Effect of ABA,arginine and sucrose on protein content of date palm somatic embryos

Abscisic acid (ABA), arginine and sucrose were evaluated for their effects on the morphology, germination rates and protein content of date palm somatic embryos (SE). Different concentrations of these supplements in the culture medium were used. The comparative study of SE length and thickness between treated and untreated SE revealed no differences, except for ABA (20 μM), which increased thickness. A decrease of water content (WC) in favor of an increase in dry weight (DW) was observed in all treated SE, especially with sucrose (90 g l⁻¹) and ABA (20 μM). Only ABA (20 and 4 μM) caused a proliferation rate of the cultures higher than those in the control. Although all the tested compounds increased protein content, ABA (20 μM) was more effective in protein enrichment than arginine and sucrose treatments. The SDS-PAGE protein profiles showed a significant difference between treated and untreated SE. A protein band of 22 kDa, identified as glutelin in a previous work, was accumulated after treatment with 20 μM ABA or 3 mM arginine. These findings may contribute to further understanding of the mechanisms involved in the accumulation of specific storage proteins in several plants.     

Diversity in daytime and night‐time transpiration dynamics in barley indicates adaptation to drought regimes across the Middle‐East

A challenge to breeding drought‐tolerant barley in the Middle‐East is that precipitation and evaporative demand patterns dictate opposite water use strategies (conservative vs. risk‐taking). To characterize these strategies, we examined high‐resolution, whole‐plant transpiration rate (TR) responses to increasing vapour pressure deficit (VPD) and nocturnal TR (TR_N) dynamics among 25 local barley genotypes, using a novel phenotyping system. These traits were specifically selected because they exist under modalities enabling the expression of both strategies. The genotypes were selected from locations spread across a large aridity gradient represented by temperature and precipitation data spanning 30 years. Here, we uncovered a substantial diversity in TR responses to VPD where slopes of the linear responses correlated negatively with local maximal temperatures, pointing to opposite drought tolerance strategies. Low canopy conductance (low slopes) was associated with higher aridity, likely to enable water‐saving, while higher conductance was associated with wetter areas, likely to enable a more aggressive water use to maximize physiological activity. TR_N was highly diverse and represented up to 15% of maximal daytime TR, pointing to the possibility of increasing water‐saving by reducing TR_N. Furthermore, we detected pre‐dawn variation in TR_N that negatively correlated with local precipitation, indicating that a tighter circadian control is associated with adaptation to drought, consistently with a circadian resonance mechanism. These findings indicate that canopy conductance and TR_N are potentially beneficial to design drought‐tolerant barley germplasm adapted to different drought regimes taking place in the Middle‐East.     

Impact of a Variable Tungsten Pollution on the Elemental Uptake of Two Plant Species

A radish and a grass species were grown in identical substrates either unpolluted or polluted by tungsten (W) at 1, 5, and 10 μg/g levels of watering solutions during 1 month under controlled laboratory conditions. Initially, at 4.1 μg/g, the W content in grass leaves reached 16 μg/g at the highest rate of W supply to the substrate. For radish, the content of W reached 22 and 29 μg/g in the leaves and roots, respectively. The overall W pollution increased significantly the mobility of major elements from substrate to grass leaves, especially at the 5 μg/g pollution level, whereas the W impact on radish leaves resulted in an increase of most contents, only Mn remaining unaffected. The roots from polluted radishes were enriched in Si by 21% and Al by 42% at low pollution, and in Si by 15% at high supply, whereas the uptake of the other elements remained unchanged. It looks like the W pollution at the levels chosen does not impact the transfer of the major and trace elements from roots to leaves of Raphanus sativus. Alternatively, metallic trace elements (Ba, Ni, Cr, Zn, W, Co) of the Raphanus sativus and Chloris gayana leaves outline similar content changes depending on the amount of W pollution. The total rare-earth element contents of the leaves of Raphanus sativus grown in the polluted substrates are lower than those of the leaves from unpolluted substrate. Their normalization in the leaves and roots of Raphanus sativus from the polluted substrates to those of the radish from non-polluted substrate provides flat patterns for both with a positive Eu anomaly for leaves, as for those of the grass and a negative Gd anomaly for roots. Also, addition of soluble W to the substrates induced an increase in the bacterial activity of the soil.     

Plasma concentrations of transdermal fentanyl and buprenorphine in pigs (Sus scrofa domesticus)

Objective

To determine the absorption characteristics of fentanyl and buprenorphine administered transdermally in swine.

Molecular detection of Treponema species organisms in foremilk and udder cleft skin of dairy cows with digital dermatitis

Tropical Animal Health and Production - Identification of reservoirs and transmission routes of digital dermatitis (DD)-associated Treponema spp. is considered an effective means for controlling DD...     

