Heterochromatin type, amount and distribution in wild species of chili peppers (Capsicum, Solanaceae)

Triple staining with the fluorochromes chromomycin A3, distamycin A and 4′-6-diamidino-2-phenylindole (CMA/DA/DAPI) was applied to somatic metaphases and interphase nuclei of 11 taxa of wild chili peppers (Capsicum), with 2n = 2x = 24 (C. annuum var. glabriusculum, C. cardenasii, C. chacoense, C. flexuosum, C. galapagoense, C. eximium, C. praetermissum and C. tovarii) and 2n = 2x = 26 (C. recurvatum, C. rhomboideum and C. villosum) to analyse heterochromatin type, amount and distribution in wild members of this genus. Heterochromatic banding patterns allowed the identification of all the taxa examined and contributed to their taxonomic grouping. GC-rich heterochromatin (CMA+/DAPI?) was typical in all taxa; only C. praetermissum possessed also AT-rich (CMA?/DAPI+) and mixed GC- and AT-rich (CMA+/DAPI+) bands. Heterochromatin amount (expressed as % of karyotype length) ranged between 1.72 (C. chacoense) and 16.82 (C. flexuosum) and was positively correlated with karyotype length in most of the taxa examined. Heterochromatin located mainly at terminal position of chromosomes but intercalary position prevailed in C. flexuosum. Nucleolus organizer regions (NOR)-associated GC-rich heterochromatin was exclusively terminal and included the distal macrosatellite and a small portion on the corresponding arm. In all the taxa analysed, an equilocal heterochromatin distribution in non-homologous chromosomes of karyotype was observed, suggesting concerted evolution of heterochromatin dispersion in Capsicum.     

Fusarium tricinctum associated with Head Blight on barley in Argentina: pathogenicity and potential degradation of the different hordein fractions

Journal of Plant Diseases and Protection - The objective of the present work was to evaluate the pathogenicity of Fusarium tricinctum in barley and to determine the potential effects on grain...     

Exploring soybean management options for environments with contrasting water availability

Soybean is commonly cultivated under rainfed conditions being water availability the main constraint. We evaluated the performance of different managements under contrasting water availability to test possible trade‐offs among managements, and to determine physiological variables explaining these yield differences. Four treatments were designed through specific combinations of cultivar, row spacing and stand density. They were classified as stress tolerance or yield potential strategies and were evaluated under two contrasting water availability treatments. Treatments ranged from 349 to 954 mm total water availability. Water stress treatments yielded 72% and 59% of the well‐watered treatment each year, similar to frequent soybean water stress levels for our production region. Management treatments showed significant yield differences (p < 0.05), but the management × water availability interaction did not (p = 0.42). No management option helped reduce negative water stress effects. Highest yields were achieved using 0.25 m row spacing, a stand density of 60 pl per m², and a high yield potential genotype. Yield variations were explained by differences in harvested seeds per unit area (R² = 0.75; p < 0.001) and total N uptake at maturity (R² = 0.93; p < 0.001) across environments. Because management strategies specifically tailored to cope with water shortages showed limited value, farmers need to target yield potential management options.     

Ultrasonographic and histopathological features in 8 cats with fibrotic small intestinal stricture

Benign stricture is an uncommon cause of chronic small intestinal obstruction in the cat. The purpose of this retrospective case series was to describe the ultrasonographic features, histopathological findings, and clinical presentation in a group of cats with benign small intestinal stricture. Inclusion criteria were cats presenting during the period 2010‐2017, and that had ultrasonography and small intestinal stricture confirmed at surgery. For each cat, clinical data and ultrasonographic findings were retrieved from the medical record, and histopathology, where available, was reviewed. Eight cats met the inclusion criteria. The location of strictures was duodenum (1/8), mid‐ to distal jejunum (4/8), and ileum (3/8). Ultrasonographic findings included gastric distension (8/8) and generalized (3/8) or segmental (5/8) intestinal dilation consistent with mechanical obstruction. Ingesta did not propagate beyond the strictured segment. Wall thickening was mild to moderate (3‐6 mm). Normal wall layering was disrupted in all cats. Strictures were predominantly hypoechoic (7/8) and associated with hyperechoic peri‐intestinal mesentery (6/8). Annular strictures (5/8) were less than 15 mm in length whereas long‐segment strictures (3/8) were greater than 15 mm in length. Histopathology showed transmural disease with fibrosis and inflammation (8/8), often (6/8) extending into the bordering mesentery. The mucosa was the most severely affected layer and epithelial injury accompanied the mucosal fibrosis/inflammation. Clinical presentation reflected delayed diagnosis of chronic bowel obstruction with debilitation (8/8), marked weight loss (8/8), and prerenal azotemia (5/8). Benign fibrostenotic stricture should be considered a differential diagnosis in debilitated young cats presenting with chronic bowel disease and ultrasonographic features of intestinal obstruction.     

