Evaluation of soybean germplasm conserved in NIAS genebank and development of mini core collections

Genetic variation and population structure among 1603 soybean accessions, consisted of 832 Japanese landraces, 109 old and 57 recent Japanese varieties, 341 landrace from 16 Asian countries and 264 wild soybean accessions, were characterized using 191 SNP markers. Although gene diversity of Japanese soybean germplasm was slight lower than that of exotic soybean germplasm, population differentiation and clustering analyses indicated clear genetic differentiation among Japanese cultivated soybeans, exotic cultivated soybeans and wild soybeans. Nine hundred ninety eight Japanese accessions were separated to a certain extent into groups corresponding to their agro-morphologic characteristics such as photosensitivity and seed characteristics rather than their geographical origin. Based on the assessment of the SNP markers and several agro-morphologic traits, accessions that retain gene diversity of the whole collection were selected to develop several soybean sets of different sizes using an heuristic approach; a minimum of 12 accessions can represent the observed gene diversity; a mini-core collection of 96 accession can represent a major proportion of both geographic origin and agro-morphologic trait variation. These selected sets of germplasm will provide an effective platform for enhancing soybean diversity studies and assist in finding novel traits for crop improvement.     

Acidification of Nova Scotia Lakes

Although water chemistry of precipitation and lakes in Nova Scotia is dominated by C1 from sea salt, correction for marine influence reveals that the dominant anion in acidified lakes is SO₄. Atmospheric deposition of non-marine SO₄ (SO₄) and NO₃- for the period 1977–1980 at 4 stations in southwest Nova Scotia averaged 47 meq SO₄ ^* m^?2 yr^?1 and 21 meq NI₃-m^?2 yr^?1 compared with 38 and 13 meq, respectively, for the average of 3 stations in the northeastern third of the province. Precipitation pH increased from 4.5 to 4.8 along the same axis. Almost 50% of the SO₄ deposition occurred when storms came from the southwest, indicating low pressure tracks which pass south of major Canadian sources of S. SO₄ ^* deposition in metropolitan Halifax (1982 bulk data) was 87 meq m^?2 yr^?1, due to local emissions of ca. 28 300 tonne S in the area, as well as LRTAP. Concurrent deposition of NO₃-N was 15 meq m^?2 yr^?1 (2.1 kg ha^?1 yr ^?1). Loadings from SO₄ deposition in the Halifax area amount to 42 kg ha^?1 yr^?1 and clearly exceed the federal guideline (M.O.I., 1983) of 20 kg ha^?1 yr^?1. Water chemistry of southwest, northeast, and Halifax area lakes show the same general SOI trends as observed for atmospheric deposition. In addition we find a positive relationship between SOI concentrations in the urban lakes and proximity to the center of the urban area.     

Genetic Diversity of the Vigna Germplasm from Thailand and Neighboring Regions Revealed by AFLP Analysis

Thailand is a center of diversity for section Angulares of the Asian Vigna (genus Vigna subgenus Ceratotropis) and 4 Vigna species are cultivated in Thailand. Using newly collected wild and cultivated germplasm of Vigna from Thailand and outgroup accessions AFLP analysis was conducted to clarify genetic diversity and relationships. The results suggest that cultivated V. umbellata and V. mungo evolved from wild relatives in a single domestication event. Vigna umbellata is poorly differentiated from its wild and weedy relatives compared to V. mungo. Results suggest northern Thailand and the neighboring Shan state, Myanmar, is the probable center of domestication for V. umbellata as wild accessions from this area and cultivated rice bean from a wide area in Asia are not greatly diverged. Vigna minima, V. tenuicaulis and V. exilis accessions in Thailand are well differentiated with considerable intra-specific variation. Vigna hirtella consists of two well differentiated subgroups, suggesting taxonomic revision may be necessary. Close genetic relationships between V. radiata and V. grandiflora, and between V. mungo and V. trinervia are confirmed. Naturally growing V. mungo populations in northern Thailand appear to be true wild species as they are well differentiated from Indian wild and Thai cultivated populations. The origin of naturally growing cowpea in Thailand needs to be further studied using a more comprehensive set of materials. This study clarifies inter and intra-specific genetic diversity and inter species relationships of Thai Vigna species.     

