Temporal and spatial propagule deposition patterns of the emerging fungal pathogen of chestnut Gnomoniopsis castaneae in orchards of north-western Italy

Two chestnut (Castanea sativa) orchards of north-western Italy were sampled with passive spore traps 35 times over 24 months. Samples were analysed through a newly developed quantitative PCR assay to quantify propagule loads of the emerging fungal pathogen Gnomoniopsis castaneae. Average propagule deposition patterns were assessed along with temporal and climatic variables, including sampling month and season, temperatures, relative humidity, precipitations, and wind. Machine learning algorithms combining information theory, fractal analysis, unbiased recursive partitioning, ordinary least squares and logistic regressions, were used to model propagule deposition patterns. The trained models were validated on independent data gathered from 24 samplings conducted in a third chestnut orchard during the same timeframe. Results showed that propagule deposition rate (DR) was variable within and among sites, with a site average ranging from 173 to 765 spores ⋅m⁻² ⋅h⁻¹. Propagule deposition was observed across all seasons, although the DR dropped substantially during wintertime (p < 0.05). Mean, maximum, and minimum temperatures, the growing degree days at 0 and 5℃ thresholds, and wind gust were all positively correlated (p < 0.05) with DR of G. castaneae. The trained models were all significant (p < 0.05), as well as their validation (p < 0.05). Fluctuations of propagule deposition throughout the year were consistent among sites and proved to be driven by temperatures. Wind gust was associated with the overall amount of propagules deposited at site level. In future, the increase in temperatures and strong winds as a result of climate change may boost the spread of G. castaneae.     

Analysis of meiotic behavior in selecting potential genitors among diploid and artificially induced tetraploid accessions of Brachiaria ruziziensis (Poaceae)

Sexuality is correlated with diploidy and apomixis with polyploidy in the Brachiaria genus. Brachiaria ruziziensis is a key species in Brachiaria breeding due to its obligate sexuality and intrinsic agronomic qualities. Interspecific crosses in the genus became feasible only when a few diploid accessions of B. ruziziensis were artificially tetraploidized and remained sexual. Hybridization has been done since, using natural tetraploid apomictic accessions of B. brizantha or B. decumbens as pollen donors. Twenty two accessions of B. ruziziensis from the Embrapa Beef Cattle germplasm collection (Campo Grande, MS, Brazil) were cytologically analyzed: 16 are natural diploids (2n = 2x = 18) and six are artificially induced tetraploids (2n = 4x = 36). The meiotic behavior in the 16 diploid accessions varied. The mean of meiotic abnormalities per accession ranged from zero to 24.46%. Meiotic behavior in the induced tetraploid accessions also varied with the mean of meiotic abnormalities ranging from 5.20% to 54.71%. The most common abnormalities observed in both the diploid and the tetraploid accessions, were those related to irregular chromosome segregation. In one tetraploid accession, with a high frequency of those, other irregularities involving chromosome orientation at metaphase plate and chromosome convergence to the poles, a meiotic mutation known as divergent spindle, were recorded. Meiotic behavior should be considered in selecting potential genitors for breeding.     

A meta-analytic review of monoterpene for fish anaesthesia

The use of anaesthetic agents has been increasing to address the welfare needs of different fish species in scientific and aquaculture practices. MS-222 is the most used synthetic anaesthetic but some limitations and side effects have been reported. Natural substances have been used as potential substitutes with clove oil playing an important role due to its eugenol content. Yet, other monoterpenes have shown anaesthetic properties in different fish species. As such, a quantitative assessment has been conducted to explicitly relate and summarise the use of monoterpenes with described anaesthetic properties in fish. A combined PubMed, Web of Science, Scopus, PubMed Central and Europe PMC electronic database search was performed, from January 2002 to August 2022, following the PRISMA guidelines. Out of 1555 articles retrieved from the literature search, 30 English reports met the criteria for inclusion in the meta-analysis through a generic inverse-variance method (random-effects model) and according to the fish age. The findings show a total of 10 different monoterpenes with high homogeneity and effectiveness in inducing anaesthesia and recovery according to the fish anaesthetic criteria. Further subgroup analysis showed these effects were independent of fish age. Meta-regression of the included studies revealed an inverse linear association between anaesthesia induction and recovery time and water bath temperature while no further correlation was found with other confounding factors (body weight, water pH and dissolved oxygen levels). Although further studies will be required, this meta-analysis provides robust evidence that different monoterpenes serve as an attractive and effective alternative for fish anaesthesia although water bath temperature also played an important role in anaesthesia outcome.     

