Root phenotyping: important and minimum information required for root modeling in crop plants

As plants cannot relocate, they require effective root systems for water and nutrient uptake. Root development plasticity enables plants to adapt to different environmental conditions. Research on improvements in crop root systems is limited in comparison with that in shoots as the former are difficult to image. Breeding more effective root systems is proposed as the “second green revolution”. There are several recent publications on root system architecture (RSA), but the methods used to analyze the RSA have not been standardized. Here, we introduce traditional and current root-imaging methods and discuss root structure phenotyping. Some important root structures have not been standardized as roots are easily affected by rhizosphere conditions and exhibit greater plasticity than shoots; moreover, root morphology significantly varies even in the same genotype. For these reasons, it is difficult to define the ideal root systems for breeding. In this review, we introduce several types of software to analyze roots and identify important root parameters by modeling to simplify the root system characterization. These parameters can be extracted from photographs captured in the field. This modeling approach is applicable to various legacy root data stored in old or unpublished formats. Standardization of RSA data could help estimate root ideotypes.     

Intraocular vaccination with an inactivated highly pathogenic avian influenza virus induces protective antibody responses in chickens

Because it is expected to induce cross-reactive serum and mucosal antibody responses, mucosal vaccination against highly pathogenic avian influenza (HPAI) is potentially superior to conventional parenteral vaccination. Here, we tested whether intraocular vaccination with an inactivated AI virus induced protective antibody responses in chickens. Chickens were inoculated intraocularly twice with 10⁴ hemagglutination units of an inactivated H5N1 HPAI virus. Four weeks after the second vaccination, the chickens were challenged with a lethal dose of the homologous H5N1 HPAI virus. Results showed that most of the vaccinated chickens mounted positive antibody responses. The median serum hemagglutination inhibition titer was 1:80. Addition of CpG oligodeoxynucleotide 2006 or cholera toxin to the vaccine did not enhance serum antibody titers. Cross-reactive anti-hemagglutinin IgG, but not IgA, was detected in oropharyngeal secretions. In accordance with these antibody results, most vaccinated chickens survived a lethal challenge with the H5N1 HPAI virus and did not shed the challenge virus in respiratory or digestive tract secretions. Our results show that intraocular vaccination with an inactivated AI virus induces not only systemic but also mucosal antibody responses and confers protection against HPAI in chickens.     

Safety of the tram car for slopes examined by stress analysis of the ground structure

For monorail systems, it is very important to ensure the safety of the ground structure. We developed a tram car for slopes that utilizes the mechanism of the monorail and analyzed the stress of the ground structure that had double rails. First, we divided the ground structure into seven components, and formulated a procedure for calculating the stress of the ground structure. As a result, the stress that acts upon the main rail and the main rail connecting part was near the allowable stress, and each calculated value was within the allowable stress. We measured the stress by running the vehicle, and compared the measured values with the calculated values. As a result, some measured values were larger than the calculated values. However, the ratio of measured value to allowable stress was 90% or less. Finally, we calculated the static loading coefficient for each part, results of which were as follows: main and subrail: 1.1; rail connection part and prop foundation part: 1.0; rail installation part: 1.3. In the recalculations, it became clear that the recalculated values exceeded the allowable stresses. These results suggest that we need to review the ground structure materials.     

A Computer Program for Automatic Watering Based on Potential Evapotranspiration by Penman Method and Predicted Leaf Area in Miniature Pot Rose Production

In this study, we developed a computer program for automatic prediction of watering time point by considering the environmental factors such as solar radiation, air temperature and relative humidity based on the multiple linear regression equation of leaf area and Penman Method. The experiments were carried out for a year in two watering experimental plots, one of which was controlled by pF value, and the other by the computer program. After comparing the results of the two plots, the following findings were obtained. In the computer program plot, the observed and predicted values of both leaf area and evapotranspiration indicated significant correlation at the 1% level, which suggested that the computer program had high prediction accuracy. In addition, no significant difference was observed between the two experimental plots with respects to the plant height, plant diameter, leaf area, leaf number, fresh weight, and dry weight, which demonstrated that the plants in the computer program plot had normal growth. On the other hand, although the number of flower buds and flowering shoots showed higher values at the end of certain cultivations in the computer program plot than those in pF value plot, we proposed that it was due to the effect of cumulative daily solar radiation in the greenhouse, rather than the watering. Thus, we have reached the conclusion that the computer program for automatic prediction of watering time point developed by this study has high applicability in miniature pot rose production.     

