Quality evaluation and prediction of Citrullus lanatus by 1H NMR-based metabolomics and multivariate analysis

(1)H NMR spectrometry in combination with multivariate analysis was considered to provide greater information on quality assessment over an ordinary sensory testing method due to its high reliability and high accuracy. The sensory quality evaluation of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) was carried out by means of (1)H NMR-based metabolomics. Multivariate analyses by partial least-squares projections to latent structures-discrimination analysis (PLS-DA) and PLS-regression offered extensive information for quality differentiation and quality evaluation, respectively. The impact of watermelon and rootstock cultivars on the sensory qualities of watermelon was determined on the basis of (1)H NMR metabolic fingerprinting and profiling. The significant metabolites contributing to the discrimination were also identified. A multivariate calibration model was successfully constructed by PLS-regression with extremely high reliability and accuracy. Thus, (1)H NMR-based metabolomics with multivariate analysis was considered to be one of the most suitable complementary techniques that could be applied to assess and predict the sensory quality of watermelons and other horticultural plants.     

Why invest in minor projects in sub-Saharan Africa? An exploration of the scale economy and diseconomy of irrigation projects

It is well-known that major irrigation projects have a strong scale economy, handicapping irrigation development in sub-Saharan Africa (SSA) because of the difficulty in formulating large-scale projects. Using project-level investment cost and performance data of major and minor irrigation projects, this paper examines the causes of the economy of scale phenomenon. We find that strong scale economy exists not only for major but also for minor projects, i.e., small- and micro-scale, projects. This is largely because of the existence of indivisible overhead costs such as high-opportunity-cost human resources for planning, designing and engineering management and supervision. We also find that large differences between major and minor projects in the absolute level of overhead as well as construction costs creates a strong scale diseconomy and results in better performance of minor projects. The advantage of minor projects holds even when their higher risk associated with the water source is taken into consideration. We argue that there is an urgent need to promote irrigation development in SSA through developing minor projects, and to reduce the heavy burden of overhead costs by developing the capacity of human resources at the national, local and farmer levels in the fields of irrigation engineering, irrigation agronomy, institutional development, and micro water management technologies.     

Chemical analysis of the product in acid-catalyzed solvolysis of cellulose using polyethylene glycol and ethylene carbonate

Degradation and decomposition of cellulose were studied in an acid-catalyzed solvolysis treatment of biomass using polyethylene glycol (PEG) and ethylene carbonate (EC). The solvolysis reaction was followed by a typical reaction system of wood liquefaction that uses sulfuric acid catalyst at 140° or 150°C at atmospheric pressure. The methods of fractionation and chemical analysis of the degraded cellulose in the solvolyzed product are discussed. The solvolyzed product was separated into several fractions, and they were hydrolyzed to release glucose and levulinic acid to determine the quantity of glucosides and levulinates in the solvolysis product. The data clearly showed that the solvolysis reaction had the same mechanism when using PEG or EC. Degradation of cellulose leads to the formation of glucosides, which then decompose, resulting in a levulinic acid structure, and producing a water-insoluble fraction. The conversion rates of both glucosides and levulinates strongly depend on the reaction conditions of the solvolysis. In particular, EC promotes faster conversion of the reactions. The method discussed here is a chemical analytical technique for characterization of the products of wood liquefaction.     

Molecular and genealogical analysis of grain dormancy in Japanese wheat varieties,with specific focus on MOTHER OF FT AND TFL1 on chromosome 3A

In the wheat (Triticum aestivum L.) cultivar ‘Zenkoujikomugi’, a single nucleotide polymorphism (SNP) in the promoter of MOTHER OF FT AND TFL1 on chromosome 3A (MFT-3A) causes an increase in the level of gene expression, resulting in strong grain dormancy. We used a DNA marker to detect the ‘Zenkoujikomugi’-type (Zen-type) SNP and examined the genotype of MFT-3A in Japanese wheat varieties, and we found that 169 of 324 varieties carry the Zen-type SNP. In Japanese commercial varieties, the frequency of the Zen-type SNP was remarkably high in the southern part of Japan, but low in the northern part. To examine the relationship between MFT-3A genotype and grain dormancy, we performed a germination assay in three wheat-growing seasons. On average, the varieties carrying the Zen-type SNP showed stronger grain dormancy than the varieties carrying the non-Zen-type SNP. Among commercial cultivars, ‘Iwainodaichi’ (Kyushu), ‘Junreikomugi’ (Kinki-Chugoku-Shikoku), ‘Kinuhime’ (Kanto-Tokai), ‘Nebarigoshi’ (Tohoku-Hokuriku), and ‘Kitamoe’ (Hokkaido) showed the strongest grain dormancy in each geographical group, and all these varieties, except for ‘Kitamoe’, were found to carry the Zen-type SNP. In recent years, the number of varieties carrying the Zen-type SNP has increased in the Tohoku-Hokuriku region, but not in the Hokkaido region.     

