Assessments of genetic diversity within a world collection of cultivated hexaploid oat (<Emphasis Type="Italic">Avena sativa</Emphasis> L.) based on qualitative morphological characters

A characterization of 10,105 accessions of hexaploid cultivated oat (Avena sativa L. sensu lato) from 85 countries of the Plant Gene Resources of Canada (PGRC) collection was conducted at Saskatoon, Saskatchewan, Canada. Eight environmentally stable morphological characters (panicle type, panicle erectness, panicle density, lemma colour, dorsal awn of lemma, ligula, major infraspecific group), differentiated into 18 character states, were used to define genetically distinct morphological groups. Comparisons of oat diversity from different countries, among the major infraspecific groups and among Canadian oat cultivars registered between 1886 and 2002 were possible. The 10,105 accessions represented 118 different morphological groups. The number of accessions in each morphological group was unevenly distributed with the 13 most frequent morphological groups including 90% of the accessions. The most frequent morphological groups in the PGRC collection were identical with the most frequent types of Canadian oat cultivars. The greatest richness of diversity was found in oat from countries with temperate climates and intensive oat breeding programmes. The oat accessions comprised 8,754 accessions of common hulled oat, 183 accessions of hull-less oat and 1,168 accessions of red oat. For red oat (A. byzantina C. Koch), West Asia was richest in diversity. The USA could be considered a secondary centre of diversity for red oat and Canada a secondary centre of diversity for hull-less oat. Morphological diversity of oat cultivars released in Canada increased during the twentieth century. The morphological groups were related to formal taxonomical infraspecific classifications of A. sativa. Applications of the concept of defining morphological groups for phenotyping a large germplasm collection are demonstrated discussed.     

Mass Fingerprints of Tomatoes Fertilized with Different Nitrogen Sources Reveal Potential Biomarkers of Organic Farming

Plant Foods for Human Nutrition - Direct-injection electron spray ionization mass spectrometry (DIESI-MS) can be used to quantify the whole set of positive and negative ions in complex biological...     

Congenital neuropathy and dilution of feather melanin in nestlings of urban-breeding northern goshawks (Accipiter gentilis).

A pair of northern goshawks (Accipiter gentilis) breeding in a public park in the city center of Hamburg, Germany, raised 12 healthy and five aberrant offspring between 1996 and 2000. Aberrant nestlings (three males and two females) had pale silver-blue plumage and displayed severe locomotor disorders. Histopathologically, the defects were characterized by adendritic feather melanocytes and mild degeneration of the cerebellar white matter. Epidemiologic results were suggestive of a hereditary autosomal recessive defect, which may have originated from close inbreeding during the foundation of Hamburg's urban population of northern goshawks.     

Impact of sugarcane yellow leaf virus (ScYLV) on the carbohydrate status of sugarcane: Comparison of virus-free plants with symptomatic and asymptomatic virus-infected plants

The carbohydrate concentration of old and young sugarcane plants, either virus-free or infected by sugarcane yellow leaf virus, was compared. Internode lengths and fresh weights of symptomatic plants were reduced, but not the sucrose concentrations. Starch and sucrose concentration in green leaf tops of mature (18 months old) was the highest in asymptomatic plants followed by symptomatic, and then by virus-free plants. Carbohydrates increased during daytime by 5–20%. The carbohydrate concentration in leaves of young, 6 months old plants was much lower than in mature plants and it increased to 500% during daytime. Asymptomatic leaves had a higher level of carbohydrates, especially starch, from late afternoon until the end of the night, suggesting a reduction of assimilate export.     

蓝变真菌引起的欧洲云杉木质部解剖学特征及纤维素酶活性的变化

选择奥地利境内阿尔卑斯山健康欧洲云杉为对象,研究室内接种蓝变真菌(Ceratocystis polonica)引起的寄主树木韧皮部和木质部解剖学特征的变化,揭示蓝变真菌引起欧洲云杉枯萎的机制.结果表明:接种1周后的4株欧洲云杉的木质部组织内,蓝变区域显著增加,4～6周后蓝变区域不再增加;而在接种无菌琼脂的2株对照欧洲云杉的木质部组织内,没有检测到蓝变区域.采用生物化学分析和组织定位技术,确定接种真菌和无菌琼脂的欧洲云杉木质部区域纤维素酶的分布和活性变化.接种2周后剥皮取样检测,接种真菌的4株欧洲云杉的木质部组织内纤维素酶含量大幅度增加,其等电聚焦电泳显示明显的纤维素酶酶带;而在接种无菌琼脂的欧洲云杉木质部区域,纤维素酶含量分布较少,其等电聚焦电泳显示微弱的纤维素酶酶带.进一步证明蓝变真菌分泌的纤维素酶能利用寄主欧洲云杉木质部的纤维素,蓝变真菌是致死阿尔卑斯山境内欧洲云杉的重要病原菌.     

