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51.
Sherin George P. R. Suresh P. A. Wahid Ramesh B. Nair K. I. Punnoose 《Agroforestry Systems》2009,76(2):275-281
The active root distribution pattern of mature rubber (Hevea brasiliensis Muell. Arg.) up to a lateral distance of 250 cm from the tree and to a soil depth of 90 cm was studied in an oxisol by employing
32P soil injection technique in Kerala, the state which accounts for 83% of rubber cultivation in India. The trees were aged
18 years and grown at a spacing of 4.9 × 4.9 m. The extent of absorption of applied 32P by the tree from various placements was assessed by radio assay of leaf and latex serum. Latex serum registered higher counts
and variability was less compared to leaf indicating the suitability of latex serum as a potential source for radio assay
for 32P studies in rubber. The results revealed that rubber is a surface feeder with 55% of the root activity confining to the top
10 cm of soil layer. Root activity declined with increasing depths and the concentration of physiologically active roots at
90 cm depth was only 6%. A more or less uniform distribution of root activity was noticed with respect to lateral distance
indicating more extensive spread of lateral roots. Concentration of physiologically active roots in the surface layer suggests
the possibility for competition under intercropped situation in mature plantations. 相似文献
52.
Nadia Korolev Encarnación Pérez-Artés Jesús Mercado-Blanco José Bejarano-Alcázar Dolores Rodríguez-Jurado Rafael M. Jiménez-Díaz Talma Katan Jaacov Katan 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(4):603-617
Verticillium dahliae isolates recovered from a new focus of severe Verticillium wilt of cotton in the northeast of Israel were tested for vegetative
compatibility using nitrate non-utilizing (nit) mutants and identified as VCG1, which is a new record in Israel. Other cotton isolates of V. dahliae from the northern and southern parts of the country were assigned to VCG2B and VCG4B, respectively. VCG1 isolates induced
severe leaf symptoms, stunting and defoliation of cotton cv. Acala SJ-2, and thus were characterized as the cotton-defoliating
(D) pathotype, whereas isolates of VCG2B and VCG4B were confirmed as the earlier described defoliating-like (DL) and non-defoliating
(ND) pathotypes, respectively. This is the first record of the D-pathotype in Israel. The host range of representative isolates
of each VCG-associated pathotype was investigated using a number of cultivated plants. Overall, the D isolates were more virulent
than DL isolates on all tested host plants, but the order of hosts (from highly susceptible to resistant) was the same: okra
(Hibiscus esculentus local cultivar), cotton (Gossypium hirsutum cv. Acala SJ2), watermelon (Citrullus lanatus cv. Crimson Sweet), safflower (Carthamus tinctorius cv. PI 251264), sunflower (Helianthus annuum cv. 2053), eggplant (Solanum melongena cv. Black Beauty), and tomato (Lycopersicon esculentum cv. Rehovot 13). The pattern of virulence of ND isolates differed from that of D and DL isolates, so that the former were
highly virulent on eggplant but mildly virulent on cotton. Tomato was resistant to all cotton V. dahliae isolates tested. RAPD and specific PCR assays confirmed that the D isolates from Israel were similar to those originating
from other countries. 相似文献
53.
Ojeda-Robertos Nadia Florencia Torres-Chablé Oswaldo Margarito Peralta-Torres Jorge Alonso Luna-Palomera Carlos Aguilar-Cabrales Aguilar Chay-Canul Alfonso Juventino González-Garduño Roberto Machain-Williams Carlos Cámara-Sarmiento Ramón 《Tropical animal health and production》2017,49(3):613-618
Tropical Animal Health and Production - The objective was to determine the frequency of gastrointestinal parasites (GP) genera affecting water buffalo (Bubalus bubalis) reared under humid tropical... 相似文献
54.
55.
