Development of colchicine‐induced tetraploid St. Augustinegrass (Stenotaphrum secundatum) lines     

Esdras M. Carbajal  M. Carolina Zuleta  Luellen Swayzer  Brian M. Schwartz  Maria Carolina Chavarro  A. Carolina Ballen‐Taborda  Susana R. Milla‐Lewis 《Plant Breeding》2019,138(6):958-966

St. Augustinegrass is well suited for lawns and commercial landscapes. While many genotypes are cross‐fertile, all cultivars are propagated vegetatively in sod production. To ensure varietal purity, development of sterile triploid hybrids by crossing tetraploid and diploid genotypes has been successfully used in other warm‐season turfgrasses. Applying this model in St. Augustinegrass would be beneficial to sod producers and turf managers who require purity for certification and uniformity for performance, respectively. This study was conducted to develop colchicine‐induced tetraploid lines of St. Augustinegrass. Seeds of cultivar ‘Raleigh’ were treated with four colchicine concentrations at four exposure times. A non‐treated control was included among the treatments. Seedlings that germinated were screened for genome size changes using flow cytometry. Line DSA 13005 and two progeny lines derived through selfing, DSA 16001 and DSA 16016, were corroborated as tetraploids (2n = 4x = 36) through chromosome counts. These lines will be used in future breeding efforts to attempt development of sterile triploid cultivars of St. Augustinegrass.  相似文献   

The efficiency of nitrogen in cattle manures when applied to a double‐annual forage cropping system          下载免费PDF全文

B. Perramon  À. D. Bosch‐Serra  F. Domingo‐Olivé  J. Boixadera 《Grass and Forage Science》2017,72(4):676-690

The use of cattle manure (CM) for fertilization presents challenges for optimizing nitrogen (N) use. Our work aimed to assess N efficiencies, in a 6‐year experiment with three biennial rotations of four crops: oat–sorghum (first year) and ryegrass–maize (second year) in a rainfed humid Mediterranean area of Spain. Fertilization treatments included the following: control (no N), 250 kg mineral N ha^?1 year^?1 (250MN), three CM rates (supplying 170, 250 and 500 kg N ha^?1 year^?1) and four treatments where the two lowest CM rates were complemented with either 80 or 160 kg mineral N ha^?1 year^?1. Treatments were distributed randomly in each of three blocks. Maximum dry‐matter yield (~44–49 t ha^?1 rotation^?1) was achieved in the third rotation, and only the control and the 170CM yielded significantly less. Within the limitations of the EU Nitrate Directive, the N steady state supply of 170CM always requires a complement of mineral N (80 kg N ha^?1) to maximize N agronomic efficiency. The maximum N‐fertilizer replacement value (250CM vs. 250MN) was 0·67, without significant differences between the two treatments in other N‐related efficiency indexes, which indicates that plants took advantage of residual‐N effects. Nitrogen losses by leaching in the 250CM treatment were around 5–7% of the N applied. This reinforces the sustainability of manure recycling in long cropping seasons.  相似文献   

Getting cosy in freshwater: Assumed to be brackish pike are not so brackish after all     

Kim Birnie‐Gauvin  Lasse Birch Hjrup  Theis Kragh  Lene Jacobsen  Kim Aarestrup 《Ecology of Freshwater Fish》2019,28(3):376-384

Pike (Esox lucius) occupy coastal streams and rivers of the Baltic Sea, where they attain large sizes (>5 kg). These large sizes are perhaps due to the fact that they can tolerate relatively high salinities and can thus forage in the nearby more productive brackish environments. In an attempt to quantify the extent to which pike utilise brackish environments, and to provide some insight into the underlying causes for brackish water migrations, we tagged 30 pike from a western Baltic river with acoustic transmitters and were able to track 21 individuals for 1 year. Based on experienced from local anglers, this population was assumed to be brackish in nature, where individuals underwent freshwater migrations to spawn. Our findings however suggest that the smallest and most active individuals make short exits into brackish waters and do so on rare occasions. Our results further indicate that neither sex nor size is related to activity level. We suggest that these patterns reflect two distinct behaviours—active and passive—and that large pike can be supported by the food availability in the river, without the need to venture into coastal zones, thus defying the conventional view that Baltic pike are all brackish in nature.  相似文献   

Whitened kernel surface: A fast and reliable method for assessing Fusarium severity on cereal grains by digital picture analysis     

