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1.
The incidence of predation of eight species of predacious mirids (Hemiptera: Miridae) present in an apple orchard of Québec
on the green apple aphid, two-spotted spider mite and European red mite were investigated. The daily consumption rates varied
from 1–2 green apple aphids forHyaliodes vitripennis Say andCampylomma verbasci Meyer to 7–9 aphids forDeraeocoris fasciolus Knight andLepidopsallus minisculus Knight.H. vitripennis consumed significantly more mites than the other mirid species with 26 and 18 mites per day for the two-spotted spider mite
and the European red mite respectively. The combined use ofH. vitripennis andL. minisculus is suggested for the control of phytophagous mites.
This paper is contribution No. 335/91.06.02R, Research Station, Agriculture Canada, Saint-Jean-sur-Richelieu, Québec, Canada. 相似文献
2.
Oxidative stress induced by reactive oxygen species has been strongly associated with the pathogenesis of neurodegenerative disorders, including Alzheimer's disease. In this study, we investigated the possible protective effects of a cocoa procyanidin fraction (CPF) and procyanidin B2 (epicatechin-(4β-8)-epicatechin) – a major polyphenol in cocoa – against apoptosis of PC12 rat pheochromocytoma (PC12) cells induced by hydrogen peroxide (H2O2). CPF (1 and 5 μg/ml) and procyanidin B2 (1 and 5 μM) reduced PC12 cell death caused by H2O2, as determined by MTT and trypan blue exclusion assays. CPF and procyanidin B2 attenuated the H2O2-induced fragmentation of nucleus and DNA in PC12 cells. Western blot data demonstrated that H2O2 induced cleavage of poly(ADP-ribose)polymerase (PARP), downregulated Bcl-XL and Bcl-2 in PC12 cells. Pretreatment with CPF or procyanidin B2 before H2O2 treatment diminished PARP cleavage and increased Bcl-XL and Bcl-2 expression compared with those only treated with H2O2. Activation of caspase-3 by H2O2 was inhibited by pretreatment with CPF or procyanidin B2. Furthermore, H2O2-induced rapid and significant phosphorylation of c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), and both of these effects were attenuated by CPF or procyanidin B2 treatment. These results suggest that the protective effects of CPF and procyanidin B2 against H2O2-induced apoptosis involve inhibiting the downregulation of Bcl-XL and Bcl-2 expression through blocking the activation of JNK and p38 MAPK. 相似文献
3.
《Saudi Journal of Biological Sciences》2023,30(2):103562
This research focused on the roasting of cocoa beans at 184 °C for 16 min duration in a superheated steam oven using two separate modes of heating: convection mode and superheated steam mode. After roasting, the antioxidant properties of the cooked cocoa were assessed as ferric reducing antioxidant power activity (FRAP), DPPH radical scavenging activity, total flavonoid content (TFC) and total phenol content (TPC). The micro structural properties of raw and processed cocoa beans were observed using scanning electron microscopy (SEM). As discovered in the scan, conventional roasting showed a nearly complete rapture of the cytoplasmic network system and the destruction of the organelles, whereas superheated steam mode showed satisfactory images. Studies indicated that superheated steam roasting preserved significantly (p < 0.05) greater antioxidant properties as opposed to conventional method of roasting. 相似文献
4.
Cocoa agroforests that retain a floristically diverse and structurally complex shade canopy have the potential to harbour
significant levels of biodiversity, yet few studies have documented the plant and animal species occurring within these systems
or within landscapes dominated by cocoa production. In this special issue, we bring together nine studies from Latin America,
Africa and Asia that document the contribution of cocoa agroforestry systems to biodiversity conservation, and explore how
the design, management and location of these systems within the broader landscape influence their value as habitats, resources
and biological corridors. Tree diversity within the cocoa production systems is variable, depending on management, cultural
differences, location and farm history, among other factors. Animal diversity is typically highest in those cocoa agroforests
that have high plant diversity, structurally complex canopies, and abundant surrounding forest cover. In general, both plant
and animal diversity within cocoa agroforests is greater than those of other agricultural land uses, but lower than in the
original forest habitat. There are several emerging threats to biodiversity conservation within cocoa production landscapes,
including the loss of remaining forest cover, the simplification of cocoa shade canopies and the conversion of cocoa agroforestry
systems to other agricultural land uses with lower biodiversity value. To counter these threats and conserve biodiversity
over the long-term, land management should focus on conserving native forest habitat within cocoa production landscapes, maintaining
or restoring floristically diverse and structurally complex shade canopies within cocoa agroforests, and retaining other types
of on-farm tree cover to enhance landscape connectivity and habitat availability. 相似文献
5.
