Agronomical,quality, and molecular characterization of twenty Italian emmer wheat (<Emphasis Type="Italic">Triticum dicoccon</Emphasis>) accessions

Emmer wheat (Triticum dicoccon Schrank, 2n = 4x = 28) consists in a hulled wheat; its cultivation has been drastically reduced during the last century as a consequence of its low yield. Recently, its agronomic and nutritive values, as well as the increase of popularity of organic agriculture, have led to a renewed interest making its cultivation economically viable in the marginal lands with an increase of the cultivated areas. In Italy, it mainly survives in few marginal lands of central and southern Italy, where local varieties, adapted to the natural environment from where they originate, are used; moreover, some selected lines have also been developed. In the present work, agro-morphological and qualitative traits, together with molecular analyses of 20 emmer accessions consisting of Italian landraces, breeding lines, and cultivars, were performed. The field experiments were conducted for two consecutive years (2001/2002–2002/2003) in two locations: Viterbo in central Italy, and Foggia in south Italy. The analyzed emmer wheat accessions showed a good amount of genetic variability for both evaluated agro-morphological and molecular traits. This study illustrates an increase in earliness, GY, TW, TKW, and YI going from landraces, breeding lines to cultivars, while the variability does not change proportionally.     

Rapid seedlings regeneration from seeds and vegetative propagation with sucker and rhizome of Eremospatha macrocarpa (Mann & Wendl.) Wendl and Laccosperma secundiflorum (P. Beauv.) Kuntze

To develop efficient seedling production methods for Laccosperma secundiflorum and Eremospatha macrocarpa, a study was conducted to examine regeneration using offsets combined with several physical and chemical treatments of seeds. Offsets categorized into small, medium and large diameters, were planted in three conditions: shaded and open nursery, and greenhouse. We tested sucker from E. macrocarpa, and sucker and rhizome from L. secundiflorum. For both species, high viability percentage (ranging from 55% to 100%) were observed for small and medium suckers planted in shaded nursery and greenhouse, against less than 49% for sucker planted in open nursery. The mean seedling emergence times were estimated to 84, 77 and 75 days after planting (DAP) for small, medium and large sucker of L. secundiflorum, respectively under open nursery condition, and 76, 75, 95 DAP for small, medium and large suckers of the same species, respectively in shaded condition. Greenhouse has a significant positive effect on E. macrocarpa seedlings emergence time. For this species, the mean seedling emergence times were estimated to 43 DAP for small sucker and 76, 93 DAP for medium and large suckers. No seedling was obtained from rhizome planted in all the growing conditions tested. Concerning seed dormancy breaking, germination percentages and rates were determined for 13 treatments. The best treatments were pre-soaking unscarified seeds for 4 days in 1.01 g l⁻¹ and 0.10 g l⁻¹ KNO₃, with 79% and 68% of germination, respectively and in 3.46 × 10⁻³ g l⁻¹ GA₃ for 68% of germination. These methods are suggested to improve germination of L. secundiflorum seeds. Successful and recommended methods for E. macrocarpa are pre-soaking scarified seeds in 3.46 × 10⁻³ g l⁻¹ and 3.46 × 10⁻⁴ g l⁻¹ GA₃, 96% and 94% of germination, respectively. Dormancy, probably a combination of mechanical and chemical dormancy, is present in the two species.     

Genetic divergence among gerbera accessions evaluated by RAPD

Genetic diversity was evaluated by RAPD markers and morpho-agronomic characters for a total of 42 accessions of Barberton daisy (Gerbera jamesonii) consisting of 29 commercial and 13 wild accessions. A total of 74 polymorphic bands were obtained employing a set of 12 primer pairs. The average genetic similarity coefficient for the 42 accessions, evaluated by Jaccard index was 0.55 ranging from 0.28 to 1.00. The genetic structure found among Barberton daisy accessions was evaluated by hierarchic classification analyses and UPGMA modeling, revealing six clusters of genotypes where two of them include the wild accessions and the remaining four including commercial material, except for wild genotype number 9. Shannon (H′) index was calculated using the molecular markers to investigate the genetic variation among the Gerbera accessions and showed higher values for the commercial cluster in comparison to the values obtained for the individuals from the non-commercial cluster, namely 0.34 versus 0.27, respectively. Therefore, both calculated indices (Jaccard and Shannon) indicated the presence of higher genetic variation among commercial accessions in comparison to the cluster representing non-commercial accessions, suggesting that genetic breeding programs may focus on commercial accessions to recombine interesting genotypes with commercially important and marketing-desired characteristics.     

