Ca2 +对小麦种根及其根毛生长发育的影响

低浓度的CaCl2对小麦种根生长、根毛发生和生长无明显影响,高浓度的CaCl2(0.1 mol/L)对种根和根毛生长有抑制作用,但不影响根毛的发生。Ca2+专一性整合剂EGTA抑制种根生长和根毛的发生及生长,添加一定浓度的外源CaCl2,这种抑制作用可被消除。CaM抑制剂TFP(三氟拉嗪)和CPZ(氯丙嗪)对种根生长、根毛发生和生长均有抑制作用,添加外源CaM可减弱或消除这种抑制作用。     

宁虫素对蔬菜、水稻害虫的毒力及药效特性研究

本研究了复方生物农药宁虫素对蔬菜、水稻害虫的毒力及药效特性,结果表明,该药集速效性、特效性于一体,对蚜虫、褐飞虱的毒力分别为：0.63ppm和2.00ppm。田间试验表明,宁虫素可有效地控制蔬菜蚜虫、小菜蛾、菜青虫、稻飞虱等的危害,防效显。田间使用宁虫素后,平均蛛虱比明显优于噻嗪酮和吡虫啉,生态安全性好。     

肝X受体α在泡沫细胞胆固醇流出中的调控作用

以THP-1巨噬细胞源性泡沫细胞为研究对象,观察肝X受体α(LXRα)在THP-1巨噬细胞源性泡沫细胞胆固醇流出中的调控作用.结果发现,22(R)-羟基胆固醇剂量依赖性增加THP-1巨噬细胞源性泡沫细胞胆固醇流出, 而DIDS剂量依赖性减少THP-1巨噬细胞源性泡沫细胞胆固醇流出.逆转录聚合酶链反应显示, 22(R)-羟基胆固醇可增加THP-1巨噬细胞源性泡沫细胞LXRα mRNA的表达, DIDS可抑制THP-1巨噬细胞源性泡沫细胞LXRα mRNA的表达.结果提示,LXRα在巨噬细胞源性泡沫细胞胆固醇流出中起着重要的调控作用,这为开发和寻找抗动脉粥样硬化药物提供了新的思路.     

Secondary galling: a novel feeding strategy among ‘non‐pollinating’ fig wasps from Ficus curtipes

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Abundances and host relationships of chigger mites in Yunnan Province,China

This paper reports on ectoparasitic chigger mites found on small mammals in Yunnan Province, southwest China. Data were accumulated from 19 investigation sites (counties) between 2001 and 2009. A total of 10 222 small mammal hosts were captured and identified; these represented 62 species, 34 genera and 11 families in five orders. From the body surfaces of these 10 222 hosts, a total of 92 990 chigger mites were collected and identified microscopically. These represented 224 species, 22 genera and three subfamilies in the family Trombiculidae (Trombidiformes). Small mammals were commonly found to be infested by chigger mites and most host species harboured several species of mite. The species diversity of chigger mites in Yunnan was much higher than diversities reported previously in other provinces of China and in other countries. A single species of rodent, Eothenomys miletus (Rodentia: Cricetidae), carried 111 species of chigger mite, thus demonstrating the highest species diversity and heaviest mite infestation of all recorded hosts. This diversity is exceptional compared with that of other ectoparasites. Of the total 224 mite species, 21 species accounted for 82.2% of all mites counted. Two species acting as major vectors for scrub typhus (tsutsugamushi disease), Leptotrombidium scutellare and Leptotrombidium deliense, were identified as the dominant mite species in this sample. In addition to these two major vectors, 12 potential or suspected vector species were found. Most species of chigger mite had a wide range of hosts and low host specificity. For example, L. scutellare parasitized 30 species of host. The low host specificity of chigger mites may increase their probability of encountering humans, as well as their transmission of scrub typhus among different hosts. Hierarchical clustering analysis showed that similarities between different chigger mite communities on the 18 main species of small mammal host did not accord with the taxonomic affinity of the hosts. This suggests that the distribution of chigger mites may be strongly influenced by the environment in which hosts live.     

Combined effect of cyprid age and lipid content on larval attachment and metamorphosis of Balanus amphitrite darwin

Various algal diets of different lipid content and composition were used to rear batches of naupliar larvae of Balanus amphitrite. The cyprids in these larval batches differed in lipid content and were used to investigate the combined effect of cyprid lipid content and cyprid age on attachment and metamorphosis. For this purpose, cyprids were aged for 0,3 and 6 d at 8°C prior to utilization in laboratory attachment assays. The percentage attachment of cyprids with similar lipid content differed significantly among the three age categories. A strong and a weak positive relationship between cyprid lipid content and attachment were monitored in young and old cyprids, respectively. A significant interaction (two‐way ANOVA) between cyprid age and lipid content was observed, indicating that these factors jointly affect larval attachment and metamorphosis in B. amphitrite from the beginning of the cyprid stage.     

