遮阴对10种野生观赏植物生长及生理特性的影响

为了探讨野生观赏植物在遮阴条件下的生态适应性及寻求适度的遮阴比例,选取兰州地区10种野生观赏植物为试验材料,比较测定不同光强生境(全光照、25%、50%、70%遮光率)对10种野生观赏植物生长和生理生化的影响。结果表明,角茴香(Hypecoum erectum)和驴蹄草(Caltha palustris)含水率随着遮阴度的增加而增加,小花草玉梅(Anemone rivularis)在75%遮阴度时干重最大,显著高于其余遮阴处理及全光照(CK)(P0.05);藤本铁线莲(Clematis florida)可溶性糖含量随着遮阴度的增加而减少,鹅绒委陵菜(Potentilla anserina)、角茴香、水杨梅(Geum aleppicum)和驴蹄草的叶绿素含量随着遮阴度的增加而增加;东方草莓(Fragaria orientalis)、角茴香和驴蹄草在全光照下丙二醛的含量显著高于其它处理(P0.05),香青(Anaphalis sinica)和水杨梅在75%遮阴度下丙二醛含量较高。综上所述,香青、莓叶委陵菜(Potentilla chinensis)、藤本铁线莲和野棉花(A.vitifolia)比较适合全光照生长;鹅绒委陵菜、小花草玉梅、东方草莓、角茴香和水杨梅可以忍耐适当的遮阴环境;驴蹄草适合在遮阴条件下生长。     

茶多酚对高酒糟日粮肉鸡生产性能和抗氧化特性的影响

本研究旨在评估添加茶多酚对高酒糟(distillers dried grain with solubles DDGS)日粮肉鸡生产性能和抗氧化特性的影响。将400只21日龄肉鸡随机分为5个处理,每个处理4个重复,每个重复20只。正对照组为玉米-豆粕型日粮,负对照组为玉米-豆粕-DDGS型日粮(15%DDGS),处理组分别在负对照日粮中添加100、300、500 mg/kg茶多酚。结果表明,与正对照组相比,后期日粮中添加15%DDGS对肉鸡生产性能无显著影响(P>0.05),但血液的GSH-Px降低8.31%(P<0.01),胸腿肉T-AOC含量降低,腿肉MDA值显著升高(P<0.05)。添加茶多酚提高了血液的T-AOC和GSH-Px活性(P<0.05)。随着茶多酚添加剂量的升高,T-AOC和GSH-Px有升高的趋势,但各水平组之间差异不显著;茶多酚添加300 mg/kg以上能显著降低胸腿肌MDA值(P<0.05),提高T-AOC含量,改善肉质的抗氧化特性。本研究结果表明,在肉鸡高DDGS日粮中添加茶多酚可以改善肉鸡机体及肉质的抗氧化特性。     

3种盐胁迫对蓟幼苗生长及生理生化的影响

采用盆栽试验研究不同浓度(0.1%、0.2%、0.3%、0.4%、0.5%、0.6%)的NaCl、Na_2SO_4、Na_2CO_3对蓟(Cirsium japonicum)幼苗苗高、叶片相对含水量、丙二醛(MDA)、抗氧化酶(POD、SOD、CAT)以及渗透调节物质(可溶性糖、游离脯氨酸)的影响。结果表明,除0.1%NaCl处理蓟苗高和叶片相对含水量高于无盐胁迫(CK)外,其余处理均低于CK,且随盐浓度增加而降低,其中,0.3%NaCl、0.4%Na_2SO_4和0.1%Na_2CO_3处理下苗高依次为CK的62.15%、58.00%和45.77%,而0.5%Na_2CO_3处理幼苗死亡;随盐处理浓度增加和处理时间延长,叶片中丙二醛含量均呈上升趋势;POD、SOD、CAT活性随盐浓度、时间变化的趋势不尽一致,3种酶活性均出现了阈值,POD出现在0.3%NaCl、0.3%Na_2SO_4、0.4%Na_2CO_3胁迫5d,SOD出现在0.3%NaCl处理3d、0.5%Na_2SO_4处理1d、0.4%Na_2CO_3处理3d,CAT出现在0.3%NaCl、0.2%Na_2SO_4、0.1%Na_2CO_3胁迫3d;相同处理时间下,随盐浓度的增加,除NaCl胁迫下游离脯氨酸(Pro)含量先增后减外,Na_2SO_4和Na_2CO_3胁迫下游离脯氨酸含量,以及3种盐胁迫下可溶性糖(SS)含量均逐渐增加。综上认为,蓟对NaCl、Na_2SO_4、Na2CO4这3种盐均具有一定的耐性,可以在低于0.3%NaCl、0.4%Na_2SO_4和0.1%Na_2CO_3条件下生存和生长。     

