147 research outputs found

    Development of a new computer-assisted technigue for efficient usage of latent heat with computer system

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     In protected horticulture, cooling techniques with latent heat has been effective for improving the growth of various kinds of plants in the summer season. It was necessary to understand special knowledge of the VETH diagrammatic drawing for effective operation of cooling with latent heat. In order to obtain the information from VETH diagrammatic drawing, it was necessary to perform a lot of calculations. It was difficult to obtain such information simply. So, a device and software were developed for getting effective information in order to manage cooling of latent heat. The developed device and software were run on the Ubiquitous Environment Control System (UECS). The rules for controlling the environment of UECS was were set up on a web site, and an information communication technique was used for controlling the environment. The developed ventilation calculated node gathered the necessary information from the other nodes via LAN automatically. The node calculated valuable information for cooling with latent heat, including the ventilation rate, and sent the calculated values, after entering the constant parameters using an http server, which was installed in the node. The developed software was run on a personal computer. The software could be used after describing various information for calculating ventilation rate and evaporation rate at the setting file. It calculated these values, and users were shown the data using graphs and text files. As a result, we could get effective information concerning cooling latent heat fairly easily by using of the developed node and the software

    Ubiquitous Environment Control System: An Internet-of- Things–Based Decentralized Autonomous Measurement and Control System for a Greenhouse Environment

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    A low-cost and flexible system for environmental measurement and control in greenhouses based on decentralized autonomous technics, Ubiquitous Environment Control System (UECS), was proposed in 2004. The UECS is composed of autonomous nodes as the minimum units of measurement and control. The nodes can connect with each other through Ethernet or Wi-Fi and can communicate information regardless of manufacturer or model. To realize automation and efficiency of protected horticultural production, two consortia for UECS development and extension were established. During the last 10 years, the UECS has been used to apply environment control in large-scale greenhouses and plant factories. The stability and utility of the UECS have been demonstrated and verified in these practical cultivations. Current research and development are being carried out to install information and communication technology (ICT) systems to improve productivity in existing small- to medium-scale greenhouses in Japan. The flexibility and concept of the UECS have been very effective to enable sophisticated environmental control technology to be applied to small- and medium-scale greenhouses. In this chapter, self-fabricated UECS, the renewal of old environmental control systems using the UECS, and Sub-GHz radio band use for communicating UECS nodes among distributed greenhouses are discussed

    Defoliating to 12-15 leaves increases calcium concentration and decreases blossom-end rot incidence in fruit of tomato plant grown under moderate water stress

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    The objectives of this study were to (i) determine the optimum number of whole leaves to retain on a tomato plant for effective blossom-end rot (BER) management and (ii) explore the relationship between shoot calcium (Ca) and fruit Ca in non-defoliated plants in two different sized fruit cultivars, a large-fruited cultivar ‘Momotaro fight’ and a medium-fruited cultivar ‘Cindy sweet’. Treatments involved maintaining 18, 15 and 12 leaves on a plant. All lateral shoots were removed regularly throughout the growing period except the shoot closest to the flowering truss in the 18-leaf treatment. At the length of 10cm, these shoots were sampled for real time Ca determination using a hand held Ca2+ meter. In the plants defoliated to 18 leaves, BER was higher in ‘Momotaro fight’ at 10% compared to 2% in ‘Cindy sweet’. Fruit growth rate was significantly increased by defoliation in ‘Momotaro fight’, however no significant difference was observed among treatments in ‘Cindy sweet’. Defoliating to 12 leaves increased daily Ca transport rate by 59% and 37% in ‘Momotaro fight’ and ‘Cindy sweet’, respectively. Defoliating to 12 leaves increased the water-soluble Ca concentration in the distal part of fruit by 34% and 14% in ‘Momotaro fight’ and ‘Cindy sweet’, respectively. In the plants defoliated to 18 leaves where only old yellowish leaves were removed, a significant steady decrease was observed in the concentration of water soluble Ca in the distal part of fruit with increase in truss order. There was a significant linear relationship between water-soluble Ca concentration in the distal part of the fruit and Ca concentration in the lateral shoot of plants defoliated to 18 leaves. We conclude that under moderate water stress by root zone restriction and also certain other BER inductive conditions, defoliation to 12–15 leaves on a tomato plant should be a promising approach for decreasing BER incidence in susceptible large fruit cultivars