Sathya K Chinnadurai Ryan DeVoe Amie Koenig Nadia Gadsen Amanda Ardente Stephen J Divers 《Veterinary anaesthesia and analgesia》2010,37(5):434-439
Objective The objective of this study was to compare an implanted direct blood pressure monitor and a non‐invasive oscillometric unit for use in anesthetized and awake green iguanas. Study design Prospective experimental trial. Animals Four male and four female adult green iguanas (Iguana iguana) weighing 1833 ± 534 g. Methods For each animal, the carotid artery was surgically exposed and the catheter tip of the pressure transducer was placed in the aortic arch. Non‐invasive blood pressure was measured using a cuff over the left femoral region. Pulse rate, respiratory rate and arterial blood pressure (ABP) measurements were taken every 5 minutes. Direct ABP measurements consisted of recording numerical values and graphic output. Simultaneous direct and indirect measurements were repeated in awake animals. Results The oscillometric device failed to provide a reading in over 80% of attempts, and failed to provide readings that correlated with direct measurements. The implanted direct transducer was capable of detecting blood pressures throughout all ABP ranges examined. Conclusions The implantable transducer was a reliable means of determining blood pressure in this study, while the oscillometric device was unreliable and often failed to provide any reading. Clinical relevance We do not recommend using the oscillometric device as described in a research or clinical setting for green iguanas. The advantages of an implantable device include the ability to monitor awake and anesthetized subjects remotely and continuously. These monitors are small, biocompatible and function across a wide range of ABP. 相似文献
56.
Khemais Abdellaoui Monia Ben Halima-Kamel Fatma Acheuk Noureddine Soltani Nadia Aribi Mohamed HabibBen Hamouda 《Pesticide biochemistry and physiology》2013
Experiments were conducted to assess the effect of gibberellic acid (GA3), a plant growth regulator, on Locusta migratoria migratoria fifth instar larvae. Newly emerged larvae were exposed to various concentrations of GA3 administered by topical application or by forced ingestion. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. GA3 toxicity was also demonstrated by perturbation of the moult processes. In fact, we noted that treated insects present exuviations difficulties due to the impossibility to reject the old integuments causing mortality in the 5th instar larvae. Histological study of proventriculus revealed alterations in the epithelial cells and absence of apolysis phenomenon. Data also showed that GA3 induced significant quantitative variation of haemolymph metabolites. These changes result in a significant decrease in the total concentration of proteins and carbohydrates and an increase in the total concentration of haemolymph lipids. 相似文献
57.
Spatial Distribution and Temporal Trends of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments from Lake Maryut, Alexandria, Egypt 总被引:2,自引:0,他引:2
Assem Omar. Barakat Alaa Mostafa Terry L. Wade Stephen T. Sweet Nadia B. El Sayed 《Water, air, and soil pollution》2011,218(1-4):63-80
Surface and core sediments from Lake Maryut, Egypt, one of the most polluted lakes in Egypt, were analyzed for polycyclic aromatic hydrocarbons (PAHs) using gas chromatography?Cmass spectrometry. This investigation represents the first extensive study of the distribution and sources of PAHs in sediments from Lake Maryut. The total PAHs concentrations (sum of 39 PAH compounds) in surface sediments varied greatly depending on the sampling location and ranged from 106 to 57,800 ng/g dry weight with a mean concentration of 6,950 ng/g. The most polluted areas are distributed in areas which are mainly influenced by municipal sewage and industrial effluent discharges, suggesting a direct influence of these sources on the pollutant distribution patterns. PAH concentrations were one to two orders of magnitude higher in comparison with those reported for riverine/estuaries systems around the world. Molecular indices, such as pyrogenic index (PI), methylphenanthrenes to phenanthrene ratio, HMWPAH/LMWPAH, A-PAHs/P-PAHs, FL/FL?+?PY, BaP/BaP?+?C, IP/IP?+?BgP, and Per/??(penta-aromatics) were calculated to evaluate different hydrocarbon origins and their relative importance. In general, sediments from the main basin and northwest basin of Lake Maryut showed the highest PAH concentrations with petrogenic signatures, indicating major sources of petrogenic PAHs in the city. On the other hand, lower levels of PAHs with a pyrogenic signature were widely recorded in areas that are distant from anthropogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. The concentrations of perylene relative to the penta-aromatic isomers are dominant especially in locations associated with terrestrial inputs and in the deepest core sediments, indicating diagenetic origin for the presence of perylene. Temporal trends of PAH concentrations in both cores sediments were influenced by input pathways and followed the economic development and the environmental policies of the Egyptian Government in the last 15 years. Finally, PAH levels in sediments were compared with Sediments Quality Guidelines (effects range median?Ceffects range low) for evaluation probable toxic effects on organism. Results suggest an ecotoxicological risk for benthic organisms mainly in the main basin area, where high concentrations of PAHs were found in sediments influenced by anthropogenic activities. 相似文献
58.
