Identification and Characterisation of Bacteria Causing Soft-rot in Agave tequilana

Agave tequilana is the raw material for the production of the alcoholic beverage tequila. A bacterial disease has affected the A. tequilana crop in recent years. Previous reports based on colony and cell morphology, Gram stain and potato rot indicated that Erwinia sp. is the main pathogen. We isolated a several bacterial isolates capable of producing soft-rot symptoms in greenhouse pathogenicity assays. An extensive characterisation involving pathogenicity tests, fatty acid profile, metabolic and physiological properties, ribosomal DNA sequence and intergenic transcribed spacer amplification (ITS-PCR) and restriction banding pattern (ITS-RFLP) was made of each isolate. Three different species: Erwinia cacticida, Pantoea agglomerans and Pseudomonas sp. were identified. Fatty acid and metabolic profiles gave low similarity values of identification but 16S rDNA sequence, ITS-PCR and ITS-RFLP confirmed the identification of E. cacticida. In the phylogenetic tree, E. cacticida from blue agave was grouped neither with E. cacticida type strains nor with Erwinia carotovora. This is the first report that associates E. cacticida with A. tequilana soft-rot symptoms.     

Is Discrimination of 13C in Potato Leaflets and Tubers an Appropriate Trait to Describe Genotype Responses to Restrictive and Well‐Watered Conditions?

Selection for drought tolerance entails prioritizing plant traits that integrate critical physiological processes occurring during crop growth. Discrimination against ¹³C (?) in leaflets (?_leaflet) and tubers (?_tuber) was compared under two water regimes in two potato‐improved varieties selected to maintain yield under drought conditions (Unica and Sarnav) and one drought susceptible European cultivar (Désirée). In the control treatment, soil water content was kept at field capacity over the whole growth cycle, while in the drought treatment water supply was restricted after tuber initiation (50 % of field capacity). Gas exchange and N content per unit leaf area (N_area) as well as ? were assessed at different stages. Sarnav showed the highest tuber yield in both water conditions, suggesting that yield in the water restriction treatment was largely driven by yield potential in this genotype. Higher stomatal conductance (g_s) and N_area and lower ?_leaflet in well‐watered Sarnav suggested higher photosynthetic capacity. Under water restriction, Sarnav maintained higher g_s indicating that carbon diffusion was a key factor for biomass accumulation under water restriction. Our results suggest the use of ? determined after tuber initiation as an indirect selection indicator for tuber yield under both well‐watered and restricted soil water availability conditions.     

Detection of hepatitis E virus shedding in feces of pigs at different stages of production using reverse transcription-polymerase chain reaction.

The aim of this study was to determine at which production stages hepatitis E virus (HEV) is shed by the highest number of pigs and to estimate the relative risk associated with each stage. For this purpose, 146 fecal samples of pigs from 21 farms were studied. In addition, 1 sample from the manure ditch and another sample of drinking water, collected directly from the trough located in the pen, were taken from 16 farms. HEV RNA was detected in fecal samples from 34 pigs (23.29%). The production stages in which most pigs excreted HEV were weaners (41.7%) and pigs in the first month of feeding (60%). The results of the statistical analysis showed that the principal significant risk stage in HEV shedding was the first month of feeding (odds ratio [OR] 19.5, 95% CI 3.59-106.07, P = 0.001) followed by the weaners stage (OR 9.3, 95% CI .78-48.42, P = 0.008). In 8 out of 16 farms tested (50%) HEV RNA was detected in raw manure and in the water trough of only 1. Detection of HEV in manure ditches raises the concern of how to deal with manure of swine origin, because it is used as soil fertilizer.     

Ecosystem services from coffee agroforestry in Central America: estimation using the CAF2021 model

The goal of sustainable coffee production requires multiple functions from agroforestry systems. Many are difficult to quantify and data are lacking, hampering the choice of shade tree species and agronomic management. Process-based modelling may help quantify ecosystem services and disservices. We introduce and apply coffee agroforestry model CAF2021 (https://doi.org/10.5281/zenodo.5862195). The model allows for complex systems with up to three shade tree species. It simulates coffee yield, timber and fruit production by shade trees, soil loss in erosion, C-sequestration, N-fixation, -emission and -leaching. To calibrate the model, we used multivariate data from 32 different treatments applied in two long-term coffee agroforestry experiments in Costa Rica and Nicaragua. Without any further calibration, the model was then applied to agroforestry systems on 89 farms in Costa Rica and 79 in Guatemala where yields had been reported previously in farmer interviews. Despite wide variation in environmental and agronomic conditions, the model explained 36% of yield variation in Costa Rica but only 15% in Guatemala. Model analysis quantified trade-offs between yield and other ecosystem services as a function of fertilisation and shading.

