Antifungal activity of resveratrol oligomers from Cyphostemma crotalarioides     

Adil E Bala  Albert Kollmann  Paul-Henri Ducrot  Amel Majira  Lucien Kerhoas  Robert Delorme  Jacques Einhorn 《Pest management science》1999,55(2):206-208

Resveratrol and its oligomers: ε-viniferine, gnetin C, Pallidol and gnetin E, as well as three new dehydrodimers, cyphostemmines A–C, have been isolated from the roots of Cyphostemma crotalarioides (Ampelidaceae). Such compounds have not been reported previously in the family Ampelidaceae. Cis ε-viniferin has also been characterized as a minor component of the extract; it may have undergone partial transformation in solution into trans ε-viniferin. ©1999 Society of Chemical Industry  相似文献   

Insecticidal activity of daphnane diterpenes from Lasiosiphon kraussianus (Meisn) (Thymelaeaceae) roots     

Adil E A Bala  Robert Delorme  Albert Kollmann  Lucien Kerhoas  Jacques Einhorn  Paul-Henri Ducrot  Danielle Aug 《Pest management science》1999,55(7):745-750

A methanol extract of roots of Lasiosiphon kraussianus (Meisn) (Thymelaeaceae) showed potent insecticidal activity against Aphis gossypii (Glov) and Drosophila melanogaster (Meig). Bioassay-driven fractionation of this extract led to the isolation and characterisation of two known daphnane diterpenoids: Excoecaria toxin (1) and wikstrotoxin D (2) . The two natural products were inferior to methomyl in activity against A gossypii and Myzus persicae (Sulz) in contact assays but were superior in ingestion assays against D melanogaster. This is the first report on insecticidal activities of compounds 1 and 2 . AChE was insensitive to the two natural products. © 1999 Society of Chemical Industry  相似文献   

葡萄种植行向对覆膜越冬膜下温度的影响     

李银芳  潘伯荣  阿迪力·吾彼尔  沈青林  方桂娟  李奇  马洪亮  辛和平 《干旱地区农业研究》2017,35(2):240-246

为消除葡萄东西行向种植双膜覆盖越冬膜上雪被不足的顾虑,2014—2015年冬季在新疆阜康进行了东西向、南北向膜下和土埋的温度逐日观测。结果表明,寒冷期最低温度东西向较高。整个冬季东西向有大于土埋的补偿温度,而南北向是低于土埋的亏缺温度。在-25.6℃的最低气温日,东西向是-3.0℃、南北向-5.4℃、土埋-4.6℃。经推算,在-37℃极端最低气温时,分别是-9.6℃、-13.6℃、-10.4℃。两种行向都经得住极端最低气温和长期低温的酷寒,东西向好于南北向。最高温度、平均温度也是东西向较高,温差则反之。10℃萌发生长的日期东西向比土埋提前37天,南北向提前35天。东西向还较南北向高产优质,生长旺盛。东西向因为优越的光照条件,可不再担忧雪被不足的问题。若采用篱架式南北向栽培,双膜越冬也是安全可靠的。  相似文献   

Livelihood Improvements Through Agroforestry: Evidence from Northern Bangladesh     

Md. Abu Hanif  Ranjan Mitra Roy  Md. Shafiqul Bari  Polash Chandra Ray  Md. Shoaibur Rahman  Md. Faruq Hasan 《Small-Scale Forestry》2018,17(4):505-522

Agroforestry is one of the most sustainable land management systems practiced around the world due to the socioeconomic benefits that it brings to farmers. In Bangladesh, farmers practice agroforestry, applying indigenous knowledge. The present study was designed to identify the present status, management practices and its role in improving the livelihoods of farmers in northern Bangladesh. Data for the study were collected through quantitative and qualitative methods. A total of 29 tree and 38 agricultural crop species were planted by the102 farmers interviewed. Mangifera indica (relative prevalence 49%) is the most predominant species, followed by Eucalyptus camaldulensis (relative prevalence 35.4%). Farmers of northern Bangladesh plant trees in cropland for fruits (90%), fuel wood (87%) and timber production (79%). Fruit trees were planted with wider spacing while forest and fuel wood species were planted with narrower spacing. Farmer’s livelihoods improved enormously by practicing agroforestry as they have more access to food, fodder and fuel wood which is reflected by greater access to livelihood capitals (except social capital). However, farmers have experienced increased incidences of pests and diseases to the annual crops and trees. Agroforestry practices increases species diversity, ensure economic return and sustain farmer’s livelihoods.  相似文献   

