Salt tolerance variability amongst Argentine Andean potatoes (Solanum tuberosum L. subsp.andigena)

Summary Salt tolerance in Andean potatoes can be a source for this trait in cultivated potatoes or be exploited to expand potato cultivation to more marginal areas. The purpose of this study was to determine salt tolerance in twelve Argentine Andean potato varieties through the response of nodal segments cultured in vitro and to evaluate whether changes in Na⁺, K⁺ or proline accumulation associate with salt tolerance. Genotypes Bianca, Airampia, Sisa Sani and Cuarentilla were the most tolerant. The most susceptible varieties were Balcacha, Runa Rosada, Collareja, Overa, Bianca Redonda and Papa Baya, while Cuarentona and Colorado Ml comprised an intermediate group. These results indicate that variability for salt tolerance exists in this germplasm, and highlights its potential use in breeding programmes. No association was found between the salt tolerance rating and changes in K⁺, Na⁺ and proline accumulation in a salt gradient, thus precluding the use of these parameters as predictors for salt tolerance of these species in in vitro studies.     

Field performance and molecular profiles of Mexican lime selections

The Mexican lime industry is interested in developing lime cultivars with improved characteristics for fresh and processing markets. The objective of this study was to determine the field performance and genetic molecular differences among four new Mexican lime [Citrus aurantifolia (Christm) Swingle] clonal selections compared to traditional thorny Mexican lime under the dry tropical conditions of Mexico. Tree growth, production, fruit quality, and molecular markers of the traditional thorny Mexican lime (MLT) cultivar were compared to the following lime selections: thornless Mexican lime (MLTS), seedless Mexican lime (MLS), ML 12-8, and ML 20-3. After 10 years of evaluation MLS showed the highest and MLTS the lowest tree growth. Most of the genotypes covered the soil surface area assigned to tree growth since they were 7 years old. Only the less vigorous MLTS required 9 years to cover the same space. MLT was the most productive selection (165 kg/tree/year, mean of 8 years of evaluation). MLS was the less productive (81 kg/tree in the same period of time). MLTS, ML 12-8, and ML 20-3 produced intermediate yields. Acidity and total soluble solids among the selections were very similar. However, MLS had the higher juice content and the lower seed number. The MLS selection is attractive for export market due to these characteristics. AFLP studies confirmed genetic differences among the five lime selections. Nevertheless, all five selections shared many bands as expected.     

Role of sex steroids in gonadal differentiation of the mussel Choromytilus chorus (Bivalvia Mytilidae) (Molina 1782)

In Chile, the species Choromytilus chorus stands out for its ecological and economic importance. This mussel has a very particular condition in the colour of the gonad, being cream‐yellow colour the male gonad and dark brown the female which is hardly desired by the consumers. In this context, the aim of this research is to determine the role that sex steroids have in gonadal differentiation of the mussel C. chorus. For this, juveniles with sizes 15–22 mm were selected, which were subjected to acute exposure in the form of bath for 60 days to four treatments: T1: dihydrotestosterone (DHT); T2: 17β‐estradiol (E2), T3: fadrozole (F) and T4: DHT‐F (DF), plus a control without chemicals. Each treatment as well as control included three replicates with 90 individuals each. The mussels undergoing treatment with E2 had a sex ratio (male:female) of 0.47 compared to 1:1 in the control group. In contrast, in the groups treated with DHT, F and DF the sex ratio changed to 2.0, 1.60 and 1.70 respectively. In the fertilization trials, all the mussels produced functional gametes, as they were able to generate gametes that were developed to morula, and veliger larva. Nevertheless, it should be noted that the size of oocytes from the group exposed to estradiol (61.12 ± 2.40 μm) was significantly higher than in other groups. These results support the hypothesis that sex steroids would be involved in sexual differentiation of marine bivalves.     

Evaluation of Mercury,Lead, Arsenic,and Cadmium in Some Species of Fish in the Atrato River Delta,Gulf of Urabá, Colombian Caribbean

The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Urabá, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg^?1, surpassing the maximum permissible limit (MPL?=?0.3 mg kg^?1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg^?1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg^?1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg^?1).     

