High molecular weight glutenin subunits in some durum wheat cultivars investigated by means of mass spectrometric techniques

The primary structures of high molecular weight glutenin subunits (HMW-GS) of 5 Triticum durum Desf. cultivars (Simeto, Svevo, Duilio, Bronte, and Sant'Agata), largely cultivated in the south of Italy, and of 13 populations of the old spring Sicilian durum wheat landrace Timilia (Triticum durum Desf.) (accession nos. 1, 2, 3, 4, 7, 8, 9, 13, 14, 15, SG1, SG2, and SG3) were investigated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and reversed-phase high performance liquid chromatography/nanoelectrospray ionization mass spectrometry (RP-HPLC/nESI-MS/MS). M(r) of the intact proteins determined by MALDI mass spectrometry showed that all the 13 populations of Timilia contained the same two HMW-GS with 75.2 kDa and 86.4 kDa, whereas the other durum wheat cultivars showed the presence of the expected HMW-GS 1By8 and 1Bx7 at 75.1 kDa and 83.1 kDa, respectively. By MALDI mass spectrometry of the tryptic digestion peptides of the isolated HMW-GS of Timilia, the 1Bx and 1By subunits were identified as the NCBInr Acc. No AAQ93629, and AAQ93633, respectively. Sequence verification for HMW-GS 1Bx and 1By both in Simeto and Timilia was obtained by MALDI mass mapping and HPLC/nESI-MSMS of the tryptic peptides. The Bx subunit of Timila presents a sequence similarity of 96% with respect to Simeto, with differences in the insertion of 3 peptides of 5, 9, and 15 amino acids, for a total insertion of 29 amino acids and 25 amino acid substitutions. These differences in the amino acidic sequence account for the determined Δm of 3294 Da between the M(r) of the 1Bx subunits in Timilia and Simeto. Sequence alignment between the two By subunits shows 10 amino acid substitutions and is consistent with the Δm of 148 Da found in the MALDI mass spectra of the intact subunits.     

Limited host range in the idiobiont parasitoid Phymastichus coffea,a prospective biological control agent of the coffee pest Hypothenemus hampei in Hawaii

Phymastichus coffea LaSalle (Hymenoptera:Eulophidae) is an adult endoparasitoid of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera:Curculionidae:Scolytinae), which has been introduced in many coffee producing countries as a biological control agent. To determine the effectiveness of P. coffea against H. hampei and environmental safety for release in Hawaii, we investigated the host selection and parasitism response of adult females to 43 different species of Coleoptera, including 23 Scolytinae (six Hypothenemus species and 17 others), and four additional Curculionidae. Non-target testing included Hawaiian endemic, exotic and beneficial coleopteran species. Using a no-choice laboratory bioassay, we demonstrated that P. coffea was only able to parasitize the target host H. hampei and four other adventive species of Hypothenemus: H. obscurus, H. seriatus, H. birmanus and H. crudiae. Hypothenemus hampei had the highest parasitism rate and shortest parasitoid development time of the five parasitized Hypothenemus spp. Parasitism and parasitoid emergence decreased with decreasing phylogenetic relatedness of the Hypothenemus spp. to H. hampei, and the most distantly related species, H. eruditus, was not parasitized. These results suggest that the risk of harmful non-target impacts is low because there are no native species of Hypothenemus in Hawaii, and P. coffea could be safely introduced for classical biological control of H. hampei in Hawaii.

     

The importance of dietary HUFA for meagre larvae (Argyrosomus regius; Asso, 1801) and its relation with antioxidant vitamins E and C

Despite the interest of meagre (Argyrosomus regius) as a fast‐growing candidate for Mediterranean aquaculture diversification, there is a lack of information on nutrition along larval development. Importance of highly unsaturated fatty acids (HUFA) and the antioxidant vitamins E and vitamin C has not been investigated yet in this species. Six diets with two levels of HUFA (0.4% and 3% dw), two of vitamin E (1500 and 3000 mg kg^?1) and two of vitamin C (1800 and 3600 mg kg^?1) were fed to 15 dah meagre larvae. Larval growth in total length and dry body weight was significantly lowest in larvae fed diet 0.4/150/180 and showed few lipid droplets in enterocytes and hepatocytes and lower HUFA contents than the initial larvae. Increase in dietary HUFA up to 3%, significantly improved larval growth and lipid absorption and deposition. Besides, among fish fed 3% HUFA, increase in vitamin E and vitamin C significantly improved body weight, as well as total lipid, 22:6n‐3 and n‐3 fatty acids contents in the larvae. Thus, the results showed that 0.4% dietary HUFA is not enough to cover the essential fatty acid requirements of larval meagre and a high HUFA requirement in weaning diets is foreseen for this species. Besides, the results also pointed out the importance of dietary vitamin E and C to protect these essential fatty acids from oxidation, increase their contents in the larvae and promote growth, suggesting high vitamin E and C requirements in meagre larvae (higher than 1500 and 1800 mg kg^?1 for vitamin E and vitamin C respectively).     

饲料中添加微生态制剂能够影响仔猪的免疫力吗?

研究表明,饲料中添加微生态制剂能够使仔猪肠道内有益微生物数量增加并直接抑制病原菌的数量.     