Diversity of plants in cocoa agroforests in the humid forest zone of Southern Cameroon 总被引:2,自引:1,他引:2
Denis J. Sonwa Bernard A. Nkongmeneck Stephan F. Weise Maturin Tchatat Akin A. Adesina Marc J. J. Janssens 《Biodiversity and Conservation》2007,16(8):2385-2400
In the humid forest zone of Southern Cameroon, farmers generally associate cocoa with native and exotic trees in complex agroforestry
systems. Despite the socio-economic and ecological importance of these systems, few studies have investigated their plant
composition. We investigated tree composition of cocoa agroforests along a gradient of market access, population density and
resource use intensity in the humid forest zone of southern Cameroon, comprising (i) the sub-region of Yaoundé, (ii) the sub-region
of Mbalmayo, and (iii) the sub-region of Ebolowa. Market access, population density and resource use intensity all decreased
from the first to the third sub-region. We quantified the diversity of tree species associated with cocoa within individual
agroforests, among agroforests in the same region, and among the three sub-regions, and classified the tree species according
to their main uses. A total of 9.1 ha belonging to 60 cocoa agroforests were inventoried in 12 villages. We encountered a
total of 206 tree species with an average of 21 tree species per agroforest. In the more urbanized area around Yaoundé, agroforests
were less diverse than in the other sub-regions. In all of the agroforests, food producing tree species tended to be more
frequent than other species. Two thirds of the food trees were native forest species and one third was introduced. From Ebolowa
to Yaoundé, the density of food producing trees doubled and the density of exotic food-producing species increased relative
to native species. Some local species producing high-value non-timber forest products were found in the agroforests, but their
density was far lower than that of exotic tree species. The agroforests also provide medicine, charcoal and other products
for household consumption and sale. We conclude that unless there are specific efforts to promote local forest tree species
in cocoa agroforests, these will progressively lose importance with increasing market access, population pressure and land
use intensity. 相似文献
6.
The triglycerides of fats from several varieties of Sapium sebiferum (L.) Roxb. were determined by means of pancreatic lipase hydrolysis technigue. Triglycerides of the fats. are composed of 9–14 kinds of triglycerides. They are similar to Cocoa butter. Fatty acid composition in 2-position of glycerides is oleic acid in more than 82%. The disaturated glycerides account for 81-88%, in which POP is in the majority (74–81%); the proportion of monosaturated glycerides is 1.8–6.0%; the trisaturated glycerides hold 9.6–15.6%, in which the main one is PPP (8.5–14.0%). The fats can be used for making Cocoa butter substitute by proper processing. Fat contents of the four varieties (“Da Li Ji Zhao”, “Wu Gong”, “Tong Chui” and “Xiao Li Ji Zhao”) cultivated in Guangxi province are richer (32.0–34.3%) than that of the wild species of the same plant. The proportion of disaturated glycerides is the highest (88.0%) and that of trisaturated glycerides is the lowest (9.6%) in fat from "Da Li Ji Zhao". 相似文献
7.
Régis Babin Gerben M. ten Hoopen Christian Cilas Frank Enjalric Yede Pierre Gendre Jean-Pierre Lumaret 《Agricultural and Forest Entomology》2010,12(1):69-79
- 1 Shade management is commonly considered to be an effective pest management strategy for cocoa mirids, yet shade management recommendations are not based on extensive knowledge of the mirid ecology in traditional cocoa agroforests.
- 2 The main objectives of the present study were an assessment of the impact of shade on the spatial distribution of mirid populations and thus the evaluation of shade management strategies.