外源NO对盐胁迫下沙打旺种子萌发和幼苗生长的影响

本研究以沙打旺(Astragalus adsurgens)种子为材料,硝普钠(sodium nitroprusside,SNP)为外源NO供体,测定不同浓度(30、60、90、120、150、200、300μmol·L~(-1))SNP处理盐胁迫(0.3%)下沙打旺的种子萌发和幼苗生长,以此探讨NaCl胁迫下外源NO在沙打旺种子萌发和幼苗生长过程中的生理调节功能。结果表明,沙打旺种子和幼苗经SNP处理后,除300μmol·L~(-1) SNP处理对盐胁迫下沙打旺种子萌发和幼苗生长起到一定的抑制作用外,其余SNP处理组均能不同程度地减缓盐胁迫造成的损伤;60μmol·L~(-1)SNP能显著降低盐胁迫对沙打旺种子造成的伤害(P0.05),该处理下沙打旺种子的发芽势、发芽率、发芽指数、活力指数、胚根长较单盐对照分别提高了54.5%、22.6%、58.2%、112.0%、43.7%,并且接近或略高于空白对照;120μmol·L~(-1)SNP明显减轻了盐对沙打旺幼苗的胁迫(P0.05),沙打旺幼苗叶片叶绿素含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性分别较单盐对照提高了208.91%、117.565%、40.24%和89.95%,丙二醛含量降低了32.55%。综上所述,适宜浓度的外源NO能够提高盐胁迫下沙打旺种子的萌发,促进幼苗叶绿素的合成,降低丙二醛含量,减少膜脂过氧化产物,保护叶绿体膜的完整性,提高SOD、CAT和POD活性,抑制过氧化物和自由基的积累,加快幼苗生长,从而缓解盐胁迫对沙打旺幼苗的伤害。     

Cytotoxic, cytoprotective and antioxidant effects of isolated phenolic compounds from fresh ginger

Twenty-nine phenolic compounds were isolated from the root bark of fresh (Yunnan) ginger and their structures fully characterized. Selected compounds were divided into structural categories and twelve compounds subjected to in-vitro assays including DPPH radical scavenging, xanthine-oxidase inhibition, monoamine oxidase inhibition, rat-brain homogenate lipid peroxidation, and rat pheochromocytoma PC12 cell and primary liver cell viability to determine their antioxidant and cytoprotective properties. Isolated compounds were also tested against nine human tumor cell lines to characterize anticancer potency. Several diarylheptanoids and epoxidic diarylheptanoids were effective DPPH radical scavengers and moderately effective at inhibiting xanthine oxidase. An enone–dione analog of 6-shogaol (compound 2) was isolated and identified to be most effective at protecting PC12 cells from H₂O₂-induced damage. Almost all tested compounds inhibited lipid peroxidation. Three compounds, 6-shogaol, 10-gingerol and an enone-diarylheptanoid analog of curcumin (compound 6) were identified to be cytotoxic in cell lines tested, with KB and HL60 cells most susceptible to 6-shogaol and the curcumin analog with IC₅₀ < 10 μM. QSAR analysis revealed cytotoxicity was related to compound lipophilicity and chemical reactivity. In conclusion, we observed distinct compounds in fresh ginger to have biological activities relevant in diseases associated with reactive oxygen species.     

Oxidative stress indicators as selection tools for salt tolerance

Oxidative stress indicators, malondialdehyde (MDA) accumulation and chlorophyll retention, were tested as tools for salt‐tolerance screening in Chloris gayana (Kunth), a forage grass exhibiting inter‐ and intra‐cultivar variability in the response to salt stress. Three types of experimental system were compared, salt shock, gradual salt treatment and leaf segments floated on control and saline solutions. Results followed the same trend in the three systems, but leaf segments or gradually salinized plants are the most convenient. Lower mean MDA and higher mean chlorophyll content were found under salinity in cv. ‘Katambora’, which is considered, from previous field trials, to be more salt tolerant than cv. ‘Boma’. Nevertheless, chlorophyll content did not give consistent results in other tests and it is not recommended for selection purposes. Within cv. ‘Boma’, clones rating higher in a salt tolerance evaluation under greenhouse conditions had lower MDA content under salinity and lower mean MDA ratios between salt‐treated and control samples. The survival of 80‘Boma’ plants under increasing NaCl concentration was assessed and MDA was measured in the leaves of very plant before the final NaCl level was reached, to assess whether it was predictive of survival capability. MDA values were significantly lower in the group surviving longer, thus, a selection based on low MDA values would have enriched the original population with more tolerant individuals.     

