Lesion development in stems of rough‐ and smooth‐barked Eucalyptus nitens following artificial inoculations with canker fungi

A study of lesion development in stems of Eucalyptus nitens following artificial inoculations with canker fungi was carried out on 16‐year‐old plantation trees. In a first trial cambium bark wounds on smooth‐ and rough‐barked trees were inoculated with the mycelium of nine species of canker fungi, including Endothia gyrosa. In a second trial spores or mycelium of E. gyrosa were applied directly onto undamaged or superficially wounded bark surfaces. Infection subsequent to artificial inoculation via wounding (whatever the wounding technique or type of inoculum) resulted in significantly larger external lesions (mean lesion area up to 35.6 cm² 20 months after inoculation) on smooth bark compared with those on rough bark (up to 19.0 cm²). Microscopic studies of infected rough and smooth bark suggest that, once smooth bark is compromised by wounding and artificial inoculation, the particular anatomical structure of smooth bark may offer less mechanical resistance to post‐penetration hyphal spread in comparison with rough bark. It is suggested that at a pre‐penetration stage under natural conditions spores of E. gyrosa more easily infect rough bark via cracks associated with this type of bark but not present in smooth bark.     

Status and ethno-medicinal usage of invasive plants in traditional health care practices: a case study from northeastern Bangladesh

Species diversity and ethno-medicinal usage of 39 species of invasive plants were explored in and around two protected areas, Khadimnagar National Park (KNP) and Rema-Kalenga Wildlife Sanctu- ary (RKWS), of northeastern Bangladesh,. Status of invasive plants were investigated in 60 sample plots with 5 different habitat types, including forest, roadside, homestead, fallow land and others (ponds, canals, water logged areas, agricultural land, etc.). Data about the usage of invasive plants in traditional health care were collected through interviewing 110 households. Among the five habitat types, fallow land (28 species) pos- sessed the highest number of species, followed by roadside (25 species), forest (23 species), homestead (22 species) and others (13 species). Based on the survey, invasive plants of study areas were also categorized into five degrees of invasiveness e.g., naturalized, introduced, possibly invasive, moderately invasive and highly invasive. Additionally, there is the linear trend between degrees of invasiveness and use percentage of invasive plants. Total 39 species of invasive plants belonging to 29 fami- lies were recorded, which are generally used to treat 37 diseases, ranging from simple headache to highly complicated eye and heart diseases. The majority of the species used by the local inhabitants were herbs (16 spe- cies), followed by some shrubs (11 species), climbers (5 species), trees (5 species) and grasses (2 species). The use percentage of aboveground plant parts were higher (70.58%) than that of underground plant parts (16.18%).     

Nitrogen transport in plants,with an emphasis on the regulation of fluxes to match plant demand

Physiological methods, especially the use of isotopes of N, have allowed for the detailed characterizations of the several putative transport systems for nitrate and ammonium in roots of higher plants. In the last decade, the cloning of genes that appear to encode both high- and low-affinity transporters represent major advances, as well as substantiating the inferences based on earlier physiological methods. Nevertheless, the unexpected plethora of genes that have been identified now presents even greater challenges, to resolve their individual functions and to attempt to place these functions in a whole plant/environmental context.     

New bioactive biomaterials based on quaternized chitosan

Chitosan was chemically modified to produce quaternary ammonium salts in order to improve its antimicrobial activity and physicochemical properties. Quaternization of N-alkyl chitosan derivatives was carried out using alkyl iodide to elaborate water-soluble cationic polyelectrolytes ( N, N, N-trimethylchitosan, TMC). TMC was characterized by (1)H NMR spectroscopy; the quaternization degree was determined from (1)H NMR spectra and by titration of iodide ion. The antibacterial activity of hydroxypropylcellulose (HPC) films or coatings associated with chitosan or TMC as biocide was evaluated against the growth of Listeria monocytogenes and Salmonella typhimurium. The HPC-chitosan and HPC-TMC coatings exhibited a total inhibition on solid medium of both bacterial strains. Experiments conducted in liquid medium showed that the inhibitory activity against the growth of Listeria innocua was improved after chemical modification. Moreover, physicochemical properties of films were evaluated to determine their potential for food applications. The addition of the antibacterial agents showed a significant impact on the moisture barrier and mechanical properties of HPC films.     