- 3 Mirid densities were measured and shade was characterized for three plots located in three different agroecological zones in the Centre region of Cameroon. Mirid densities generally followed a negative binomial law. Geostatistical procedures were used to characterize spatial distribution of mirid density. Light conditions were assessed using hemispherical photography.
- 4 Populations of Sahlbergella singularis were highly aggregated in the plots. Semivariance analysis and kriging visualized the spatial dependence of mirid densities. Clearly distinguishable mirid pockets of 20–30 adjacent infested cocoa trees were identified in two of the three plots.
- 5 The high diversity of shade tree species and the large variability in density and size of shade trees resulted in a considerable heterogeneity of plot light conditions. Percentage transmitted light varied in the range 9.4–80.1% in the most heterogeneous plot.
- 6 For two of the three plots, mirid pockets were aggregated in those areas where light transmission was highest. In the third plot, relatively high mirid densities and the presence of an alternative host resulted in a more homogeneous distribution. The importance of these findings for improved mirid control is discussed.
8.
Dung Beetle and Terrestrial Mammal Diversity in Forests, Indigenous Agroforestry Systems and Plantain Monocultures in Talamanca, Costa Rica 总被引:2,自引:0,他引:2
In order to explore the importance of indigenous agroforestry systems for biodiversity conservation, we compared the abundance,
species richness and diversity of dung beetles and terrestrial mammals across a gradient of different land use types from
agricultural monocultures (plantains) to agroforestry systems (cocoa and banana) and forests in the BriBri and Cabécar indigenous
reserves in Talamanca, Costa Rica. A total of 132,460 dung beetles of 52 species and 913 tracks of 27 terrestrial mammal species
were registered. Dung beetle species richness and diversity were greatest in the forests, intermediate in the agroforestry
systems and lowest in the plantain monocultures, while dung beetle abundance was greatest in the plantain monocultures. The
number of mammal tracks per plot was significantly higher in forests than in plantain monocultures, whereas mammal species
richness was higher in forests than in either cocoa agroforestry systems or plantain monocultures. Species composition of
both terrestrial mammals and dung beetles also varied across the different land use types. Our study indicates that indigenous
cocoa and banana agroforestry systems maintain an intermediate level of biodiversity (which is less than that of the original
forest but significantly greater than that of plantain monocultures) and provide suitable habitat for a number of forest-dependent
species. Although the agroforestry systems appear to serve as favorable habitats for many terrestrial mammal species, their
potential positive contribution to mammal conservation is being offset by heavy hunting pressure in the reserves. As in other
agricultural landscapes, the conservation of biodiversity in Talamanca will depend not only on maintaining the existing forest
patches and reducing the conversion of traditional agroforestry systems to monocultures, but also on reducing hunting pressure. 相似文献
9.
10.
Geok -Yong Tan Wai -Koon Tan 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1990,80(2):258-264
Summary Quantitative inheritance of resistance to Phytophthora pod rot (Ppr) was studied in cocoa hybrid progeny from 12 Trinitario x Amazonian crosses and their reciprocal crosses. The crossing scheme was similar to a factorial design. Disease was assessed by the number and percentage of infected pods on each tree. Highly significant differences due to general combining abilities (GCA) were obtained for all characters, except for the GCA of Trinitario on total pod production. Differences for specific combining ability (SCA) were not significant for all characters. There were no significant differences between reciprocal crosses. The Trinitario clone K82 provided the only source for the hybrid progenies of strong Ppr resistance to the hybrid progenies, while K20 provided moderate resistance. Other parental clones — KA2-101, KA5-201, KEE 2, KEE 5, and KEE 52 — produced progenies which were susceptible to Ppr. It is evident that resistance to Ppr in cocoa is inherited additively. Maternal and cytoplasmic effects were assumed to have no influence on inheritance of resistance. It is also concluded that resistance to Ppr of the kind shown by K82 is likely to be horizontal resistance. Breeding for high-yielding cultivars combined with Ppr resistance is the most effective way of controlling Ppr of cocoa on the crops of growers with small holdings in Papua New Guinea. 相似文献