Yasuomi Ibaraki

Plant tissue culture engineering

Part 1: Machine Vision Evaluation of photosynthetic capacity in micropropagated plants by image analysis/Y. Ibaraki Monitoring gene expression in plant tissues/J.J. Finer, S.L. Beck, M.T. Buenrostro-Nava, Y. Chi, P.P. Ling Applications and potentials of artificial neural networks in plant tissue culture/V.S.S. Prasad, S. Dutta Gupta Evaluation of plant suspension cultures by texture analysis/Y. Ibaraki Part 2: Bioreactor Technology Bioengineering aspects of bioreactor application in plant propagation/S. Takayama, M. Akita Agitated, thin-films of liquid media for efficient micropropagation/ J. Adelberg Design, development and applications of mist bioreactors for micropropagation and hairy root culture/M.J. Towler, Y. Kim, B.E. Wyslouzil, M.J. Correll, P.J. Weathers Bioreactor engineering for recombinant protein production using plant cell suspension culture/W.W. Su Types and designs of bioreactors for hairy root culture/Y-E Choi, Y-S Kim, K-Y Paek Oxygen transport in plant tissue culture systems/W.R. Curtis, A.L. Tuerk Temporary immersion bioreactor/F. Afteen Design and use of the wave bioreactor for plant cell culture/R. Eibl, D. Eibl Part 3: Mechanized Micropropagation Integrating automation technologies with commercial micropropagation/C.J. Sluis Machine vision and robotics for the separation and regeneration of plant tissue cultures/P.H. Heinemann, P.N. Walker Part 4: Engineering Cultural Environment Closed systems for high quality transplants using minimum resources/T. Kozai Aeration in plant tissue culture/S.M.A. Zobayed Tissue culture gel firmness: measurement and effects on growth/S.I. Cameron Effects of dissolved oxygen concentration on somatic embryogenesis/K. Kurata, T. Shimazu A commercialized photoautotrophic micropropagation system/T. Kozai, Y. Xiao Intelligent inverse analysis for temperature distribution in a plant culture vessel/H. Murase, T. Okayama, Suroso Part 5: Physical Aspects of Plant Tissue Engineering Electrical control of plant morphogenesis/C.G. Carmen The uses of ultrasound in plant tissue culture/V. Gaba, K. Kathiravan, S. Amutha, S. Singer, X. Xiaodi, G. Ananthakrishnan Acoustic characteristics of plant leaves using ultrasonic transmission waves/M. Fukuhara, S. Dutta Gupta, L. Okushima Physical and engineering perspectives of in vitro plant cryopreservation/E.E. Benson, J. Johnston, J. Muthusamy, K. Harding

Automation of somatic embryo production

Automation could enhance the use of somatic embryogenesis for micropropagation in two ways: as effective tools for research on somatic embryogenesis, and for improving the efficiency of embryo production by reducing labor costs. Processes expected to be automated for somatic embryo production are: (1) evaluation of embryogenic cultures, (2) embryo development, (3) harvesting, (4) post-harvesting (pre-delivery) processes for enhancing conversion and preparing for delivery. In this review, the techniques related to the automation of each process are introduced and discussed.

Estimation of the chlorophyll content of micropropagated potato plants using RGB based image analysis

A method has been developed for rapid and non invasive determination of chlorophyll content of leaves of micropropagated potato plants using RGB based image analysis. Among the trichomatic colors, R and G negatively correlated with the chlorophyll content, while a positive correlation was observed with B chromate. Compared to mean brightness value, the use of mean brightness ratio considerably improved the relationship of the tricolors with chlorophyll content. The brightness values and ratios of the primary colors are modeled as linear correlation functions for chlorophyll content. A significant correlation was observed between the model predicted chlorophyll content with the chlorophyll content measured by chlorophyll content meter. Spectral properties such as luminosity and saturation were also found to be negatively correlated with the chlorophyll content. The relationship was improved by combining the mean brightness ratio at B band region with luminosity. The potential of the imaging system in micropropagation has been discussed.

Antifungal effect of 405‐nm light on Botrytis cinerea

There is very little information on the fungistatic or fungicidal effect of visible light. This study investigated the effect of 405‐nm light, generated by a light‐emitting diode array, on the economically important fungus Botrytis cinerea. The mycelial growth of B. cinerea was inhibited to the greatest extent by light at 405 and 415 nm and was negligibly inactivated at 450 nm, suggesting the presence of a photosensitizing compound that absorbs light mainly at wavelengths of 405–415 nm. Delta‐aminolevulinic acid, a precursor of endogenous photosensitizer porphyrins, was used to determine the role of these porphyrins in 405‐nm light‐mediated photoinactivation of the fungus. Concentration‐dependent inhibition of spore germination by delta‐aminolevulinic acid and accumulation of singlet oxygen in the spores was observed when the spores were exposed to 405‐nm light. These results suggest that the excitation of endogenous porphyrins and subsequent accumulation of singlet oxygen could partially explain the 405‐nm light‐mediated photoinactivation of B. cinerea. The development of symptoms in detached tomato leaves inoculated with B. cinerea spores was significantly reduced by irradiation with 405‐nm light, indicating that 405‐nm light has a potential use for controlling plant diseases caused by B. cinerea.