     

Determination of reference intervals for metabolic profile of Hanwoo cows at early,middle and late gestation periods

Background

Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, there is little metabolic profile data available about Korean Hanwoo cows. Therefore, this study aimed to determine the reference intervals of metabolic profile for Korean Hanwoo cows.

Methods

Healthy animals (2,205) were selected and divided into early (day 1 to 95), middle (day 96 to 190) and late (day 191 to 285) period according to their gestating period. Metabolic profile including total protein (TP), albumin (Alb), urea (UREA), glucose (Glu), total cholesterol (T-Cho), long-chain fatty acid (LCFA), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), creatinine (Crea), calcium (Ca), inorganic phosphorous (iP) and magnesium (Mg) were analyzed using a TBA-40FR automatic biochemical analyzer. The data of Korean Hanwoo cows were then compared to those of the Japanese Wagyu cows.

Results

Most of the data of the Korean Hanwoo cows were relatively higher than those of Japanese Wagyu cows, with the exception of Glu and GGT. This may indicate that the nutritional level of feed for the Korean Hanwoo cows was higher than that of the Japanese Wagyu cows because of the different feeding system. In particular, relatively higher levels of UREA and LCFA were observed in the Korean Hanwoo cows, and this may also contribute to the low reproduction efficiency.

Conclusions

These findings may provide some theoretical basis for understanding the reproductive and feeding situation of Korean Hanwoo cows.     

Marketing of meat sheep with intensive finishing in southern state of Mexico

The objective of the present study was to quantify the marketing margins of cold sheep carcass and barbacoa meat in the southern state of Mexico. Data were obtained from the production chain links (production, industrialization, and marketing) where the marketing margins were calculated along with the benefit/cost (B/C) ratio. In the absolute marketing margin of the final consumer price per kilogram of carcass meat, the producer obtained US$2.7/kg (47 %) of the utilities, while the intermediaries obtained US$3.1/kg (53 %). Considering the final cooked product in barbacoa (typical dish), the margin was US$6.3/kg (29 %) for the producer and US$15.2/kg (71 %) for the intermediaries. The B/C ratio was 1.0, 1.1, 2, and 1.3 for the producer, stocker, butcher, and barbacoa seller, respectively. It is concluded that the best marketing channel for the producer was the producer-stocker-processor (butcher and barbacoa seller). The highest marketing margin was for the intermediaries followed by the producer. The order of importance of the B/C kilogram ratio of meat was for the butcher first, then barbacoa seller, and lastly stocker and producer.     

A preliminary study on the effects of dietary supplementation of brewers yeast and nucleotides, singularly or in combination, on juvenile red drum (Sciaenops ocellatus)

This study was designed to evaluate the effects of dietary supplementation with brewers yeast (Brewtech^®) and nucleotides (Optimûn), either singularly or in combination, on red drum growth, body composition, stress responses and possible resistance to Amyloodinium ocellatum infection. Juvenile red drum (～1 g initially) fed practical fish‐meal‐based diets for 6 weeks had similar weight gain regardless of whether the diet was unsupplemented (basal) or supplemented with brewers yeast (2% of diet), nucleotides (Optimûn at 0.2% of diet) or both brewers yeast (2% of diet) and nucleotides (Optimûn at 0.2% of diet). Dietary effects on hepatosomatic index, intraperitoneal fat ratio or whole‐body composition were not significant, except that fish fed the singular nucleotide supplement had a significantly higher whole‐body lipid content compared with fish fed the basal diet. No significant dietary effects on cortisol response were observed after a 15 min confinement stress test perhaps because of the extreme variation among individual fish. Subsequently, in situ challenge by co‐habitation with A. ocellatum caused 100% mortality regardless of dietary treatment within a 48 h period. It is concluded that dietary supplementation of brewers yeast and nucleotides did not promote enhanced growth or improved cortisol response and resistance to uncontrolled amyloodiniosis in juvenile red drum, at least at the tested dosages.     

Insulin-like growth factor (IGF)-I and -II and IGF binding proteins in serum and mammary secretions during the dry period and early lactation in dairy cows.

