Salinity Stress Promote Drought Tolerance of Chenopodium Quinoa Willd

A greenhouse experiment was conducted to investigate the impact of water and salt stress in Quinoa plants (Chenopodium quinoa Willd.). Irrigation treatments using saline solutions of 0 (control), 50(T₁), 200(T₂), 400(T₃), 600(T₄), and 800(T₅) mM sodium chloride (NaCl) were adopted. The results indicated that quinoa plants can tolerate water stress (50%FC) when irrigated with moderately saline water (T₁ and T₂, respectively). Salinity stress increases quinoa drought tolerance in terms of biomass production. Neither osmotic stress nor ions deficiency/toxicity seems to be determinant under T₁ and 100%FC. Salinity induced a significant increase of sodium (Na⁺) and chloride (Cl^?), while reduced magnesium (Mg²⁺) and calcium (Ca²⁺) in stems, leaves, seed’s coating, and seeds. The potassium (K⁺)/Na⁺ ratio never fell below 1 with T₁; yet, fell to 0.78 and 0.89 with T₂ for 100% and 50%FC, respectively. The seed coat limited the passage of possibly toxic concentrations of Na⁺ and Cl^? to seed interior, as high Na⁺ and Cl^? was found in the seed coat.     

家禽病毒性肿瘤病发病机制研究进展

<正>病毒性肿瘤病是家禽最为常见的自发性疾病,可致肿瘤性死亡和生产性能下降,造成重大经济损失。这类疾病包括由反转录病毒引起的禽白血病、禽网状内皮组织增生症、火鸡淋巴细     

Trafficking of molecules between parasitic plants and their hosts

Parasitic plants have evolved various methods of invading host plants. Some invade aerial parts, whereas others invade the roots to obtain necessary nutrients for their development. Phelipanche and Orobanche spp. (broomrapes) and Cuscuta spp. (dodders) are holoparasitic plants that subsist on roots and shoots, respectively, of a variety of agricultural crops. These weeds are able to connect directly with the vascular system of the host, thereby acquiring the water, minerals and carbohydrates necessary for their own growth and reproduction. This exploitation by parasitic plants often causes severe losses in yield quality and quantity of host crops. The key to an effective means for controlling parasitic plants lies in the development of resistant crops, supported by an improved understanding of broomrape and dodder biology. The haustoria formed at the junctions of parasite and host open the way for translocation of a variety of molecules and macromolecules from the host to the parasite. At the same time, however, the haustoria also open opportunities for the development of methods to control parasitic plants. This review will summarise the current knowledge on translocation of siRNAs, mRNAs, viruses, sugars, proteins and herbicides from host to parasitic plants and the potential significance of such molecules to the parasite. Improved understanding of the molecular exchange between host plants and their parasites is expected to lead to the development of state‐of‐the‐art, effective approaches to parasitic weed management.     

Biology and efficiency of phytoseiid mites as affected by cucumber leaves

The biology of the phytoseiid mitesPhytoseiulus persimilis Athias-Henriot,Phytoseius finitimus Ribaga andAmblyseius gossipi Elbadry was studied using the cucumber leaves as a rearing substrate. The consumption of the two-spotted spider miteTetranychus urticae Koch by the different stages ofP. persimilis was higher than that of their counterparts of the other two predators. The present study revealed that cucumber leaves were adequate fot the development and reproduction ofP. persimilis andP. finitimus, while this rearing substrate was inadequate for the biology ofA. gossipi.     

The biological effects of three insect growth regulators onCulex pipiens L

Tests were made to determine the possible juvenilizing effects of three insect growth regulators (IGRs) namely, IKI 7899, SIR 8514 and Dowco 439 on immature stages and adults ofCulex pipiens L. using the IC₅₀ values (concentration to inhibit the emergence of 50% of adults) as a criterion. The results indicated that IKI 7899 (0.00031 μg/ml) proved to be the most effective compound followed by SIR 8514 (0.0052 μ/ml) and Dowco 439 (0.029 μg/ml). Apart from lethal action, treatment of fourth larval instars with the IC₂₅ values (concentration to inhibit the emergence of 25% of adults) of the above-mentioned IGRs affected the reproductive capacity of surviving adults. Moreover, larval treatments with these compounds led to a marked prolongation in the duration of first gonotrophic cycle. There was also an increase in the proportion of survived females/males ofC. pipiens after these larval treatments.     

Efficacy of spheroplastic and cell-wall competent vaccines for Mycobacterium avium subsp. paratuberculosis in experimentally-challenged baby goats

