Objective:To determine the structure of triterpenoid isolated from avocado seeds and the cytotoxic effect on MCF-7 and Hep G2 cells.Methods:The powder sample was macerated with ethanol,followed with separation of the ...Objective:To determine the structure of triterpenoid isolated from avocado seeds and the cytotoxic effect on MCF-7 and Hep G2 cells.Methods:The powder sample was macerated with ethanol,followed with separation of the extract by column chromatography.The target compound was monitored on thin layer chromatography plate and reagent Lieberman–Buchard.The isolated compound was characterized by spectral analysis,mainly ultraviolet,infrared,and liquid chromatographymass spectroscopy and their spectroscopic data with those reported in literature were compared.In vitro cytotoxic activity was investigated against Vero,MCF-7,and Hep G2 cell lines using MTT assay.Results:A triterpenoid compound was isolated from ethanol extract.The extracts,fraction(F3),and the isolated compound showed a significant cytotoxic activity against all investigated cell lines.MTT assay showed that the triterpenoid isolate inhibited cell proliferation of MCF-7 and Hep G2 cell line with the IC50 values of 62 mg/m L and 12 mg/m L,respectively,and was safe to normal cells.Conclusions:The results of the present study reveal that triterpenoid from avocado seeds have the potential for further development as anticancer agents.展开更多
The detection in August 2015 of the Oriental Fruit Fly (Bactrocera dorsalis Hendel, Diptera: Tephritidae) in the Redland area in Miami-Dade County, Florida triggered a quarantine that restricted the movement of fruit ...The detection in August 2015 of the Oriental Fruit Fly (Bactrocera dorsalis Hendel, Diptera: Tephritidae) in the Redland area in Miami-Dade County, Florida triggered a quarantine that restricted the movement of fruit fly host material in an approximately 99-square mile (256-square kilometer) area. The quarantine affected 4000 acres of fruit bearing commercial avocado groves. Approved post-harvest treatments for B. dorsalis and avocado included in the USDA Treatment Manual were acceptable for immediate certification and movement of fresh avocados from the quarantine area. However, it was unknown if Florida avocados would meet quality standards (US combination grade) after the treatments. Three post-harvest treatments that combine methyl bromide fumigation and cold storage periods were tested on six avocado varieties from Florida. The treatments differed in the durations of the fumigation and cold treatment periods. A seven day transit period at 8.3°C (47°F) was added to account for the time when the fruit leaves the packing house until it is sold by retailers. None of the six varieties had met the US combination grade after the treatments and transit period. Treated fruit exhibited both internal (pulp) and external (skin) damage. Damage was attributed to the fumigation component of the treatment, but the six varieties tolerated the cold portion of the treatment. Damage by fumigation ranged from 26% - 100%. In general, the longer the fumigation period the worse the effect. The need for alternative post-harvest treatments for Florida avocados is discussed.展开更多
Objective:To explore the effect of Persea americana supplementation on inflammation,oxidative stress,and lipid profiles in ovariectomized rats fed with a high-fat diet and exposed to radiation.Methods:The control grou...Objective:To explore the effect of Persea americana supplementation on inflammation,oxidative stress,and lipid profiles in ovariectomized rats fed with a high-fat diet and exposed to radiation.Methods:The control group was sham operated,while groups 2-5 were ovariectomized and fed a high-fat diet.Groups 4 and 5 were exposed toγ-radiation(1 Gy/week for 5 weeks)after ovariectomy.Groups 3 and 5 were treated with 1 mL/250 g/day of Persea americana for one month.Serum levels of estrogen,alanine aminotransferase,aspartate aminotransferase,cholesterol,triglycerides and lipoproteins were measured.Additionally,hepatic oxidative stress,inflammatory and fibrogenic markers were evaluated.Results:Persea americana treatment reduced the oxidative stress markers as well as the levels of triglyceride,total cholesterol,and low-density lipoprotein cholesterol,which in turn lowered hepatic fat accumulation.Moreover,it suppressed hepatic inflammatory mediators(interleukin-6,tumor necrosis factor-α,and C-reactive protein)and downregulated pro-fibrogenic markers(transforming growth factor-βand tissue inhibitor of metalloproteinase-1).Conclusions:Persea americana provides protection against ovariectomy,and gamma radiation-mediated hepatic inflammation not only through its antioxidant,anti-inflammatory,lipid-lowering effect but also by modulating the fibrogenic markers.展开更多
Avocado is a fruit which had a caloric density of 1.7 kcal per gram and a half unit (~70 g) is composed by 114 kcal, 4.6 g of fibers, 345 mg of potassium, 19.5 mg of magnesium, 1.3 mg of vitamin E and 57 mg of phytost...Avocado is a fruit which had a caloric density of 1.7 kcal per gram and a half unit (~70 g) is composed by 114 kcal, 4.6 g of fibers, 345 mg of potassium, 19.5 mg of magnesium, 1.3 mg of vitamin E and 57 mg of phytosterols. Approximately 75% of fiber’s avocado contents are considered insoluble and 25% are soluble. The avocado contains lipids that consist of 71% from monounsaturated fatty acids (MUFA), 13% from polyunsaturated (PUFA) and 16% from saturated fatty acids (SFA). Recent researches have shown that avocado may improve hypercholesterolemia and may be useful in the treatment of hypertension and type 2 diabetes mellitus (T2DM). This way, avocado plays an important role in the cardiovascular health. This review summarizes the potential benefits of avocado consumption in the prevention of cardiovascular risk factors and metabolic diseases.展开更多