    Fasciation in Strawberry Floral Organs and Possible Implications for Floral Transition

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    Fasciation in strawberry is characterized by an enlarged and flattened receptacle, clustering of flowers, and altered inflorescence architecture. However, the developmental process of fasciated flowers remains obscure. In this study, the fasciation incidence and developmental process in the primary fruit and inflorescence architecture were evaluated and compared for the non-susceptible cultivars, ‘Nyoho’ and ‘Sagahonoka’ and one of the most susceptible cultivars, ‘Ai-Berry’. The severity and frequency of flower and inflorescence fasciation was clearly greater in the vigorously growing large plants of ‘Ai-Berry’ compared to small plants and large plants of the other two cultivars. In ‘Ai-Berry’, the deformation of the large shoot apical meristem (SAM) into an oval shape was the initial symptom observed before and during floral transition. Such oval-shaped SAMs often differentiated two or more leaf primordia almost at the same time, which then developed into divided multiple vegetative SAMs before floral transition and linearly-fasciated SAMs during floral transition, respectively. The development of fasciation symptoms was observed after downregulation of FaTFL1. Although inflorescence or receptacle fasciation could be controlled when early and rapid floral induction was achieved by intermittent low-temperature treatment, severe fasciation was observed in late-flowered plants which were either not responsive or not subjected to this treatment. These results indicate that fasciation of floral organs may be triggered and develop during floral transition and that temperature fluctuations around boundary values between floral inhibition to induction may cause a half-finished or slowly processed floral transition and finally result in severe fasciation in vigorously growing ‘Ai-Berry’ plants

    Positional differences of intronic transposons in pAMT affect the pungency level in chili pepper through altered splicing efficiency

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    トウガラシの辛味レベルを変化させる遺伝子変異を発見 -激辛・中辛・辛くないを作り分ける-. 京都大学プレスリリース. 2019-08-30.Capsaicinoids are unique compounds that give chili pepper fruits their pungent taste. Capsaicinoid levels vary widely among pungent cultivars, ranging from low‐pungency to extremely pungent. However, the molecular mechanisms underlying its quantitative variation have not been elucidated. Our previous study identified various loss‐of‐function alleles of the pAMT gene, which led to low‐pungency. The mutations in these alleles are commonly defined by Tcc transposon insertion and its footprint. In this study, we identified two leaky pamt alleles (pamtL1 and pamtL2) with different levels of pAMT activity. Notably, both alleles had a Tcc transposon insertion in intron 3, but the locations of the insertions within the intron were different. Genetic analysis revealed that pamtL1, pamtL2 and a loss‐of‐function pamt allele reduced capsaicinoid levels to about 50%, 10%, and less than 1%, respectively. pamtL1 and pamtL2 encoded functional pAMT proteins, but they exhibited lower transcript levels compared with the functional‐type. RNA‐seq analysis showed that intronic transposons disrupted splicing in intron 3, which resulted in simultaneous expression of functional pAMT mRNA and non‐functional splice variants containing partial sequences of Tcc. The non‐functional splice variants were more dominant in pamtL2 than that in pamtL1. This suggested that the difference in position of the intronic transposons could alter splicing efficiency, which led to different pAMT activities and reduced capsaicinoid content to different levels. Our results provide a striking example where intronic transposons caused allelic variations, which contributed to quantitative differences in secondary metabolite contents

