Genetics of resistance to Phytophthora capsici in the Mexican pepper‘Line 291

In order to establish a genetic model of the resistance to Phytophthora cupsici in Capsicum annuum genotype‘Line 29′, three experiments were conducted which included, as well as‘Line 29′, the susceptible genotype‘Morron INIA 224’and several of its F₁, F₂, F₃ and backcrosses. Plants with 4–6 leaves were inoculated by irrigating the culture substrate with a zoospore suspension of isolate B 1. The F² test was applied to the segregating generations to test whether there were one, two, three or four genes involved in the resistance. Additivity and equal weight of all the genes in the final effect were assumed. The hypothesis that best explained the results obtained was the one that assumed three genes in‘Line 29′; at least four alleles had to be present in any genotype for it to behave as resistant. The possible influence of isolate aggressiveness and inoculation method on the results is discussed.     

Sedative effects of dexmedetomidine,dexmedetomidine–pethidine and dexmedetomidine–butorphanol in cats

The purpose of this study was to assess the clinical effects of dexmedetomidine, both alone and combined with pethidine or butorphanol, in cats. A prospective randomized blind study was performed. Thirty cats were randomly assigned to three groups of 10 animals: D: dexmedetomidine (20 μg/kg IM); DP: dexmedetomidine (10 μg/kg IM) and pethidine (2.5 mg/kg IM); DB: dexmedetomidine (10 μg/kg IM) and butorphanol (0.4 mg/kg IM). Quality of sedation, analgesia, muscle relaxation and the possibility of performing some clinical procedures were compared using a multifactorial scale. Sedation, analgesia and muscle relaxation increased progressively over time and did not differ in the three protocols. The three protocols facilitated the completion of several clinical procedures. The clinical variables studied showed a similar behaviour in the three protocols and remained close to the baseline, except for a drop in heart rate in protocol D. In conclusion, dexmedetomidine, either alone or combined with pethidine or butorphanol, offers suitable sedation, analgesia and relaxation to perform various clinical procedures in cats.     

Dietary phosphorus does not reduce the risk for spinal deformities in a model of adjuvant‐induced inflammation in Atlantic salmon (Salmo salar) postsmolts

Inflammation is a non‐specific protective mechanism towards injury known to affect bone remodelling. This study aimed to investigate the effect of Freund’s complete adjuvant (FCA) induced‐inflammation on the prevalence of spinal deformities of Atlantic salmon postsmolts fed with two different dietary P levels. Sextuple groups of salmon postsmolts were fed with either a low‐phosphorous (6 g kg^?1 available P, LP) or a high‐phosphorous (9 g kg^?1 available P) diet for a period of 101 days. On Day 102, individually tagged fish were subjected to (i) single injection with FCA (0.125 mg kg^?1 BW) dissolved in phosphate‐buffered saline (PBS) (ii) placebo injection with PBS or (iii) sham injection (insertion of needle only) or (iv) remained untreated. On Day 103, fish were given a common diet for 174 days in seawater. No significant differences in body weight were observed. Injected fish, particularly the FCA group, had more compressions in the injection site than untreated fish. No effect of diet and no interaction between treatment and diet were observed. Severe scoliosis was observed in ～7% of FCA‐injected individuals, corresponding to a mixture of bone malformations in the tail region. In conclusion, experimentally induced inflammation may be an independent risk factor for bone deformities in Atlantic salmon.     

Xylem vessel diameter as a factor in resistance of Ulmus minor to Ophiostoma novo‐ulmi

An investigation has been carried out to study the relationship between the susceptibility of Ulmus minor to Ophiostoma novo‐ulmi and the diameter of its xylem vessels. Vessel diameters have been analysed in seven Spanish elms of known susceptibility, taking measurements from second and third year rings in 3‐year‐old branches. In the second year rings no relationship could be observed between the vessel diameters and the susceptibility of the trees. In the third year rings the mean diameter and the percentage of vessels larger than 100 μm were found to be significantly greater for the group of elms of high susceptibility. In the third year rings the vessel transectional area (VTA) and the theoretical hydraulic conductance (THC) were calculated. The decrease in VTA and THC became increasingly noticeable in the group of high susceptibility elms as vessels of larger diameter were excluded from the calculation. Xylem vessel diameters and the proportion of large vessels were correlated with the susceptibility of U. minor to Dutch elm disease. How these properties influence the dispersal of the fungus, the sap flow and the tree's ability to compartmentalize the disease is discussed.     

Relationships between rock fragment cover and soil hydrological response in a Mediterranean environment

Rock fragments are a key factor for determining erosion rates, particularly in arid and semiarid environments where vegetation cover is very low. However, the effect of rock fragments in non-cultivated bare soils is still not well understood. Currently, there is a need for quantitative information on the effects of rock fragments on hydrological soil processes, in order to improve soil erosion models. The main objective of the present research was to study the influence of rock fragment cover on run-off and interrill soil erosion under simulated rainfall in Mediterranean bare soils in south-western Spain. Thirty-six rainfall simulation experiments were carried out at an intensity of 26.8 mm h⁻¹ over 60 min under three different classes of rock fragment cover (<50%, 50–60% and >60%). Ponding and run-off flow were delayed in soils with high rock fragment cover. In addition, sediment yield and soil erosion rates were higher in soils with a low rock fragment cover. The relationship between soil loss rate and rock fragment cover was described by an exponential function. After this first set of experiments, rock fragments were removed from sites with the highest cover (>60%) and the rainfall simulation experiments were repeated. The steady-state run-off rate and soil loss increased significantly, showing that run-off and soil erosion were partly conditioned by rock fragment cover. These results have significant implications for erosion modelling and soil conservation practices in areas with the same climate and soil characteristics.     