Identification of anthocyanins in the sprouts of buckwheat

The anthocyanin profiles and varieties/breeding line differences of anthocyanin concentrations in common/tartary buckwheat sprouts have been studied. Four anthocyanins, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-galactoside, and cyanidin 3-O-galactopyranosyl-rhamnoside, were isolated from the sprouts of common buckwheat, were separated using high-performance liquid chromatography (HPLC), and were identified using reversed-phase liquid chromatography (LC)/electrospray ionization-mass spectrometry (ESI-MS)/MS techniques. In tartary buckwheat sprouts, two anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside) were identified. Among 19 common/tartary buckwheat varieties/breeding lines, Hokkai T10 contained the highest amounts of anthocyanins. Cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside concentrations in 6-10 days after seeding sprouts of Hokkai T10 ranged from 0.16 to 0.20 mg/g dry wt and from 5.55 to 6.57 mg/g dry wt, respectively. In addition, dark-grown sprouts of Hokkai T10 accumulated 0.091 and 2.77 mg/g dry wt of cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside whereas other varieties/breeding lines accumulated trace amounts of anthocyanins. Given its anthocyanin-rich red cotyledons, Hokkai T10 is a promising line for use as "Moyashi" type sprouts and is strongly recommended as a new functional food, rich in dietary anthocyanins.     

土地利用变化对塔里木河中游胡杨林的影响研究

本研究区位于塔里木河中游地区,本研究选取耕地变化、输水堤防的建设以及油气田开发三种土地利用方式,在大量野外调查的基础上,在3S技术和历史数据的支持下,分析了这些土地利用方式变化对胡杨林生态系统的影响。研究结果表明:研究区1992年之后内耕地大量增加,输水堤防对堤防内外侧胡杨生态系统具有不同影响,油气田开发会造成生态破坏和环境污染等问题。     

Effects of paclobutrazol on the physiological characteristics of Malus halliana Koehne Seedlings under drought stress via principal component analysis and membership function analysis

To study the effect of paclobutrazol (PBZ) on Malus halliana seedlings under water stress, principal component analysis (PCA) and membership function analysis (MFV) were employed to evaluate the effects of PBZ on gas exchange, fluorescence, and physiological characteristics. M. halliana seedlings, each with approximately ten leaves, were subjected to drought conditions and different concentrations of exogenous PBZ (CK, C0, C1, C2, C3, and C4) were then applied in pot experiments. The results showed that the effects of PBZ were concentration dependent. Compared to the CK treatment, the use of PBZ increased the intercellular CO₂ concentration (C_i), nonphotochemical quenching coefficient (NPQ), peroxidase activity (POD), relative electrical conductivity (REC), and proline (Pro) and malondialdehyde (MDA) contents. The POD activity was higher by 124.24, 132.26, 93.75, 77.42, 85.29, and 90.63% in the CK, C0, C1, C2, C3, and C4 groups, respectively, at 15 days than at 0 day. The decrease in the net photosynthetic rate (P_N), stomatal conductance (g_s), transpiration rate (E), maximum quantum yield of PS2 (Φ_PSII), maximal quantum yield of PSII photochemistry (F_v/F_m), photochemical quenching coefficient (qP), catalase (CAT), and superoxide dismutase (SOD) activity were effectively controlled. The g_s of the CK and C2 groups at 15 days were reduced by 55.74% and 22.55%, respectively, compared to that of the treated seedlings at 0 day. In summary, the results of the evaluation by PCA and MFV showed that the effect of PBZ on M. halliana seedlings under water stress was most significant when the concentration was 100?mg L^?1.     