Yuechun Zhao J. Nigel B. Bell Abdul Wahid Sally A. Power 《Water, air, and soil pollution》2011,216(1-4):451-462
The response to ozone (O3) of a range of Chinese leafy vegetables was investigated with respect to both inter- and intra-specific differences in sensitivity. In the interspecific experiment local Chinese cultivars of pak choi, rape, leaf mustard, leaf lettuce and coriander were fumigated with 90?ppb O3 for 9?h daily for 22?C30?days. A similar fumigation was carried out using four different cultivars of pak choi. Sequential measurements were made of leaf injury, photosynthetic rate, stomatal conductance and chlorophyll fluorescence, together with dry weights at a final harvest. O3 injury appeared as white or yellow blemishes on the leaf surface of all species. The first signs of injury were seen following only 3-days?? O3 exposure (pak choi); the extent of injured leaf area increased over time for all species and cultivars, with 44.6% of the leaf area visibly injured for leaf mustard, the species with the greatest extent of injury, following 30-days?? exposure. Significant reductions in photosynthetic rate (22.7?C40.7%) and stomatal conductance (19.1?C33.1%) were found for all species and cultivars following O3 exposure. Plant productivity was also reduced in O3 compared to filtered air, with significant yield reductions for all species (11.1?C50.8% above-ground dry weight) as well as for all cultivars of pak choi (15.8?C28.1% above-ground dry weight). The mechanisms for observed impacts are discussed, together with the implications for current and future production of vegetables in the southern China province of Guangdong. 相似文献
59.
Nazia Hassan Muhammad Sohail Saddiq Saqib Bashir Shahbaz Khan Muhammad Ashfaq Wahid 《Journal of plant nutrition》2013,36(14):1676-1692
AbstractOne of the problems in obtaining high wheat yield is the unavailability of micronutrients in balanced quantities. Zinc is an essential micronutrient due to its involvement in many metabolic processes in plant. In this experiment, seeds of two wheat cultivars (Faisalabad-2008 and Lasani-2008) were subjected to soak in aerated Zn solution of 0.1 and 0.01?M for 12?hr. For the seed coating, Zn was adhered to the wheat seeds by using Arabic gum by using zinc sulfate (ZnSO4·7H2O) as a source. Untreated dry seeds were considered as a control. Results indicated that field emergence was improved by Zn seed treatments, maximum numbers of seedlings were observed in seed priming with 0.01?M Zn solution. Seed osmoprimed with 0.01?M Zn solution improved the grain yield, biological yield, and other yield related traits. Grain and straw Zn enrichment were also enhanced in seed osmoprimed with 0.01?M Zn solution. 相似文献
60.
De Bona Gicele Sbardelotto Vincenzi Simone De Marchi Fabiola Angelini Elisa Bertazzon Nadia 《植物病害和植物保护杂志》2021,128(3):715-724
Journal of Plant Diseases and Protection - In the present study, a commercial chitosan soluble in acid solution and obtained from shrimp shell waste, with a molecular weight of 173 kDa and... 相似文献