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41.
Topsoils affected by surface mining suffer severe physical degradation and lose most of their earthworm populations. After mining, replaced soils are planted to grassland and managed to improve soil structure. Earthworm inoculation into selected restored areas produced populations similar to those of undisturbed soils within 3 years. Soil properties in inoculated areas were compared with those of controls to evaluate the contribution of casts to bulk soil aggregation, and soil organic matter and root content responses to earthworm activity. Crumb porosity and coarse particle content were measured in water-stable macro-aggregates and earthworm casts to establish whether aggregates were formed by earthworms. Over a 5- to 6-year period, inoculation increased stable aggregation (>2 μm, >60 μm and >3 mm), even at 0- to 5-cm depth where it reduced soil organic matter content. Productivity and root content were also increased by inoculation; roots and organic matter were re-distributed to greater depth. Crumb porosity decreased with casts > aggregates (inoculated plots) > aggregates (control plots). Coarse particle content increased with casts < aggregates (inoculated plots) < aggregates (control plots). Coarse particle and porosity data were consistent with much of the newly aggregated soil being processed and formed by earthworms as casts. Whilst levels of soil organic matter were often closely associated with percentage stable aggregation, root content showed weaker associations. Aggregation percentage was most closely associated with abundance of Aporrectodea longa , although at particular depths significant correlations were also obtained for Aporrectodea caliginosa and Lumbricus terrestris . Results suggest that earthworms, rather than plant roots, initiate aggregation in severely degraded grassland soils. 相似文献
42.
Tapinoma indicum (Forel) (Hymenoptera: Formicidae) is a nuisance pest in Asia countries. However, studies on T. indicum are limited, especially in the field of molecular biology, to investigate the species characteristic at the molecular level. This paper aims to provide valuable genetic markers as tools with which to study the T. indicum population. In this study, a total of 143,998 microsatellite markers were developed based on the 2.61 × 106 microsatellites isolated from T. indicum genomic DNA sequences. Fifty selected microsatellite markers were amplified with varying numbers of alleles ranging from 0 to 19. Seven out of fifty microsatellite markers were characterized for polymorphism with the Hardy–Weinberg equilibrium (HWE) and linkage disequilibrium (LD) analysis. All seven microsatellite markers demonstrated a high polymorphic information content (PIC) value ranging from 0.87 to 0.93, with a mean value of 0.90. There is no evidence of scoring errors caused by stutter peaks, no large allele dropout, and no linkage disequilibrium among the seven loci; although loci Ti-Tr04, Ti-Tr09, Ti-Te04, Ti-Te13, and Ti-Pe5 showed signs of null alleles and deviation from the HWE due to excessive homozygosity. In conclusion, a significant amount of microsatellite markers was developed from the data set of next-generation sequencing, and seven of microsatellite markers were validated as informative genetic markers that can be utilized to study the T. indicum population. 相似文献
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Agar blocks colonized by Sclerotinia sclerotiorum, causal agent of lettuce drop, were used as inoculum in screening for resistance to this pathogen in the greenhouse.Since the degree of resistance to the pathogen among cultivars varied with the time observed after inoculation, resistance was assessed by the number of days for 50% of the plants of each cultivar to die, as well as the number of plants that died. The cultivars ‘PI (Plant Introduction) 250427’, ‘Taiwan’, ‘PI 251790’, ‘PI 255568’, ‘MSU 73-44’ and ‘Bibb’ were found to have a higher level of resistance to S. sclerotiorum than the cultivar ‘Grand Rapids’ at 12 or 15 days following inoculation. 相似文献
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Imada T Abdul Rahman MA Kashiwazaki Y Tanimura N Syed Hassan S Jamaluddin A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(1):81-83
Eight clones of monoclonal antibodies (Mabs) to Nipah virus (NV) were produced against formalin-inactivated NV antigens. They reacted positive by indirect immunofluorescent antibody test, and one of them also demonstrated virus neutralizing activity. They were classified into six different types based on their biological properties. These Mabs will be useful for immunodiagnosis of NV infections in animals and further research studies involving the genomes and proteins of NV. 相似文献
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Randhir Singh Bhatt Nira Manik Soren Artabandhu Sahoo Shaikh Abdul Karim 《Tropical animal health and production》2012,45(1):167-176
Improvement in body condition was assessed in 40 cull ewes (>6 years), equally distributed in two groups and realimented with ad libitum roughage (gram straw) and two levels of concentrate feeding, i.e., 2.5 % (T1) of live weight (LW) and ad libitum (T2). Five representative animals from an initial 45 were slaughtered at the initiation of the study (0 day) and five animals from each treatment at 44, 67, and 90 days of experiment for carcass attributes. Improvement in body condition score (BCS), nutrient utilization, feed efficiency, and carcass traits were assessed at 44, 67, and 90 days. Metabolism trial of 6-day collection of feed, feces, and urine samples was conducted on five representative ewes from each group after 60 days of feeding. The level of concentrate feeding on LW gain and BCS was significant, and the duration of realimentation showed a linear improvement (P?<?0.001). The digestibility and intake of dry matter, organic matter, and crude protein was higher (P?<?0.05) in T2. The N intake, absorption, and balance showed a similar trend. Increase (P?<?0.05) in total N, trichloroacetic acid precipitable N, and ammonia N was observed with extension of realimentation period. Blood metabolic profile also showed improvement (P?<?0.05) from an undernourished state to normal after alimentation. Animals in T2 accumulated higher LW with minimal expenditure of metabolizable energy (73.4 vs 79.1 MJ) and higher efficiency of feed conversion during 68 to 90 days of realimentation. Linear improvement (P?<?0.01) in carcass traits (preslaughter weight, empty live weight, hot carcass weight, dressing percentage, and amount of subcutaneous and intramuscular fat) and composition of longissimus dorsi muscle was observed. Ad lib concentrate supplementation for a period of 90 days may thus be considered appropriate for achieving desired efficiency of gain and improvement in body condition of cull ewes for quality mutton production. 相似文献
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Effects of nano-silver impregnation on brittleness, physical and mechanical properties of heat-treated hardwoods 总被引:1,自引:1,他引:0
Hamid Reza Taghiyari Aliakbar Enayati Hadi Gholamiyan 《Wood Science and Technology》2013,47(3):467-480
The present study investigates the effect of heat treatment of untreated and nano-silver-impregnated Populus nigra, Populus deltoides and Fagus orientalis on the physical and mechanical properties. Specimens were impregnated with a 200-ppm aqueous silver nanoparticles suspension. Heat treatment was carried out at temperatures of 135 ± 3 °C and 185 ± 3 °C. Nano-silver impregnation aggravated the effects of heat treatment. Although significant in some cases, nano-silver impregnation did not seem to have great effect on physical properties. It may be concluded that although NS impregnation aggravated the effects of heat treatment on solid woods, other factors may also be involved such as the species and density of the wood. 相似文献