Physiological Specialization of Fusarium oxysporum f. sp. lactucae, a Causal Organism of Fusarium Root Rot of Crisp Head Lettuce in Japan

In 1995, Fusarium root rot of crisp head lettuce, caused by Fusarium oxysporum f. sp. lactucae, was simultaneously found in the Shiojiri and Kawakami areas of Nagano Prefecture, Japan. The Shiojiri and Kawakami isolates differed in pathogenicity to lettuce cultivars. Because of this distinct physiological specialization, these Shiojiri and Kawakami isolates should be designated as race 1 and race 2, respectively, using lines VP1010 (highly resistant to race 1), VP1013 (highly resistant to race 2) and variety Patriot (highly susceptible to both races) as differential varieties. This is the first report of races of Fusarium oxysporum f. sp. lactucae, Received 21 September 2000/ Accepted in revised form 21 March 2001     

Chemical characterization of milk oligosaccharides of an African lion (Panthera leo) and a clouded leopard (Neofelis nebulosa)

The Carnivora include the superfamilies Canoidea and Feloidea. In species of Canoidea other than the domestic dog, Canis lupus, the milk contains only traces of lactose and much larger concentrations of oligosaccharides. In this study, lactose was found to be the dominant saccharide in the milk or colostrum of two species of Feloidea, namely the African lion (Panthera leo) and the clouded leopard (Neofelis nebulosa). In addition to lactose, the following oligosaccharides were characterized in the milk of a lion; Neu5Gc(α2‐3)Gal(β1‐4)Glc (3′‐NGc‐SL), Fuc(α1‐2)Gal(β1‐4)Glc (2′‐fucosyllactose) and GalNAc(α1‐3)[Fuc(α1‐2)]Gal(β1‐4)Glc (A‐tetrasaccharide). The colostrum of a clouded leopard contained 3′‐NGc‐SL, Gal(α1‐3)Gal(β1‐4)Glc (isoglobotriose) and A‐tetrasaccharide. These oligosaccharides differ in some respects from those previously identified in another species of Feloidea, the spotted hyena (Crocuta crocuta). These milks contained 3′‐NGc‐SL and A‐tetrasaccharide, while spotted hyena colostrum did not; however, it contained Neu5Ac(α2‐3)Gal(β1‐4)Glc (3′‐NAc‐SL) and Gal(α1‐3)[Fuc(α1‐2)]Gal(β1‐4)Glc (B‐tetrasaccharide).     

Seasonal variation in docosahexaenoic acid content in horse mackerel caught in the East China Sea

ABSTRACT:   The fatty acid composition in horse mackerel caught off Nagasaki, off Tsushima Island, and in the middle of the East China Sea was investigated. The ratios of monoenoic and polyenoic acids to the total fatty acids in the Nagasaki and bull trawl catch specimens had a negative correlation. The docosahexaenoic acid (DHA; 22:6n-3) ratios of total fatty acids in summer-caught specimens were lower than those in winter-caught specimens, and this tendency was significantly clearer in smaller-sized fish, while DHA levels in tissues varied little throughout the year. Consistently high levels of DHA were found in various fishing areas, which suggests that horse mackerel offers a stable source of DHA.     

Chemical components and body color of horse mackerel caught in different areas

ABSTRACT: The chemical components and body color of horse mackerel caught between July 1997 and May 2000 were studied. The fish were caught with small- to medium-sized purse seine offshore from Nagasaki and from Tsushima, and with bull trawl seine and medium- to large-sized purse seine in the East China Sea. The crude lipid content of the fish caught offshore from Tsushima was higher than that of the others, and there were no significant differences among the other catches. The extractive nitrogen content of the fish caught with bull trawl seine was somewhat lower than that of the others. The body colors of the fish differed from those suggested by their common names: Kuroaji (black) , Kiaji (yellow), and Shiroaji (white). The crude lipid content and body color indicated that there was no difference in quality among the catches, with the exception of the crude lipid content of the Tsushima catch.     

Hydrography and spatial variability in the size distribution of phytoplankton along the Kurile Islands in the western subarctic Pacific Ocean

Spatial variability in the size distribution of the phytoplankton community along the Kurile Islands, in the western subarctic Pacific Ocean, was investigated in terms of chlorophyll a concentrations in August and September, 1990. Analysis of dynamic height relative to 1,500 db and temperature–salinity diagrams at 50 m depth revealed five major oceanographic regions in this study area. The characteristic hydrography was clearly related to the surface distribution of chlorophyll a concentrations. As a warm core ring originating from the Kuroshio water was cooled by the surrounding water and meteorological conditions, its physical, chemical, and biological characteristics changed. Dominant picoplankton were replaced by a 10-2 μm size fraction in the warm core ring. In the Oyashio region, physical structures were less variable but concentrations of chlorophyll a were most variable and cells larger than 10 μn dominated. An anticlockwise eddy found in the Oyashio water showed the highest concentration of chlorophyll a. In the Okhotsk region, the chlorophyll standing stock was small with a low percentage of cells larger than 10 μm in spite of high nitrate concentrations. Along the Kurile Islands and Hokkaido Island, the surface mixed layer was not well defined; surface nitrate concentrations were relatively high, and the chlorophyll standing crop was also high with low percentages of picoplankton. The spatial heterogeneity in the dominance of cells larger than 10 μm in phytoplankton assemblages seems to be clearly associated with the effect of nitrate availability determined by water structure.