Molecular characterization of pathogenic Escherichia coli isolated from diarrheic and in-contact cattle and buffalo calves

Tropical Animal Health and Production - Escherichia coli field isolates from calves were characterized and categorized into the most significant diarrheagenic pathotypes using polymerase chain...     

Genetic variability of transpiration response to vapor pressure deficit among soybean (Glycine max [L.] Merr.) genotypes selected from a recombinant inbred line population

Limited observations of soybean plant response of transpiration rate (TR) to vapor pressure deficit (VPD) have indicated the existence of genotypes with nearly constant TR at high VPD. The range of expression of this trait in a given population within a species has not been explored. To initiate study of this possibility, 22 genotypes from a RIL population derived from a cross of PI 416937 and Benning were characterized for their VPD response. Genotype PI 416937 has been shown to reach a maximum TR at a VPD as low as 2 kPa. Surprisingly, Benning was not found to have a continually increasing TR with VPD, but rather it had a two-segment TR response very similar to PI 416937. Unexpectedly, only one of the studied RILs had a TR response similar to the parents. Thirteen RILs had a continually increasing TR with increasing VPD. Eight RILs reached a maximum TR occurring at VPD of about 1.3 kPa, significantly lower value than that of the parents. While the inheritance of the maximum TR trait is clearly complex, these results offer encouragement that the VPD at which plants limit TR might vary so that the trait can be tailored to maximize potential yield increase in different water-deficit environments.     

New technique for rose production in soilless culture system and disease reduction

Rose flower is one of the most important cut flowers, with the world's highest production rate. Soilless culture has been increasingly popular in plant production worldwide in the past few decades. In two separate trials, the efficacy of Trichoderma harzianum, Anearobacillus migululanas, slow filtration, and UV ultraviolet (UV) treatment and sand filtration in eliminating Fusarium oxyporum, artificially added in the recirculating nutrient solution, was evaluated with Rosea hybrid plants grown in closed soilless systems. The dynamics of these fungi in the recirculating nutrient solution and in the sand filter was also investigated. T. harzianum, A. migululanas, UV treatment and slow sand filtration were effective in reducing Fusarium root rot. However, slow sand filtration may be a more feasible disinfection method than UV because of lower costs of installation and maintenance and for its adaptability to a wide range of production systems. Moreover, these disinfection techniques can be successfully combined with the application of antagonistic microorganisms.     

INFLUENCE OF VARIOUS PHYSICAL PARAMETERS ON ANTHER CULTURE OF BARLEY

This study describes the effect of some parameters on anther culture of barley to optimize the plant regeneration condition of this species. The embryo formation and plant regeneration from anthers of three barley cultivars (‘Igri’, ‘Saida’ and ‘Libya’) were investigated. The effects of length of flag leaves, stage of microspore development, and pre-treatments (mannitol or cold pre-treatment) of anthers were investigated. Results showed significant responses. Anthers at the mid uninucleate to mid-late uninucleate stage gave the best anther culture response showing 80, 60, and 30% anther development in ‘Igri’, ‘Saida’ and ‘Libya’ barley cultivars, respectively. The use of mannitol (0.3 M) or 20 days cold pre-treatments showed the best results for embryo and green-plant production.     

Development of EST-SSR markers and construction of a linkage map in faba bean (Vicia faba)

To develop a high density linkage map in faba bean, a total of 1,363 FBES (Faba bean expressed sequence tag [EST]-derived simple sequence repeat [SSR]) markers were designed based on 5,090 non-redundant ESTs developed in this study. A total of 109 plants of a ‘Nubaria 2’ × ‘Misr 3’ F₂ mapping population were used for map construction. Because the parents were not pure homozygous lines, the 109 F₂ plants were divided into three subpopulations according to the original F₁ plants. Linkage groups (LGs) generated in each subpopulation were integrated by commonly mapped markers. The integrated ‘Nubaria 2’ × ‘Misr 3’ map consisted of six LGs, representing a total length of 684.7 cM, with 552 loci. Of the mapped loci, 47% were generated from multi-loci diagnostic (MLD) markers. Alignment of homologous sequence pairs along each linkage group revealed obvious syntenic relationships between LGs in faba bean and the genomes of two model legumes, Lotus japonicus and Medicago truncatula. In a polymorphic analysis with ten Egyptian faba bean varieties, 78.9% (384/487) of the FBES markers showed polymorphisms. Along with the EST-SSR markers, the dense map developed in this study is expected to accelerate marker assisted breeding in faba bean.