Assam of the northeastern region of India is unique in terms of its rich biodiversity and multiple ethnicity of its people. The impact of the resultant socio-religio-cultural diversity is also reflected in the diverse...Assam of the northeastern region of India is unique in terms of its rich biodiversity and multiple ethnicity of its people. The impact of the resultant socio-religio-cultural diversity is also reflected in the diverse traditional ways of silkworm farming. We report the genetic diversity of Persea bombycina “Som” from different locations of Goalpara district of Assam, India, where random amplified polymorphic DNA (RAPD) marker was used in this study. RAPD analyses of ten genotypes of “Som” from Goalpara district of Assam, India with B19 RAPD primer generated 86 bands, showing an average of 8.6 bands per sample and 30.2% (26 bands) of these were polymorphic. The number of bands per accession ranged from 5 to 10 with a mean of 8.6 and the size range of the amplified bands was 250 - 6000 bp. In a UPGMA phenetic dendrogram based on Jaccard’s coefficient, the P. bombycina accessions showed a high level of genetic variation, as indicated by genetic similarity and revealed 10 “Som” genotypes in to three major clusters. This study may be useful in identifying diverse genetic stocks of P. bombycina, which may then be conserved on a priority basis. The RAPD primer used in this study was able to distinguish all the 10 genotypes of “Som” plants, which can be used to assess genetic diversity.展开更多
Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana(P. americana)(traditionally used in Cameroon against diabetes) on β-glucosidase, β-glucosidase, maltase...Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana(P. americana)(traditionally used in Cameroon against diabetes) on β-glucosidase, β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results:The tested extracts strongly inhibited β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from(1.07 ± 0.03) to(31.77 ± 1.17) μg/mL.Among the tested extracts, P. americana was the most active against sensitive enzymes(IC50 of1.07 ± 0.03 to 15.63 ± 1.23). But, none of the extracts showed interesting inhibitory effect against β-glucosidase as their percentage inhibitions were less than 16%. From gas chromatographymass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P.americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.展开更多
The use of traditional breeding for improvement of avocado cultivars is time consuming, hence other methods such as genetic transformation by Agrobacterium is indispensable to adopt. The strain GV3850/pBI121gave best ...The use of traditional breeding for improvement of avocado cultivars is time consuming, hence other methods such as genetic transformation by Agrobacterium is indispensable to adopt. The strain GV3850/pBI121gave best transformation outcome compared to five other binary vectors (AGL1/pCGP904;AGL1/pBI121;GV3850/pCGP904;LBA4404/pCG-P904 and LBA4404/pBI121) under different pH and acetosyringone concentrations. The optimal condition for reliable transformation was by using 200 μM acetosyringone and a pH of 5.2. Transformed embryonic shoots co-cultivated with GV3850/pBI121 were tested using the histochemical x-gluc assay. Further analysis was conducted by polymerase chain reaction using specific primers for the reporter gene (GUS).展开更多
Avocado is a commercially valuable fruit crop cultivated in tropical and subtropical climates throughout the world. Taxonomists recognize three horticultural races of avocado, consisting of Mexican (Persea americana v...Avocado is a commercially valuable fruit crop cultivated in tropical and subtropical climates throughout the world. Taxonomists recognize three horticultural races of avocado, consisting of Mexican (Persea americana var. drymifolia), Guatemalan (P. americana var. guatemalensis), and West Indian (P. americana var. americana) varieties. Published research that attempted to differentiate among the horticultural races by using leaf chemistry found that sesquiterpene content was only useful for discrimination of pure Mexican from Guatemalan and West Indian, but not to distinguish between Guatemalan and West Indian races. This study presents a sampling method for analysis of sesquiterpenes from avocado leaf, branch and trunk samples. Our results indicate that sesquiterpene content from leaves and small diameter branches (2.5 cm) was highly variable;however, sesquiterpenes were much less variable within wood from larger diameter branches and trunk samples, providing information representative of avocado varietal differences. In addition to chemotaxonomic applications, information on sesquiterpene content of avocado wood is needed for identification of host-based attractants for a new avocado pest, the redbay ambrosia beetle (Xyleborus glabratus). This insect vectors a fungal pathogen that causes laurel wilt, a lethal vascular disease that currently threatens avocado production in south Florida, USA. Females of X. glabratus identify appropriate host trees based on emissions of terpenoids, particularly α-copaene. Our results are discussed in terms of how proximo-distal distributions of sesquiterpenes may function as host-location cues by this invasive wood-boring pest.展开更多