    トウガラシ(Capsicum baccatum)における カプサイシノイド含量の変異とその非辛味系統

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    The chili pepper (Capsicum) is both an important spice and fresh vegetable worldwide. C. baccatum is a lesser known domesticated species that is native to the Andean region. Fruit traits such as color, shape, and pungency markedly vary in this species. C. baccatum has potential as a bioresource for future chili pepper breeding programs. Although extensive studies have been conducted on the pungency of C. annuum, that of C. baccatum has not been examined in as much detail. In the present study, capsaicinoid contents were analyzed in 36 C. baccatum accessions. Capsaicinoid contents ranged between 0 and 4,258 μg/gDW. Furthermore, a negative relationship was observed between capsaicinoid contents and fruit weights. Although the pungency of C. baccatum is regarded as low-mild, very few non-pungent accessions were detected ; only one non-pungent accession (‘Kaleidoscope’) was identified among the C. baccatum accessions examined. In order to validate the stability of non-pungency in the accession, capsaicinoid contents were determined at different harvest dates, along with other accessions with different pungencies. Although capsaicinoid contents in other C. baccatum accessions changed with the picking date, capsaicinoid was not detected in ‘Kaleidoscope’ at any date. The non-pungent accession reported here may be useful for future C. baccatum pepper breeding programs. トウガラシ(Capsicum 属)は世界的に重要な香辛料および野菜である.C. baccatum は南米原産のマイナーな栽培種であるが,果色,果形や辛味など果実形質に多様性が認められることから,トウガラシ遺伝資源として注目されている.トウガラシの辛味性についてはC. annuum 種において多くの研究が行われているが,C. baccatum 種においては十分研究されていない.  本研究では,C. baccatum 36系統について辛味成分カプサイシノイドの含量を調査した.カプサイシノイド含量の幅は0 ~4,258 ㎍ /gDW であった.また果実重と辛味成分含量の間に負の相関が認められた.C. baccatum の辛味は低〜中程度であるが,非辛味系統はほとんど認められず,唯一1 系統(‘Kaleidoscope’)が非辛味であった.この非辛味の安定性を調査するために,辛味程度の異なる系統とともに異なる収穫時期におけるカプサイシノイド含量を調査した.  他のC. baccatum 系統ではカプサイシノイド含量は収穫時期で変化したが,‘Kaleidoscope’ ではいずれの収穫時期でもカプサイシノイドは検出されなかった.本研究で見出された非辛味系統は将来のC. baccatum の育種において有用であろう

    Effect of boron deficiency on tip burn and malformed fruit incidence in strawberries

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    Boron (B) is an essential micro element for plants and plays important roles in the synthesis and functions of cell wall. B deficiency has been reported as one of the causes of fruit malformation in strawberries. We investigated the effect of B deficiency on flower and fruit development of forced strawberries for two cropping seasons (2015-2017). In the second season, B was resupplied for B-deficient plants and we investigated changes in fruit development. When B-free nutrient solutions were supplied, tip burn began to occur in newly emerging leaves and calyx 2 to 3 months later, and fruit malformation including seedy or only partly developed fruits with undeveloped achenes occurred frequently. However, these deficient symptoms were quickly disappeared by supplying B containing nutrient solutions. In conclusion, B nutrition is closely related to the occurrence of fruit malformation through fertility of pollen and pistils, and also development of receptacle tissue in strawberries. It should be possible to reduce fruit malformation in strawberries by proper control of B nutrition. B(ホウ素)は植物にとって必須な微量要素であり,イチゴの受精不良果発生要因の1 つである.そこで2015年度と2016年度の2 回にわたりB 欠乏がイチゴの受精不良果発生に及ぼす影響について調査した.また,2016年度はB 欠乏処理後にB 回復処理を行い,その後のイチゴの果実形態の変化についても調査した.その結果,B欠乏処理を行うと蒸散機能の低い新葉や花芽においてチップバーンが発生し,種浮き果や部分不受精を主とした受精不良果が多発した.しかし,B 回復処理を行うことでこれらの症状が改善することが明らかになった.B は受精不良果発生に関係しており,欠乏条件下で根から吸収させると急速に若い成長中の組織に転流することが示されたことから,B 栄養をコントロールすることでB 不足によるイチゴの受精不良果発生を軽減できる可能性があると考えられる