Metagenomic analysis using 16S ribosomal RNA genes of a bacterial community in an urban stream,the Tama River,Tokyo     

Md. Shaheed Reza  Nanami Mizusawa  Ayaka Kumano  Chiharu Oikawa  Daisuke Ouchi  Atsushi Kobiyama  Yuichiro Yamada  Yuri Ikeda  Daisuke Ikeda  Kazuho Ikeo  Shigeru Sato  Takehiko Ogata  Toshiaki Kudo  Mitsuru Jimbo  Ko Yasumoto  Kazutoshi Yoshitake  Shugo Watabe 《Fisheries Science》2018,84(3):563-577

In an effort to determine genus- or species-level taxonomic profiles and diversity of bacterial consortia in the Tama River around urban Tokyo, next-generation sequencing technology targeting a 16S ribosomal RNA (rRNA) gene amplicon was employed. Metagenomic analysis performed by an Ion Personal Genome Machine after sequentially filtering samples through 5-, 0.8- and 0.2-μm filters yielded 1.48 Gb of 16S sequences (average 2.38 M reads/sample). The results indicated that half of the bacterial sequences belonged to Proteobacteria, followed by Bacteroidetes, Actinobacteria and Cyanobacteria. Flavobacterium (Bacteroidetes), possibly including a potential fish pathogen, was the most numerous genera in the Tama River metagenome, and accounted for?~?16% of assigned 16S reads, followed by Mycobacterium. Other dominant bacterial genera including Zoogloea, Sediminibacterium, Hyphomicrobium, Sphingopyxis, Thiothrix and Lysobacter, were thought to be associated with waste water and sludge. MiSeq metagenomic analysis revealed that environmental factors, particularly water temperature, influenced the bacterial composition throughout the year, with a strong negative correlation observed for Proteobacteria and a positive correlation for Bacteroidetes. In terms of bacterial genera, Flavobacterium was positively correlated with temperature, while Polaromonas, Pseudomonas and Bradyrhizobium were negatively correlated with this, suggesting dynamic change in the free-living bacterial population throughout the year and versatile adaptation strategies in relation to environmental factors.  相似文献   

Replacement of de‐oiled rice bran by soaked and fermented sweet potato leaf meal: Effect on growth performance,body composition and expression of insulin‐like growth factor 1 in Labeo rohita (Hamilton), fingerlings          下载免费PDF全文

Shweta Meshram  Ashutosh D Deo  Sarvendra Kumar  Md Aklakur  Narottam P Sahu 《Aquaculture Research》2018,49(8):2741-2750

A 60‐day feeding trial was conducted to determine the growth performance and expression of insulin‐like growth factor 1 gene (IGF‐I gene) in Labeo rohita fingerlings fed with either raw, soaked or fermented sweet potato leaf meal (SPLM) by completely replacing de‐oiled rice bran (DORB), following a completely randomized design. Seven isonitrogenous (30%) and isocaloric (1.8 MJ/100 g) diets were prepared by replacing DORB with 50% and 100% raw, soaked and fermented sweet potato leaf meal, maintaining DORB‐containing diets as a control. Weight gain %, SGR (specific growth rate) and PER (protein efficiency ratio) were significantly (p < 0.05) higher when 100% DORB was replaced by fermented SPLM in comparison to other treatment groups. The fermented and soaked SPLM‐fed groups had registered with lower FCR value. The expression of growth regulating gene IGF‐I mRNA and RNA/DNA ratio was found to be significantly higher (p < 0.05) in soaked and fermented SPLM‐fed groups. In this study, the body protein and lipid composition did not vary significantly (p > 0.05). Hence, the study concludes that the fermented sweet potato leaf meal using Chaetomium globosum can replace 100% DORB in the diet of Labeo rohita without any detrimental effect on growth performance.  相似文献   

The occurrence of postharvest gray-mold rot of sweet persimmon caused by <Emphasis Type="Italic">Botrytis cinerea</Emphasis> in Korea     

Md. Aktaruzzaman  Young-Gyu Lee  Tania Afroz  Byung-Sup Kim 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(1):245-251