The cultivation of fruit trees generally requires a nursery phase during which the young seedlings are monitored and treated to improve their ability to adapt to the environment. This leads to the production of seedli...The cultivation of fruit trees generally requires a nursery phase during which the young seedlings are monitored and treated to improve their ability to adapt to the environment. This leads to the production of seedlings that are used to create orchards. It consists of four essential steps or operations: 1) The germination phase of the seeds in germinators for the production of rootstocks;2) Transplanting into pots or bags;3) Fertilisation in order to obtain seedlings of a satisfactory vigour (stem diameter) ready for grafting. The nursery phase requires a good understanding and mastery of plant regeneration and fertilisation techniques. In Cameroon, the demand for avocado (Persea americana) fruits is increasing, but the supply is not keeping up with this demand. After a summary monograph on the production practices of avocado seedlings in the Yaounde area, this work aims to optimise the aforementioned three steps in order to obtain seedlings of sufficient sizes for grafting. Three factors are considered in this study: 1) The substrate (Substrate), whose effects are evaluated by the germination rate (GR), the daily average germination (DAG) and the root volume of seedlings (RootV). 2) The transplanting date (TransD), determined by considering three dates including 40 (Trans40), 65 (Trans65) and 75 (Trans75) days after sowing, and 3) Fertilisation using biological fertilisers, evaluated by testing four fertilisation levels, Fert1 (10 gr of 20-10-10 plus 10 gr fowl droppings), Fert2 (Acaulospora tuberculata), Fert3 (Gigaspora margarita) and Fert4 (Mixed mycorrhizal strains of Gigaspora margarita and Acaulospora tuberculata). This third factor is evaluated by growth parameters including leaf area (LeafA), chlorophyll index (ChlorInd), gain in Plant height (GainPltH) and plant diameter (GainPltD). The trial took place in the First Seed company, a seed production unit located in the Simbock district of Yaounde for the field phase, and the Biological Control Laboratory of the Institute of Agricultural Research for Development (IRAD), Nlolbisson, Yaounde. Two trials were conducted, the first with the objective of determining the best substrate with a completely randomized block design in 2 replications, three substrates/replication. The second trial was done with a factorial design (Split plot) with three replicates, the main factor being the Transplanting Date (TransD) and the second factor the biological fertilizer. Data were separated using least significant difference at 5% treshhold. Results indicate a highly significant effect of substrate on RootV (p = 5.00E-03). This effect translated by an increase of 49.42% and 19.53% of root volume on sawdust respectively to sand and soil. Sawdust (100%) and soil (98%) affect germination by 8 days reduction over sand and the germination rate on these two substrates is higher than the one on sand (92%). The early transplanting (TransD40) allows a better growth of the seedlings in terms of stem length and the collar diameter. The only observation variable that stands out for the early nursery stage fertilisation is leaf area, which shows significant differences between the 4 fertilisation formulae tested. The chlorophyll index and leaf area are also strongly correlated with the seedling growth parameters. Our results show that the early transplanting stage (40 days after planting) combined with a germination on white sawdust should be proposed to reduce the production cycle of grafted seedlings in association with early application of biofertilisers or organic fertilizer.展开更多
Diabetes-induced dyslipidaemia has been associated with an increased risk of atherosclerosis and coronary heart diseases. Persea americana fruit has been reported to possess anti-diabetic properties. Therefore, this s...Diabetes-induced dyslipidaemia has been associated with an increased risk of atherosclerosis and coronary heart diseases. Persea americana fruit has been reported to possess anti-diabetic properties. Therefore, this study assessed the lipid profile and likely cardio-protective effects of hydroethanolic extracts of P. americana fruits in alloxan-induced diabetic Wistar rats. Thirty-five male rats (150 ± 30 g) were divided into 5 groups (n = 7) and treated orally as follows;groups I-II were normal animals treated with distilled water (0.3 ml/day) and P. americana (300 mg/kg) only respectively. Animals in groups III-V were made diabetic using alloxan monohydrate (100 mg/kg i.p.) and treated orally with distilled water (0.3 ml/day), P. americana (300 mg/kg) and glibenclamide (5 mg/kg) respectively for 21 days. Fasting blood glucose level was monitored prior to, after induction