    Comparison of LEDs, Fluorescent Lamps and Incandescent Bulbs for Long-day Treatment of Forcing Strawberries as Affected by Respective Color Temperature

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    Long day (LD) treatment is frequently applied for horticultural crops, including strawberry, and sufficient effect similar to 4 to 6hours of day time elongation in the evening can be achieved by 1 to 3hours of night break in the mid night. Incandescent lamps (IC) have long been an important light source, but the general incandescent lamps are out of production and have been replaced with LED or florescent lamps (FL). Thus, we compared light sources and their color temperature (2,800K, warm white similar to IC; 6,500K, daylight) in different lighting programs. The effectiveness of 3 and 4cycles of alternate intermittent lighting, 30min on/30min off, were equal to and larger than 2hours of night break, respectively. Measured intensity of illumination (lux) at the canopy surface by 2,800K LED (6.9W) and FL (12W) was 1.50 and 0.95times as large as IC (54W), but leaf growth under LED and FL was similar to and less vigorous than IC, respectively. On the other hand, intensity values of illumination by 6,500K LED (6.9W) and FL (12W) were both 1.20times as large as 2,800K ones, but 6,500K light sources were much less effective compared to 2,800K ones. Daylight type LED and FL which have higher luminance efficiency but emit less red light compared to warm white ones, are not suitable as alternative light sources for IC

    Effect of seed cold PEG–priming concentration and period followed by re–drying on germination, growth and flowering of Eustoma grandiflorum (Raf.) Shinn ʻExe Lavenderʼ

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    This study aimed to investigate whether seed cold priming by PEG‒6000, followed by re‒drying would affect the germination, growth, and flowering of Eustoma ‘Exe Lavender’ raised seedling under high temperatures. Seeds of control treatment were not treated with cold‒priming or re‒drying. In experiment 1, seeds were cold‒primed with water and PEG‒6000 at ‒0.75 and ‒1.5 MPa for 5 weeks at 10°C in the dark and then subjected to re‒dried and storage for 30 days at 10°C. The results showed that cold‒primed seeds germinated earlier than those of the control. Compared to water treatment, plants grown from PEG‒6000 treatments and re‒drying showed similar germination rate, bolting rate, days to bolting, bolting node and flowering rate. In experiment 2, cold priming periods by water and ‒1.5 MPa PEG‒6000 were investigated for 4, 5, 6, 7, and 8 weeks. ‘Exe Lavender’ seeds treated with cold water and in the dark for longer than 5 weeks increased their percentage of radicle emergence and decreased germination rate after 30 days of re‒drying and storage. Meanwhile, those treated with cold-PEG did not protrude the radicle even for 8 weeks of priming and maintained the germination rate after re‒drying and storage. Days to bolting and days to flowering tended to decrease when the priming period decreased. The results suggest that the seed cold priming treatment by ‒1.5 MPa PEG‒6000 and subsequent re‒drying improved germination rate and maintained bolting rate and flowering rate in Eustoma compared to cold priming treatment by water raised seedling under high temperature conditions

    Effect of Beginning Date of Intermittent Low Temperature Treatments on Flowering of Tray-grown Strawberry 'Nyoho'

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     Intermittent low temperature storage is expected to be a new artificial flower-inducing treatment and becoming to be a practical procedure as it does not require expensive equipment or much energy cost. Tray-grown ‘Nyoho’ plants were placed in a refrigerator (15°C, in the dark) for 3 days and then transferred to a further outdoor shelter for 3 days. Plants were transferred at noon and this cycle was repeated twice (3D/3D). Such 3D/3D treatments were begun on August 22, 25, 28, 31, and September 3and the effectiveness on flowering was determined for 2 years. Both in 2012 and 2013, treatments begun before August 28 were less effective compared to the treatments begun on August 28 or later. Continuous 6 days of 15°C storage (6D) was effective to some extent, but 6D from August 25 was apparently less effective compared to those begun later. Both in intermittent and continuous treatments for ‘Nyoho’, it was confirmed that any flower-inducing effect became relatively small and unstable when the treatments were begun before 28 August in Okayama
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