In this study, we identified the causative agent of postharvest gray-mold rot in sweet persimmon fruit that were collected from Gangneung, Gangwon Province, Korea in October 2016. Symptoms included extensive growth of mycelia on post harvested fruit. The fungus was isolated from infected fruit and cultured on potato dextrose agar (PDA). For identification of the fungus, we examined morphology characteristics and rDNA sequencing analysis of the fungus and confirmed its pathogenicity according to Koch’s postulates. The results of morphological examinations, pathogenicity tests, 5.8S rDNA sequences of the internal transcribed spacer regions (ITS1 and ITS4) and the five nuclear protein-coding genes G3PDH, HSP60, RPB2, MS547 and TUB revealed that the causal agent of postharvest gray-mold rot on sweet persimmon fruit in Korea was Botrytis cinerea.  相似文献   

A simple technique for accurate estimation of fertilization rate with specific application to Clarias gariepinus (Burchell, 1822)          下载免费PDF全文

Victor T Okomoda  Ivan Chong Chu Koh  Sherif Md Shahreza 《Aquaculture Research》2018,49(2):1116-1121

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Hydathode morphology and role of guttation in excreting sodium at different concentrations of sodium chloride in eddo     

Md. Babul Hossain  Nobuhiko Matsuyama 《Plant Production Science》2016,19(4):528-539

Mature leaves of field-grown eddo plants were used for observing hydathode morphology by light and scanning electron microscopies. There were approximately five hydathode pores on the adaxial surface of each leaf tip. A ring structure with two borders around the pore was detected in this study. Further observations revealed a large cavity underneath the pores. The cavity was directly connected to vascular bundles that lacked a bundle sheath, via intercellular spaces among loosely organized parenchyma cells. Many crystal cells were present around the cavity and vascular bundles. To evaluate the role of guttation in sodium excretion under salinity stress, eddo plants were grown in hydroponic solutions containing 0, 1, 4, 8, and 12 mM sodium chloride (NaCl) for 7 d. As the NaCl concentration in the hydroponic solution increased, the sodium contents increased in leaf blades, petioles, and roots but remained unchanged in corms. The sodium concentration in the guttation fluid increased; however, the volume of guttation fluid decreased with increasing NaCl concentrations. Therefore, sodium elimination via guttation decreased with increasing NaCl concentrations. The ratios of the sodium content in guttation fluid to that of leaf blades, leaves, and whole plants decreased with increasing NaCl concentrations. The ratios of potassium to sodium contents in leaves, roots, and guttation fluid also decreased as the NaCl concentration increased. These results indicate that guttation did not eliminate sufficient sodium to play a role in adjusting sodium homeostasis and the ratios of potassium to sodium contents in eddo plants under saline conditions.  相似文献   

Salinity stress response in estuarine fishes from the Murray Estuary and Coorong,South Australia     

Md. Afzal Hossain  Shefali Aktar  Jian G. Qin 《Fish physiology and biochemistry》2016,42(6):1571-1580

Estuaries are unstable ecosystems and can be changed by the environmental and anthropogenic impact. The Murray Estuary and Coorong were degraded by drought and low freshwater input in the last decade and therefore transformed into the largest hyper-saline lagoon in Australia. This study evaluates the physiological stress of two estuarine fish species (small-mouthed hardyhead Atherinosoma microstoma and Tamar goby Afurcagobius tamarensis) to the induced salinity change in captivity. The test fishes were collected from the Coorong and transported to the laboratory in the water from the Coorong. Each fish species was exposed to different levels of salinity, and a number of enzymes were assessed to measure the stress response of fish to salinity change. The activity of reactive oxygen species was significantly increased with the salinity change in both fish species compared with the fish in the control. Significant salinity effect on superoxide dismutase activity was observed on Tamar goby but not on small-mouthed hardyhead. Conversely, the impact of salinity on catalase activity was detected on small-mouthed hardyhead but not on Tamar goby. The study reveals that the induction of physical stress by salinity changes occurred in both Tamar goby and small-mouthed hardyhead despite the varying response of antioxidant enzymes between fish species. The study provides an insight into the understanding of physiological adaptation in estuarine fish to salinity change. The results could improve our knowledge on stress response and resilience of estuarine fish to hypo- and hyper-salinity stress.  相似文献