of diabetes mellitus, and on day 21 post-treatment, respectively. Thereafter, retro-orbital blood samples were collected after anaesthesia and analysed for insulin, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL) levels, apolipoproteins A1 and B, superoxide dismutase (SOD) and catalase activities, reduced glutathione (GSH), Vitamin C and malondialdehyde levels, respectively. VLDL, atherogenic index (AI) and ApoB/A1 ratio were estimated mathematically. Pancreatic and cardiac structures were also investigated using Haematoxylin and Eosin stains. Treatment with P. ameriacana extracts reduced (p P. americana treated diabetic group. The hydro-ethanol fruit extract of Persea americana attenuates diabetes induced dyslipidaemia and reduces the susceptibility to cardiac impairment in experimental diabetes mellitus.展开更多
The present study was undertaken to evaluate the protective effects of Hydroethanolic leaves extract of <em>Persea americana</em> (HEPA) against Antouka Super<sup><span style="font-family:Ver...The present study was undertaken to evaluate the protective effects of Hydroethanolic leaves extract of <em>Persea americana</em> (HEPA) against Antouka Super<sup><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</sup></span>(AS) induced hepatotoxicity in male Japanese quail. In total, 40 immature male Japanese quails aged 28 days were used and divided equally into 5 groups. The groups were designed as the control group (received only a 10 ml/kg of distilled water) and the AS group (75 mg/kg b.w). Other three groups received AS (75 mg of AS/kg b.w) plus HEPA (50, 100, and 200 mg/kg b.w/day respectively) by the oral route. After 60 days of the experiment, the crushed liver was performed to obtain homogenate. The protective effects of HEPA on the biochemical parameters, oxidative stress biomarkers and histology changes in the liver were evaluated. The results indicated that AS treatment caused significant alterations in the clinical signs and behavior. It induces the increase in the content of Urea, Creatinine, Protein, AST and ALT in liver tissues and serum. The activities of enzymatic oxidative stress markers such as Superoxide Dismutase (SOD);Catalase (CAT) and Total Peroxidase (POD) also showed significant perturbations in AS-treated quails. Histopathological examination of the liver of AS-treated quails revealed liver lesions characterized by moderate to severe degenerative changes showing a number of hepatocytes undergo fatty changes, focal aggregation of the lymphocytes, multiple necrotic changes and inflammatory infiltrate. The administration of HEPA however, markedly ameliorated the toxicity of AS by protecting the levels of aforesaid biomarkers to near normal levels. These results suggested that HEPA due to its phytochemical constituents with antioxidant properties possesses significant effects against AS-induced toxicity. However, these effects were more pronounced at a dose of 200 mg/kg bw.展开更多
Fossil leaf remains of two new species of Persea Mill., belonging to the family Lauraceae collected from the lower part of the Siwalik sediments(Gish Clay Formation of Sevok Group, Middle Miocene) of Darjeeling foot...Fossil leaf remains of two new species of Persea Mill., belonging to the family Lauraceae collected from the lower part of the Siwalik sediments(Gish Clay Formation of Sevok Group, Middle Miocene) of Darjeeling foothills of eastern Himalaya, are described. The new species are Persea miogamblei sp. nov. and Persea neovillosa sp. nov.. On the basis of leaf architecture(size, shape and venation pattern) fossil leaves described in this article closely resemble modern leaves of Persea gamblei(King ex Hook. f.) Kosterm. and Persea villosa(Roxb.) Kosterm.. The geographic distribution of the fossils and their modern counterparts are discussed and on that basis tropical evergreen vegetation with a warm and humid climate at the time of deposition of the Siwalik sediments is suggested in contrast to the present day tropical deciduous vegetation in this area. The present finding also suggests probable migration of these lauraceous taxa to Southeast Asia.展开更多
Aims Species interactions regulate the invasiveness of non-native species and as declines of native tree species escalate,exotic tree species that offer supplementary resources to animal seed-dispersers should expand ...Aims Species interactions regulate the invasiveness of non-native species and as declines of native tree species escalate,exotic tree species that offer supplementary resources to animal seed-dispersers should expand their distributions as they fill ecological roles.Our primary objective was to forecast impacts from an imminent biological invasion(laurel wilt disease)by quantifying resources provided by native(threatened)and exotic fruits(disease-resistant)and associated bird foraging preferences.Methods In the southeastern USA,we tested for redundancy among the resources provided by native and exotic fruits to overwintering birds.Comparisons between abundant subcanopy species Persea borbonia(native)and Cinnamomum camphora(exotic)were paramount considering the widespread disease-induced decline of P.borbonia,and the biological and phylogenetic similarities between these species.Across two winter survey periods,we quantified fruit removal and documented bird species using motion-activated