Effects of stocking density, periphyton substrate and supplemental feed on biological processes affecting water quality in earthen tilapia–prawn polyculture ponds

The technical and economic potentials of tilapia, Oreochromis niloticus (L.), and giant river prawn, Macrobrachium rosenbergii (de Man), polyculture in periphyton-based systems are under investigation in an extensive research programme. This article is a combined analysis of data from four experiments exploring the effects of periphyton, fish, prawn and feed on water quality. Factor analysis and ancova models applied to the combined dataset allowed to identify the underlying ecological processes governing the system, and construct conceptual graphic models of the periphyton–environment relationships observed. With the first factor, variability in water quality was due to autotrophic (photosynthesis and nutrient uptake) and heterotrophic (respiration and decomposition) processes affecting water quality in opposite directions. With the second factor, variability was related to decomposition on the bottom and nutrient release into the water column, algae production and sedimentation. The analysis of the relationships between both factors and the growth rates of tilapia and prawn in the different systems allowed a better understanding of the functioning of tilapia–prawn ponds, and indicates that their joint culture is technically feasible and economically viable. Therefore, this technology is recommended for poverty alleviation and nutritional security in rural Bangladesh as well as in other countries of the region.     

Effects of replacing fishmeal with fermented and non‐fermented rapeseed meal on the growth,immune and antioxidant responses of red sea bream (Pagrus major)

The effect of rapeseed meal (RM) and Aspergillus oryzae fermented rapeseed meal (RM‐Koji) on red sea bream (Pagrus major) was examined. Three groups of fish (initial weight, 4.5 ± 0.02 g) were fed a basal diet (RM0) and two test diets where half of fishmeal was replaced by RM (RM50) and RM‐Koji (FRM50) for 56 days. The obtained results showed that fish fed RM0 and FRM50 exerted significantly higher growth performance, feed utilization and haemoglobin level but lower triglyceride and cholesterol than RM50 group (p < 0.05). Interestingly, except of antiprotease activity, all the immune parameters including lysozyme, respiratory burst (NBT) and bactericidal activities were significantly increased in fish fed RM0 and FRM50 diets compared to RM50 diet (p < 0.05). In addition, malondialdehyde and reactive oxygen metabolites were significantly reduced in RM0 and FRM50 groups over RM50 group (p < 0.05). The present results suggest that fermented RM induced better growth performance and immune responses than feeding red sea bream with non‐fermented RM and both RM and RM‐Koji improved the antioxidative status of fish, making RM‐Koji an interesting candidate as a functional feed for aquatic animals.     

Studies of infectivity and pathogenicity of an isolate of Trypanosoma evansi in Yankasa sheep.

The course of experimental infection and pathogenicity of an isolate of Trypanosoma evansi were investigated using eight infected and six uninfected control Yankasa sheep. The sheep were each infected intravenously via the jugular vein with approximately 2.0 x 10(6) T. evansi parasites. The effects of the parasite on body temperature, packed cell volume (PCV), haemoglobin, erythrocytes, total protein, were monitored three times a week for approximately 9 weeks. Body weights were determined once every week for the duration of the experiment. The results showed that all the infected sheep were positive for the parasite. The prepatent period varied between 3 and 6 days. T. evansi produced parasitaemic waves at an average of 8.3 days interval. Two distinct forms of the disease were produced namely, acute (4-14 days postinfection), and chronic (43-59 days postinfection). Anaemia was a distinct feature of the disease. While the mean rectal temperatures were significantly elevated (P < 0.05), the mean values of the haematological parameters of the infected sheep dropped significantly (P < 0.05) compared to the preinfection levels. Observed clinical signs included pale mucous membrane, epiphora, loss of appetite, emaciation, dullness and rough hair coat together with fluctuating pyrexia which in most cases coincided with rise in parasitaemia. It is suggested that the isolate of T. evansi is pathogenic for Yankasa sheep.