盐碱胁迫对燕麦幼苗Na~+、K~+含量及产量的影响

以燕麦耐盐碱性品种白燕二号和盐碱敏感性品种草莜一号为试验材料,采用中性盐NaCl、Na2SO4及碱性盐Na2CO3、NaHCO3按摩尔比1∶1混合,研究不同盐、碱胁迫对燕麦生物产量及吸收Na+、K+的影响。结果表明,随着盐、碱胁迫浓度的增加,2个品种根、茎、叶中Na+含量增加,K+含量减少,K+/Na+和生物量下降,盐胁迫下K+/Na+及生物量降幅小于碱胁迫,Na+含量增幅小于碱胁迫;且同浓度胁迫下,盐胁迫较碱胁迫叶片中Na+含量较低,K+含量、K+/Na+较高。2个品种间存在差异,盐、碱胁迫下白燕二号中增加的Na+含量小于草莜一号,减少的K+含量、K+/Na+及生物量小于草莜一号,尤其在高盐、碱胁迫下叶片中K+含量及K+/Na+远大于同浓度下的草莜一号;白燕二号比草莜一号根中截留Na+和地上部选择性吸收K+能力强。     

黄土沟壑区旱地仁用杏品种不同花型的数量分布及遗传分析

对黄土沟壑区旱地条件下"龙王帽"、"白玉扁"的不同花型数量分布及遗传力进行了分析,结果表明:"龙王帽"的有效花比例高达91.8,具有较大的丰产潜力,宜作为旱地主栽品种;"白玉扁"有效花比例仅为41.2,雌蕊败育率较高,丰产潜力小,仅宜作为授粉品种;花型主要受遗传因素控制(遗传力高达0.99),环境影响较小.     

高压水蒸气蒸馏法提取和厚朴树枝有效精油成分

为了有效利用和厚朴的树枝,在1.5、1.7、2.1 MPa等不同压力条件下,对和厚朴树枝进行高压水蒸气蒸馏以提取有效成分厚朴酚与和厚朴酚。对蒸馏液和废液进行气相色谱-质谱(GCMS)分析,并以有机溶剂提取出的厚朴酚与和厚朴酚作为全部提取量,计算厚朴酚与和厚朴酚的转移率。结果表明,1.5 MPa高压水蒸气蒸馏的精油收率为4.53%,厚朴酚与和厚朴酚的转移率分别为33.61%和30.59%。2.1 MPa高压水蒸气蒸馏的精油收率最高(9.05%),但是厚朴酚与和厚朴酚的转移率比1.5 MPa条件下的转移率降低。在高温高压条件下,短时间内从和厚朴树枝中得到了高提取率的厚朴酚与和厚朴酚。和厚朴的蒸馏压力越高,各成分的提取率越高,但随着压力的增加,提取成分有可能发生化学变化。     

海带岩藻聚糖及其级分在氧化应激条件下对肉鸡巨噬细胞免疫功能的影响

【目的】在氧化应激条件下,研究海带岩藻聚糖及其级分对肉鸡巨噬细胞免疫功能的影响,初步探讨海带岩藻聚糖及其级分的免疫调节功能与抗氧化作用的关系。【方法】以叔丁基过氧化氢（tBOOH）为活性氧诱导剂,加入肉鸡腹腔巨噬细胞培养液中,测定细胞培养液中抗氧化酶的变化,巨噬细胞分泌一氧化氮（NO）、诱导型一氧化氮合成酶（iNOS）、以及细胞因子IL-1和TFN-α等免疫指标的变化。【结果】用tBOOH处理后的巨噬细胞,细胞存活率显著下降（P＜0.05）,乳酸脱氢酶（LDH）和丙二醛（MDA）显著升高（P＜0.05）,SOD和GSH-Px酶活性显著降低（P＜0.05）。巨噬细胞的吞噬活性显著降低（P＜0.05）,NO、iNOS和呼吸爆发显著降低（P＜0.05）,细胞因子IL-1分泌量显著下降（P＜0.05）,表明细胞出现明显的氧化损伤。在培养液中加入海带岩藻聚糖及其级分,能够缓解细胞的氧化应激,使得细胞存活率上升,LDH和MDA降低,SOD和GSH-Px升高,免疫指标均有不同程度的恢复。【结论】海带岩藻聚糖及其级分具有抗氧化活性,不同级分的抗氧化活性存在差异,其中级分Ⅲ、级分Ⅳ的作用较强。海带岩藻聚糖对巨噬细胞的免疫促进作用与其抗氧化活性有关。     

