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1.
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• Carbon isotope composition (δ13C) is a complex trait involved in acclimation, adaptive processes and related to water use efficiency (WUE) and/or productivity. 相似文献
2.
Maha A. Shoaib Mahmoud F. Mahmoud Nagla Loutfy Mohamed A. Tawfic Marek Barta 《Journal of pest science》2010,83(1):27-32
In the laboratory, a commercial neem-based insecticide—Nimbecidine®—was evaluated as a potential pest management tool for the terrestrial snail, Monacha obstructa (Pfeiffer, 1842) (Hygromiidae). Effects of different concentrations of the botanical insecticide on food consumption and egg hatchability of the terrestrial snail were studied. Generally, food consumption of immature and adult snails decreased as the concentrations of Nimbecidine® increased. At the highest concentration (10 ml/l), the snails avoided contacting with food completely. The food intake of immature individuals was significantly (p < 0.05) more affected by the Nimbecidine® treatment (at 1.25 ml/l) than that of adults. LC50 of Nimbecidine® for the treated eggs was 2.18 ml/l, and eggs failed to hatch at concentration of 10 ml/l. Nimbecidine® showed sufficient biological activity against the food consumption and eggs viability of M. obstructa, thus the preparation has a potential to protect field crops from this pest snails. 相似文献
3.
Frank H. Arthur 《Journal of pest science》2012,85(2):261-265
Hard red winter wheat was treated at 0 (untreated control), 25, 50, 75, and 100% of the label rate of the insecticide Storicide II ® , which is chlorpyrifos-methyl and deltamethrin applied at label rates of 3 and 0.5 ppm, respectively. Paired male and female Rhyzopertha dominica F., the lesser grain borer, were exposed at 27°C and 60% RH on wheat treated at each of the five rates above for 2, 4, 8, 16, or 32 h, and then transferred to untreated wheat and held for 1 week at the same environmental conditions. After this 1-week holding period, the parental adults were removed, mortality was assessed, and the wheat was then held for 7 weeks at the same environmental conditions to determine progeny production. As the concentration and exposure interval increased, mortality of both sexes approached 100%, but at the intermediate concentration–time combinations male mortality was greater than female mortality. Progeny production also decreased with increasing concentration of Storicide II® as the exposure time increased, with non-linear patterns of decrease at the lower concentrations and time combinations and linear decline at the higher levels of concentration and time. Results seem to indicate greater susceptibility of males to Storicide II®, and also show delayed parental mortality from the insecticide exposure and sub-lethal effects of reduced progeny production. 相似文献
4.
We evaluated fungal decay and mold resistance, leaching, and water absorption of nano-compounds and Paraloid B72® (PB72) in treated wood specimens to develop new methods of consolidation by combining nano-particles and consolidants. Scots pine wood specimens were treated with dispersions of nano-CuO, nano-ZnO, nano-B2O3, nano-TiO2, and nano-CeO2. PB72 treatments of nano-particle-treated wood specimens were then carried out by either vacuum or immersion for 24 h. Previously, decayed wood specimens were also consolidated with the nano-compounds and PB72. PB72 treatments reduced element release from treated wood specimens. Nearly all nano-compounds + PB72 treatments increased the biological performance of treated wood specimens against decay fungi tested. PB72-only treated wood specimens had the highest weight losses in decay tests. No improvements were obtained in mold resistance tests when the nano-compounds and PB72 were combined. In nano-compound-only treatments, unleached specimens showed slightly lower water absorption values compared to untreated control specimens. Incorporation of PB72 into nano-compound-treated wood specimens resulted in considerably lower water absorption and volumetric swell. In previously decayed specimens treated with the nano-compounds and PB72 solution, water absorption after 2-h immersion declined compared to control specimens. 相似文献
5.