cameras in the field.Physical and chemical fruit characteristics were also quantified.Important Findings Foraging bouts on both P.borbonia and C.camphora fruits were documented for four native bird species.There was no difference in selectivity between fruit types during Year 1 of our survey,but there was a significant preference for C.camphora fruit in Year 2;the change in preference was correlated with significantly lower temperatures in Year 2.While the pulp/seed ratio and moisture content differed,the nutritional content of fruit pulp(g/100 g)was similar between fruit types.Given the apparent redundancy among these native and exotic fruit resources,we forecast increases in the consumption and dispersal of exotic propagules following the widespread laurel wilt disease-induced decline of P.borbonia and other native fruit bearing members of Lauraceae.This empirically based prediction is among the first to document exotic forest pathogens as indirect threats to native bird-plant interactions and potential facilitators of exotic plant invasion.展开更多
基金Supported by Ministry of Finance of Indonesia through Education Fund Management Institution(LPDP)under a contract number PRJ-541/LPDP.3/2016
文摘Objective:To determine the structure of triterpenoid isolated from avocado seeds and the cytotoxic effect on MCF-7 and Hep G2 cells.Methods:The powder sample was macerated with ethanol,followed with separation of the extract by column chromatography.The target compound was monitored on thin layer chromatography plate and reagent Lieberman–Buchard.The isolated compound was characterized by spectral analysis,mainly ultraviolet,infrared,and liquid chromatographymass spectroscopy and their spectroscopic data with those reported in literature were compared.In vitro cytotoxic activity was investigated against Vero,MCF-7,and Hep G2 cell lines using MTT assay.Results:A triterpenoid compound was isolated from ethanol extract.The extracts,fraction(F3),and the isolated compound showed a significant cytotoxic activity against all investigated cell lines.MTT assay showed that the triterpenoid isolate inhibited cell proliferation of MCF-7 and Hep G2 cell line with the IC50 values of 62 mg/m L and 12 mg/m L,respectively,and was safe to normal cells.Conclusions:The results of the present study reveal that triterpenoid from avocado seeds have the potential for further development as anticancer agents.
文摘The detection in August 2015 of the Oriental Fruit Fly (Bactrocera dorsalis Hendel, Diptera: Tephritidae) in the Redland area in Miami-Dade County, Florida triggered a quarantine that restricted the movement of fruit fly host material in an approximately 99-square mile (256-square kilometer) area. The quarantine affected 4000 acres of fruit bearing commercial avocado groves. Approved post-harvest treatments for B. dorsalis and avocado included in the USDA Treatment Manual were acceptable for immediate certification and movement of fresh avocados from the quarantine area. However, it was unknown if Florida avocados would meet quality standards (US combination grade) after the treatments. Three post-harvest treatments that combine methyl bromide fumigation and cold storage periods were tested on six avocado varieties from Florida. The treatments differed in the durations of the fumigation and cold treatment periods. A seven day transit period at 8.3°C (47°F) was added to account for the time when the fruit leaves the packing house until it is sold by retailers. None of the six varieties had met the US combination grade after the treatments and transit period. Treated fruit exhibited both internal (pulp) and external (skin) damage. Damage was attributed to the fumigation component of the treatment, but the six varieties tolerated the cold portion of the treatment. Damage by fumigation ranged from 26% - 100%. In general, the longer the fumigation period the worse the effect. The need for alternative post-harvest treatments for Florida avocados is discussed.
文摘Objective:To explore the effect of Persea americana supplementation on inflammation,oxidative stress,and lipid profiles in ovariectomized rats fed with a high-fat diet and exposed to radiation.Methods:The control group was sham operated,while groups 2-5 were ovariectomized and fed a high-fat diet.Groups 4 and 5 were exposed toγ-radiation(1 Gy/week for 5 weeks)after ovariectomy.Groups 3 and 5 were treated with 1 mL/250 g/day of Persea americana for one month.Serum levels of estrogen,alanine aminotransferase,aspartate aminotransferase,cholesterol,triglycerides and lipoproteins were measured.Additionally,hepatic oxidative stress,inflammatory and fibrogenic markers were evaluated.Results:Persea americana treatment reduced the oxidative stress markers as well as the levels of triglyceride,total cholesterol,and low-density lipoprotein cholesterol,which in turn lowered hepatic fat accumulation.Moreover,it suppressed hepatic inflammatory mediators(interleukin-6,tumor necrosis factor-α,and C-reactive protein)and downregulated pro-fibrogenic markers(transforming growth factor-βand tissue inhibitor of metalloproteinase-1).Conclusions:Persea americana provides protection against ovariectomy,and gamma radiation-mediated hepatic inflammation not only through its antioxidant,anti-inflammatory,lipid-lowering effect but also by modulating the fibrogenic markers.