MAGNETIC RESONANCE IMAGING OF INTRACRANIAL TISSUE ACCUMULATIONS IN DOMESTIC DUCKS (Anas platyrhynchos f. dom.) WITH FEATHER CRESTS

The crested breed of domestic duck (Anas platyrhynchos f. dom.) has been described as a variety which has high pre- and postnatal mortalities, malformations in skull and brain anatomy, and several central nervous deficiencies. In addition, intracranial tissue accumulations have been diagnosed in purebred Crested ducks. The incidence, heredity and inheritance of these accumulations as well as their pathogenesis are still generally unknown. The aims of this study were to examine the head of Crested ducks, plain-headed duck breeds, and their crossbreeding relating to the incidence of intracranial alterations. These examinations were performed using magnetic resonance imaging. We found a high incidence of intracranial tissue accumulations in domestic ducks with feather crests. Creasted ducks had more intracranial tissue deposits than plain-headed ducks (p < 0.001). In the present study a correlation between the volume of the crest cushion and the volume of the intracranial tissue deposit could not be found (r = 0.014). Some of the Crested ducks had encephaloceles in addition to the crest cushion.     

Characterization of local and peripheral immune system in pregnant and nonpregnant ewes

Modulation of the immune system is known to be important for successful pregnancy but how immune function might differ between the lymph nodes draining the reproductive tract and peripheral lymph nodes is not well understood. Additionally, if immune system changes in response to the presence of an embryo during early pregnancy, and if this response differs in local versus peripheral immune tissue, has not been well characterized. To address these questions, we examined expression of genes important for immune function using NanoString technology in the ampulla and isthmus of the oviduct, endometrium, lymph nodes draining the reproductive tract (lumbo-aortic and medial iliac) as well as a peripheral lymph node (axillary), the spleen, and circulating immune cells from ewes on day 5 of the estrous cycle or pregnancy. Concentrations of estradiol and progesterone in plasma were also determined. Principal component analysis revealed separation of the local from the peripheral lymph nodes (MANOVA P = 3.245e-08, R² = 0.3) as well as separation of tissues from pregnant and nonpregnant animals [lymph nodes (MANOVA P = 2.337e-09, R² = 0.5), reproductive tissues (MANOVA P = 2.417e-14, R² = 0.47)]. Nine genes were differentially (FDR < 0.10) expressed between lymph node types, with clear difference in expression of these genes between the lumbo-aortic and axillary lymph nodes. Expression of these genes in the medial iliac lymph node was not consistently different to either the axillary or the lumbo-aortic lymph node. Expression of IL10RB was increased (FDR < 0.05) by 24% in the reproductive tissue of the pregnant animals compared to nonpregnant animals. Analysis of gene categories revealed that expression of genes of the T-cell receptor pathway in reproductive tract tissues was associated (P < 0.05) with pregnancy status. In conclusion, assessment of gene expression of reproductive and immune tissue provides evidence for a specialization of the local immune system around the reproductive tract potentially important for successful establishment of pregnancy. Additionally, differences in gene expression patterns in reproductive tissue from pregnant and nonpregnant animals could be discerned as early as day 5 of pregnancy. This was found to be associated with expression of genes important for T-cell function and thus highlights the important role of these cells in early pregnancy.     

Soil aggregation,aggregate stability,organic carbon and nitrogen in different soil aggregate fractions under forest and shrub vegetation on the Loess Plateau,China

Revegetation has been reported as one of the most effective counter measures to reduce soil and water erosion on the Loess plateau in China. Soil aggregate stability and the distribution of organic carbon and nitrogen in different aggregate fractions would be affected by different plant communities. The objectives of this study were to elucidate the effects of different plant communities on soil aggregate stability and the distribution of organic carbon and nitrogen in different aggregate fractions in order to prove that the different plant covers enhance soil aggregate stability.