Hydration Rates for Various Types of Mexican Maize Based on Single‐Kernel Measurements

Hydration kinetics for sound maize kernels in liquid water, determined by single‐kernel measurements for three different Mexican maize types, yielded water diffusion coefficients ordered as Celaya corn > Toluca corn > Palomero corn, at all temperatures examined. These diffusion coefficients are lower than those reported earlier for maize grains, possibly due to the fact that in the present study damaged kernels were rigorously excluded. The energies of activation determined from the Arrhenius plots were ordered as Palomero corn > Celaya corn = Toluca corn and were similar in value to those reported earlier for other maize types. Damage to the surface of the maize kernels during the hydration experiments occurs at a significant frequency. Even minor surface lacerations can strongly affect the rate of hydration of the kernels. Experiments with maize grains selectively varnished in various parts of their surface show that the entry of water into the kernels occurs predominantly through the pericarp, not through the tip cap, though the tip cap has a higher water inflow per unit area.     

Seeding date influence on camelina seed yield, yield components, and oil content in Chile

Camelina (Camelina sativa L.) was introduced for the first time in Chile in 2008 as a potential feedstock for biodiesel and also as high omega-3-containing seed oil for the salmon feed industry. The objective of this study was to determine the optimum seeding date to maximize camelina seed yield in South Central Chile. The experiment was conducted under dryland conditions in Chillán, El Carmen, Los Angeles, Gorbea, and Osorno in 2008 and in Chillán and Los Angeles in 2009. The experimental design was a RCB with a split-plot arrangement with four replicates, where the main plot was the seeding date (five dates) and the sub-plot the spring type cultivars (Gold of Pleasure, Suneson, and Blaine Creek). Seeding dates at each environment were targeted to 30 April, 15 May, 30 May, 30 June, and 30 July of 2008 and 2009. The combined analysis of variance indicated no cultivar main effect or interactions with cultivar. The date by environment interaction was significant for seed yield. There were no seed yield differences among seeding dates in Chillán and El Carmen. The first three seeding dates were the highest yielding in Los Angeles and Osorno, and only the first seeding date was significantly higher in seed yield in Gorbea. Highest seed yield at Los Angeles, Gorbea, and Osorno were 1995, 1310, and 2314 kg ha⁻¹. Seed oil content was not different among seeding dates in Chillán and El Carmen. Highest seed oil content occurred at Osorno and Gorbea on the first three seeding dates and ranged from 420 to 457 g kg⁻¹. Spring camelina cultivars are well adapted to South Central Chile as a winter annual crop when seeded before 15 May except in Osorno when seeded before 30 May. No disease or insectpests were observed except for Aster Yellow infestation at Chillán and Los Angeles. Camelina has great potential as an oilseed for biodiesel and as a source of omega-3 for the pharmaceutical industry but markets for it need to be developed locally for camelina to become an option for growers.     

Lentil (Lens culinaris L.) growth promoting rhizobacteria and their effect on nodulation in coinoculation with rhizobia

Lentil is cultivated in Chilean Mediterranean drylands, in areas with soils that are nutrient depleted and eroded. Inoculation of lentil with rhizobia in co-inoculation with growth promoting rhizobacteria would allow higher biomass and an opportunity for early nodulation and increased nitrogen fixation. The objective of this research was to select rhizosferic bacteria (PGPR) from lentils and to evaluate their effect on lentil nodulation in co-inoculation with rhizobia. Sixty three lentil rhizobacteria isolates where obtained from nine soils in the mediterranean area. These were fingerprinted through BOX-PCR reducing the number to 57 distinct strains. The strains were evaluated for ACCdeaminase activity, IAA production and compatibility with rhizobia. Seventeen strains showed ACC-deaminase activity, all of them synthesized IAA and 38 were compatible with the rhizobia. Ten selected strains were identified as Pseudomonas spp. through 16S rRNA sequencing. The strains were inoculated in lentil seedlings growing on seed germination pouches, to evaluate nodule formation. The strain LY50a increased early nodulation in 85% in comparison to the control inoculated with rhizobia (AG-84) only. In conclusion, bacteria from the rhizosphere from Mediterranean soils of Chile can be used as nodulation promoters in lentils.     

Effect of increasing docosahexaenoic acid content in weaning diets on survival,growth and skeletal anomalies of longfin yellowtail (Seriola rivoliana,Valenciennes 1833)

Five isoproteic (54.8%) and isolipidic (24.1%) microdiets, which varied in their docosahexaenoic acid (DHA) content (0.25%, 0.75%, 1.64%, 1.99% and 3.17%; dw), were manufactured to determine its effects on longfin yellowtail Seriola rivoliana larvae in terms of fish biological performance, whole body fatty acid profile and incidence of skeletal anomalies from 30 dah (11.31 ± 1.79 Total Length, TL) to 50 dah (19.80 ± 0.58 mm TL). The inclusion of dietary DHA up to 3.17% (dw) improved larval resistance to air exposure, although DHA did not significantly affect fish final growth or final survival. Indeed, high levels of dietary DHA (1.99% and 3.17%, dw) tended to increase the incidence of skeletal anomalies in S. rivoliana larvae, albeit no significant differences were observed. Furthermore, the occurrence of severe anomalies such as kyphosis and lordosis, was mainly associated to the larvae fed the highest levels of dietary DHA. In terms of survival, increasing dietary DHA levels did not significantly affect longfin yellowtail survival rate, despite a tendency for enhanced survival. The results of the present study proved that the inclusion of dietary DHA in inert diets up to a 3.17% (dw) and a DHA/EPA ratio above 3.1 increased the final survival and stress resistance in S. rivoliana larvae.