A Mycobacterium avium subspecies paratuberculosis (MAP) vaccine that reduced the incidence of clinical disease or reduced fecal shedding of MAP would aid control of Johne's disease (JD). The objective of the present study was to evaluate the efficacy of four MAP vaccine combinations, including cell-wall competent (CWC) alum adjuvant, CWC-QS21 adjuvant, cell-wall deficient (CWD) alum adjuvant and CWD-QS21 adjuvant vaccines. Eighty baby goats were vaccinated at 1 and 4 weeks of age with one of these vaccines or a sham control vaccine consisting of alum adjuvant. Kids were challenged orally with approximately 6.0 × 10⁹ organisms in four divided doses of 1.5 × 10⁹ organisms using a goat isolate of MAP. Vaccinated challenged and challenged control groups had 10 and 6 kids per group, respectively. Half of the kids within each group were necropsied at either 6 or 9 months post-challenge. Gross and microscopic lesions and relative number of acid-fast bacilli were evaluated and scored at necropsy. Results indicated all challenged kids had some lesions compatible with JD suggesting none of the vaccines prevented infection. Three vaccines (CWC-alum, CWC-QS21 and CWD-QS21) reduced lesion scores by 46–51% at 9 months. CWD-alum vaccine resulted in a more severe (+33.5%) lesion score than sham-vaccinated challenged control. Lesion scores were greater at 9 months than at 6 months post-challenge in the sham-vaccinated challenged group and CWD-alum vaccinated group, while lesion scores were generally stable with remaining vaccines. Mean fecal CFU/g were significantly different across time from challenge to 9-month necropsy (p = 0.043) and the CWC-QS21 vaccine group had a marked reduction in fecal CFU/g at all time points post-challenge. A reduction in MAP CFU/g was also detected in necropsy tissues from kids given the CWC-alum, CWC-QS21 and CWD-QS21 vaccines, and increased CFU/g were detected in tissues from kids given the CWD-alum vaccine. Immunological tests evaluated included, humoral response evaluation by AGID, ELISA and Western blot, and cell mediated response by comparative PPD skin testing (M. avium, Old Johnin, M. bovis and Lot 2 Johnin PPD's), and production of MAP induced γ-interferon. Vaccination also resulted in false-positive PPD skin test reactions for M. avium PPD, Old Johnin PPD and γ-interferon tests. When a 2-mm cutoff above normal skin thickness was used to define positive skin test reactions, false-positive reactions for M. bovis were detected in only 2 of 32 kids given a vaccine with QS21 adjuvant.     

Histomorphometric analysis of the irides of dogs, camels, buffalos and donkeys

The present study was carried out to investigate the morphological and histomorphometrical characters of irides in dogs, camels, buffalos, and donkeys. The findings of the study revealed that, morphologically, the irides were consisted of an anterior border layer, a middle layer of connective tissue stroma and a posterior layer of pigmented epithelium. Interestingly, the anterior borders of all investigated animals were not enveloped by a distinct epithelial or endothelial lining, but on contrary, the posterior border was covered by pigmented epithelium. The constrictor and dilator iridial muscles were well developed in dogs, weakly developed in donkeys, and with an intermediate position in camels and buffalos. Morphometric analysis revealed significant species differences in the mean total thickness of the iris and its different layers. In addition significant differences were also found between the ratio of the means of different layers to the total thickness of the iris at the pupillary, middle and ciliary borders. In conclusion, these variations might be related to the different lifestyles and visual behaviour of the investigated animals.     

Early Embryonic Development of the Camel Lumbar Spinal Cord Segment

The lumbar spinal cord segment of the camel embryo at CVRL 2.4 to 28 cm was examined. Major changes are occurring in the organization of the lumbar spinal cord segments during this early developmental period. At the CVRL 2.4, 2.7 and 3.6 cm the three primary layers, ependymal cells layer, mantle cells layer, marginal cells layer in the developing lumber spinal cord segment were demonstrated. The mantle layer is the first to show striking differentiation, while the marginal layer is represented by thin outer rim. Proliferation and differentiation of the neuroepithelial cells in the developing spinal cord produce the thick lateral walls, thin roof and floor plates. The spinal ganglion and dorsal root of the spinal nerve are differentiated. At 2.7 cm CVRL differential thickening of the lateral walls produces a shallow longitudinal groove called sulcus limitans , which separates the dorsal part (alar plate) from ventral part (basal plate). The ventral root of the spinal nerve, the spinal cord and ganglion are embedded in loose mesenchyme, which tends to differentiate into spinal meninges. At 3.6 cm CVRL the basal plate, which is the future ventral gray horn, seem to be quite voluminous and the dorsal and ventral roots unite to form the beginning of the spinal nerve. At 5.5 cm CVRL the alar plates enlarge forming the dorsal septum. At 8.4 cm to 10.5 cm CVRL the basal plates enlarge, and bulge ventrally on each side of the midline producing the future ventral medium fissure, and the white and gray matters can be recognized. At 28 cm CVRL the lumen of the spinal cord is differentiated into the central canal bounded dorsally and ventrally by dorsal and ventral gray commissures, and therefore the gray matter takes the appearance of a butterfly.The lumber spinal nerve and their roots are well distinguished.     

Antioxidants and radical scavenging properties of vegetable extracts in rats fed aflatoxin-contaminated diet

The present study evaluated the protection role of garlic, cabbage, and onion extracts against the toxic effects of aflatoxin. One hundred and twenty mature male Sprague-Dawley rats were randomly assigned to eight experimental groups and treated for 15 days with extracts with or without aflatoxin. Blood samples were collected from all animals from the retro-orbital venous plexus at the end of the experimentation period for biochemical analysis. Livers and kidneys were removed at the end of the treatment period for determination of glutathione, malondialdehyde, and superoxide dismutase. The results indicated that animals treated with aflatoxin showed significant signs of aflatoxicosis. Extracts alone had insignificant effects on all parameters tested, whereas cotreatment with aflatoxin and extracts resulted in a significant improvement in all parameters; moreover, garlic extract was found to be the most effective in the prevention of aflatoxin-induced toxicity and free radical generation in rats.