Liver microsomal biotransformation of albendazole in deer, cattle, sheep and pig and some related wild breeds

Albendazole (ABZ) biotransformation was studied in vitro in liver microsomes of adult noncastrated male farm animals (ram, buck, bull and boar), castrated adult males (wether, billy and hog), and free living males (fallow buck, red deer stag, mouflon ram, roe buck and wild boar). Liver microsomal fractions were incubated with either ABZ or racemic albendazole sulphoxide (ABZSO). ABZ was extensively metabolized to the (+) and (-) enantiomers of ABZSO, whereas ABZSO underwent a slow oxidation to albendazole sulphone (ABZSO2) in all species. In all species both ABZSO enantiomers were detected. The chiral ratio, (+)-ABZSO/(-)-ABZSO, was greater than one in farm animals, mouflon and wild boar, and less than one in three species of deer. For total ABZ sulphoxidation, deer like species had lower values compared to the other species. Mouflon ram and ram had lower total sulphoxidation rates compared to wethers, as well as ABZ suphoxidation towards (+)-ABZSO. No significant difference occurred comparing ABZSO formation in mouflon ram and ram, but ABZSO2 formation rate in mouflon ram was higher than in rams and wethers. Roe deer stag, fallow buck and red deer stag did not differ in both total-ABZSO and (-)-ABZSO synthesis rates and roe deer stag and fallow buck did not differ in synthesis rates of (+)-ABZSO and ABZSO2. The bull differed from other species in all metabolites studied, except for red deer stag and boar in (-)-ABZSO synthesis rate. The extent of ABZSO sulphonation to ABZSO2 in bull microsomes was more than twice that of other species.     

Virulence of the nine serovar reference strains of Haemophilus paragallinarum

The virulence of the reference strains of the nine currently recognized Kume serovars of Haemophilus paragallinarum was investigated. The capacity of the H. paragallinarum strains to cause the typical clinical signs of upper respiratory tract disease associated with infectious coryza in unvaccinated, nasal-challenged chickens was assessed. Differences in virulence were assessed by means of a standardized scoring system for clinical signs. All nine strains were pathogenic to chickens, producing typical clinical signs of infectious coryza. The highest clinical signs score was obtained for serovar C-1 (1.72), while the lowest clinical signs score was obtained for serovar C-4 (0.32). Our results indicate that virulence differences exist among the serovars of H. paragallinarum.     

Protection conferred by bivalent and trivalent infectious coryza bacterins against prevalent serovars of Avibacterium (Haemophilus) paragallinarum in Mexico

The protection and level of hemagglutination-inhibition (HI) antibodies conferred in infectious coryza bivalent- and trivalent-immunized chickens against Avibacterium (Haemophilus) paragallinarum field isolates of the prevalent serovars in Mexico (A-1, A-2, B-1, and C-2) were investigated. The bivalent bacterin (A-1 and C-1) conferred significant protection and increased HI antibodies against isolates of serovars A-1, A-2, and C-2, but not against a serovar B-1 isolate. The trivalent bacterin (A-1, B-1, and C-2) conferred protection and increased HI antibodies against all four of the isolates. The results confirmed that in poultry areas where serovar B-1 is prevalent, the inclusion of this serovar in bacterins is needed to confer protection against infectious coryza caused by A. (H.) paragallinarum isolates of serovar B-1.     

Binderless fiberboard from steam exploded banana bunch

Musacea bunch was pretreated and used to produce fiberboard with non-synthetic binders. The lignocellulosic material was steam exploded with a thermomechanical aqueous vapor process in a batch reactor. The effect of the pretreatment and the pressure conditions on the physical–mechanical responses of the fiberboard was evaluated and the conditions maximizing the responses were found. Response surface methodology with a central composite design was used. The variables studied and their respective variation ranges were: pretreatment severity, 3.16–4.84; pressing temperature, 133–217 °C; pressing pressure, 3.95–14.04 MPa. The fiberboards obtained were good quality and satisfied the requirements of the relevant standard specifications. The effect of the pretreatment severity on the lignin, cellulose and xylans content was also determined by an analysis of variance. The decrease in xylans was clearly related to the increase in the dimensional stability of the fiberboards.