Physiological traits and cereal germplasm for sustainable agricultural systems     

R. A. Richards  M. Watt  G. J. Rebetzke 《Euphytica》2007,154(3):409-425

Plant breeding is not a discipline that readily comes to mind when agricultural sustainability is being considered. Sustainability is normally associated with farming practices such as stubble retention, direct-drilling, or amelioration practices such as contour farming or liming, or rotation practices for nutrient management and disease control. The contribution of plant breeding will be in providing germplasm for these changed practices and devising new methods of selection. This paper reviews opportunities where plant breeding can contribute to improvements in sustainable farming practices. The emphasis is on rainfed cropping systems and cereal improvement. The main contribution for breeding is to (i) increase crop water and nutrient use so that less escapes from the root profile; and (ii) preserve the soil resource with conservation farming systems by developing cultivars specifically adapted to changed farming systems and competitive cultivars that reduce herbicide use. To achieve these outcomes identification of desirable traits, suitable selection methods and development of appropriate germplasm are discussed.  相似文献   

Otoscopic evaluation of epithelial remnants in the tympanic cavity after total ear canal ablation and lateral bulla osteotomy     

Meghan M. Watt BS  Penny J. Regier DVM  MS  DACVS-SA  Cassio R. A. Ferrigno DVM  PhD  Marina J. McConkey DVM  DACVS-SA  W. Alexander Fox-Alvarez DVM  MS  DACVS-SA  Judith Bertran DVM  MS  DACVS-SA 《Veterinary surgery : VS》2020,49(7):1406-1411

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Molecular cloning of two types of GAP complementary DNA from human placenta   总被引：96，自引：0，他引：96  

M Trahey  G Wong  R Halenbeck  B Rubinfeld  G A Martin  M Ladner  C M Long  W J Crosier  K Watt  K Koths 《Science (New York, N.Y.)》1988,242(4886):1697-1700

The ras p21 GTPase-activating protein (GAP) was purified from human placental tissue. Internal amino acid sequence was obtained from this 120,000-dalton protein and, by means of this sequence, two types of complementary DNA clones were isolated and characterized. One type encoded GAP with a predicted molecular mass of 116,000 daltons and 96% identity with bovine GAP. The messenger RNA of this GAP was detected in human lung, brain, liver, leukocytes, and placenta. The second type appeared to be generated by a differential splicing mechanism and encoded a novel form of GAP with a predicted molecular mass of 100,400 daltons. This protein lacks the hydrophobic amino terminus characteristic of the larger species, but retains GAP activity. The messenger RNA of this type was abundantly expressed in placenta and in several human cell lines, but not in adult tissues.  相似文献   

The association of a herpesvirus with generalised disease in a kitten     

P B Spradbrow  C Carlisle  D A Watt 《The Veterinary record》1971,89(20):542-544

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The Oxidative Stress,Antioxidant Profile and Acid–base Status in Preterm and Term Canine Neonates          下载免费PDF全文

CI Vannucchi  D Kishi  FM Regazzi  LCG Silva  GAL Veiga  DSR Angrimani  CF Lucio  M Nichi 《Reproduction in domestic animals》2015,50(2):240-246

During the initiation of neonatal pulmonary respiration, there is an exponential increase in reactive oxygen species that must be scavenged by antioxidant defences. However, neonate and preterm newborns are known to possess immature antioxidant mechanisms to neutralize these toxic effects. The purposes of this study were to compare the development of antioxidant system between preterm and term canine neonates and to evaluate the magnitude of acid–base balance during the initial 4 h of life. A prospective study was conducted involving 18 neonatal puppies assigned to Term Group (63 days of gestation; n = 5), Preterm‐57 Group (57 days of gestation; n = 8) and Preterm‐55 Group (55 days of gestation; n = 5). Neonates were physically examined through Apgar score and venous haemogasometry within 5 min, 2 and 4 h after birth. No difference on amniotic fluid and serum superoxide dismutase (SOD), glutathione peroxidase (GPx) and the marker of oxidative stress (thiobarbituric acid reactive substances; TBARS) was verified. Irrespective of prematurity, all neonates presented low vitality, hypothermia, acidosis, hypoxaemia and hypercapnia at birth. However, term puppies clinically evolved more rapidly than preterm newborns. During the course of the study, premature neonates presented more severe complications, such as prolonged hypoxaemia and even death. In conclusion, premature puppies have no signs of immature enzymatic mechanisms for controlling oxidative stress, although SOD and GPx may participate in achieving acid–base balance. Aside from initial unremarkable symptoms, premature puppies should be carefully followed up, as they are at high risk of succumbing to odds of prematurity.  相似文献   

Involvement of PAPP‐A and IGFR1 in Cystic Ovarian Disease in Cattle          下载免费PDF全文

FM Rodríguez  M Colombero  AN Amweg  E Huber  NC Gareis  NR Salvetti  HH Ortega  F Rey 《Reproduction in domestic animals》2015,50(4):659-668

Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has been shown that intra‐ovarian factors, such as members of the insulin‐like growth factor (IGF) system, may contribute to follicular persistence. The bioavailability of IGF to initiate its response by binding to specific receptors (IGFRs) depends on interactions with related compounds, such as pregnancy‐associated plasma protein A (PAPP‐A). The aim of this study was to determine IGFR1 and PAPP‐A expression both in follicles at different stages of development and in cysts, to evaluate the roles in the etiopathogenesis of COD in cattle. The mRNA expression of PAPP‐A was higher in granulosa cells of large tertiary follicles than in cysts, whereas the protein PAPP‐A present in the follicular fluid from these follicles showed no differences. Although no PAPP‐A mRNA expression was detected in smaller tertiary follicles, in their follicular fluid, this protease was detected in lesser concentration than in cysts. The mRNA expression of IGFR1 was lower in granulosa cells from cystic follicles than in those from tertiary ones. However, the protein expression of this receptor presented the highest levels in cystic structures, probably to increase the possibility of IGF response. The data obtained would indicate that animals with COD have an altered regulation of the IGF system in the ovary, which could be involved in the pathogenesis of this disease in cattle.  相似文献   

