Reviews in Agricultural Science
Online ISSN : 2187-090X
Volume 4
Showing 1-7 articles out of 7 articles from the selected issue
  • Saori Yamamoto
    2016 Volume 4 Pages 1-7
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    Most avian species have breeding seasons that are appropriate for their survival. The hypothalamic-pituitary-testicular axis controls the endocrine system and the onset of breeding. The Tetraonidae (a family of birds in the order Galliformes) live in extreme environments where their breeding season is restricted by ambient factors, particularly day length. In the breeding season, male Tetraonidae birds prominently express combs over their eyes (supraorbital combs), the expression of which is controlled by testosterone, a well-known androgen. Testosterone also regulates immunocompetence and there is a trade-off between the cost for condition and the benefit for reproduction in the expression of sexual traits like the comb. Thus, the comb may be the specific indicator projecting male quality. This article reviews the effects of the endocrine system on reproduction and expression of the comb in male Tetraonidae.

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  • M.S.A. Mamun, Koji Tsuchida, Takeo Onishi, Ken Hiramatsu, Atsushi Iwas ...
    2016 Volume 4 Pages 8-20
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    Medaka is familiar to Japanese people as a small fish inhabiting paddy fields, agricultural water channels and ponds. This would be a consequence of adaptation of medaka to the agricultural management calendar during the long history of Japanese paddy production. However, medaka has been categorized as “vulnerable” in the Red List of Threatened Wildlife of Japan since 1999. Habitat deterioration due to the recent modernization of paddy fields and agricultural channels is suggested as a likely cause. On the other hand, medaka has a history of more than a century as an excellent experimental model vertebrate like zebrafish, and a draft nucleotide sequence of the whole genome was released in 2007. Such biological information can be successfully applied to the conservation of medaka in paddy fields and channels. We summarize genetic analyses of medaka including our own research to elucidate the effects of the modernization of agricultural water channels to the subpopulation structure of medaka. We also focus on the analytical methods such as PCR-RFLP, RAPD and microsatellite and examples of their use in population structure analyses of various organisms that are much more detailedly examined for conservation purpose than medaka. Conservation efforts of medaka in paddy fields would be most successful if they are harmonized with the paddy production there. Practices to promote production and add values to the products such as “medaka rice” are mentioned in this context.

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  • Yanyan Dai, Masateru Senge, Kohei Yoshiyama, Pengfei Zhang, Fuping Zha ...
    2016 Volume 4 Pages 21-35
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    Soil-borne diseases are one of the major constraints in the production of many economically important crops, especially vegetables and ornamentals. In the past decades, soil fumigants (such as methyl bromide) were the most common approach to control soil-borne diseases. However, such chemical treatments caused environmental hazards; thus, nonchemical soil disinfection methods are being widely pursued in recent years. Among these, soil solarization is one of the most promising methods to control soil-borne diseases. Soil temperature, mulching materials, soil moisture, and climatic conditions are the critical factors that affect the disinfection efficiency. In addition, other factors, for example, soil type; soil color; airtight state of glasshouse; etc. also influence the efficiency. Soil solarization controls soil-borne pests and diseases, nematodes, and weeds, and also influences soil properties and plant growth and yield. Although there are many merits for soil solarization, it also has significant limitations, for example, the relatively long duration of the process, the dependency on climatic conditions, inconsistencies in controlling high-tolerant pests, and problems related to used plastic film disposal. In order to increase treatment efficacy and predictability, integration of solarization with other disinfestation methods is recommended.

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  • Tokumasa Horiike
    2016 Volume 4 Pages 36-45
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    Phylogenetic analysis using molecular data such as DNA sequence for genes and amino acid sequence for proteins is very common not only in the field of evolutionary biology but also in the wide fields of molecular biology. The reason is that DNA sequencing became very popular and a huge amount of sequence data of genes and proteins are available in the public online database. Since many molecules (genes or proteins) which have various evolutionary rates are available, it is important to choose the suitable molecule for the phylogenetic analysis of a given lineage. For example, when the evolutionary rate of the gene (or protein) is too much higher for a given lineage, the substitution of nucleotide (or amino acid) is saturated. In this case, the accuracy of the phylogenetic analysis decreases. The methods for phylogenetic analysis are improving along with the evolution of computer science. Thus, there are many methods to infer phylogenetic tree, and many programs for each method are available. This mini review shows that general pattern of phylogenetic analysis, and explains some representative methods (Unweighted pair group method with arithmetic, Neighbor-joining method, Maximum parsimony method, maximum likelihood method, and Bayesian method). In the phylogenetic analysis, the most important feature is the interpretation of the phylogenetic tree. Therefore, several distinct points to evaluate a phylogenetic tree are also explained. These include, “validity of the tree shape”, “evolutionary distance”, and “validation of each internal branch”. Towards the end, the procedure of evaluating a phylogenetic tree with an example using MEGA 7 is presented.

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  • Pengfei Zhang, Masateru Senge, Yanyan Dai
    2016 Volume 4 Pages 46-55
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    Salt added to nutrient solution is an easy method that can improve tomato fruit quality, but plant growth and fruit production are negatively affected. Salinity reduces tomato root elongation rate and lateral root growth due to restriction of root cell growth and increased root lesion. Tomato leaf, shoot height and stem diameter reduced under salinity stress caused by photosynthesis reduction, tissues expansion reduction and cell divided inhibition. Salinity also reduces leaf chlorophyll content, stomatal resistance and photosynthetic activities. Total yield of tomato is significantly reduced at salinity equal and above 5 dS m-1, and a 7.2% yield reduction per unit increase in salinity. Salinity can decrease root water uptake through its osmotic effect, and subsequently induce water stress. Fruit quality is the only parameter which is positively affected with increased salinity.

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  • Methavee Peanparkdee, Satoshi Iwamoto, Ryo Yamauchi
    2016 Volume 4 Pages 56-65
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    Microencapsulation is a technique that has been widely used in the food and pharmaceutical industries. This technique can be used to reduce the cost of production, to increase the stability of compounds, to mask undesirable tastes, and to improve the release properties of compounds in food industries. Currently, microcapsules are utilized in beverage, bakery, meat, poultry, and dairy products. Moreover, microencapsulation has been used to increase stability, to mask bitter taste, to improve the release properties of drugs, and to provide specific drug delivery in pharmaceutical industries. The challenge of microencapsulation is in selection of the appropriate conditions for producing highly effective microcapsules. Many factors affect the quality of microcapsules, including preparation techniques, types of core material, and types of wall material. We provide an overview of the current research on the applications of microencapsulation in food and pharmaceutical industries, the selection of suitable conditions for developing high efficiency microcapsules, and future trends in microencapsulation.

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  • Sachi Sri Kantha
    2016 Volume 4 Pages 66-72
    Published: 2016
    Released: March 29, 2019
    JOURNALS FREE ACCESS

    In this editorial, Francis Crick's research corpus of 105 papers, spanning from 1950 to 2013, is promoted as useful guides in manuscript preparation for graduate students. Especially to be noted is Crick and his co-authors' versatility in formulating the different components of a research paper such as, title composition, abstract writing, brevity in describing the experimental results or hypotheses, discussion and/or future projections, and acknowledgment composition.

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