麦后移栽棉生育及生理特性对水分亏缺的响应

在防雨棚测坑试验条件下,研究了不同生育阶段水分亏缺对麦后移栽棉生长发育及生理特性的影响。结果表明,蕾期水分亏缺抑制了植株的正常生长发育,棉花株高、茎粗和叶面积指数等生长发育指标均随水分亏缺程度的增大而减小,而花铃期水分亏缺对其影响较小;在植株快速生长阶段,蕾铃数和叶面积指数呈现良好的对数正相关关系,决定系数达到0.90以上;不论蕾期还是花铃期,与对照处理相比,水分亏缺均显著提高了叶片可溶性糖和丙二醛(MDA)的质量分数,且随水分亏缺程度的增大而增大,进而限制了蕾铃的正常生长发育,复水后可溶性糖与MDA均降低至与对照无明显差异的程度。     

Relationships between ultimate pH and antioxidant enzyme activities and gene expression in pork loins

Ultimate pH (pH_u) is a major determinant factor of meat quality. In this study, we investigated the effects of pH_u on the muscle antioxidant capacity, and the relationship between pH_u and muscle antioxidant capacity of pigs. A total of 137 pigs from three pig breeds with the same feeding condition were slaughtered and used to measure the pH_u, superoxide dismutase (SOD), glutathione peroxidase (GSH‐PX), total antioxidant capacity (T‐AOC), and malondialdehyde (MDA) content, and gene expression of SOD1 and GPX4. Loins from 137 pigs of three breeds were classified based on pH_u into three groups: low (L‐pH: ≤5.50), intermediate (I‐pH: 5.51‐5.90), and high (H‐pH: ≥5.91). A majority of loins (47.5%–52%) were classified into the intermediate group. The results suggested that the pH_u value was correlated with the activity of SOD, GSH‐PX, T‐AOC, and MDA, and gene expression of SOD1 and GPX4 in all pigs. In addition, our results also indicated a linear relationship between the pH_u value and antioxidant traits. The pH_u value accounted for 23%–40% of the variation in the antioxidant traits. These results suggested that increased pH_u reduce the lipid peroxidation, and also indicated that pHu may be a key factor explaining the variation in the activity of antioxidant enzymes and gene expression in pork loins.     

木霉不同施用方式对黄瓜膜脂过氧化作用、保护性酶活性及枯萎病防效的影响

采用3株对黄瓜枯萎病菌有较好拮抗作用的木霉,棘孢木霉Trichoderma asperellum 525、哈茨木霉T.harzianum 610和拟康氏木霉T.pseudokoningii 886,研究木霉不同施用方式对黄瓜幼苗叶片膜脂过氧化作用、保护性酶活性及防治枯萎病效果的影响。结果显示,所有木霉处理均能够提高黄瓜幼苗的株高和茎粗,增加幼苗地上部和地下部鲜重,对黄瓜枯萎病的防效均达到64%以上。播种后8~14 d,各处理的黄瓜幼苗叶片质膜透性和丙二醛(MDA)含量不同程度下降,保护性酶活性不同程度的提高,其中以先接种拟康氏木霉886,2 d后接种病原菌的T886-F处理的提高程度最显著。播种后14 d,该处理的叶片质膜透性和MDA含量比只接种病原菌的F处理分别下降了37.02%和14.80%,同时,叶片的SOD、POD、CAT、PPO活性分别比F增加了46.82%、34.93%、18.75%和11.63%。以上结果说明,本研究的3株木霉均能通过改善黄瓜幼苗叶片膜脂过氧化能力,增加保护酶活性,促进幼苗生长,防治黄瓜枯萎病。在实际应用中,提前施入木霉菌剂,有利于促进黄瓜的生长、提高幼苗抗病性、提高病害防治效果。本研究结果为木霉菌剂的高效使用、保障黄瓜安全生产提供指导。     

Oxidant related biochemical traits are significant indices in triticale grain yield under drought stress condition

Two separate experiments, one as drought stress conditions and the other one as the normal irrigation conditions based on randomized complete block design with three replications were implemented to examine 20 triticale (Triticoseclae wittamack X) genotypes of which 19 genotypes have recently been generated by crossing different parent lines and the other one was Javaniloo, a common cultivar. Based on the results of different statistical techniques and comparing relationships among traits for normal irrigation and stress condition, enzymatic antioxidant could be used as criteria for screening tolerant genotypes of triticale. On the other hand, it is pointed out that superoxide dismutase are the most important criteria to achieve higher tolerant genotypes through indirect selection. Furthermore, hydrogen peroxide and malondialdehyde content having high relationship with rain yield are also the different possible criteria for screening triticale genotypes for water stress conditions in which genotypes with lower content of these traits could be screened.