文摘Avocado is a fruit which had a caloric density of 1.7 kcal per gram and a half unit (~70 g) is composed by 114 kcal, 4.6 g of fibers, 345 mg of potassium, 19.5 mg of magnesium, 1.3 mg of vitamin E and 57 mg of phytosterols. Approximately 75% of fiber’s avocado contents are considered insoluble and 25% are soluble. The avocado contains lipids that consist of 71% from monounsaturated fatty acids (MUFA), 13% from polyunsaturated (PUFA) and 16% from saturated fatty acids (SFA). Recent researches have shown that avocado may improve hypercholesterolemia and may be useful in the treatment of hypertension and type 2 diabetes mellitus (T2DM). This way, avocado plays an important role in the cardiovascular health. This review summarizes the potential benefits of avocado consumption in the prevention of cardiovascular risk factors and metabolic diseases.
文摘Assam of the northeastern region of India is unique in terms of its rich biodiversity and multiple ethnicity of its people. The impact of the resultant socio-religio-cultural diversity is also reflected in the diverse traditional ways of silkworm farming. We report the genetic diversity of Persea bombycina “Som” from different locations of Goalpara district of Assam, India, where random amplified polymorphic DNA (RAPD) marker was used in this study. RAPD analyses of ten genotypes of “Som” from Goalpara district of Assam, India with B19 RAPD primer generated 86 bands, showing an average of 8.6 bands per sample and 30.2% (26 bands) of these were polymorphic. The number of bands per accession ranged from 5 to 10 with a mean of 8.6 and the size range of the amplified bands was 250 - 6000 bp. In a UPGMA phenetic dendrogram based on Jaccard’s coefficient, the P. bombycina accessions showed a high level of genetic variation, as indicated by genetic similarity and revealed 10 “Som” genotypes in to three major clusters. This study may be useful in identifying diverse genetic stocks of P. bombycina, which may then be conserved on a priority basis. The RAPD primer used in this study was able to distinguish all the 10 genotypes of “Som” plants, which can be used to assess genetic diversity.
基金supported by the 2016 CIIT-TWAS Postdoctoral Fellowship(grant number:3240293205)
文摘Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana(P. americana)(traditionally used in Cameroon against diabetes) on β-glucosidase, β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results:The tested extracts strongly inhibited β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC50 ranging from(1.07 ± 0.03) to(31.77 ± 1.17) μg/mL.Among the tested extracts, P. americana was the most active against sensitive enzymes(IC50 of1.07 ± 0.03 to 15.63 ± 1.23). But, none of the extracts showed interesting inhibitory effect against β-glucosidase as their percentage inhibitions were less than 16%. From gas chromatographymass spectrum analysis, 10 and 8 compounds were identified in Piper umbellatum and P.americana extracts respectively, using NIST library 2014. Conclusions: Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.
文摘The use of traditional breeding for improvement of avocado cultivars is time consuming, hence other methods such as genetic transformation by Agrobacterium is indispensable to adopt. The strain GV3850/pBI121gave best transformation outcome compared to five other binary vectors (AGL1/pCGP904;AGL1/pBI121;GV3850/pCGP904;LBA4404/pCG-P904 and LBA4404/pBI121) under different pH and acetosyringone concentrations. The optimal condition for reliable transformation was by using 200 μM acetosyringone and a pH of 5.2. Transformed embryonic shoots co-cultivated with GV3850/pBI121 were tested using the histochemical x-gluc assay. Further analysis was conducted by polymerase chain reaction using specific primers for the reporter gene (GUS).
文摘Avocado is a commercially valuable fruit crop cultivated in tropical and subtropical climates throughout the world. Taxonomists recognize three horticultural races of avocado, consisting of Mexican (Persea americana var. drymifolia), Guatemalan (P. americana var. guatemalensis), and West Indian (P. americana var. americana) varieties. Published research that attempted to differentiate among the horticultural races by using leaf chemistry found that sesquiterpene content was only useful for discrimination of pure Mexican from Guatemalan and West Indian, but not to distinguish between Guatemalan and West Indian races. This study presents a sampling method for analysis of sesquiterpenes from avocado leaf, branch and trunk samples. Our results indicate that sesquiterpene content from leaves and small diameter branches (2.5 cm) was highly variable;however, sesquiterpenes were much less variable within wood from larger diameter branches and trunk samples, providing information representative of avocado varietal differences. In addition to chemotaxonomic applications, information on sesquiterpene content of avocado wood is needed for identification of host-based attractants for a new avocado pest, the redbay ambrosia beetle (Xyleborus glabratus). This insect vectors a fungal pathogen that causes laurel wilt, a lethal vascular disease that currently threatens avocado production in south Florida, USA. Females of X. glabratus identify appropriate host trees based on emissions of terpenoids, particularly α-copaene. Our results are discussed in terms of how proximo-distal distributions of sesquiterpenes may function as host-location cues by this invasive wood-boring pest.
