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Summary A collection of subterranean clover lines singled out from populations of the species Trifolium brachycalycinum and T. subterraneum collected in Sicily, Italy, was examined at two localities for flowering time and at one locality for oestrogen content and seed yield. The structure and variation of the populations of the two species were compared. The relationship between flowering time of the populations and some environmental features of their collection sites was examined to assess whether the maturity requirements of the two species were similar and to frame selection models focused on developing varieties of appropriate maturity. Populations of T. subterraneum were, on average, more complex than those of T. brachycalycinum, being characterized by higher number of lines per population and greater intra-population variation for flowering time, oestrogen content and seed yield. Furthermore, populations of T. subterraneum were, on average, about 15 days earlier than sympatric populations of T. brachycalycinum. Both the greater variation and the relative earliness of T. subterraneum occurred irrespective of the environments of origin of the populations. Inferences are drawn on the adaptive advantages that such features confer to T. subterraneum. Mean flowering time of the populations increased on increasing annual rainfall and altitude of the collection sites. However, the changes in maturity appeared almost exclusively related to variations in rainfall in T. subterraneum, while in T. brachycalycinum the effect of altitude was greater and that of rainfall less marked than in the former species. 相似文献
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Spanu V. Virdis S. Scarano C. Cossu F. De Santis E. P. L. Cosseddu A. M. 《Veterinary research communications》2010,34(1):87-90
In vitro activities of 16 antibiotics were tested against 36 Staphylococcus aureus (SA) strains isolated from raw sheep’s milk cheese from six dairies. The minimum inhibitory concentration (MIC) was determined using a broth microdilution method (CLSI). All 36 isolates were analyzed for the presence of the accessory gene regulator gene, agr (I–IV), and genes encoding resistance to methicillin (mecA), erythromycin (ermA), penicillin (blaZ), and vancomycin (vanA-B). The isolates were also analyzed for similarities in pulsed-field gel electrophoresis (PFGE) patterns. SA strains showed resistance to ampicillin (36.1%), penicillin (33.3%), tetracycline (11.1%), and cloxacillin (2.8%) but were susceptible (≥94.4%) to 12 out of 16 tested antimicrobials. The overall susceptibility of the strains to oxacillin, vancomycin, and erythromycin was confirmed by the absence of the mecA, vanA-B, and ermA genes. The PFGE results showed that 32 strains belonged to 10 different clusters (P1–P10) while four strains were untypeable. 相似文献
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L. Maddau C. Perrone A. Andolfi E. Spanu B. T. Linaldeddu A. Evidente 《Forest Pathology》2011,41(2):85-89
Two phytotoxic metabolites, p‐hydroxybenzaldehyde and indol‐3‐aldehyde, were isolated and identified by spectroscopic methods from solid cultures of Discula quercina, an endophytic fungal pathogen frequently associated with oak decline in Italy. In addition, the fungus produced an unusual acyclic keto acid as a major metabolite, which was identified by spectroscopic and chemical methods as 5‐oxo‐6E,8E‐octadecadienoic acid. In leaf puncture assays on Quercus suber and Q. ilex leaves, indol‐3‐aldehyde proved to be more toxic than p‐hydroxybenzaldehyde, while 5‐oxo‐6E,8E‐octadecadienoic acid was inactive even at the highest concentration used (1 mg ml?1). Although indol‐3‐aldehyde is a known microbial metabolite, its phytotoxic activity has hitherto not been reported. This report is the first to describe the production of phytotoxic compounds by D. quercina. 相似文献
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The genomes of the barley, Arabidopsis and pea powdery mildew are significantly larger than those of related fungi. This is due to an extraordinary expansion of retro-trasposons that are evident as repetitive elements in the sequence. The protein coding genes are fewer than expected due to an overall reduction in the size of gene families, a reduction in the number of paralogs and because of the loss of certain metabolic pathways. Many of these changes have also been observed in the genomes of other taxonomically unrelated obligate biotrophic pathogens. The only group of genes that bucks the trend of gene loss, are those encoding small secreted proteins that bear the hall marks of effectors. 相似文献
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Spanu PD Abbott JC Amselem J Burgis TA Soanes DM Stüber K Ver Loren van Themaat E Brown JK Butcher SA Gurr SJ Lebrun MH Ridout CJ Schulze-Lefert P Talbot NJ Ahmadinejad N Ametz C Barton GR Benjdia M Bidzinski P Bindschedler LV Both M Brewer MT Cadle-Davidson L Cadle-Davidson MM Collemare J Cramer R Frenkel O Godfrey D Harriman J Hoede C King BC Klages S Kleemann J Knoll D Koti PS Kreplak J López-Ruiz FJ Lu X Maekawa T Mahanil S Micali C Milgroom MG Montana G Noir S O'Connell RJ Oberhaensli S 《Science (New York, N.Y.)》2010,330(6010):1543-1546
Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this life-style, obligate biotrophy, remains unknown. We present the genome analysis of barley powdery mildew, Blumeria graminis f.sp. hordei (Blumeria), as well as a comparison with the analysis of two powdery mildews pathogenic on dicotyledonous plants. These genomes display massive retrotransposon proliferation, genome-size expansion, and gene losses. The missing genes encode enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, probably reflecting their redundancy in an exclusively biotrophic life-style. Among the 248 candidate effectors of pathogenesis identified in the Blumeria genome, very few (less than 10) define a core set conserved in all three mildews, suggesting that most effectors represent species-specific adaptations. 相似文献
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Pietro D Spanu 《中国农业科学(英文版)》2014,(2):233-236
The genomes of the barley,Arabidopsis and pea powdery mildew are signif icantly larger than those of related fungi.This is due to an extraordinary expansion of retro-trasposons that are evident as repetitive elements in the sequence.The protein coding genes are fewer than expected due to an overall reduction in the size of gene families,a reduction in the number of paralogs and because of the loss of certain metabolic pathways.Many of these changes have also been observed in the genomes of other taxonomically unrelated obligate biotrophic pathogens.The only group of genes that bucks the trend of gene loss,are those encoding small secreted proteins that bear the hall marks of effectors. 相似文献
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