Charles Adarkwah Daniel Obeng-Ofori Carmen Büttner Christoph Reichmuth Matthias Schöller 《Journal of pest science》2010,83(4):471-479
The red flour beetle, Tribolium castaneum (Herbst), is one of the most serious secondary pests that feeds on a wide range of durable stored products including cereals, cereal products and other high value produce such as cocoa beans and dried fruits. Toxicity and protectant potential of Calneem® oil derived from the seeds of the neem tree Azadirachta indica A. Juss. towards T. castaneum were evaluated in stored wheat in the laboratory using contact toxicity, grain treatment, persistency, progeny emergence and repellency assays. Calneem® contains about 0.3% azadirachtin as its major active ingredient. The Calneem® was applied at six dosages (0.1, 0.2, 0.5, 1.0, 2.0 and 3.0% v/v). The oil was emulsified with water using 0.07% soap. All dosages of Calneem® oil were toxic and highly repellent to T. castaneum with an overall repellency in the range of 52–88%. The highest dosage of 3.0% of Calneem® oil tested killed at least 90% of the beetles within 72 h on grain, and 88% mortality was obtained on filter paper. T. castaneum mortality was dose dependent. The development of eggs to adults on cracked wheat was significantly (P < 0.05) inhibited by Calneem® oil treatments. The effectiveness of Calneem® oil was significantly reduced by the length of storage after application. The results obtained suggest good potential for the practical use of Calneem® oil as grain protectant for stored product pest control. The use of plant materials such as neem oil may be a safe, cost-effective method of grain preservation against pest infestation amongst low-resource poor farmers who store small amounts of grains. 相似文献
6.
Growth and physiological performance of multipurpose tree species can be severely constrained by low phosphorus (P) availability
in highly weathered soils. Limitations to plant growth are accentuated by seasonal dry periods. The overall objective of this
study was to examine P fertilization and irrigation effects on survival, growth, biomass partitioning, foliar nutrients, intrinsic
water-use efficiency (WUE) indexed by δ13C, Rhizobium nodulation, and carbohydrate content as an indicator of resprouting potential, of mimosa (Albizia julibrissin Durz.), a N2-fixing tree species being tested for browse in agroforestry practices in south-central USA. In a field experiment carried
out during two growing seasons near Booneville, Arkansas, USA, mimosa had a strong growth response to irrigation. The trial
was arranged in a split plot design with three replications with irrigation as main plot treatment and P as sub-plot treatment.
Mean total plant aboveground biomass at the end of the second growing season was 9.8 and 44.1 g plant−1 for the rainfed treatment without and with 300 mm of irrigation water, respectively. Placed P fertilization increased mean
total aboveground biomass from 19 g plant−1 for the 0-P treatment to 69 g plant−1 for the treatment with 90 kg P ha−1 year−1. Similarly, irrigation consistently increased stem basal diameter, total height, survival, root, stem, foliar and total aboveground
biomass, and number of nodules per plant. Phosphorus fertilization increased basal diameter, and root and stem biomass in
both irrigation treatments, survival and nodulation in the rainfed treatment, and foliar and total aboveground biomass in
the rainfed +300 mm irrigation treatment. There was a decrease of foliar δ13C suggesting that WUE decreased with P fertilization. In a pot experiment, seedlings were subjected to a factorial combination
of two irrigation treatments and six P levels in a randomized complete block design. Irrigation increased basal diameter,
root, stem, foliar and total biomass, leaf area and nodulation, whereas P fertilization (i.e., levels from 0 to 3.68 g P kg−1 soil) had similar effect in all the above variables except foliar biomass. Foliar P concentration to obtain 90% of the maximum
total plant biomass (critical level) was estimated at 0.157%. Total nonstructural and water soluble carbohydrate, and starch
concentrations increased non-linearly with irrigation and P addition suggesting impaired re-growth potential after defoliation
of seedlings with reduced water supply and at low soil P availability. Results of this study indicated strong limitations
for growth and regrowth potential of mimosa on a highly weathered soil with very low P availability and seasonal water content
shortages. Placed (i.e., near the plant base) application of P appeared to be a good strategy to fertilize perennial woody
plants. 相似文献
7.
A series of experiments were conducted in which adults, pupae, and 4-week-old larvae of Tribolium castaneum (Herbst), the red flour beetle, were exposed separately on concrete arenas partially treated (14.4% of the total area) with the insecticide chlorfenapyr (Phantom®) at 1.1 g of active ingredient/m2. A flour food source (patch) was also provided in the untreated portions of the arenas. In the first trial, adult mortality averaged 60.0 ± 10.6%, but progeny production occurred in the provided food patches. Pupal mortality was only 8.3 ± 3.1%, indicating that when adult emergence occurred, those adults were able to escape exposure, and there was no difference in progeny production from that in untreated controls (P = 0.27). In the second trial, few larvae exposed in choice and no-choice arenas were able to emerge as normal adults. In a final trial, residual efficacy declined during a 3-week period, with larvae being more susceptible than adults. Results show mobility of life stage may be a determining factor when assessing susceptibility of T. castaneum to contact insecticides. 相似文献
8.