文摘The cultivation of fruit trees generally requires a nursery phase during which the young seedlings are monitored and treated to improve their ability to adapt to the environment. This leads to the production of seedlings that are used to create orchards. It consists of four essential steps or operations: 1) The germination phase of the seeds in germinators for the production of rootstocks;2) Transplanting into pots or bags;3) Fertilisation in order to obtain seedlings of a satisfactory vigour (stem diameter) ready for grafting. The nursery phase requires a good understanding and mastery of plant regeneration and fertilisation techniques. In Cameroon, the demand for avocado (Persea americana) fruits is increasing, but the supply is not keeping up with this demand. After a summary monograph on the production practices of avocado seedlings in the Yaounde area, this work aims to optimise the aforementioned three steps in order to obtain seedlings of sufficient sizes for grafting. Three factors are considered in this study: 1) The substrate (Substrate), whose effects are evaluated by the germination rate (GR), the daily average germination (DAG) and the root volume of seedlings (RootV). 2) The transplanting date (TransD), determined by considering three dates including 40 (Trans40), 65 (Trans65) and 75 (Trans75) days after sowing, and 3) Fertilisation using biological fertilisers, evaluated by testing four fertilisation levels, Fert1 (10 gr of 20-10-10 plus 10 gr fowl droppings), Fert2 (Acaulospora tuberculata), Fert3 (Gigaspora margarita) and Fert4 (Mixed mycorrhizal strains of Gigaspora margarita and Acaulospora tuberculata). This third factor is evaluated by growth parameters including leaf area (LeafA), chlorophyll index (ChlorInd), gain in Plant height (GainPltH) and plant diameter (GainPltD). The trial took place in the First Seed company, a seed production unit located in the Simbock district of Yaounde for the field phase, and the Biological Control Laboratory of the Institute of Agricultural Research for Development (IRAD), Nlolbisson, Yaounde. Two trials were conducted, the first with the objective of determining the best substrate with a completely randomized block design in 2 replications, three substrates/replication. The second trial was done with a factorial design (Split plot) with three replicates, the main factor being the Transplanting Date (TransD) and the second factor the biological fertilizer. Data were separated using least significant difference at 5% treshhold. Results indicate a highly significant effect of substrate on RootV (p = 5.00E-03). This effect translated by an increase of 49.42% and 19.53% of root volume on sawdust respectively to sand and soil. Sawdust (100%) and soil (98%) affect germination by 8 days reduction over sand and the germination rate on these two substrates is higher than the one on sand (92%). The early transplanting (TransD40) allows a better growth of the seedlings in terms of stem length and the collar diameter. The only observation variable that stands out for the early nursery stage fertilisation is leaf area, which shows significant differences between the 4 fertilisation formulae tested. The chlorophyll index and leaf area are also strongly correlated with the seedling growth parameters. Our results show that the early transplanting stage (40 days after planting) combined with a germination on white sawdust should be proposed to reduce the production cycle of grafted seedlings in association with early application of biofertilisers or organic fertilizer.
文摘Diabetes-induced dyslipidaemia has been associated with an increased risk of atherosclerosis and coronary heart diseases. Persea americana fruit has been reported to possess anti-diabetic properties. Therefore, this study assessed the lipid profile and likely cardio-protective effects of hydroethanolic extracts of P. americana fruits in alloxan-induced diabetic Wistar rats. Thirty-five male rats (150 ± 30 g) were divided into 5 groups (n = 7) and treated orally as follows;groups I-II were normal animals treated with distilled water (0.3 ml/day) and P. americana (300 mg/kg) only respectively. Animals in groups III-V were made diabetic using alloxan monohydrate (100 mg/kg i.p.) and treated orally with distilled water (0.3 ml/day), P. americana (300 mg/kg) and glibenclamide (5 mg/kg) respectively for 21 days. Fasting blood glucose level was monitored prior to, after induction of diabetes mellitus, and on day 21 post-treatment, respectively. Thereafter, retro-orbital blood samples were collected after anaesthesia and analysed for insulin, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL) levels, apolipoproteins A1 and B, superoxide dismutase (SOD) and catalase activities, reduced glutathione (GSH), Vitamin C and malondialdehyde levels, respectively. VLDL, atherogenic index (AI) and ApoB/A1 ratio were estimated mathematically. Pancreatic and cardiac structures were also investigated using Haematoxylin and Eosin stains. Treatment with P. ameriacana extracts reduced (p P. americana treated diabetic group. The hydro-ethanol fruit extract of Persea americana attenuates diabetes induced dyslipidaemia and reduces the susceptibility to cardiac impairment in experimental diabetes mellitus.
