Japanese pear black spot and apple alternaria blotch

The pathogenicity and taxonomy of 15 isolates of Alternaria spp. from pear and apple were compared. Only isolates from Asian pear ( Pyrus pyrifolia ) from Italy and Korea were virulent on leaves and young fruits of the susceptible Asian pear cv. Nijisseiki. Their conidial morphology was typical of A. gaisen (= A. kikuchiana ). Only isolates of A. mali from USA were virulent on susceptible American apple cvs Indo and Red Gold. No virulence was demonstrated in any isolate/host combination among isolates from stem infections of Asian and European pear ( Pyrus communis ), leaf spots of European apple, and ripe fruit rots of Chinese pear ( Pyrus ussuriensis ), European pear and apple. These non-virulent isolates could be readily distinguished from A. gaisen and A. mali by their pattern of branching of conidial chains, the branching associated with A. alternata sensu stricto being most common among non-virulent isolates. This limited survey implies that A. gaisen is only virulent to Asian pear and the toxigenic form of A. mali to certain American apple cultivars; also that A. gaisen is not established outside eastern Asia or the toxigenic form of A. mali outside eastern Asia and parts of USA.     

Induced plant defences in biological control of arthropod pests: a double‐edged sword

Biological control is an important ecosystem service delivered by natural enemies. Together with breeding for plant defence, it constitutes one of the most promising alternatives to pesticides for controlling herbivores in sustainable crop production. Especially induced plant defences may be promising targets in plant breeding for resistance against arthropod pests. Because they are activated upon herbivore damage, costs are only incurred when defence is needed. Moreover, they can be more specific than constitutive defences. Nevertheless, inducible defence traits that are harming plant pest organisms may interfere with biological control agents, such as predators and parasitoids. Despite the vast fundamental knowledge on plant defence mechanisms and their effects on natural enemies, our understanding of the feasibility of combining biological control with induced plant defence in practice is relatively poor. In this review, we focus on arthropod pest control and present the most important features of biological control with natural enemies and of induced plant defence. Furthermore, we show potential synergies and conflicts among them and, finally, identify gaps and list opportunities for their combined use in crop protection. We suggest that breeders should focus on inducible resistance traits that are compatible with the natural enemies of arthropod pests, specifically traits that help communities of natural enemies to build up. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Application of an electrophoretically detectable genetic marker to ploidy testing in brown trout (Salmo trutta L.) triploidised by heat shock

A phosphoglucose isomerase (PGI) variant, of brown trout (Salmo trutta L.), expressed in adipose fin tissue, was incorporated into experimental batches through selective crossing of brood-stock having the PGI-3 (110) marker gene. PGI-3 (110) homozygous females were crossed with PGI-3 (100) homozygous males to yield all PGI-3 (110/100) progeny. These were subject to heat shock for 10 min at 28°C, commencing 10 min after insemination. Electrophoretic examination of fry indicated that diploids and triploids were separable on the basis of PGI-3 banding patterns, having staining ratios of 1:2:1 and 4:4:1, respectively. This confirmed the retention of an extra maternal PGI-3 (110) gene in triploid individuals. Potential applications of this marker in triploid studies in brown trout are discussed.     

Alteration of nitrogen metabolism by alpha-ketoglutarate administration in growing lambs fed high nonprotein nitrogen-containing diets

Two completely randomized design experiments were conducted, using either 10, 38-kg (Exp. 1) or 10, 26-kg (Exp. 2) Hampshire x Western wether lambs, to study the effects of alpha-ketoglutarate (AKG) administration on N metabolism. Lambs were fed 890 and 885 g DM/d in Exp. 1 and 2, respectively, of corn-cottonseed hull basal diets with urea added to attain CP levels of 10.6 and 10.5% in Exp. 1 and 2, respectively. Experiments consisted of 10 d of adaptation followed by 7 d of infusion and excreta collection. Lambs were infused continuously either i.v. (Exp. 1) or abomasally (Exp. 2) with control solutions (CON) or solutions containing 41.3 g AKG/d (AKG). In Exp. 1, fecal and urinary N excretion and N retention were not affected (P greater than .10) by treatment. Compared to CON in Exp. 2, AKG infusion increased (P less than .10) fecal N output (6.6 vs 5.9 g N/d) but did not affect (P greater than .10) the amount of N retained (4.4 vs 3.5 g N/d). Compared to CON, AKG increased (P less than .10) urinary NH3 N excretion in Exp. 1. Serum urea N was lower (P greater than .10) for AKG than for CON in Exp. 1 but was not affected (P greater than .10) by treatment in Exp. 2. In Exp. 1, AKG appeared to reduce activities of several serum enzymes that function in amino N metabolism. In Exp. 1, compared to CON, AKG decreased (P less than .10) aspartate but increased (P less than .10) asparagine in serum.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lung sounds in cattle, horses, sheep and goats