Does the level of forage neutral detergent fiber affect the ruminal fermentation,digestibility and feeding behavior of goats fed cactus pear?

This study aimed to evaluate the effects of forage neutral detergent fiber (fNDF) levels on the voluntary feed intake, digestibility, ruminal fermentation and feeding behavior of goats fed diets with cactus pear. Five non‐lactating ruminally cannulated goats fed ad libitum were randomly assigned to a 5 × 5 Latin square design. Treatments consisted of levels of fNDF at 0, 109, 222, 339 and 463 g/kg of dry matter (DM) in cactus pear‐based diets. The intakes of DM and NDF were quadratically affected (p ≦ .045) by fNDF levels. Voluntary water intake (VWI) increased linearly as the fNDF levels increased in the diet. The digestibility coefficients of organic matter, NDF and ether extract and total digestible nutrients concentration were quadratically affected (p ≦ .048) by fNDF levels. The ruminal pH linearly increased (p = .001) with fNDF levels, ranging from 5.44 to 5.81 for diets containing 0 and 463 g fNDF/kg DM, respectively. The fNDF levels promoted a linear increase (p = .006) in chewing time, linearly decreased (p = .007) resting time and quadratically affected (p = .033) rumination time. The inclusion of fNDF in the diets provided favorable conditions for ruminal function, digestibility and feeding behavior in goats fed diets containing cactus pear.     

Gas exchange,biomass, whole-plant water-use efficiency and water uptake of peach (Prunus persica) seedlings in response to elevated carbon dioxide concentration and water availability

We examined the interactive effects of elevated CO2 concentration ([CO2]) and water stress on growth and physiology of 1-year-old peach (Prunus persica L.) seedlings grown in 10-dm3 pots in open-top chambers with ambient (350 micromol mol-1) or elevated (700 micromol mol-1) [CO2]. Seedlings were supplied weekly with a non-limiting nutrient solution. Water was withheld from half of the plants in each treatment for a 4-week drying cycle, to simulate a sudden and severe water stress during the phase of rapid plant growth. Throughout the growing season, seedlings in elevated [CO2] had higher assimilation rates, measured at the growth [CO2], than seedlings in ambient [CO2], and this caused an increase in total dry mass of about 33%. Stomatal conductance, total water uptake, leaf area and leaf number were unaffected by elevated [CO2]. Because seedlings in the two CO2 treatments had similar transpiration despite large differences in total dry mass, water-use efficiency (WUE) of well-watered and water-stressed seedlings grown in elevated [CO2] was an average of 51 and 63% higher, respectively, than WUE of comparable seedlings grown in ambient [CO2]. Elevated [CO2] enhanced total biomass of water-stressed seedlings by 31%, and thus ameliorated the effects of water limitation. However, the percentage increases in total dry mass between well-watered and water-stressed seedlings were similar in ambient (53%) and elevated (58%) [CO2], demonstrating that there was no interaction between elevated [CO2] and water stress. This finding should be considered when predicting responses of trees to global climate change in hot and dry environments, where predicted temperature increases will raise evaporative demands and exacerbate the effects of drought on tree growth.     