The optimum conditions for β-thujaplicin production in a Cupressus lusitanica cell suspension culture were investigated. The conditions required for β-thujaplicin production were clearly different from the conditions for cell growth. The initial phosphate concentration and pH did not affect β-thujaplicin production. A total nitrogen source concentration higher than 3.2 mM suppressed production due to the presence of the ammonium ion. β-Thujaplicin production was observed at 95 mg/l without adding the ammonium ion to the medium. Strict control of major inorganic nutrients was not necessary to produce β-thujaplicin. This finding seems to be favorable for future automated production of β-thujaplicin in commercial cell culture plants. 相似文献
9.
We used energy dispersive X-ray fluorescence (EDXRF) to determine the seasonal variation of selected trace elements (Cr, Mn, Zn, Cu, Se and Fe) and some potential toxic elements (Cd, Pb and Br) in Juniperus thurifera subsp. africana Maire (Cupressaceae) a rare medicinal tree, growing indigenously in Aurès Mountains of Algeria. The precision of the results was assessed by analyzing the certified reference material IPE44 (WEPAL) grass leaves. Results showed J. thurifera was characterized by high Cr and Mn contents. During autumn and winter mineral concentrations were higher in general. The levels of Cr, Se and Mn were higher during autumn and winter than during spring and summer. Zn contents were higher during summer than in other seasons. Cu content did not vary by season. The potential toxic elements in J. thurifera (Pb > Cd > Br) were below the permissible limits recommended by the Joint WHO/FAO guidelines except for Pb in autumn and winter. 相似文献
10.
Xudong He Fagen Li Mei Li Qijie Weng Jisen Shi Xiaoyong Mo Siming Gan 《New Forests》2012,43(3):383-394
Interspecific hybrids of Eucalyptus urophylla S. T. Blake × E. tereticornis Smith were used for quantitative genetic analysis of cold hardiness (CH) and growth traits height (H), diameter at breast height (D) and volume (V) at 0.5, 1.5, 2.5 and 4 years of age. The effect of E. tereticornis male variance was significant (P < 0.05) for CH as well as 2.5- and 4-year-old growth except for H
4, and E. urophylla female × E. tereticornis male interaction was significant for 0.5- and 1.5-year-old growth and CH except for CH
0.5, whereas E. urophylla female effect was not significant for the majority of traits analyzed. Both additive and dominance gene action were present
in the genetics of all the traits measured at most ages, indicating that those traits may be improved by hybrid breeding.
The σ
D
2/σ
A
2 ratios tended to decline after 1.5 years of age in CH and growth traits, implying that breeding value predictions derived from older performance might be more reliable. Estimates
of narrow-sense heritability (h
2
) for CH and growth ranged from 0.03 ± 0.05 to 0.28 ± 0.13, depending on trait and age. Additive genetic correlations between CH and V were 0.28 ± 0.48 and 0.69 ± 0.30 at ages 1.5 and 2.5, respectively, suggesting that selection for growth would cause a favorable
increase in cold hardiness in E. urophylla × E. tereticornis hybrids. 相似文献
11.
Jianming Gao Yong Zhang Chunguo Wang Shougong Zhang Liwang Qi Wenqin Song 《New Forests》2009,37(3):333-344
Amplified fragment length polymorphism (AFLP) was used in genetic fingerprinting of 22 elite Chinese Populus deltoides and Populus × canadensis accessions. The results indicated that each of the nine AFLP primer pairs selected generated fingerprint profiles that were
unique to each of the accessions. Therefore, each accession was definitively identified by any of the nine primer pairs. Furthermore,
the inter-accession genetic relationships inferred based on 461 polymorphic fragments from the nine AFLP primer pairs were
largely consistent with phylogenetic relationships based on morphologic traits. Bootstrap analysis showed that three AFLP
primer pairs were required to obtain genetic similarity values with a maximum CV of 10% while 10 AFLP primer pairs could give
a maximum CV of 5%. Thus, AFLP can readily be applied for a rapid and accurate evaluation of the degree of similarity between
poplar cultivars. In this study, the number of AFLP fragments used was sufficient to establish a reliable estimate of genetic
similarity among accessions, with a maximum CV of 5.12%. Therefore, the information on the genetic relationships among the
poplar accessions generated in this study in connection with knowledge on agronomic traits may have an impact on poplar breeding
and planting in China. 相似文献
12.
