield due to shading was not detected, but we confirmed that shading treatment affected the dry weights of source-sink units, fruit volume, increase in volume of the fruits, and fruit quality parameters, such as sugar accumulation, acid content, and rind color. Qualitatively, the carbon balance of Satsuma mandarin fruit is comparable to that of tomato fruit or rice panicle, but quantitatively, the carbon balance of Satsuma mandarin fruit may differ, as shown by low sink relative growth rate. In addition, fruit growth parameters such as translocation rate for a fruit and fruit relative growth rate showed significant positive correlations with dark respiration, despite the shading treatment. The fruit carbon demand may be simply described by fruit dark respiration as the sum of new photosynthetic carbon and stored carbon translocation for a fruit.
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  • Emelie C. ABLAZA, Katsumi ISHIKAWA, Makito MORI
    2013 Volume 51 Issue 1 Pages 57-61
    Published: 2013
    Released: April 11, 2013
    JOURNALS FREE ACCESS
    An alternative plant nutrition technique was investigated for wheat production with late-summer sowing. Distilled water (DS) for control, electrokinetic-treated water (EKTW), seaweed yeast extract water (SYE), and mineral spring water (SW) were tested for their physical and chemical properties. Each water type was used in the vernalization of wheat seeds and for once-weekly irrigation of wheat plants, which were grown in a phytotron that simulated field conditions with late-summer sowing. Wheat plants watered with SYE showed rapid leaf emergence, produced fewer tillers and attained their final height sooner than the treatments, indicating a shorter vegetative growth period. Plants treated with SYE water exhibited early heading and maturity, resulting in the shortest overall cultivation period. Thousand-grain weight was significantly higher in SYE-treated wheat (25.77 g) compared with the control (19.26 g). Wheat treated with EKTW produced the longest spikes and highest number of grains per spike. Thus, vernalization and irrigation with different natural waters influenced wheat growth and development, which are critical for the viability of late-summer sowing as an alternative wheat production technology. SYE and EKTW influenced the two most important criteria for absolute yield; the average weight and number of grains, respectively.
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