排序方式: 共有42条查询结果,搜索用时 15 毫秒
11.
Abstract: The utility of a species can be divided into its direct, indirect, and options values. In the marine environment, direct consumptive values predominate and often lead to overexploitation at the expense of significant options values derived through bioprospecting for natural products. We surveyed the waters of the Egyptian Red Sea coast (Gulf of Aqaba [north] and the Red Sea [south]) for species of sea cucumbers and analyzed extracts from species for a range of bioactivities with potential biomedical applications. All habitat types were surveyed within these regions. We found 22 species of sea cucumber of which two, Holothuria fuscogilva and Holothuria flavomaculata , were recorded in Egypt for the first time. Although none of the species identified were unique to the Gulf of Aqaba, 10 species were only found in the Red Sea sector. Bioassay results showed that although no species had antibacterial activity, most extracts exhibited activity against Candida and Leishmania but were most active against a LoVo mammalian carcinoma cell line. Our most significant finding was the intraspecific variation in bioactivity in individuals collected from different habitat types and sectors of the coast. This variation may reflect the effect of environment on secondary metabolite production or may indicate significant genetic diversity between populations within a species. Our results indicate a potentially significant options value to sea cucumbers through bioprospecting. Given the importance of economic development in countries such as Egypt and the perceived low conservation value of invertebrates such as sea cucumbers, the linking of these factors to conservation is vital for the maintenance and sustainable exploitation of these animals . 相似文献
12.
13.
水杨酸对铅胁迫下黄瓜幼苗叶片膜脂过氧化的影响 总被引:10,自引:0,他引:10
以黄瓜幼苗为材料,研究了外源水杨酸对铅胁迫下黄瓜幼苗叶片膜脂过氧化的影响。结果表明:水杨酸使铅胁迫的黄瓜幼苗叶片的丙二醛(MDA)含量下降,可溶性蛋白质含量升高,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性降低;在0~1 mmol.L-1范围内的外源SA对铅胁迫的黄瓜幼苗叶片的丙二醛含量下降量和超氧化物歧化酶活性增加量与水杨酸处理浓度呈正相关,与外源水杨酸处理浓度呈正相关,而过氧化物酶活性增加量与外源水杨酸浓度呈负相关。外源水杨酸的作用可能是通过提高黄瓜叶片对膜脂过氧化的抗性来提高黄瓜幼苗对铅毒害的耐受力。 相似文献
14.
拮抗菌对黄瓜枯萎病菌的室内生物活性 总被引:16,自引:0,他引:16
测定了从沤肥浸渍液和土壤中分离并筛选得到对黄瓜枯萎病菌的室内生物活性的6个菌株,编号为94-I、94-Ⅱ、94-Ⅲ、96-Ⅰ和98-Ⅱ,测定其孢子悬浮培养16h时对黄瓜枯萎菌的抑制率分别为48.29%、0.00%、60.69%、39.28%、61.29%和72.32%,孢子和菌丝有的变畸形并产生大泡囊;平皿拮抗试验表明,其活体浓度为50%时对黄瓜枯萎病菌的抑制率最大分别为74.52%、83.27%、90.60%、88.59%、89.35%和94.30%;而其相同浓度高压蒸汽灭活后的代谢产物对黄瓜枯萎病菌的抑制率最大分别为33.215、52.22%、62.84%、46.57%、47.61%和70.34%。 相似文献
15.
16.
17.
采用田间试验,对乙蒜素乳油在长沙、广州、山东、北京四地的黄瓜及土壤中的残留进行了研究,结果表明乙蒜素在黄瓜中的消解速度较快,乙蒜素在黄瓜中半衰期分别为广州3.47d,长沙1.37d,山东2.10d,北京3.18d;乙蒜素在土壤中半衰期分别为广州3.34d,长沙2.46d,山东2.60d,北京2.89d;41%乙蒜素乳油兑水稀释1500倍(乙蒜素浓度为33.75mg·L^-1),使用2次,末次施药7d后,乙蒜素在未检出-0.011mg·kg^-1,在土壤中为未检出。该药属于易降解农药(T1/2〈30d),按推荐剂量使用是安全的。 相似文献
18.
建立了黄瓜和土壤中啶氧菌酯残留量的检测分析方法,对啶氧菌酯在黄瓜和土壤中的消解动态及残留规律进行了研究。啶氧菌酯的最小检出量为3.5×10^-11g;在黄瓜和土壤基质中的最低检出浓度均为0.005mg·kg^-1。对黄瓜和土壤2种基质,设置了0.005、0.05、0.25 mg·kg^-13个添加水平,每个添加水平设置5个重复,啶氧菌酯在黄瓜和土壤中的添加回收率为68.61%-122.4%,变异系数为1.06%-17.2%。田间试验结果表明:啶氧菌酯在天津地区黄瓜和土壤中的残留消解半衰期分别为5.71d和12.9 d,在山东地区黄瓜和土壤中的残留消解半衰期分别为2.70d和10.3 d,在江苏地区黄瓜和土壤中的残留消解半衰期分别为9.76d和14.9 d。距最后一次施药5d时,啶氧菌酯在黄瓜中的最高残留量为0.014mg·kg^-1,远低于欧盟规定的黄瓜中啶氧菌酯最大残留限量0.05mg·kg^-1。 相似文献
19.
应用固化酶检测黄瓜中氨基甲酸酯类农药 总被引:1,自引:0,他引:1
通过向固定液中加入适量明胶构成BSA-GA-gelatin系统,从而对传统交联固化酶法进行了改进,不仅提高了固化乙酰胆碱酯酶的活性而且经固定化的乙酰胆碱酯酶具有较好的稳定性,在常温下保存45d后仍未见酶活性有明显下降.在研究过程中分别对BSA、GA、明胶的最佳浓度进行了考察,最佳使用浓度分别为5%、0.5%、和0.1%.把乙酰胆碱酯酶固定到96孔酶标板上并与酶标仪联用减少了因目视颜色变化带来的误差,提高了检测结果的准确性.针对以往农药残留速测法普遍采用的表面冲洗法进行农药残留提取的方法进行了改进,使提取效率大大提高,对大多数残留农药的提取效率可达到80%以上而且方法快速、简便.该方法用来检测氨基甲酸酯类农药具有简便、快速、准确、灵敏度较高的特点,对黄瓜中5种氨基甲酸酯类农药的检测灵敏度在0.1~0.2 mg/kg范围内. 相似文献
20.
IntroductionDuringthepastseveraldecadesnumerousinvestigationsonproductivity,physiologyandecologyofplantssubjectedtotheincreas?.. 相似文献