Root system architecture and its relationship to the vegetative reproduction function in horsenettle (Solanum carolinense)

Horsenettle ( Solanum carolinense L.) is a weed species that can spread via the root system and root fragments. This study investigated the developmental pattern of the subterranean system of horsenettle in an experimental plot containing plastic plates that limited the radial growth of the individual plants in each section of the plot. The vertical architecture of the root system in the 10 month old and 16 month old plants was elucidated by excavating the plants from the experimental plot. The root system consisted of a reiterative arrangement of branching root units, which grew horizontally and then bent vertically. The relationship between the morphology of the branching roots and the vegetative reproduction in a 17 month old plant was investigated. Different sections of the rooting system had different functions: the bending part forms new shoots; the horizontal part extends into the surrounding area; and the vertical part is used for storage. Consequently, the subterranean system of horsenettle develops through a reiterative arrangement of the branching root unit, which has functionally differentiated parts.     

Developmental changes in mRNA expression in immune-associated cells of intestinal tract of broiler chickens after hatch and by dietary modification

Developmental changes in the immune‐related cells of the gut during the first 2 weeks post hatching were determined in broiler chickens fed a corn–soybean meal (CS) based diet, a semi‐purified diet with high fat (HF) and a high carbohydrate (HC) diet. The expression of CD3 and interferon‐gamma (IFN‐γ) mRNA increased during 3–7 days of age. When the chicks were fed the CS diet, the expression of interleukin‐2 mRNA in the foregut did not increase with age. The expression of iNOS mRNA was lowered at 3 days of age in the fore‐ and mid gut but the expression was constant at the other days of age. TLR‐2 mRNA expression increased in three section of the gut during 3–7 days of age, while TLR‐4 expression increased during 0–3 days of age. Chicks fed the HC diet showed higher interleukin‐2 but lower IFN‐γ mRNA expression than birds fed the CS diet. Feeding the HF diet tended to decrease the expressions determined. These findings suggest that the functional maturation of the T cell does not always correlate with an increase in T cell numbers, maturation of innate immunity may occur earlier than that of T cells and possibly the dietary composition modifies the developmental pattern.     

Detection of QTLs to reduce cadmium content in rice grains using LAC23/Koshihikari chromosome segment substitution lines

To advance the identification of quantitative trait loci (QTLs) to reduce Cd content in rice (Oryza sativa L.) grains and breed low-Cd cultivars, we developed a novel population consisting of 46 chromosome segment substitution lines (CSSLs) in which donor segments of LAC23, a cultivar reported to have a low grain Cd content, were substituted into the Koshihikari genetic background. The parental cultivars and 32 CSSLs (the minimum set required for whole-genome coverage) were grown in two fields with different natural levels of soil Cd. QTL mapping by single-marker analysis using ANOVA indicated that eight chromosomal regions were associated with grain Cd content and detected a major QTL (qlGCd3) with a high F-test value in both fields (F = 9.19 and 5.60) on the long arm of chromosome 3. The LAC23 allele at qlGCd3 was associated with reduced grain Cd levels and appeared to reduce Cd transport from the shoots to the grains. Fine substitution mapping delimited qlGCd3 to a 3.5-Mbp region. Our results suggest that the low-Cd trait of LAC23 is controlled by multiple QTLs, and qlGCd3 is a promising candidate QTL to reduce the Cd level of rice grain.     

Herpesviral haematopoietic necrosis of goldfish, Carassius auratus (L.)

Abstract. In the spring of 1992 and 1993, an epizootic with severe mortality occurred among cultured goldfish. Carassius auratus (L.), in Aichi and Nara Prefectures in Japan. A herpes-virus was isolated from moribund goldfish that induced cytopathic effects in FHM and EPC cells. The isolate was sensitive to IUdR (5-iodo-2-deoxyuridine), acid (pH 3) and ether. Transmission studies confirmed the pathogenicity of the viral isolate for goldfish while it was not pathogenic for fancy carp, Cyprinus carpio L. Diseased fish had no visible external signs except for listlessness, but internally there was softening and discolouration of the spleen and kidney, and necrotic foci in the haematopoietic tissue, splenic pulp, pancreas, and lamina propria and submucosa of the intestine. Electron microscopy revealed enveloped visions ranging from 170 to 220nm in diameter with hexagonal nucleocapsids (115–117nm edge-to-edge diameter). The disease has been designated as herpesviral haematopoietic necrosis (HVHN), and to date, is the only herpesvirus infection to be described in goldfish.