2株广西鹅源基因XII型新城疫病毒的病原学分析

【目的】深入了解2株广西鹅源基因XII型新城疫病毒(NDV)的病原学特征,为NDV流行分布的系统监测和新城疫(ND)的科学防控提供参考依据。【方法】对2株广西鹅源基因XII型NDV(Goose/China/GX02/2018和Goose/China/GX17/2018)进行病毒噬斑纯化,通过致死鸡胚平均死亡时间(MDT)和脑内接种致病指数(ICPI)试验确定其致病性,分析F蛋白和HN蛋白氨基酸序列与参考毒株的差异位点,并基于F基因全长进行遗传进化分析。【结果】经过DF-1细胞4个代次噬斑纯化可获得2株分离株的纯化株,对应的MDT分别为54和48 h,ICPI均为1.65。2株分离株的基因组长度均为15192 nt,其3’端引导序列为55 nt,5’端尾随序列为114 nt;基于F基因核苷酸序列相似性构建的基因XII型NDV系统发育进化树显示,2株分离株(Goose/China/GX02/2018和Goose/China/GX17/2018)均属于基因XIIb亚型,与我国广东分离株属于同一基因亚型,且我国2010年的分离株、2011年的分离株及2017年后的分离株分别形成3个小分支。2株...     

沙芥愈伤组织培养的初步研究

采用沙芥种子作为无菌外植体来源时,以0.1升汞消毒10～12min的效果较好.下胚轴和子叶均在MS+2,4-D 0.01 mg·L-1+NAA 2 mg·L-1+6-BA 0.5 mg·L-1+3.0蔗糖+0.5琼脂(pH5.8)中可诱导出愈伤组织.愈伤组织的最佳继代培养基为MS+NAA 2mg·L-1+KT0.5 mg·L-1+3.0蔗糖+0.5琼脂(pH5.8).     

The evolution of agriculture in ants

Cultivation of fungi for food by fungus-growing ants (Attini: Formicidae) originated about 50 million years ago. The subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. These patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species farm a diversity of cultivars, and that cultivars are shared occasionally between distantly related ant species, probably by lateral transfer between ant colonies.     

大果沙棘全光照喷雾嫩枝扦插育苗试验

在全光照自动喷雾条件下,对大果沙棘嫩枝插条采用IBA、NAA、ABT-l号、ABT-2号4种植物生长调节剂,各3种浓度梯度的浸泡处理2 h,可明显促进插条生根。在供试的13种处理中,IBA 100 m g.L-1处理效果最好,生根率可达到98.8%。     

Effect of Alkali Stress on Soluble Sugar, Antioxidant Enzymes and Yield of Oat

Alkali stress can cause severe crop damage and reduce production. However, physiological processes involved in alkali stress in oat seedlings are not well understood. In this study, physiological responses and yield of oat to alkali stress were studied using the alkali-tolerant oat genotype Vao-9 and the alkali-sensitive oat genotype Baiyan 5. The results were: (i) low concentrations of alkali stress (25 and 50 mmol L-1) significantly reduced the yield and grain weight while increased the oat grain number per spike. A negative correlation between yield and malondialdehyde (MDA) content at the jointing and grain filling stages and positive correlations between yield on one hand and superoxide dismutase (SOD), and peroxidase (POD) activities on the other at the jointing stage were observed. There was a positive correlation between MDA and soluble sugar at the grain filling stage; (ii) soluble sugar content was increased at the jointing and grain filling stages and decreased at the heading stage by alkali stress; (iii) alkali stress increased the SOD activity during the heading and grain filling stages, and increased the POD activity at the heading stage. As compared to the control, the increase of MDA contents in alkali-treated oat was observed, during the jointing, heading and grain filling stages; (iv) under alkali stress, the oat genotype Vao-9 showed higher antioxidant enzyme activity and lower soluble sugar contents during the heading stage, and lower MDA contents than those in the oat genotype Baiyan 5 under alkali stress. The result suggested that the high ROS scavenging capacity and soluble sugar levels might play roles in oat response to alkali stress.