Measuring leaf necrosis and chlorosis of bamboo induced by typhoon 0613 with RGB image analysis

Symptoms of leaf necrosis or chlorosis of bamboo induced by Typhoon 0613 (T0613) were analyzed using RGB image analysis in Yamaguchi city, Japan. Results showed a closely positive relationship between Green/Red (G/R) value for indoor taking images of bamboo individual leaves and chlorophyll meter value (SPAD) with regression coefficient of 0.961. The relation between G/R value of room taking images and Necrotic Area Percentage (NAP) for bamboo individual leaves showed an inverse logistic function relationship, with the correlated coefficient equaling to 0.958. Both leaf chlorosis and necrosis can be quantitatively estimated by RGB image analysis. Moreover, the variance of Green/Luminance (G/L) value for the same leaf was less than that of G/R for images taken in the conditions with large light difference, especially for green leaves. G/L value also exhibited a closer relationship with SPAD value of leaves with chlorosis than that of G/R values at the same condition. The relationship between G/L value for bamboo canopies and the Distance from Coastline (DC) was also closer than that of the G/R value for the images taken at field sites with big light difference.

Estimation of light intensity distribution in a culture vessel

Distribution of photosynthetic photon flux density (PPFD) in a culture vessel was estimated using a sensor film for measuring the integrated solar radiation. A plantlet model whose leaves were constructed from sensor film was used to simulate a potato plantlet. The plantlet model was put into a culture vessel and, after exposure to culture conditions for 20 days, PPFD was estimated for each individual model leaf based on the degree of fading of the sensor film. The method was able to demonstrate the light intensity distribution patterns inside a small test tube under downward lighting conditions. This technique allows for the estimation of light intensity distribution patterns inside a small culture vessel, which was previously difficult to measure by conventional methods.

Nondestructive evaluation of the photosynthetic properties of micropropagated plantlets by imaging photochemical reflectance index under low light intensity

The photochemical reflectance index (PRI) of micropropagated potato leaves was estimated nondestructively from outside the culture vessel using a PRI imaging system developed by the present group. The PRI was determined under low light intensity conditions after dark treatment and compared with the chlorophyll fluorescence parameter Fv/Fm, which denotes photosystem II maximum quantum yield. Short-term high-light treatment decreased Fv/Fm of the plantlets. Culture conditions such as temperature and sucrose concentration also affected Fv/Fm. A linear relationship between the PRI and Fv/Fm was observed in both cases of high-light treatment and different culture conditions, suggesting the potential of the PRI to be used as a substitute for Fv/Fm. PRI estimated from reflection images under low light intensity conditions may be used for rapid and noninvasive evaluation of photosynthetic properties of micropropagated plantlets in a similar manner to Fv/Fm.

Responses of some landscape trees to the drought and high temperature events during 2006 and 2007 in Yamaguchi, Japan

Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel and spectral reflectance. Results show that after the dry, hot and windy summer in 2007, many landscape trees in Yamaguchi City tended to respond the extreme weather events by reducing their leaf surface area and receiving less radiation energy. Premature leaf discoloration or defoliation appeared on some landscape tree species and leaf necrosis occurred on tip and margin of many Kousa dogwood (Cornus kousa) trees at unfavorable sites. Described by image pixel analysis method, the leaf necrotic area percentage (LNAP) of sampled dogwood trees averaged 41.6% and the sampled Sasanqua camellia (Camelia sasanqua) tree also showed fewer flowers in flower season of 2007 than that in 2006. By differential analysis of partial discolored crown, it presented a logistic differential equation of crown color for sweet gum (Liquidambar styraciflua) trees. It suggested that the persistent higher temperature and lower precipitation could be injurious to the sensitive landscape trees at poor sites, even in relative humid area like Yamaguchi.

Development of an Android-tablet-based system for analyzing light intensity distribution on a plant canopy surface

We developed an Android application system for easy estimation of PPFD distribution.The system output a PPFD histogram on the canopy surface from a reflection image.The system can be applied for plant production under artificial lighting. An Android application system for the simple and real-time estimation of light intensity distribution on a plant canopy surface was developed, and its usefulness was tested under artificial lighting. The application system was designed to semi-automatically analyze the photosynthetic photon flux density (PPFD) distribution on the canopy from a reflection image acquired by the tablet. A single manual measurement by a quantum sensor at a point on the canopy was performed to build a regression model that estimated the PPFD on leaves from the pixel values of the image. Measured and estimated PPFD histograms, as well as parameters derived from histograms, were compared at three different growth stages of a plant canopy in a closed plant factory with artificial lighting. The measured and estimated histograms exhibited a similar pattern at each growth stage with close values of the parameters. The results suggested that the reflection-image-based estimation system developed in this study was a useful method for analyzing the light conditions under artificial lighting. Although the developed system will require additional improvements in automation and performance before it can be applied to actual cultivation-management procedures, this simple method for estimating the light intensity distribution is expected to help improve the efficiency and reproducibility of light control methods used for plant production.

Evaluation Of Plant Suspension Cultures By Texture Analysis

Plant cell suspension culture has been widely used as a way for cell proliferation in research and is extending to commercial use. To make the best use of this technique, it is essential to maintain cell quality. Selection of cell suspensions having desirable properties is a routine work in plant cell suspension culture [1]. Image analysis techniques appear to be one of the promising methods for evaluation of cell suspension cultures because it can offer non-destructive monitoring of culture giving an objective index for visual information [1,2]. The macroscopic visual appearance of cell suspensions may vary with colour and size distribution of cell aggregates in the cell suspensions, depending on culture conditions, culture periods, or cell lines. Hence, the visual texture of a macroscopic image of a cell suspension may be used for evaluation of cultured cell quality [1,3]. In this chapter, the feasibility and problems of methods for the non-destructive evaluation of cell suspension cultures will be discussed, focusing on texture analysis of macroscopic images of cell suspensions. First, macroscopic images will be compared with microscopic images from the viewpoint of their use for non-destructive evaluation of cell suspension cultures, and basics of texture analysis for biological objects will be explicated. Next, as an example of application of texture analysis for macroscopic images, a research on evaluation of somatic embryogenic potential of carrot cell suspension culture will be introduced.