The purpose of this paper is to emphasize the importance of pulmonary auscultation for the clinician. It suggests a clarification and simplification of the terminology to be used which would be helpful to veterinary students and allow better communications between veterinarians. The interpretation of these sounds and the relationships to conditions and diseases of the lungs in cattle, horses, sheep and goats are discussed.     

Effect of plant roots on the germination of microsclerotia ofVerticillum dahliae

Root observation boxes were used to study the effects of hosts and non-hosts on the germination of microsclerotia ofV. dahliae. The effects of roots on microsclerotia were examined within a radius of 1 mm around the root tip. Host plants such as potato and field bean induced a higher percentage of germination of the microsclerotia than a non-host such as barley. A susceptible potato cultivar stimulated germination more than a resistant cultivar. The germination percentage and the number of hyphae per microsclerotium decreased with distance from the root surface regardless of the plant species or cultivar.     

Relation between milk urea content and nitrogen excretion from lactating cows

Abstract

Thirty-two Chinese Holstein lactating cows were used to investigate the relationship of milk urea nitrogen (MUN) and nitrogen excretion loading to the environment. Cows were fed a similar amount of forage, and concentrates according to milk production. Total collection of urine and faeces were conducted continuously for three days. The milk urea nitrogen was significantly correlated to total nitrogen excretion (R ²=0.70), urinary nitrogen excretion (R ²=0.85), and nitrogen excretion from faeces (R ²=0.22). The following equation was proposed to predict total nitrogen excretion (TNE) (g/d) based on milk urea nitrogen (MUN) (mg/dl): TNE?=?15.46(±1.83)×MUN?+?193.40(±28.79). The results obtained in this study suggested that MUN might be used to predict TNE from lactating cows.     

Metabolic responses to exogenous bovine somatotropin in Friesian cows of low or high genetic merit

Basal hormone/metabolite concentrations and responses to intravenous challenges of glucose, insulin and epinephrine were examined in Friesian cows from selection lines of low or high genetic merit treated with recombinantly-derived bovine somatotropin (bST) or control formulation in a 2 x 2 factorial design. Cows from the low genetic merit (low breeding index, LBI) line had previously been shown to be more responsive to the galactopoietic effects of bST (50 mg/day) than those from the high breeding index (HBI) line. Despite this, comparisons of metabolic differences were not confounded by differences in energy balance because bST treatment had also caused an increase in voluntary intake of cut pasture. Circulating levels of somatotropin, insulin-like growth factor-I (IGF-I) and insulin were greater in bST-treated than control cows but neither bST treatment nor selection line influenced basal concentrations of glucose, non-esterified fatty acids (NEFA), beta-hydroxybutyrate, urea or creatinine. Treatment with bST produced a small increase in sensitivity of cows to the lipolytic effects of epinephrine and this effect was similar in both selection lines. HBI cows had greater circulating insulin levels following the glucose challenge than LBI cows but bST treatment did not affect the insulin response to exogenous glucose. Whereas bST treatment retarded the glycogenolytic response to epinephrine and the clearance of blood glucose in response to insulin in LBI cows, it had no effect on epinephrine-stimulated glycogenolysis, and caused enhanced glucose clearance in response to insulin, in HBI cows. Results are consistent with bST altering the homeorhetic control of metabolism but do not adequately explain the greater responsiveness of LBI cows to the galactopoietic effects of bST.