Effects of difference in fertilization treatments on nitrification activity in tea soils

Abstract

It is generally recognized that the nitrification activity in acid soils is very low. Indeed, nitrification in mineral soils has been found to be negligible at pH values below 5.0 (Dancer et al. 1973; Nyborg and Hoyt 1978). However, it was reported that autotrophic nitrification occurred in some tea soils at pH levels far below 5.0 (Walker and Wickramasinghe 1979; Hayatsu and Kosuge 1993). An acidophilic ammonia-oxidizing bacterium has been recently isolated from strongly acidic tea soils in Japan (Hayatsu 1993). On the other hand, fertilization has-been considered to be an important factor influencing nitrification in agricultural soils. For example, several studies have shown that the addition of ammoniacal fertilizer to soils can lead to the increase of the populations of Nitrosomonas (McLaren 1971; Ardakani et al. 1974). Liming of acidic soils also tends to stimulate the nitrification activity (Dancer et al. 1973; Nyborg and Hoyt 1978). Although nitrification has been studied in a wide variety of agricultural soils, there is little information available on nitrification in tea soils. The effect of fertilization on nitrification in tea soils is poorly documented.     

Effects of polyolefin‐coated fertilizer on nutritional quality of spinach plants

Pot experiments were conducted in order to evaluate the effects of four different urea or ammonium containing polyolefin‐coated fertilizers (POCFs) on the nutritional quality of spinach (Spinacia olèracea L.) and to investigate the mechanisms of these effects in comparison with conventional, rapidly available fertilizer. Compared to the conventional fertilization method yield was decreased in all the four POCF treatments due to less available fertilizer nitrogen (N) and/or realized ammonium nutrition. However, application of POCFs decreased oxalate and nitrate contents and increased ascorbate concent in spinach. Decreased oxalate and nitrate contents were attributed to lower nitrate availability in the soil having caused by the controlled‐released characteristic of POCFs and/or ammonium nutrition. Increased ascorbate content was due to both decreased oxalate and decreased nitrogen contents of the spinach plants. It was concluded that band applications of urea or ammonium containing POCFs improved the nutritional quality of spinach due to realized ammonium nutrition and/or less amount of available fertilizer N.     

New sources of compact spike morphology determined by the genes on chromosome 5A in hexaploid wheat

Little is known about the relationship between compact spike loci in hexaploid wheat species. We studied two new compact spike mutants of common wheat Triticum aestivum L. (2n?=?6x?=?42, genome formula BBAADD). The new compact spike genes, C ⁷³⁹ of MCK 739 and Cp of near-isogenic line Mironovskaya 808 (Vrn1), were mapped using aneuploid stocks and microsatellite markers. The C ⁷³⁹ and Cp loci were distally linked with the microsatellite marker Xbarc319 in the F₂ populations of MCK 739?×?‘Novosibirskaya 67’ and Cp-Mironovskaya 808 (Vrn1)?×?‘Saratovskaya 29’. It was evident that the loci affecting compact spikes in T. aestivum mutants were located on chromosome 5AL distal from Q locus. These loci also affected to semi-dwarfism. We named this locus Cp1 (C ompact p lant 1) for all accessions. Cp1 was allelic to C ¹⁷⁶⁴⁸ gene located on the chromosome 5AL of tetraploid wheat [Triticum durum Desf. (2n?=?4x?=?28, genome formula BBAA)]. These dominant genes on chromosome 5AL will be utilized as new gene resources of compact spike morphology in hexaploid wheat. Relationship between loci Q and Cp1 was also discussed.     

Recombination around the <Emphasis Type="Italic">P</Emphasis> locus for long glume phenotype in experimental introgression lines of <Emphasis Type="Italic">Triticum aestivum</Emphasis> – <Emphasis Type="Italic">Triticum polonicum</Emphasis>

A set of experimental introgression lines of Triticum aestivum L. cv. Novosibirskaya 67 (N67)—Triticum polonicum L. line IC 12196 was developed using a small-scale bulk breeding method. The linkage map in chromosome 7A was constructed using F₂ hybrids of N67/IC12196 and 34 microsatellite markers. The P gene was flanked by the centromeric markers, Xgwm890 (18.6 cM) and Xbarc108 (20.0 cM) on the long arm of chromosome 7A. Among 124 introgression lines, 118 lines were hexaploid (2n = 6x = 42), and 6 were tetraploid (2n = 4x = 28). Among hexaploid accessions, 68 were long-glumed, whereas 50 were normal-glumed. Thirty-four polymorphic microsatellite markers were scored for either the N67 alleles or IC 12196 alleles in 124 introgression lines derived from N67/IC 12196. The UPGMA dendrogram showed five clusters; Cluster 1 mainly contained hexaploid introgression lines with long glumes. Although the alleles around the P locus were recombined with IC1296 alleles, the distal end of the chromosome contained N67 alleles. Cluster 2 mainly contained normal glumed, hexaploid introgression lines. These predominantly had the N67 alleles on the long arm of chromosome 7A and the short arm proximal to the centromere. Cluster 3 contained long-glumed, hexaploid wheat lines with relatively high level of recombination. Cluster 4 contained non-parental alleles. Cluster 5 contained the group of tetraploid wheat lines. These tetraploid lines have IC12196 alleles on both arms of chromosome 7A. The frequency spectrum of parental alleles and chromosomal blocks among introgression lines suggested that T. aestivum – T. polonicum hybridization can rapidly give rise to a new landrace due to selective introgression of the P gene.     