Genetic mapping provides evidence for the role of additive and non-additive QTLs in the response of inter-specific hybrids of <Emphasis Type="Italic">Eucalyptus</Emphasis> to <Emphasis Type="Italic">Puccinia psidii</Emphasis> rust infection

Eucalypts are susceptible to a wide range of diseases. One of the most important diseases that affect Eucalyptus plantations worldwide is caused by the rust fungus Puccinia psidii. Here, we provide evidence on the complex genetic control of rust resistance in Eucalyptus inter-specific hybrids, by analyzing a number of full-sib families that display different patterns of segregation for rust resistance. These families are totally unrelated to those previously used in other inheritance studies of rust resistance. By using a full genome scan with 114 genetic markers (microsatellites and expressed sequence tag derived microsatellites) we also corroborated the existence and segregation of a resistance locus, explaining 11.5% of the phenotypic variation, on linkage group 3, corresponding to Ppr1. This find represents an additional validation of this locus in totally unrelated pedigree. We have also detected significant additive × additive digenic interactions with LOD >10.0 on several linkage groups. The additive and epistatic QTLs identified explain between 29.8 and 44.8% of the phenotypic variability for rust resistance. The recognition that both additive and non-additive genetic variation (epistasis) are important contributors to rust resistance in eucalypts reveals the complexity of this host-pathogen interaction and helps explain the success that breeding has achieved by selecting rust-resistant clones, where all the additive and non-additive effects are readily captured. The positioning of epistatic QTLs also provides starting points to look for the underlying genes or genomic regions controlling this phenotype on the upcoming E. grandis genome sequence.     

Three-dimensional microvascolature remodeling study of pig periovulatory follicles using vascular corrosion casts

Veterinary Research Communications -     

History and Trends of Sediment Contamination by Heavy Metals Within and Close to a Marine Area of National Interest: The Ligurian Sea off Cogoleto-Stoppani (Genoa, Italy)

Due to its remarkable sediment pollution caused by past industrial activities, the Mediterranean coastal area facing the town of Cogoleto (near Genoa) has been declared of “national interest”. Seven sediment cores were analysed to provide information on history and trend of heavy metal inputs, with a particular focus on Cr. Grain-size compositions and ²¹⁰Pb chronologies account for a strong influence of terrigenous inputs near the coast and the mouth of the Lerone Creek (draining the industrial settlement), with sand contents and accumulation rates varying from 40.3% and 0.7 cm year^?1 near shore to 2.5% and 0.1 cm year^?1 offshore. Heavy metal concentrations are high, notably Cr and Ni, and to a lesser extent, Ag, Hg, Pb, Cu and Zn. Cr, that shows past values up to 3,642 µg g^?1, presents only minor recent decreases. In the area, it has both natural and anthropogenic sources and their relative contributions were distinguished on the basis of Cr/Ni ratios. These are 1–1.5 in soils and rocks of the Lerone Creek catchment area but reach very high values (up to 10) in marine sediments due to the anthropogenic contribution. The anthropogenic influence is higher near the creek mouth, gradually decreases offshore and is negligible at the most distal site (ca. 2.9 km from the coast).     

The Frankincense tree (<Emphasis Type="Italic">Boswellia sacra</Emphasis>, Burseraceae) from Oman: ITS and ISSR analyses of genetic diversity and implications for conservation

DNA sequences from the ITS region of the nuclear genome and Inter-Simple Sequence Repeat markers (ISSR) were used to estimate genetic diversity among and within populations of the Frankincense tree Boswellia sacra from Dhofar, Oman. This is a culturally and ecologically relevant species that is showing symptoms of decline due to anthropic factors and, possibly, global warming. ITS sequences were 511 bp long and showed low (6.4%) variation among geographically different populations. The four selected ISSR primers yielded 93 reproducible bands, of which 91 (97.9%) were polymorphic in the 97 individual profiles obtained. Total genetic diversity (H _T) and average heterozygosity within populations (H _S) resulted fairly low (0.22 and 0.136, respectively). The accession from Wadi Dowkah, an UNESCO world heritage site, showed the lowest level of genetic diversity (H _E = 0.107), while the eastern populations from the Hasik area harboured a slightly greater amount of variation. Analysis of Molecular Variance showed that differentiation among populations was relatively high (38.1%), possibly due to the reduced gene flow between the largely isolated stands of Boswellia (N _m = 0.39). Genetic distances and AMOVA suggested a clear differentiation between the eastern and western coastal populations, while those from the internal area did not form a consistent group. For conservation, the eastern sites should be given priority as core populations harbouring significant amounts of allelic diversity. Reasons for reinforcing the more depauperated stands, such as Wadi Dowkah, with local plant material only or, alternatively, with the introduction of germplasm from genetically distinct stands are discussed.