Impact of atmospheric CO2 and plant life forms on soil microbial activities

From the global change perspective, increase of atmospheric CO₂ and land cover transformation are among the major impacts caused by human activities. In this study, we are addressing the combined issues of the effect of CO₂ concentration increase and plant type on soil microbial activities by asking how annual and perennial plant groups affect soil microbial processes under elevated CO₂. The experimental design used a mix of species of different growth forms for both annuals and perennials. Our objective was: (1) to determine how two years of annual or perennial plant cover and CO₂ enrichment could affect Mediterranean soil microbial processes; (2) to test the resistance and the resilience of these soil functional processes after a natural perturbation. We determined the effects of 2 years atmospheric CO₂ enrichment on soil potential respiration (SIR), denitrification (DEA) and nitrification (NEA) activities. We could not find any significant effect of CO₂ increase on SIR, DEA and NEA. However, we found a strong effect of the plant cover type, i.e. annuals versus perennials, on the potential microbial activity related to N cycling. DEA and NEA were significantly higher in soil under annual plants while SIR was not significantly different. To determine whether these changes would survive a natural perturbation, we carried out a rain event experiment once the experimental treatments (i.e. different plant cover and atmospheric CO₂ concentration) were stopped. The soil potential respiration, as expressed by the SIR, was not affected and remained stable. DEA rates converged rapidly under annuals and perennials after the rain event. Under both annuals and perennials NEA increased significantly after the rain event but remained significantly higher in the soil with annual plants. The relative change of the soil microbial processes induced by annual and perennial plants was inversely related to the density and the diversity of the corresponding microbial functional groups.     

Comparison between vegetation indices for detecting spatial and temporal variabilities in soybean crop using canopy sensors

Precision Agriculture - Crop monitoring through remote sensing techniques enable greater knowledge of average variability in crop growth. Canopy sensors help provide information on the variability...     

Effects of dietary medium-chain triacylglycerols (tricaprylin and tricaproin) and phospholipid supply on survival, growth and lipid metabolism in common carp (Cyprinus carpio L.) larvae

The present study investigated the interaction of dietary medium-chain fatty acids (MCFA) and phospholipids (PL) on survival, growth and lipid metabolism in common carp larvae. Nine diets based on casein and dextrin and with a variable lipid part were tested in triplicate for 22 days post first feeding. The 3×3 design consisted of three triacylglycerols (3% of diet) combined with three different lipid supplements. Tested triacylglycerols were triolein (TOL), tricaprylin (TC8) and tricaproin (TC6), and lipid supplements were 2% soybean oil (low-fat diets without PL), 2% soybean lecithin (low-fat diets with 2% PL) or both 2% soybean lecithin and 6% TOL (high-fat diets with 2% PL).

In the first step, both TC6 and TC8 resulted in improved survival and growth rates compared to TOL, irrespective of the PL supply. In the second step, TC8 decreased survival and growth rates, whereas the difference between TC6 and TOL became less. Histological signs of impaired intestinal absorption of neutral lipids were evidenced in larvae fed TOL without PL and also in high-fat diets with 2% PL. The latter diets also resulted in poorer growth rates compared to low-fat diets with 2% PL. These results suggest that the quantitative PL requirement of larvae increases as the dietary level of long-chain triacylglycerols increases. Larvae fed TC6 or TC8 showed enlarged liver and hepatocyte volume and a decreased level of body neutral lipids. Based on β-hydroxybutyrate (β-HBA) measurements in whole larvae, TC8 was found to be more ketogenic than TC6. TC6 and TC8 affected differently the fatty acid profile of larval body neutral lipids. TC6 did not induce the appearance of MCFA, whereas TC8 feeding resulted in a low level of 8:0 and relatively high levels of 10:0 (3.8% of total fatty acids). Neither 8:0 nor 10:0 were found in larval polar lipids.

This study confirmed the essentiality of PL in common carp larval diets and underlines differences in the utilization of TC6 and TC8, which both initially stimulate growth during the first week, but only temporarily in the case of TC8.     