Use of a computerized system for evaluation of equine spermatozoal motility

Three ejaculates from each of 3 stallions were used to evaluate a computerized system (Hamilton-Thorn motility analyzer; HTMA) for measuring equine spermatozoal motility. Variance components (ejaculate-within-stallion, chamber-within-ejaculate, and microscopic field-within-chamber) were determined for each stallion after diluting ejaculates to 25 x 10(6) spermatozoa/ml with a skim milk-glucose seminal extender. The HTMA was compared with frame-by-frame playback videomicrography (VIDEO) for determining: percentage of spermatozoal motility and spermatozoal number in microscopic fields; curvilinear velocity and straight-line velocity of individual spermatozoa for 5 track types; and repeatability of those velocity measurements. The effect of spermatozoal number per microscopic field on incidence of intersecting spermatozoa and the outcome of intersecting spermatozoa also were evaluated. Greatest variability in motility measures was generally attributed to the microscopic field-within-chamber component. The HTMA was highly correlated with VIDEO for estimation of spermatozoal numbers per microscopic field (r = 0.99; P less than 0.001) and motility (r = 0.97; P less than 0.001); however over the entire range of spermatozoal numbers, the HTMA yielded higher spermatozoal numbers per microscopic field (P less than 0.05) and higher motility (P less than 0.05) than did VIDEO. The HTMA- and VIDEO-derived measurements of curvilinear and straight-line velocities were highly correlated for all spermatozoal track types, but both measures were higher (P less than 0.05) by use of the HTMA than by use of VIDEO for most track types. For 3 of 5 track types, measurements of curvilinear and straight-line velocities were less variable (P less than 0.05), using the HTMA, rather than VIDEO.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of source and amount of fertilizer nitrogen and nitrification inhibitors on the yield and nitrate concentration of glasshouse lettuce

Abstract. Urea and ammonium were compared with and without nitrification inhibitors (nitrapyrin and dicyandiamide) as a possible means of reducing the nitrate concentration in winter lettuce grown in the glasshouse. Neither inhibitor had a significant effect on nitrate concentrations at the lower rate of applied nitrogen (138 kg ha⁻¹ N). At the higher rate of urea (414 kg ha⁻¹ N) dicyandiamide significantly reduced the nitrate concentration but this was accompanied by an unacceptable loss in yield and quality thought to be due to phytotoxic effects of the high level of residual ammonium. Nitrapyrin had no effect on the nitrate concentrations in lettuce.     

Use of contrast radiography in the investigation of tenosynovitis and bursitis in horses

Contrast radiography, using a 25 per cent solution of sodium diatrizoate, has been used for the investigation of tenosynovitis and bursitis in horses. The procedure was undertaken on a series of 32 clinical cases and on specimens obtained at autopsy. Lesions affecting the extensor tendon sheaths at the carpus, the digital sheath, the tarsal sheath and the bursae at the elbow, hock and fetlock were examined by this means. The results showed the procedure offered the clinician useful information about the nature of the interior of these structures, particularly as regards the presence of adhesions and anastomoses between adjacent sheaths and joint capsules. Together with other clinical and laboratory findings, contrast radiography can assist in assessing the prognosis and in formulating appropriate treatment.     

Surgical remodelling of the femoral trochlea: an experimental study.

Surgical deepening of the groove in the femoral trochlea is a technique commonly employed in the correction of patellar dislocation in dogs. In order to discover how this deep articular defect repairs the operation was studied experimentally in young goats. Observations were made on the appearance of the trochlea and the histologic changes that had taken place after approximately six, 12, and 40 weeks. The abraded groove became filled with fibrocartilage with a relatively smooth surface and it articulated freely with the patella. The majority of the replacement tissues arose by differentiation of the granulation tissue which initially filled the groove, but there appeared to have been some contribution made by the hyaline cartilage at the margins of the groove.     

Attempts to transferRubus andFragaria viruses into herbaceous hosts

Attempts were made to transfer several types of viruses affectingRubus andFragaria species to herbaceous hosts of low tannin content. Despite use of phosphate buffers, nicotine sulphate solutions, and various lyophilization techniques, all inoculations were unsuccessful.Samenvatting Er werden pogingen ondernomen, verschillende typen van mozaïekvirussen van framboos en van aardbei met sap op kruidachtige, weinig of geen looistoffen bevattende planten over te brengen. Er werd gebruik gemaakt van fosfaatbuffers, van oplossingen van nicotinesulfaat en van droogvries-methoden vooraf de looistoffen uit het materiaal te verwijderen. De resultaten van de inoculatieproeven waren echter alle negatief.

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Research carried on at the Instiuut voor Plantenziektenkundig Onderzoek, Wageningen, Nederland. Supported in part by a fellowship from the John Simon Guggenheim Memorial Foundation, New York.

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Technical Paper No. 944 of the Oregon Agricultural Experiment Station. Contribution of the Department of Botany and Plant Pathology of this Station, and of the Instituut voor Plantenziektenkundig Onderzoek (I.P.G.), Wageningen.