国槐叶黄酮的抗氧化活性研究

本文采用ABTS清除体系、DPPH清除体系、H2O2/Fe2+/水杨酸检测体系、亚硝基清除体系、普鲁士蓝法、邻苯三酚自氧化法研究了国槐叶黄酮的抗氧化活性,并同芦丁、Vc进行了比较。结果表明,国槐叶黄酮对几种自由基均有不同的清除效果,在质量浓度为50μg/mL时,国槐叶黄酮对羟基自由基(·OH)、ABTS、DPPH、亚硝基自由基(NO2-)和超氧阴离子自由基(O2-·)的清除率为分别62.09%、47.70%、43.28%、22.11%、21.83%;与芦丁、Vc相比较,国槐叶黄酮清除ABTS、DPPH自由基的能力低于芦丁和Vc,而清除NO2-、.OH的能力高于芦丁和Vc,对O2-·的清除能力低于Vc而高于芦丁,其次国槐叶黄酮具有很好的还原力。由此说明,国槐叶提取物可以作为天然抗氧化剂,可以应用在医药食品领域。     

禽畜养殖粪便中多重抗生素抗性细菌研究

通过对新乡地区8家养猪场和11家养鸡场饲喂抗生素情况的调研,发现头孢氨苄、阿莫西林、卡那霉素、庆大霉素等4种抗生素是该地区被普遍使用的兽药抗生素。通过多点取样法和微生物培养技术对3家养鸡场和3家养猪场不同养殖时期的粪便进行单一抗生素和多重抗生素抗性细菌的检测,结果表明养鸡场堆置1周的粪便中抗头孢氨苄的细菌比例最高,达到65.90%,对所研究的3种和4种抗生素同时抗性的比例高达8.60%—12.51%和9.73%,明显高于饲喂中药的对照养鸡场样本检测结果(0.02%—2.73%和0.12%)。养猪场堆置1周的粪便中检测到抗头孢氨苄的细菌比例也是最高,达到49.12%上,但养猪场粪便中多重抗生素抗性细菌的比例明显低于养鸡场。同时研究发现,在两种养殖场中,幼龄期粪便中检测到的多重抗性细菌比例明显高于成熟期粪便,这可能与养殖过程中鸡、猪在幼龄期由于防病和促生长等因素而同时大剂量使用多种抗生素有关。     

石羊河流域武威绿洲春玉米水氮耦合效应

为探讨西北旱区春玉米最佳的水氮耦合模式,在甘肃石羊河流域武威绿洲边缘进行田间正交试验,研究不同生育阶段水量分配及施氮量对春玉米群体产量和水氮利用的影响.结果表明：石羊河流域武威绿洲春玉米籽粒产量随施氮量的增加而增加;施氮量为300 kg·hm^-2、拔节期灌水136 mm时的籽粒产量最大.籽粒灌溉水利用效率随灌水量的增加而降低;全生育期灌水340 mm时增施氮肥可使籽粒产量和籽粒灌溉水利用效率同时提高;施氮量为300 kg·hm^-2、苗期和灌浆期分别灌水34 mm时籽粒灌溉水利用效率最大.各因素对玉米植株全氮累积总量的影响由大到小依次为：施氮量、拔节期灌水、苗期灌水、灌浆期灌水和抽穗期灌水.石羊河流域武威绿洲春玉米水氮耦合最佳模式为：施氮量300 kg·hm^-2,苗期、拔节期、抽穗期和灌浆期分别灌水34、136、68和102 mm.     

螺旋藻在光胁迫时的抗逆性研究

螺旋藻对于环境的变化有很强的适应性.以钝顶螺旋藻为实验材料,测定螺旋藻在受到较强光照胁迫时藻体的电导率以及脯氨酸、丙二醛和过氧化氢酶系的含量.在3000 lx光照下,螺旋藻6个藻株的电导率以及脯氨酸、丙二醛和过氧化氢酶系的含量比在1000 lx光照下明显升高,螺旋藻的电导率最高上升了2～6倍;细胞内的脯氨酸含量最多增加5倍,最少增加13%;丙二醛的含量增加40%～100%;过氧化氢酶的含量上升范围在19%～80%,过氧化物酶的含量上升范围在20%～100%.说明螺旋藻在受到光胁迫时自身会启动相关保护机制,产生一定的抗逆性,以适应环境的变化.