Depletion study and estimation of withdrawal periods for florfenicol and florfenicol amine in pacu (Piaractus mesopotamicus)

The intensive production of farmed fish is at a global all‐time high, and the control of bacteria proliferation in fish farms requires the frequent use of antimicrobials. This practice raises important environmental concerns related to the emergence of antimicrobial‐resistant bacteria strains. Only a few antimicrobial drugs have been approved for use in aquaculture, one of which is florfenicol. This work studies the depletion and withdrawal period of florfenicol and its main metabolite, florfenicol amine, in pacu (Piaractus mesopotamicus), a neotropical characin widely farmed in the southern hemisphere. Juvenile pacu (average weight of 724 g) were stocked in a closed‐loop laboratory system with controlled water temperature (25.8°C), and were fed for 10 consecutive days with a diet containing an intended dose of 10 mg/florfenicol per kg bw. Muscle and skin tissues were collected at 1, 3, 6, 8, 10, 12 and 16 days post‐treatment, and florfenicol and florfenicol amine were quantified using a validated ultra‐high performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS) method. The limits of quantitation for florfenicol and florfenicol amine were 10 ng/g in muscle and 50 ng/g in skin. Considering a maximum residue limit of 1000 ng/g for the sum of florfenicol and florfenicol amine in muscle with skin in natural proportions a withdrawal period of 5 days (water temperature 25.8°C) or 129 degree days was calculated on the basis of the upper limit of the one‐sided 95% confidence interval for the 99^th percentile derived from the residue depletion study.     

Odor Modification in Salmon Hydrolysates Using the Maillard Reaction

The aim of this work was to study the effect of adding sugar during proteolysis to promote the Maillard reaction and mask the initial fish odor and off-flavors generated. An experimental design, based on the Doehlert plan, was used to study the influence of hydrolysis conditions (time, temperature, sugar, and antioxidant addition) on the odor characteristics of hydrolysates, soluble protein levels, and amino acid content. Results showed that the lowest level of sugar (10 g of D-xylose added to 1 kg of by-products) was enough to develop a grilled odor in hydrolysates. In the hydrolysis conditions used—i.e., enzyme inactivation at 95°C for 30 min—hydrolysis temperature had no effect on grilled odor production but significantly affected the soluble protein fraction, as did hydrolysis time. Soluble protein content and essential amino acid content increased with the enzymatic reaction but were not modified by adding sugar. Hydrolysis conditions that promote Maillard reactions while keeping a nutritional balance have been identified.     

Synthesis and in-vitro antifungal activity of 6-trifluoromethyipyrazolo[3,4-6d]pyrimidin-4(5H)-thiones

Twelve 6-trifluoromethylpyrazolo[3,4-d]pyrimidin-4(5H)-thiones were prepared by the reaction between 4-thiocarbamoyl-5-aminopyrazoles and trifluoroacetic anhydride. They were tested in vitro for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. The EC50 and MIC values of four compounds were comparable or inferior to those of reference commercial fungicides in controlling Sclerotinia minor, Corticium solani and Phytium ultimum.     

Application of a putative fatty-acid binding protein to discriminate serologically the two European quarantine root-knot nematodes, Meloidogyne chitwoodi and M. fallax, from other Meloidogyne species

Two major proteins, Mcf-A67 and Mcf-B66, were identified by mini two-dimensional polyacrylamide gel electrophoresis in order to distinguish the two European quarantine root-knot nematodes, Meloidogyne chitwoodi and M. fallax, from eight other species. These quarantine proteinic markers have been microsequenced after enzymatic digestion. The internal amino acid sequences exhibit similarities to members of a family of low molecular weight intracellular lipid-binding proteins. Moreover, to explore a simple, rapid, and inexpensive way to identify the two quarantine nematodes, dot blot hybridizations were performed using an antiserum (A67) produced from the longest amino-acid sequence of the protein Mcf-A67. Although several proteins stained on the M. chitwoodi and M. fallax western blot membranes, the two nematodes were easily distinguished from other root-knot nematodes, on dot blot assays with soluble proteins extracted from a single female. Because of its specificity and sensitivity, the use of the A67 antiserum to improve the diagnosis of the two European quarantine root-knot nematodes is discussed.