文摘The present study was undertaken to evaluate the protective effects of Hydroethanolic leaves extract of <em>Persea americana</em> (HEPA) against Antouka Super<sup><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">®</sup></span>(AS) induced hepatotoxicity in male Japanese quail. In total, 40 immature male Japanese quails aged 28 days were used and divided equally into 5 groups. The groups were designed as the control group (received only a 10 ml/kg of distilled water) and the AS group (75 mg/kg b.w). Other three groups received AS (75 mg of AS/kg b.w) plus HEPA (50, 100, and 200 mg/kg b.w/day respectively) by the oral route. After 60 days of the experiment, the crushed liver was performed to obtain homogenate. The protective effects of HEPA on the biochemical parameters, oxidative stress biomarkers and histology changes in the liver were evaluated. The results indicated that AS treatment caused significant alterations in the clinical signs and behavior. It induces the increase in the content of Urea, Creatinine, Protein, AST and ALT in liver tissues and serum. The activities of enzymatic oxidative stress markers such as Superoxide Dismutase (SOD);Catalase (CAT) and Total Peroxidase (POD) also showed significant perturbations in AS-treated quails. Histopathological examination of the liver of AS-treated quails revealed liver lesions characterized by moderate to severe degenerative changes showing a number of hepatocytes undergo fatty changes, focal aggregation of the lymphocytes, multiple necrotic changes and inflammatory infiltrate. The administration of HEPA however, markedly ameliorated the toxicity of AS by protecting the levels of aforesaid biomarkers to near normal levels. These results suggested that HEPA due to its phytochemical constituents with antioxidant properties possesses significant effects against AS-induced toxicity. However, these effects were more pronounced at a dose of 200 mg/kg bw.
基金financial assistance from the Department of Science and Technology, New Delhi
文摘Fossil leaf remains of two new species of Persea Mill., belonging to the family Lauraceae collected from the lower part of the Siwalik sediments(Gish Clay Formation of Sevok Group, Middle Miocene) of Darjeeling foothills of eastern Himalaya, are described. The new species are Persea miogamblei sp. nov. and Persea neovillosa sp. nov.. On the basis of leaf architecture(size, shape and venation pattern) fossil leaves described in this article closely resemble modern leaves of Persea gamblei(King ex Hook. f.) Kosterm. and Persea villosa(Roxb.) Kosterm.. The geographic distribution of the fossils and their modern counterparts are discussed and on that basis tropical evergreen vegetation with a warm and humid climate at the time of deposition of the Siwalik sediments is suggested in contrast to the present day tropical deciduous vegetation in this area. The present finding also suggests probable migration of these lauraceous taxa to Southeast Asia.
基金the National Estuarine Reserve System under an award from the Estuarine Reserves Division,Office of Ocean and Coastal Resource Management,National Ocean Service,National Oceanic and Atmospheric Administration(Award#NA11NOS4200080)。
文摘Aims Species interactions regulate the invasiveness of non-native species and as declines of native tree species escalate,exotic tree species that offer supplementary resources to animal seed-dispersers should expand their distributions as they fill ecological roles.Our primary objective was to forecast impacts from an imminent biological invasion(laurel wilt disease)by quantifying resources provided by native(threatened)and exotic fruits(disease-resistant)and associated bird foraging preferences.Methods In the southeastern USA,we tested for redundancy among the resources provided by native and exotic fruits to overwintering birds.Comparisons between abundant subcanopy species Persea borbonia(native)and Cinnamomum camphora(exotic)were paramount considering the widespread disease-induced decline of P.borbonia,and the biological and phylogenetic similarities between these species.Across two winter survey periods,we quantified fruit removal and documented bird species using motion-activated cameras in the field.Physical and chemical fruit characteristics were also quantified.Important Findings Foraging bouts on both P.borbonia and C.camphora fruits were documented for four native bird species.There was no difference in selectivity between fruit types during Year 1 of our survey,but there was a significant preference for C.camphora fruit in Year 2;the change in preference was correlated with significantly lower temperatures in Year 2.While the pulp/seed ratio and moisture content differed,the nutritional content of fruit pulp(g/100 g)was similar between fruit types.Given the apparent redundancy among these native and exotic fruit resources,we forecast increases in the consumption and dispersal of exotic propagules following the widespread laurel wilt disease-induced decline of P.borbonia and other native fruit bearing members of Lauraceae.This empirically based prediction is among the first to document exotic forest pathogens as indirect threats to native bird-plant interactions and potential facilitators of exotic plant invasion.