Distribution of photoperiod-insensitive allele Ppd-A1a and its effect on heading time in Japanese wheat cultivars

The Ppd-A1 genotype of 240 Japanese wheat cultivars and 40 foreign cultivars was determined using a PCR-based method. Among Japanese cultivars, only 12 cultivars, all of which were Hokkaido winter wheat, carried the Ppd-A1a allele, while this allele was not found in Hokkaido spring wheat cultivars or Tohoku-Kyushu cultivars. Cultivars with a photoperiod-insensitive allele headed 6.9–9.8 days earlier in Kanto and 2.5 days earlier in Hokkaido than photoperiod-sensitive cultivars. The lower effect of photoperiod-insensitive alleles observed in Hokkaido could be due to the longer day-length at the spike formation stage compared with that in Kanto. Pedigree analysis showed that ‘Purple Straw’ and ‘Tohoku 118’ were donors of Ppd-A1a and Ppd-D1a in Hokkaido wheat cultivars, respectively. Wheat cultivars recently developed in Hokkaido carry photoperiod-insensitive alleles at a high frequency. For efficient utilization of Ppd-1 alleles in the Hokkaido wheat-breeding program, the effect of Ppd-1 on growth pattern and grain yield should be investigated. Ppd-A1a may be useful as a unique gene source for fine tuning the heading time in the Tohoku-Kyushu region since the effect of Ppd-A1a on photoperiod insensitivity appears to differ from the effect of Ppd-B1a and Ppd-D1a.     

Ecology and conservation of two endangered subspecies of the leopard cat (Prionailurus bengalensis) on Japanese islands

The conservation of rare species on islands is a special challenge, especially when the islands are faced with increasing human impact. Two endangered wild felids in Japan provide a contrast that is useful for examining conservation strategies. The Iriomote cat (Prionailurus bengalensis iriomotensis) is endemic to Iriomotejima Island in Okinawa, and the Tsushima leopard cat (Prionailurus bengalensis euptilurus) occurs in the Tsushima islands in Japan, although a related subspecies found in the Korean Peninsula. Population size was approximately 100 individuals for each subspecies. While the population of Iriomote cat appears relatively stable, the population and abundance of the Tsushima leopard cat has decreased in recent decades. Because of their small population sizes and restricted habitats both are listed as endangered species/subspecies in Japan’s Red List, and the Iriomote cat is listed as an endangered subspecies in the IUCN Red List. Although both are similar-sized felids living on small islands, their ecological characteristics such as food habit, habitat selection, and density differ. These differences seem to be caused by the climate, the biological environment (the species composition of fauna in each island, and the presence of competitors), and the artificial background. The threats facing these two felids are also similar. Habitat destruction, traffic accidents, and negative influences by introduced species are the principal threats to be addressed for their conservation. At the same time, there are differences in the degree of impact by each threat, in each species’ conservation programs in practice, and in the stages of progress and operation of programs. These differences are partly because they have different ecological features and partly because the social background of each island, such as human population, main industry, and historical relationship between human and wildlife, are quite different. We will compare the ecology and state of these two wild felids and discuss the different conservational situations in relation to felid ecology and human society.     

The T allele at the g.1471620G>T in the EDG1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marbling

Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G > T , in the 5' flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 ( EDG1 ) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G > T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G > T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G > T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the allele was absent or at very low frequencies in the other breeds that have not been strongly selected for high marbling. Based on this finding, we hypothesized that the pressure of the strong selection for high marbling in Japanese Black breed has increased the frequency of the T allele at the g.1471620G > T SNP in the EDG1 .     

PCR-DGGE analysis of bacterial communities in <Emphasis Type="Italic">funazushi</Emphasis>, fermented crucian carp with rice,during fermentation

Funazushi (fermented Crucian Carp with rice) is a fermented fish product found only around Lake Biwa in Shiga Prefecture, Japan. It is characterized by a unique cheese-like flavor and characteristic sour taste. We analyzed the changes in the microbial community during funazushi fermentation by denaturing gradient gel electrophoresis of PCR-amplified 16S rDNA fragments (PCR-DGGE) and by plate counts. The plate counts showed that lactic acid bacteria reached 8.0 log₁₀ CFU/g within 7 days of fermentation initiation before decreasing slowly to 4.0 log₁₀ CFU/g during the remainder of 1-year study period. PCR-DGGE revealed that the dominant bacteria in the initial (days 14 and 30) and latter (days 90, 180, and 360) periods of fermentation were Lactobacillus plantarum and L. acetotolerans. This is the first identification of L. acetotolerans in funazushi as traditional cultivation techniques have not been sufficiently sensitive. This is the first report of PCR-DGGE being used to assess the microbial community in funazushi. This technique was also found to be effective in profiling microbial diversity.     

Identification and validation of a quantitative trait locus associated with wheat yellow mosaic virus pathotype I resistance in a Japanese wheat variety

Yellow mosaic disease, caused by wheat yellow mosaic virus (WYMV), is one of the most serious diseases of winter wheat (Triticum aestivum L.) in Japan. The three pathotypes of WYMV are distributed in different geographical areas: pathotype I is found mainly in western and central Japan (Kanto), pathotype II in northern Japan (Tohoku and Hokkaido) and pathotype III on the southern island of Japan (Kyushu). A total of 246 doubled‐haploid (DH) lines, derived from a cross between ‘Yumechikara’ (resistant) and ‘Kitahonami’ (susceptible), were evaluated for 2 years for their resistance to WYMV pathotype I. A single major quantitative trait locus, Q.Ymym, mapping to chromosome 2D was associated with resistance to pathotype I in ‘Yumechikara’. This is the first time a QTL responsible for pathotype I resistance has been identified. Fine mapping of Q.Ymym indicated that it was on a tight linkage block originating from ‘Yumechikara’, and the markers associated with this block will accelerate the development of varieties resistant to WYMV pathotype I.