Investigation of the Heavy Metal Sources in Relation to Automobiles

In order to investigate the sources of roadside heavy metal pollution, auto tire, gasoline, gas oil, kerosene, paint for road markings (white, yellow and red), the soot from the discharge spout, auto tire rubber, asphalt pavement, gray paint and anticorrosive on the guardrail were gathered together and analyzed. As a consequence, Pb may be originally from yellow and red road markings, and gray paint or anticorrosive. Hg is mainly emitted from the combustion of premium gasoline and diesel soot is an important source of As, Ni and Zn. Cd and Zn are mainly emitted from the abrasion of tire rubber. The wear of asphalt pavement is considered to be a source of Ni and V.     

Dual origin of the cultivated rice based on molecular markers of newly collected annual and perennial strains of wild rice species, Oryza nivara and O. rufipogon

The direct ancestor of rice (Oryza sativa L.) is believed to be AA genome wild relatives of rice in Asia. However, the AA genome wild relatives involve both annual and perennial forms. The distribution of the retrotransposon p-SINE1-r2, a short interspersed nuclear element (SINE) at the waxy locus was analyzed in diverse accessions of the AA genome wild relatives of rice (O. rufipogon sensu lato). Most annual wild rice accessions had this retrotransposon, while most perennial types lacked this element, contradicting results to the previous studies. Results presented here suggest that O. sativa has dual origin that lead to indica-japonica differentiation. Results suggest the indica line of rice varieties evolved from the annual genepool of AA genome and the japonica varieties from the perennial genepool of AA genome wild rice.     

Decline of <Emphasis Type="Italic">Pinus thunbergii</Emphasis> Parlat. stands due to excess soil moisture caused by a buried andosol layer at a coastal sand site in Hokkaido,northern Japan

To demonstrate the effect of excess soil moisture on the decline of a coastal Pinus thunbergii stand in Oshamanbe, southwestern Hokkaido, Japan, soil moisture content was monitored for 4 years. The saturated hydraulic conductivities (K _S) of different soil types (coastal sand, supplied topsoil, and buried concreted andosol) and the distribution of the buried concreted andosol layer were investigated. We also examined needle length to verify the real-time response of P. thunbergii to excess soil moisture. Soil moisture content at the heavily damaged site was more heterogeneous than that at the slightly damaged site, and a sensor near the ground always reported a higher soil moisture content at the heavily damaged site than at the slightly damaged site. The buried concreted andosol layer was always found at the heavily damaged site. The K _S of the andosol layer was 10⁻⁵, suggesting that this layer is less permeable to water, leading to excess soil moisture at this site. P. thunbergii needles from the heavily damaged site were shorter than those from the slightly damaged site, possibly because of water stress. Together with other symptoms observed at the study sites, i.e., crown dieback and intense lateral growth, this information leads us to conclude that the decline of P. thunbergii stands at the heavily damaged site in Oshamanbe was caused by excess soil moisture due to the less permeable buried concreted andosol layer.     

Isolation and characterization of lectins from the AG-D group of binucleate <Emphasis Type="Italic">Rhizoctonia</Emphasis> species

Isolates from 18 anastomosis groups (AGs) of binucleate Rhizoctonia were screened for lectin activity. Eight AGs (AG-B, AG-D, AG-F, AG-G, AG-H, AG-I, AG-R and AG-U) had low to moderate lectin activities. Among these, members of AG-D and AG-I had the highest activity. Partially purified lectins from AG-D preferentially agglutinated human blood type A to type B and O. Mucin and galactose were the most potent inhibitors among the tested carbohydrates. The molecular masses of these lectins ranged from 12.7 kDa for the monomer to 62 kDa for the pentamer type. Proline, alanine, glutamic acid, aspartic acid, leucine, threonine, serine and tyrosine were the major amino acid components of these lectins. Lectins from AG-D were stable at 4–50°C and from pH 6.0 to 10.0. When assayed with isoelectric focusing, these lectins gave bands at pI 9.30. Specificity of lectins from AG-D to galactose and its derivatives suggest a possible recognition role in this fungal species.     

Mitotic disruption by a novel pyrimidine herbicide, NS-245852, in oat (Avena sativa L.) roots

The effects of a novel pyrimidine herbicide, NS-245852 [2-chloro-6-fluorophenyl-4-(trifluoromethyl)thieno[2,3-d]pyrimidine-2-yl-ketone], on mitosis in oat ( Avena sativa L. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10⁻⁷ mol L⁻¹ of NS-245852, and swollen root tips were induced at 5 × 10⁻⁸ mol L⁻¹. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS-245852 is the inhibition of polymerization of tubulin into microtubules.