Mode of transmission and morphological structures of two <Emphasis Type="Italic">Eremothecium</Emphasis> species between <Emphasis Type="Italic">Riptortus pedestris</Emphasis> and soybean

Eremothecium ashbyi and E. coryli were present in the maxillary and mandibular stylet pouches of the contaminated heads of the true bug Riptortus pedestris collected during a field survey, 2007. Ascospores of E. ashbyi and E. coryli were taken up in the stylet pouch when R. pedestris fed on soybean seeds infected with the respective fungus. In the case of E. ashbyi, the ascospores had subsequently germinated and were recognized as large masses of mycelia in the stylet pouch. In contrast, masses of E. coryli including buds of irregular size and shape were recognized about 3 days after. These results proved that these yeasts are taken up and become lodged in the stylet pouch when the insect feeds on infected host plants. In stylet sheaths stained with erythrosine, E. ashbyi was found as fragments of mycelia and E. coryli was found as small buds. These observations yield evidence to confirm that E. ashbyi and E. coryli are transmitted as fragments of mycelia and as small buds, respectively, after the insect has fed on infected host plants.     

An interpretation of the conductometric titration curve of humic acid

Methods of fractionating the functional groups of humic acid by conductometric titration were examined. Replacement titration, in which a sample solution is titrated with a standard acid solution after adding an excess amount of a standard base, seems to be a suitable method. By this method, the functional groups of humic acid were fractionated into three clusters of different dissociation constants, designated as VW (very weak), W (weak), and S (strong) clusters. The VW cluster was presumed to include phenolic hydroxyl residues, carboxyl residues and nitrogenous bases of very high pK's. The W cluster was presumed to include various aliphatic and aromatic carboxyl residues and nitrogenous bases of medium pK's, whereas the S cluster was presumed to include carboxyl residues of low pK₁ of salicylate or phthalate. A humic acid sample obtained from the A horizon of Shitara “kuroboku” soil had 0.78 me/g of the VW cluster, 3.24 me/g of the W cluster and 1.90 me/g of the S cluster.     

Some Physico-chemical characteristics of soils influenced by Taal Volcano in reference to soil productivity

Soils of the northwestern part of the Taal Volcano in the Philippines representing four geomorphological units (upper, middle, and lower slopes and alluvial plains) were investigated and related to soil productivity. Results revealed that the soils on the upper and middle slopes contained higher amounts of organic matter and available P and displayed a low P retention together with more favorable physical properties such as loamy soil texture, loose and friable and well-drained soils compared to those on the lower slopes and in the alluvial plains. Due to these favorable soil characteristics, sustained agricultural production was higher at the upper elevations than at the lower elevations. Year-round multistorey / mixed cropping systems of cultivation in the upper and middle landscapes were also made possible because the higher precipitation was evenly distributed coupled with cooler temperatures compared the conditions on the lower slopes and in the alluvial plains. On the other hand, the soils on the lower slopes and in the alluvial plains had a clayey texture and contained a lower amount of organic matter and available P, in addition to the lower precipitation, resulting in reduced land utilization, as indicated by the limited types of crops grown and lower yield of crops.     

Rare earth elements and other trace elements in wastewater treatment sludges

In order to evaluate the possibility of contamination of soil with trace elements by the application of sludges to soil, the contents of rare earth elements (REEs; La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and other trace elements (Be, As, Ag, Cd, Sb, Cs, Bi, and U) in wastewater treatment sludges were determined. In sludges of night soil treatment plants (night soil sludges) and sludges of wastewater treatment plants in the food industry (food industry sludges), the distribution patterns of REEs normalized versus average REEs in the continental crust were almost flat. It was considered that the REE patterns of uncontaminated sludges reflected the pattern of the continental crust. The crust-normalized REE patterns of sludges of wastewater treatment plants in the chemical industry (chemical industry sludges) and municipal sewage sludges did not always show flat plots. The sludges that did not show a flat REE pattern were considered to be contaminated with some of the REEs.

The coefficient of variation of each element determined among the 10 samples of night soil sludges and the 14 samples of sewage sludges ranged from 34 to 77% and from 26 to 84%, respectively. Among the 10 samples of food industry sludges and the 10 samples of chemical industry sludges, the coefficient ranged from 60 to 143% and from 67 to 172%, respectively. The variations of the content of each element among the food industry sludges or the chemical industry sludges were larger than those among the night soil sludges or the sewage sludges.

The contents of Be, As, Cs, REEs, and U in all the sludges were lower than or the same as those in a field soil. Some of the food and chemical industry sludges contained larger amounts of Ag, Cd, and Sb than the soil. All the night soil sludges and sewage sludges contained much larger amounts of Ag and Bi than the soil.     

Fractional determination of functional groups of humic acids by conductometric titration

The conductometric replacement titration proposed in a previous report disclosed that the functional groups of humic acids are fractionated into three clusters of different dissociation constants, designated as VW, W and S clusters. In this paper, the method was examined to ascertain the relationship between the concentration of a sample and the amounts of fractionated clusters. The total amounts of fractionated clusters as well as the amount of the S cluster were directly proportional to the concentration of the sample, whereas the amount of the VW cluster decreased a little as concentration increased. The same method, applied to various types of humic acids in Japan, showed that the sums of the functional groups and the ratios of the S cluster to the sums likewise decreased in the order of A type > B and P types > Rp type. The total acidities determined by conductometry were nearly equal to the sums of carboxyl determined by Blom's method and phenolic hydroxyl determined by Folin's method.     

Molecular mapping and identification of candidate gene conferring organophosphate-sensitive reaction in sorghum (Sorghum bicolor)

Some sorghum cultivars are sensitive to organophosphate insecticides, which cause red to purple injury spots and, in severe cases, leaf death. Sensitivity to organophosphates is conditioned by a single locus on chromosome 5. We constructed a high-density genetic map around the locus, termed osr, using DNA markers, and delimited osr to a 377-kb region on the short arm of chromosome 5. Sequence analysis of this region predicted 19 gene candidates. Four of the candidates are homologous to a disease resistance NBS-LRR gene. mRNA-Seq analysis of gene expression and SNPs from two resistant cultivars (‘JN43’ and ‘Greenleaf’) and one sensitive cultivar (‘Nakei MS3B’) suggest that one or more members of this NBS-LRR gene family are osr. Our results suggested that the recessive allele of osr results in sensitivity to OP insecticides.     

A novel waxy allele in sorghum landraces in East Asia

A loss of granule‐bound starch synthase I (GBSS I) activity results in starch granules that contain mostly amylopectin and little or no amylose, a phenotype described as waxy. Previously, two phenotypic classes of waxy alleles, wx^a, associated with no detectable GBSS I, and wx^b, associated with apparently inactive GBSS I in the endosperm, were reported in sorghum (Sorghum bicolor (L.) Moench). In this study, the waxy alleles in a sorghum core collection were investigated using DNA markers. Of the 337 sorghum accessions examined, 17 accessions that were confirmed to be waxy by a negative iodine staining result and 16 were found to be wx^a. A novel waxy allele, wx^c, was found in a Taiwanese landrace. This allele consists of a +1G to C mutation in the 5′ splice site at the intron 10–exon 11 boundary, a mutation that most likely resulted in the suppression of GBSS I gene expression. A DNA marker specific for wx^c was produced to distinguish the wx^c allele from other alleles, allowing the identification of heterozygous non‐waxy plants.