Genotypic variation in patterns of root distribution, nitrate interception and response to moisture stress of a perennial ryegrass (Lolium perenne L.) mapping population   总被引：1，自引：0，他引：1  

J. R. Crush  H. S. Easton†  J. E. Waller  D. E. Hume†  M. J. Faville† 《Grass and Forage Science》2007,62(3):265-273

Genotypic variation in patterns of root distribution, nitrate interception and response to moisture stress were assessed in both parents and 198 progeny of a perennial ryegrass (Lolium perenne L.) full‐sibling mapping population. This was carried out in metre‐deep tubes of sand culture in a glasshouse experiment. The proportion of root dry matter (DM) weight in the top 10 cm of sand ranged from 0·33 to 0·75 and values of log₁₀(1 ? K), where K is the constant for an exponential model relating root DM weight and root depth, also showed wide variation among genotypes. The proportion of a pulse of ¹⁵N recovered in whole plants ranged from 0·124 to 0·431. There was a positive linear correlation between the proportion of ¹⁵N recovered and plant total DM weight, but no relationship between nitrate interception and patterns of distribution of DM weight of roots. Some genotypes responded to moisture stress by increasing root growth, and in others root growth was inhibited. It is concluded that this below‐ground variability in root variables may be an evolutionary adaptation by plant populations to survive heterogeneity in soil biotic and edaphic factors.  相似文献   

Streptococcus canis multilocus sequence typing in a case series of dogs with ulcerative keratitis     

Andra E. Enache  Catriona Mitchell  Christiane Kafarnik  Andrew S. Waller 《Veterinary ophthalmology》2020,23(2):252-258

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Markers of long term silent carriers of Streptococcus equi ssp. equi in horses     

John Pringle  Monica Venner  Lisa Tscheschlok  Andrew S. Waller  Miia Riihimäki 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(6):2751-2757

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Soil nematode populations beneath faeces from reindeer treated with ivermectin     

Gregor W. Yeates  Jackie T. Hrabok  Antti Oksanen  Mauri Nieminen  Peter J. Waller 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(2):126-133

Abstract

The size and composition of the nematode assemblage in soil beneath faecal material derived from reindeer treated with ivermectin oral, or ivermectin subcutaneous formulations in early winter in northern Finland, was studied over a two-year period. This study was performed on both ungrazed and grazed areas that typify the reindeer habitat of the region and comparisons were also made with soil nematodes recovered from soils receiving untreated faecal material. Although significant differences in numbers of soil nematode fauna were observed between treatments on individual occasions, none of the differences occurred consistently with treatment, or with time. These results showed no adverse environmental impact of the faeces of reindeer given either formulation of ivermectin in early winter on soil nematode communities in subsequent years.  相似文献   

Coffee rust—epidemiology and control     

J.M. Waller 《Crop Protection》1982,1(4):385-404

The history and spread of coffee rust, from its first detection in Sri Lanka to the latest developments in Central America, are discussed. The epidemiology of the disease has been a subject of controversy in the past, but during the last decade most of the questions concerning the mode of spore dispersal seem to have been answered. Although it is necessary to investigate further the influence of host physiology on some epidemiological factors, such as latency and sporulation, sufficient is now known of the epidemiology of the disease to predict its behaviour in different regions and to devise provisional chemical control schedules. Copper fungicides still remain the most widely used chemicals but some of the more modern systemic fungicides are showing great potency. Advances in spraying techniques, with concomitant reductions in volumes and doses, have made chemical control more economic. The chemical control of coffee rust is greatly influenced by socioeconomic and physiographic factors as well as by the agronomy of the crop. Resistant varieties have so far played little part in coffee rust control, but some lines from Arabica-Robusta hybrids may show durable resistance.  相似文献   

Heterozygote detection for maple syrup urine disease in cattle     

PJ HEALY  JA DENNIS 《Australian veterinary journal》1995,72(9):346-348

SUMMARY The clinical, pathological and biochemical manifestations of maple syrup urine disease (MSUD) are similar in Poll Hereford and Poll Shorthorn X Poll Hereford calves. No significant differences were observed in branched-chain amino acid concentrations in plasma, or of branched-chain keto acid dehydrogenase activity in fibroblasts, between Poll Herefords homozygous normal and heterozygous for the mutation responsible for MSUD. Haemopoietic chimerism resulted in incorrect diagnosis of the MSUD genotype in 30% of non-identical twins when blood DNA was analysed using allele-specific amplification. Hair roots are shown to be a suitable source of target DNA for genotyping Poll Hereford cattle for the MSUD mutation. Twelve of 203 (5.8%) aged Poll Hereford bulls, sampled at saleyards during the last 4 months of 1993, were found to be heterozygous for the mutation. In contrast, the mutant sequence was detected in only 1 of 150 (0.7%) 2- and 3-year-old Poll Hereford bulls offered for sale at 2 stud sales held during 1993, suggesting that the prevalence of the disease may decline over the next few years.  相似文献   

Regulation of Prostaglandin Secretion and Proliferation of Bovine Endometrial Stromal Cells by Platelet-activating Factor     

U Tiemann  JA Davidson  PJ Hansen 《Reproduction in domestic animals》1995,30(3):141-143

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Ivermectin in ovine parasite control.     

P J Waller  I A Barger 《The Veterinary record》1992,130(26):583-584

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βbT-mannosidosis in Salers calves in Australia     

PJ HEALY  GN KIDD  RE REUTE  C BUNCE  I HOSIE  T STAPLETON 《Australian veterinary journal》1992,69(6):145-145

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The comparative pathogenicity of four serovars of Actinobacillus (Haemophilus) pleuropneumoniae   总被引：1，自引：0，他引：1  

RJ ROGERS  LE EAVES  PJ BLACKALL  KF TRUMAN 《Australian veterinary journal》1990,67(1):9-12

The pathogenicity of 2 isolates of each of serovars 7, 3, 1 and 2 of Actinobacillus pleuropneumoniae was tested by intranasal inoculation into 60, 6-week-old large white pigs. Four dose rates varying from 0.27 to 560 x 10(6) organisms per pig with 10-fold serial dilutions were used. Surviving pigs were necropsied 7 days after inoculation. The proportion of pigs dying and developing gross lesions following infection was significantly greater for pigs given serotype 1 than for each of the other 3 serotypes, which did not differ significantly from each other. Twelve of 16 pigs given either of the 2 isolates of serovar 1 died after acute illness and 1 of 44 pigs given either of the 2 isolates each of serovars 7, 3 and 2 died. Pigs given serovar 1 showed high temperatures, severe respiratory distress, frothy haemorrhagic nasal discharge and weight loss. Lung lesions were produced in all 16 pigs given serovar 1, in 7 of 14 pigs given serovar 7, 7 of 14 pigs receiving serovar 3 and in 5 of 16 pigs given serovar 2. The lethal infections were characterised by a severe acute fibrinohaemorrhagic necrotising pleuropneumonia, whereas non-lethal cases had lung lesions ranging from necrotising purulent pleuropneumonia to abscessation. Significant differences between isolates in proportions of tissues culture positive for A. pleuropneumoniae for serovars 7 and 2, but not for serovars 3 and 1 suggested that isolates may vary in virulence within serovars, but more detailed studies are needed to clarify this point.  相似文献