Report of an outbreak of swine fever in Auckland     

I.G. Watt B.V.Sc.  G.V. Wallace B.V.Sc. 《New Zealand veterinary journal》2013,61(1):7-9

Extract

Swine fever is an acute septicaemic disease, caused by a filterable virus, producing high fever and prostration, with frequently almost 100% morbidity and mortality, and characterised on post mortem by haemorrhages in skin, kidney, spleen and lymph glands. It is widely recognized as a very serious disease in overseas countries. The cost of annual control in the U.S.A. alone is estimated at £10,000,000. The virus of swine fever can be easily carried by animate and inanimate objects, is fairly resistant to natural destruction and is readily communicable. Strenuous efforts have been made in the past to keep it out of this country. Considerable loss occurs in an outbreak and, if uncontrolled, swine fever would spread extremely rapidly and gain a firm hold. In countries like America and England, the disease has got so far out of hand that the slaughter policy is impracticable and a costly vaccination campaign is the only method of controlling the disease.  相似文献   

Effect of stem guying on the incidence of resin pockets     

Michael S. Watt  Geoff M. Downes  Trevor Jones  Maria Ottenschlaeger  Alan C. Leckie  Simeon J. Smaill  Mark O. Kimberley  Rod Brownlie 《Forest Ecology and Management》2009

Although resin pockets are a major cause of degrade for appearance grade timber, little is known about the environmental conditions that control the incidence of these defects. Water stress and mechanical bending stress due to tree sway in strong winds are thought to contribute to the formation of resin pockets, but this is based on anecdotal evidence from observations of resin pocket occurrence. Controlled experiments are required to better understand the factors leading to resin pocket formation.  相似文献   

Influence of initial planting spacing and genotype on microfibril angle,wood density,fibre properties and modulus of elasticity in Pinus radiata D. Don corewood     

Jean-Pierre Lasserre  Euan G. Mason  Michael S. Watt  John R. Moore 《Forest Ecology and Management》2009

Pinus radiata D. Don trees from six clones, grown at initial spacings of 2500 stems ha⁻¹ and 833 stems ha⁻¹ were destructively harvested. For these trees wood properties were measured on radial slices sampled at a height of 1.4 m above the ground. Relative to wide spacing, close initial stand spacing significantly reduced microfibril angle (MFA) and ring width and significantly increased dynamic modulus of elasticity (MOE), fibre length, latewood percentage and cell wall thickness. Density and fibre width were not significantly different between spacing treatments. Examination of the influence of genetic population on wood properties indicated that genotype significantly influenced MFA, MOE and ring width. The key wood properties MFA, MOE and fibre length were regressed against tree diameter, height and stem slenderness. All three wood properties were most strongly correlated with stem slenderness. Multiple regression models developed for MFA, MOE and ring width accounted for respectively 62%, 81% and 58% of the variation in these variables. The following changes occurred in sampled properties with increasing ring number: MFA and ring width declined markedly; MOE and fibre length increased markedly; latewood percentage and cell wall thickness increased slightly; and density and fibre width did not show any radial trend.  相似文献   

Soil quality relationships with tree growth in exotic forests in New Zealand     

Craig W. Ross  Michael S. Watt  Roger L. Parfitt  Robyn Simcock  John Dando  Graham Coker  Peter W. Clinton  Murray R. Davis 《Forest Ecology and Management》2009

Quantitative information on the relationships between site quality and plantation productivity (dominated by the exotic species Pinus radiata) is required to achieve goals for sustainable forest production. Soil quality is a key component of site quality. A nationwide study of soil quality measurements is reported for 35 representative forest sites, covering a wide range of climatic and edaphic conditions found throughout New Zealand's plantation forest estate, representing most of the soils used for plantation forestry in New Zealand. The objectives of the study were to find the most important soil properties that discriminated among eight New Zealand Soil Orders and determine relationships between Soil Orders and early tree growth rates for P. radiata and Cupressus lusitanica. Soil physical and chemical properties were measured to identify key soil indicators of soil quality related to tree productivity. Tree growth was measured after four years on small plots planted at very high stand density (40 000 stems ha⁻¹). A factorial design was used to examine the influence of three factors on tree productivity: two species, P. radiata D. Don (ectomycorrhizal) and C. lusitanica Miller (endomycorrhizal); with and without fertilizer; and low or high disturbance (soil compaction and/or topsoil scalping by machinery). Carbon content, Phosphorus (P) retention, and soil physical properties that index the degree of soil compactness were strongly correlated to Soil Order. These properties are similar to soil quality factors that correlated with tree growth. Discriminant analyses of soil quality parameters by Soil Order clustered soils based on P retention (phosphate absorption capacity), subsoil Carbon (C), and subsoil air capacity (volume % of voids at 10 kPa matric potential). Allophanic Soils and Podzols clustered (from plots of first versus second canonical variates) separately from the other Soil Orders, which were somewhat clustered on the second variate within a broad clustering on the first variate. Soil Orders were ranked for tree growth rates for both species: pumice Andisols > Inceptisols > tephric Andisols > Entisols > Ultisols > Spodosols (NZ classification: for P. radiata is Pumice > Brown > Pallic > Allophanic > Recent > Raw > Ultic > Podzol and for C. lusitanica Pumice > Pallic > Allophanic > Brown > Raw > Ultic > Recent > Podzol).  相似文献