Inheritance and heritability of resistance to citrus leprosis

ABSTRACT The genetic inheritance of resistance to leprosis, the most important viral disease of citrus in Brazil, was characterized through the phenotypic assessment of 143 hybrids resulting from crosses between tangor 'Murcott' (Citrus sinensis x C. reticulata) and sweet orange 'Pêra' (C. sinensis), considered to be resistant and susceptible to the disease, respectively. All plants were grafted onto Rangpur lime (C. limonia) and inoculated with Citrus leprosis virus, cytoplasmic type through the infestation with viruliferous mites, Brevipalpus phoenicis. The experiments were arranged in a completely randomized block design with 10 replicates. Incidence and severity of the disease in leaves and stems as well as plant growth parameters (plant height and stem diameter) were recorded for 3 years after the infestation with the viruliferous mites. The average values of all variables were analyzed using principal component analysis, discriminant factorial analysis, estimation of the clonal repeatability coefficients, and frequency of the distributions of the average values for each measured variable. The principal component analysis resulted in the identification of at least two groups with resistance and susceptibility to leprosis, respectively. About 99% of all hybrids were correctly classified according to the discriminant factorial analysis. The broad-sense heritability coefficients for characteristics associated with incidence and severity of leprosis ranged from 0.88 to 0.96. The data suggest that the inheritance of resistance to leprosis may be controlled by only a few genes.     

Nutrients Accumulation,Biometric, Chlorophyll and Potassium Indexes and Production in Minituber Potato as Function of Potassium Doses in Organic and Hydroponic Conditions

ABSTRACT

Potato is one of the most economically important crops in Brazil. In this crop, potassium (K) is the most accumulated nutrient and has significant and positive effect on potato plant growth and tuber yield. Thus, the aim of this work was to determine the effects of K doses on nutrients accumulation, biometric, chlorophyll, and K indexes in potato plants grown. Two experiments were installed simultaneously in an unheated greenhouse with Agata cultivar. The experiment 1 was carried out in pot with commercial organic substrate with five K doses (0, 0.66, 1.32, 1.98, and 2.64 g dm^3?1). The experiment 2, nominated hydroponic system, with washed sand above a layer of expanded clay pebbles where the plants received daily nutrient solution application. The treatments were five K doses (0.0, 2.5, 5.0, 7.5 e 10.0 mmol L^?1). The biometrics data were collected 21 days after emergence and at harvest. Both experiments were set at a randomized block design with four replications. In both experiments, no visual symptoms of deficiency or excess were observed but only in plants at 0 mmol L^?1 of K. In both experiments, K doses interacted with some biometric and chlorophyll indexes measured in the fourth completely expanded leaf with portable SPAD and Dualex devices, commonly used as a guide to in-season fertilizer N management, leading to recommend their use only in plants properly nourished in K. K critical concentration in the fourth fully expanded leaf was 61.7 g kg^?1.     

Clinical evaluation of a cryptococcal antigen latex agglutination test for diagnosis of cryptococcosis in cats

A commercial cryptococcal antigen latex agglutination test was used to evaluate sera from 20 cats with cryptococcosis and 184 cats without cryptococcosis. Cryptococcal antigen was detected in the sera from 19 of 20 cats with cryptococcosis. Antigen was not detected in sera from any of the cats without cryptococcosis. The test had sensitivity of 95% and specificity of 100%.     

Effect of biotin supplementation on milk yield of Girolando cows reared in a tropical climate

Tropical Animal Health and Production - The objective of this study was to evaluate the effect of biotin supplementation on milk yield and the reproductive efficiency in Girolando cows. The study...     

Environmental degradation of the insect growth regulator methoprene: V. Metabolism by houseflies and mosquitoes

The metabolism of methoprene (I, isopropyl (2E,4E)-11-methoxy-3,7,11-trimethyl-2,4-dodecadienoate, trademark Altosid) was investigated in larval mosquitoes and houseflies. The most abundant primary metabolite in third- and fourth-instar Aedes and fourth-instar Culex larvae was the hydroxy ester while the hydroxy acid predominated in third-instar Musca larvae. Biological isomerization of the double bond at C-2 in I (i.e., conversion of (E) to (Z)) was an effective mode of insect detoxication, but these dipterans apparently cannot isomerize the (2Z) isomer of I to methoprene. In general, piperonyl butoxide and triorthocresyl phosphate slightly increased the morphogenetic activity of I in these insects.