Malignant melanoma of the eyelid in a red squirrel (Sciurus vulgaris orientis)

A 6-year-old male red squirrel (Sciurus vulgaris orientis) developed bilateral tumors of upper and lower eyelids. The tumors in the left lid recurred despite surgical removal. Necropsy revealed metastasis to the lung. The neoplastic cells were epithelioid and highly pleomorphic, and only a few cells contained melanin granules. Occasionally melanoma cells were immunoreactive for S100, neuron-specific enolase and vimentin, and a small number of cells for cytokeratin. Ultrastructurally, the presence of premelanosomes was confirmed in the cytoplasm. Possible presence of cytokeratin-positive neoplastic melanocytes should be taken into account when differentiating a nonpigmented epithelioid melanoma from other tumors such as anaplastic carcinomas.     

Detection and sequence analysis of DNA polymerase and major envelope protein genes in koi herpesviruses derived from Cyprinus carpio in Gunma prefecture, Japan

Koi herpesvirus (KHV), which is believed to be an emerging virus, causes fatal diseases in carps. Since the 1990s, the presence of KHV has been confirmed in several countries. In Japan, from 2003 to 2004, large outbreaks of KHV infection in farmed carps resulted in the death of numerous fishes. From April to May 2004, we collected 43 dead or dying carps exhibiting typical symptoms of KHV infection in Gunma prefecture. To conduct a molecular epidemiologic study of KHV in our prefecture, we amplified DNA polymerase and the major envelope protein genes of KHV derived from carp gills using newly designed primers. We also performed sequence analysis of both genes of KHV. Sensitivity of our PCR method for amplification of DNA polymerase and the major envelope protein genes of KHV was 3 x 10(2) (100 fg) and 3 x 10(3) (1000 fg) copies of KHV genome, respectively. We detected both DNA polymerase and major envelope protein genes in 37 of 43 carps (86%). No mutation was found in both the genes sequenced from 11 strains, which included two foreign strains and one domestic strain. The results suggested that KHV strains derived from carps in our prefecture were closely related genetically to the other KHV strains.     

Comparative genetic mapping of homoeologous genes for the chlorina phenotype in the genus <Emphasis Type="Italic">Triticum</Emphasis>

Triticum monococcum L. (2n = 2x = 14, A^mA^m genome) is one of the most ancient of the domesticated crops in the Middle East, but it is not the ancestor of the A genome of durum wheat (T. durum Desf. 2n = 4x = 28, genomes BBAA) and bread wheat (T. aestivum L., 2n = 6x = 42, genomes BBAADD). It has been suggested that some differentiation has occurred between the A^m and A genomes. The chlorina mutants at the cn-A1 locus located on chromosome 7AL have been described in T. aestivum L. and T. durum, and a chlorina mutant has been found in T. monococcum. The aims of our study were to establish linkage maps for chlorina mutant genes on chromosome 7A of T. aestivum and T. durum and chromosome 7A^m of T. monococcum and to discuss the differentiation that has occurred between the A and A^m genomes. The chlorina mutant gene was found to be linked with Xhbg234 (8.0 cM) and Xgwm282 (4.3 cM) in F₂ plants of T. aestivum ANK-32A/T. petropavlovskyi k54716, and with Xbarc192 (19.5 cM) and Xgwm282 (12.0 cM) in F₂ plants of T. durum ANW5A-7A/T. carthlicum #521. Both the hexaploid and tetraploid wheats contained a common marker, Xgwm282. In F₂ lines of T. monococcum KT 3-21/T. sinskajae, the cn-A1 locus was bracketed by Xgwm748 (25.7 cM) and Xhbg412 (30.8 cM) on chromosome 7A^mL. The distal markers, Xhbg412, Xgwm282, and Xgwm332, were tightly linked in T. aestivum and T. durum. The common marker Xhbg412 indicated that the chlorina mutant genes are located on chromosome 7AL and that they are homoeologous mutations.