Updated on 2023/10/21


SANADA Atsushi

Associate Professor


Associate Professor

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From Graduate School 【 display / non-display

  • Tokyo University of Agriculture   Graduate School, Division of Agriculture   Doctoral program (second term)   Completed

    2003.04 - 2006.03

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Degree 【 display / non-display

  • 博士(国際農業開発学) ( 2006.03   東京農業大学 )

Employment Record in Research 【 display / non-display

  • Tokyo University of Agriculture   Faculty of International Agriculture and Food Studies   Department of International Agricultural Development   Assistant Professor

    2009.04 - 2021.03

  • Tokyo University of Agriculture   Faculty of International Agriculture and Food Studies   Department of International Agricultural Development   Associate Professor


Papers 【 display / non-display

  • Characterizing Root Morphological Responses to Exogenous Tryptophan in Soybean (Glycine max) Seedlings Using a Scanner-Based Rhizotron System Reviewed International coauthorship International journal

    Atsushi Sanada and Shinsuke Agehara

    plants   12   2023.01

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    Tryptophan is a precursor of indole-3-acetic acid (IAA), which is the major auxin involved in the regulation of lateral root formation. In this study, we used a scanner-based rhizotron system to examine root growth and morphological responses of soybean (Glycine max, ‘Golden Harvest’) seedlings to exogenous tryptophan. Seeds were sown directly in the rhizotron filled with field soil. Tryptophan was applied at 1.9 and 3.8 mg plant−1 by soil drenching or foliar spray. Canopy and root projected area were monitored by analyzing canopy and rhizotron images using ImageJ software. Seedlings were sampled at the first trifoliate stage, 18 days after sowing (DAS), and root morphology was determined by analyzing washed root images using WinRHIZO software. According to contrast analysis, when all tryptophan treatments were pooled, tryptophan application increased canopy and root projected area by 13% to 14% compared with the control at 18 DAS. Tryptophan application also increased root dry matter accumulation by 26%, root:shoot ratio by 24%, and secondary root number by 13%. Tryptophan applied by soil drenching also increased root length and surface area of fine roots (<0.2 mm diameter) by 25% and 21%, respectively, whereas it slightly inhibited primary root elongation. The efficacy of tryptophan soil drenching in stimulating root formation became greater with increasing the application rate. These results suggest that exogenous tryptophan induces auxin-like activities in root development. Soil drenching of tryptophan appears to be an effective strategy in improving the establishment of soybean. Importantly, this strategy is easily implementable by commercial growers with no negative side effect.

    DOI: 10.3390/plants12010186

  • Quick and inexpensive root and shoot evaluation methods using a scanner-based rhizotron system and ImageJ in soybean (Glycine max) Reviewed International coauthorship

    AGEHARA Shinsuke, SANADA Atsushi

    Root Research   29 ( 1 )   5 - 19   2020.03

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    Authorship:Last author, Corresponding author   Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Root Research  

    <p>We developed a scanner-based rhizotron system composed of a wood frame and acrylic sheets to perform non-destructive root evaluation. The main objective of this study was to develop a quick and inexpensive method to estimate root and shoot traits of soybean (<i>Glycine max</i>) seedlings using our rhizotron and ImageJ, a free image processing program. Soybean seeds were sown in rhizotrons, and root and canopy images were collected periodically over 18 days. Seedlings were sampled at the end of the experiment for additional growth measurements. Root images were analyzed using ImageJ and two commercial programs (WinRHIZO Tron for rhizotron images and WinRHIZO for washed root images). For rhizotron images, root projected area measured by ImageJ and WinRHIZO Tron showed significant linear correlations, with R<sup>2</sup> ranging from 0.556 and 0.751. Leaf area measured non-destructively by ImageJ and destructively using a leaf area meter also showed a high linear correlation (<i>R</i><sup>2</sup> = 0.678), suggesting that ImageJ is a useful tool to evaluate both root and leaf growth of soybean seedlings. Although WinRHIZO Tron can provide additional root measurements simultaneously, it was extremely laborious and time-consuming (up to 60 min/image) compared to ImageJ (2–3 min/image). For washed root images, there was a high linear correlation (<i>R</i><sup>2</sup> = 0.919) in root projected area measured by ImageJ and WinRHIZO. These results demonstrate that our rhizotron combined with image analysis techniques using ImageJ allows non-destructive, quick, and inexpensive root and shoot growth evaluation for soybean seedlings.</p>

    DOI: 10.3117/rootres.29.5

    CiNii Articles

  • Enhancing salinity tolerance in tomatoes at the reproductive stage by increasing pollen viability Reviewed International journal

    Nasratullah Habibi, Mohammad Yosuf Fakoor, Shah Mahomoud Faqiri, Zarir Sharaf, Mohammad Sadiq Hotak, Nelofar Danishyar, Mohammad Mustafa Haris, Khuwaja Safiullah Osmani, Takashi Shinohara, Naoki Terada, Atsushi Sanada, and Kaihei Koshio

    Bionatura   8 ( 1 )   2023.03

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    Language:English   Publishing type:Research paper (scientific journal)  