Marine Ollier  Vincent Talle  Anne‐Laure Brisset  Zo Le Bihan  Simon Duerr  Marc Lemmens  Ellen Goudemand  Olivier Robert  Jean‐Louis Hilbert  Hermann Buerstmayr 《Plant Breeding》2019,138(1):69-81

Fusarium head blight (FHB) is a cereal disease of major importance responsible for yield losses and mycotoxin contaminations in grains. Here, we introduce a new measurement approach to quantify FHB severity on grains based on the evaluation of the whitened kernel surface (WKS) using digital image analysis. The applicability of WKS was assessed on two bread wheat and one triticale grain sample sets (265 samples). Pearson correlation coefficients between Fusarium‐damaged kernels (FDK) and WKS range from r = 0.77 to r = 0.81 and from r = 0.61 to r = 0.86 for the correlation between deoxynivalenol (DON) content and WKS. This new scoring method facilitates fast and reliable assessment of the resistance to kernel infection and shows significant correlation with mycotoxin content. WKS can be automated and does not suffer from the “human factor” inherent to visual scorings. As a low‐cost and fast approach, this method appears particularly attractive for breeding and genetic analysis of FHB resistance where typically large numbers of experimental lines need to be evaluated, and for which WKS is suggested as an alternative to visual FDK scorings.  相似文献   

Paternal genomotype affects female growth in a hybrid fish complex          下载免费PDF全文

Sara Carona  Maria J. Collares‐Pereira  M. Filomena Magalhães 《Ecology of Freshwater Fish》2017,26(4):719-721

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Spawning time and place of the Japanese eel Anguilla japonica in the North Equatorial Current of the western North Pacific Ocean     

Satoshi Ishikawa  Kunihiro Suzuki  Tadashi Inagaki  Shun Watanabe  Yobuo Kimura  Akihiro Okamura  Tsuguo Otake  Noritaka Mochioka  Yuzuru Suzuki  Hiroshi Hasumoto  Machiko Oya  Michael J Miller  Tae Won Lee  Hans Fricke  Katsumi Tsukamoto 《Fisheries Science》2001,67(6):1097-1103

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Studies on the Safety and Immunogenicity of the South African Bluetongue Virus Serotype 2 Monovalent Vaccine: Specific Detection of the Vaccine Strain Genome by RT‐PCR     

S. Hammoumi  E. Breard  C. Sailleau  P. Russo  C. Grillet  C. Cetre‐Sossah  E. Albina  R. Sanchis  M. Pepin  J.‐M. Guibert  And S. Zientara 《Zoonoses and public health》2003,50(7):316-321

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Differentiation of Staphylococcus sciuri Strains Isolated from Free‐Living Rodents and Insectivores     

T. Hauschild  S. Schwarz 《Zoonoses and public health》2003,50(5):241-246

Twenty‐nine Staphylococcus sciuri strains isolated from free‐living insectivores and rodents were comparatively analysed for their biochemical capacities and their SmaI macrorestriction patterns. The 29 S. sciuri isolates represented 21 different biotypes and 22 different SmaI macrorestriction types. This observation confirmed that S. sciuri isolates obtained from insectivores and rodents living in natural environments constituted a heterogeneous population. Cluster analysis revealed that the macrorestriction patterns and the biochemical profiles matched in some cases. However, S. sciuri isolates that exhibited the same or closely related biochemical profiles were also found to be associated with different macrorestriction patterns. Analysis of the 29 S. sciuri isolates for their plasmid content and their sensitivity to antimicrobial agents showed that most of the isolates were plasmid‐free and susceptible to all antimicrobial agents tested.  相似文献   

    

Hans Ostwald 《Forstwissenschaftliches Centralblatt》1938,60(18):561-570

Zusammenfassung Vorliegender Aufsa\ ist der vierte einer kleinen Schriftenreihe, die dem Gedenken des verstorbenen Unio.-Prof. Dr. Dr. h. c. E. Ostwald gewidmet ist und die das von ihm erworbene wissenschaftliche Gedankengut und seine Eikenntnisse, in gedrängter Kürze zusammengefa\t, wiedergeben foll. Es wird deshalb absichtlich zu sonstigen Ausführnngen, die den gleichen Gegenstand behandeln, nicht Stellung genommen.  相似文献   

    

Georg Henner  Fabricius und F. Kollmann 《Forstwissenschaftliches Centralblatt》1940,62(2):46-48

Ohne Zusammenfassung  相似文献