The efficacy of several herbicides in the vineyard and their toxicity to grapevines

Application of several herbicides and a combination of herbicides in two vineyards resulted in a perfect control of Bermuda grass by glyphosate and mixed or alternate applications of MSMA and dalapon. Johnson grass was eliminated by MSM A with and without the addition of dalapon. Dalapon combined with MSMA reduced the yield of the grapevines and their growth, as measured by the weight of pruning. Yields were also significantly reduced by aminotriazole and in one vineyard also by simazine. Reduced vegetative growth was caused by MSMA and glyphosphate. MSMA and glyphosphate reduced the chlorophyll content of the grape leaves and the reducing sugar content of the canes in winter. Amino triazole reduced the reducing sugar content of both leaves and canes and the nitrogen content of the canes. In one vineyard simazine reduced the chlorophyll content of the leaves and increased the nitrogen content of the canes. MSMA alone and in combination with dalapon increased the arsenic content of leaves, canes and fruits of grapevines. Arsenic levels were the highest in the canes, but still did not exceed 0.6 ppm. Levels were lowest in fruits and did not exceed 0.1 ppm. Dalapon reduced the chlorophyll content of leaves in June and increased it in July. It also affected the reducing sugar content of leaves and canes without affecting yields or growth.     

ULTRASONOGRAPHIC ANATOMY OF THE TEMPOROMANDIBULAR JOINT IN HEALTHY PURE-BRED SPANISH HORSES

The objective was to describe the normal ultrasonographic appearance of the soft tissue and bony structures of the temporomandibular joint in Pure-Bred Spanish horses using frozen and plastinated sections performed as anatomical references. The temporomandibular joint of five healthy Pure-Bred Spanish horses and the head specimens from 12 Pure-Bred Spanish cadavers that were subjected to euthanasia for reasons other than temporomandibular joint problems were studied sonographically and anatomically. An 11 MHz linear-array transducer was used to obtain longitudinal ultrasonographic images of the temporomandibular joint from rostral, lateral, and caudal approaches. For anatomic study, a gross dissection was performed on six temporomandibular joints. The other six head specimens were first frozen at -30 degrees C for 48h and then, at -70 degrees C for a week. Three millimeter thick anatomic sections were collected in the same plane as the sonographic planes. These sections were plastinated, photographed, and compared with the corresponding ultrasonographic images. The articular surfaces, the articular cartilage, the disc, the intra-articular fat tissue, the joint capsule, and other structures were clearly visualized sonographically. Structures identified on the ultrasonographic images were in accordance with those identified on the corresponding anatomic sections. We confirmed the appearance of structures of the equine temporomandibular joint that have been described previously but we also identified the caudal fibrous expansion of the disc, the caudal compartment of the dorsal synovial pouch, and the lateral ligament. Our results define a reference that will aid in sonographic evaluation of the equine temporomandibular joint region.     

An Earlier Uterine Environment Favors the In Vivo Development of Fresh Pig Morulae and Blastocysts Transferred by a Nonsurgical Deep-uterine Method

This study aimed to evaluate the effect of recipient-donor estrous cycle synchrony on recipient reproductive performance after nonsurgical deep-uterine (NsDU) embryo transfer (ET). The transfers (N=132) were conducted in recipients sows that started estrus 24 h before (–24 h; N=9) or 0 h (synchronous; N=31), 24 h (+24 h; N=74) or 48 h (+48 h; N=18) after the donors. A total of 30 day 5 morulae or day 6 blastocysts (day 0=onset of estrus) were transferred per recipient. The highest farrowing rates (FRs) were achieved when estrus appeared in recipients 24 h later than that in the donors (81.1%), regardless of the embryonic stage used for the transfers. The FR notably decreased (P<0.05) when recipients were –24 h asynchronous (0%), synchronous (61.3%) or +48 h asynchronous (50%) relative to the donors. No differences in litter size (LS) and piglet birth weights were observed among the synchronous and +24 h or +48 h asynchronous groups. While a +24 h asynchronous recipient was suitable for transfers performed with either morulae (FR, 74.3%; LS, 9.2 ± 0.6 piglets) or blastocysts (FR, 84.6%; LS, 9.8 ± 0.6 piglets), a + 48 h asynchronous recipient was adequate for blastocysts (FR, 87.5%; LS, 10.4 ± 0.7 piglets) but not for morulae (FR, 30.0%; LS, 7.3 ± 2.3 piglets). In conclusion, this study confirms the effectiveness of the NsDU-ET technology and shows that porcine embryos tolerate better a less advanced uterine environment if they are nonsurgically transferred deep into the uterine horn.