Concentrations of IGF-I and IGF-II, and IGF binding proteins (IGFBP) in serum and mammary gland secretions were surveyed during the dry period and early lactation of 30 Holstein cows. Although there was a threefold drop in the concentration of IGF-I in serum from the last week of the dry period to parturition (81 +/- 7 to 24 +/- 3 ng/ml, P less than .01), there was no significant change in serum IGF-II concentration during this period (150 +/- 17 vs 173 +/- 13 ng/ml, P greater than .05). Furthermore, a 57% increase in serum IGF-I was observed from the last week of lactation to the second week of drying off (100 +/- 5 to 157 +/- 8 ng/ml, P less than .05). Changes in serum IGF-II were not observed (126 +/- 11 vs 150 +/- 10 ng/ml, respectively; P greater than .05). Although IGF-I, IGF-II, and IGFBP concentrations in mammary secretions peaked 2 wk before parturition (2.95 +/- 1.1, 1.83 +/- .6, and 7.27 +/- .76 micrograms/ml, respectively), total output/quarter was highest in colostrum (394 +/- 119, 295 +/- 132, and 2,680 +/- 1,967 micrograms/quarter, respectively). Weekly milking of two individual quarters during the dry period did not affect (P greater than .05) IGF-I or IGF-II concentration (ng/ml) or total output (microgram/quarter) and milk yield in colostrum and milk (2 wk and 7 wk) compared with the ipsilateral quarter. The data support the hypothesis that IGF-I may be transported by the mammary gland epithelium. Furthermore, the secretion mechanisms of IGF-I, IGF-II, and IGFBP by the gland may be related to each other.     

Transgressive segregation in inter and intraspecific crosses of barley

Summary Six populations of F₂-derived lines of barley and their parents were evaluated for heading date, plant height, grain yield, bundle weight, and harvest index in a replicated experiment in the field. These data were used to estimate the minimum number of effective factor pairs segregating for each trait, the number of favorable factors contributed by each parent in a cross, and the frequencies and magnitudes of transgressive segregates.Heading date, plant height, and harvest index were controlled by three to four effective factor pairs, whereas grain yield and bundle weight were controlled by five or more.All three H. spontaneum strains used in our study contributed one or more useful genes for each of the traits, grain yield, heading date, plant height, bundle weight, and harvest index. Therefore, it seems that H. spontaneum can be a useful source of favorable genes for quantitative traits, especially for grain yield, which could be incorporated into barley varieties readily by backcrossing. Transgressive segregates for grain yield in the interspecific crosses may provide the basic materials for improving the productivity of cultivated barley varieties.Journal Paper No. J-9760 of the Iowa Agric. and Home Econ. Exp. Stn., Ames, IA 50011. Project 2227. Supported in part by a grant from the Science and Education Administration-Cooperative Research, United States Department of Agriculture.     

Pinus pinaster Ait. tree mortality following wildfire in Spain

Maritime pine (Pinus pinaster Ait.) is the tree species most affected by wildfire in the Iberian Peninsula. Prediction of the probability of fire-injured tree mortality is critical for management of burned areas, evaluation of the ecological and economic impact of wildfire and prescribed fire planning and application. Pine bark beetles (Scolytidae) frequently attack burned maritime pine stands and cause extensive post-fire mortality throughout the Iberian Peninsula. In the present study, maritime pine trees were monitored for three years following 14 wildfires in four ecotypes in Spain (11 fires in Galicia (Galician ecotype - NW Spain), one fire in Portillo (Meseta-Castellana ecotype - Central Spain), one fire in Rodenal (Rodenal ecotype - Central Spain), and one fire in Genalguacil (Sierra Bermeja ecotype - SW Spain)). Data on tree attributes, crown and bole injury, ground fire severity, Ips sp. presence and tree survival were obtained by examining 3085 trees. Logistic regression models for predicting the probability of delayed maritime pine mortality were developed by use of generalized estimated equations (GEE). An ample range of response to fire damage in mortality was evident among the four ecotypes and different models were fitted for each. The most important variables for predicting tree mortality were total crown volume damaged, presence of Ips sp. attack and cambium kill rating. The results highlight the extensive presence of Ips sp. in burned maritime pine forests and its importance in tree mortality process, the ample range of response of P. pinaster, in terms of post-fire mortality, as well as the need to develop site specific mortality models for the different ecotypes of this species following fire.