Mayumi Sato Kazuto Seki Kazuhito Kita Yoshinari Moriguchi Makoto Hashimoto Keita Yunoki Masao Ohnishi 《Journal of Wood Science》2009,55(1):32-40
The diterpene compositions in the bark of branches were investigated for two families of the F1 hybrid, Kurile larch (Larix gmelinii var. japonica Pilg.) × Japanese larch [Larix kaempferi (Lamb.) Carr.] (hereafter F1) and their parents clones. 13-Epimanool, larixol, larixyl acetate, 13-epitorulosyl acetate (not detected in L. gmelinii var. japonica), isopimaric acid, abietic acid, dehydroabietic acid, and neoabietic acid were detected. Larixol and abietic acid represented
more than 50% of the diterpene content in L. gmelinii var. japonica and L. kaempferi, respectively. Larixol and abietic acid were the predominant diterpene components in the F1, and the proportions of these diterpenes were between those of the parental species. Therefore, the diterpene compositions
in the F1 were hereditarily infl uenced by their parents. The ratios of labdane, pimarane, and abietane diterpenes suggested that the
main diterpene biosynthesis pathway in L. gmelinii var. japonica was from copalyl diphosphate (CDP) to labdane-type diterpenes, and that in L. kaempferi was from CDP to abietane-type diterpenes via pimarane type. Furthermore, linear discriminant analysis suggested that the
diterpene contents are effective indices for the discrimination of the hybrid seedlings.
Part of this article was presented at the Annual Meetings of the Japan Society for Bioscience, Biotechnology, and Agrochemistry
in Kyoto, March 2006, and in Tokyo, March 2007 相似文献
13.
The effect of Thidiazuron (TDZ), basal media and light quality on adventitious shoot regeneration from in vitro cultured stem of Populus albaxP berolinensis were determined to establish a high efficiency shoot regeneration system from stem explants of P. alba~P berolinensis. Stems ofPopulus alba~P berolinensis were collected from cultured shoots in vitro derived from dormancy buds of 3-year-old seedlings. The stem explants were cultured on MS medium containing 0.02-mg·L-1NAA (naphthaleneacetic acid), and 0.1, 0.3, 0.5 and 1.0 mg·L-1 concentrations of TDZ to determine the effect of TDZ on shoot regeneration. Three basal media, i.e. MS, woody plant medium (WPM) and B5, were used to test their influences of different media on adventitious shoot regeneration. Green, red, blue and yellow plastic films in comparison with florescent light as control were used to observe their effects on shoot regeneration. The results showed that differ- ent concentrations of TDZ had an evident influence on shoot regeneration. Lower concentration of TDZ (0.1 mg·L-1) resulted in more ad- ventitious shoot regeneration and higher concentration of TDZ (〉0.1 mg·L-1) inhibited shoot regeneration. Among different media, MS medium exhibited a high efficiency for shoot regeneration, followed by WPM medium, while B5 medium inhibited shoot regeneration. Normal light and yellow light exhibited better effects on shoot regeneration, compared with other light. 相似文献
14.
Isabelle Dusfour Nicole L. Achee Ireneo Briceno Russell King John P. Grieco 《Journal of pest science》2010,83(1):41-46
Anopheles albimanus Wiedemann is one of the primary vectors of malaria in northern Belize. The primary breeding sites for this species in Central
America are fresh water wetlands that are found in close proximity to agriculture and, in particular, sugarcane fields. The
use of insecticides and herbicides on these crops leads to the introduction of chemicals into the surrounding wetlands. The
potential for the development of insecticide resistance is, therefore, quite high. A study was undertaken to obtain comparative
data on the resistance status of An. albimanus in northern Belize in relation to agriculture practices. Larval surveys were conducted at four collection points in marshes
juxtaposed to different crop types: Dubloon (DB)—control site located 300 m from any agriculture; Little Belize (LB)—mixed
crop agricultural with some human settlements; and Chan Chen (CC) and Buena Vista (BV)—year round sugarcane production. Time
mortality curves were obtained by exposing F1 larvae to DDT 1 μg/ml, malathion 1 μg/ml, and permethrin 0.05 μg/ml. Significant
differences in mortality rates from the four sites were observed only to malathion. The DB sites contained larvae that were
the most susceptible overall, in congruence with its distance from crops. Larvae from LB exhibited a medium level of tolerance.
Finally, the two populations collected at the edge of sugarcane fields (CC and BV) exhibited the highest tolerance to malathion.
These results represent first data on the impact of agriculture on the resistance status of malaria vectors in northern Belize.
The effect of malathion on An. albimanus insecticide resistance reinforces the concerns of the potential impact of agriculture usage on the efficacy of vector control
program. 相似文献
15.
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