    This study was conducted to mitigate the adverse effects of sodium chloride stress on the reproductive parameters of tomatoes. This experiment was conducted in the greenhouse of the laboratory of tropical horticultural science, department of International agricultural development, Tokyo University of Agriculture. The design was a factorial CRD (completely randomized design) with five sodium chloride (0 mM, 50 mM, 100 mM, 150 mM, and 200 mM) treatments and four primings (0 MPa, 0.4 MPa, 0.8 MPa, and 1.2 MPa) treatments. Micro-Tom seeds were soaked in polyethylene glycol (PEG6000). Salinity was applied through irrigation water when the first flower bloomed. Reproductive-related parameters such as the number of flowers per plant, pollen viability, pollen germination, pollen tube length, number of fruits per plant, fruits size and yield per plant were measured. It was observed that salinity affected the tomato plants severely during the flowering stage, and many flowers did not bear fruit due to the decrease in pollen viability. In addition, electrolyte leakage increased under salt stress, while priming decreased this parameter. Priming improved the number of flowers, pollen viability, and fruits per plant. The best priming treatments were 0.8 MPa and 1.2 MPa for promoting and enhancing tolerance in the reproductive stage.

    DOI: 10.21931/RB/2023.08.01.25

  • Micro-Tom Tomato Response to Fertilization Rates and the Effect of Cultivation Systems on Fruit Yield and Quality Reviewed International journal

    Naoki Terada, Kalara Dissanayake, Chiharu Okada, Atsushi Sanada and Kaihei Koshio

    horticulturae   9 ( 367 )   2023.03

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    Language:English   Publishing type:Research paper (scientific journal)  

    Fertilization is essential for the optimal growth and development of crops; however, the amount of fertilizer can cause positive or negative effects depending on its rate. In addition, the culti-vation system plays a significant role in determining vegetative growth and fruit quality. Therefore, the objectives of this study were to examine the Micro-Tom response to different fertilization rates (first experiment), and to assess the effect of three different cultivation systems on its growth, yield, and fruit quality (second experiment). The fertilization rates used were (A) no fertilizer application control, (B) 0.026 g L−1, (C) 0.052 g L−1, (D) 0.13 g L−1, (E) 0.26 g L−1 standard, (F) 0.52 g L−1, and (G) 1.3 g L−1, and the cultivation systems were conventional, organic, and hydroponic. The results of the first experiment showed that plant growth and yield of Micro-Tom were highly influenced by the fertilization rate and Micro-Tom recorded the highest yield at 0.52 g L−1. In terms of the second experiment, the hydroponically grown Micro-Tom tended to accumulate amino acid, while organic and conventional systems showed more accumulation of sugars and organic acid; the highest yield was recorded in the hydroponic system. The yield obtained in the hydroponic systems was more than double that of the soil cultivation methods. The findings of this study can contribute to promoting the organic and hydroponic cultivation of tomatoes.

    DOI: https://doi.org/10.3390/horticulturae9030367

  • Influence of the Hypobaric Method in Physicochemical Fruit Quality Traits of Yellow and Purple Passion Fruit Stored in Cold Temperature Reviewed

    Viera William, Shinohara Takashi, Sanada Atsushi, Terada Naoki, Koshio Kaihei

    The Horticulture Journal   advpub ( 0 )   2023

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    Language:English   Publisher:The Japanese Society for Horticultural Science  

    <p>Passion fruit (<i>Passiflora edulis</i>) is a tropical fruit that can be consumed fresh or processed. It is a typical respiratory climacteric fruit which is highly perishable because of the loss of water that causes dehydration and thus shrinkage, affecting the fruit appearance; in addition, some quality traits such as fruit weight, firmness and vitamin C content can also be influenced. Therefore, this fruit has a short shelf life. Storage in low temperatures has been assessed to extent the passion fruit shelf life remaining its fruit quality traits; however, information about the application of the hypobaric method in this fruit is null. The objective of this research was to evaluate the physical and chemical characteristics of the yellow and purple passion fruit under hypobaric storage conditions in low temperature. Results showed the hypobaric method had a positive effect in decreasing fruit weight loss, declining the loss of firmness, and reducing the degradation of vitamin C during the storage period. It decreased the evolution of ethylene which is positive to delay fruit senescence, and the production of CO<sub>2</sub>. Finally, it was the only method which avoids the shrinkage completely in the purple passion fruits (‘Gulupa’, ‘Summer Queen’, and ‘Ruby Star’) and showed minor shrinkage in ‘POR1’ (yellow passion fruit). This method is considered as a promising technique to improve fruit storage.</p>

    DOI: 10.2503/hortj.qh-081

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Books and Other Publications 【 display / non-display

  • 沙漠学事典

    日本沙漠学会編( Role: Joint author)

    丸善出版  2020.08 

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    Total pages:534   Responsible for pages:302-303   Language:Japanese   Book type:Dictionary, encyclopedia


  • 国際農業開発入門-環境と調和した食料増産をめざして-

    ( Role: Joint author)

    筑波書房  2017.04 

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    Total pages:293   Responsible for pages:85-101   Language:Japanese   Book type:Textbook, survey, introduction