Uptake of Sr from microcline and biotite by ectomycorrhizal fungi in a Norway spruce forest

Ectomycorrhizal (EM) fungi growing in symbiosis with tree seedlings have been found in laboratory experiments to stimulate weathering and the uptake of nutrients from silicate minerals. In the present study, we used the natural abundance of strontium isotopes to confirm that these fungi obtain strontium from biotite and microcline under field conditions. Minerals enriched in radiogenic ⁸⁷Sr were introduced into fungal in-growth mesh bags and placed under a 5-10 cm thick humus layer developed on boulders in a Norway spruce (Picea abies (L.) Karst) forest in south-western Sweden. EM root tips were sampled above the mesh bags and the ⁸⁷Sr/⁸⁶Sr ratio was used to calculate the fraction of Sr in the root tips that originated from the minerals. In the EM root tips sampled above the mesh bags containing the different minerals, 1.5% of the Sr originated from biotite and 6.4% from microcline. The amount of Sr was more than 300 times higher in the mesh bags containing microcline than in those containing biotite, indicating that proportionally more Sr was released from the biotite. This study demonstrates that EM fungi have the potential to take up measurable amounts of nutrients, such as Ca and K, from microcline and biotite in the field.     

烤烟功能性状变化对叶片烟碱含量的影响

为研究烤烟功能性状变化对烟碱含量的影响,以‘云烟87’为研究对象,对2018年在四川省广元烟区不同试验地随机采集的大田种植烤烟进行植物形态学和生物化学特征分析。结果表明,烟株生物量积累特征和不同分配模式对烟碱含量影响显著。其中,总生物量、根生物量、茎生物量、茎重比和比叶重越大,烟碱含量越高;烟碱含量随叶重比增大而降低。回归分析表明,茎生物量和根重比与烟碱含量变化关系密切(R²=0.91,P<0.001),比叶重和第5片叶SPAD值与烟碱含量的回归模型达极显著水平(R²=0.987,P<0.001)。基于生物量分配特征和叶功能性状特征可以较好地表征烟碱含量变化。     

Effects of the aromatase inhibitor Fadrozole on plasma sex steroid secretion and oocyte maturation in female coho salmon (Oncorhynchus kisutch) during vitellogenesis

17-estradiol, 17-20-dihydroxy-4-pregnen-3-one (17-20-P), and testosterone levels were measured in plasma samples obtained from vitellogenic coho salmon (Oncorhynchus kisutch) before and 32 days after injection of the aromatase inhibitor Fadrozole (AI). Plasma 17-estradiol levels decreased significantly 6 h after injection in all AI treated fish. The higher the dose the longer the maintenance of low plasma 17-estradiol levels. Inversely, plasma 17-20-P increased significantly 6 h after injection in all AI treated fish, and the higher the dose the longer the maintenance of high plasma 17-20-P levels. At 48 h after injection plasma testosterone levels were significantly higher in the AI treated groups. The oocyte maturation index showed that multiple injections with AI retarded oocyte development. Besides, oocyte diameter and GSI were lower in the same group, which presented high incidence of atresia of vitellogenic oocytes. The ovarian follicles and brain of the fish which received multiple injections secreted less 17-estradiol, in vitro. These findings suggest that aromatase inhibitors such as Fadrozole may have a potential as a tool to regulate sexual development in salmon.     

日粮中相继添加CS87、F89和CIM对山羊瘤胃代谢的影响

选取 5头装有永久性瘤胃瘘管的去势公山羊 ,以青干花生秧 +精料为基础日粮。实验采取前后自身对照的方法。第一阶段为对照期 ;第二阶段基础日粮内添加 15mg/kg·BW·d的CS87;第三阶段精料内添加 8mg/kg的F89。第四阶段精料内添加 0 .1mg/kg·BW的CIM。与第一阶段相比 ,瘤胃液中TVFA水平在第二、第三、第四阶段分别提高 17.4 7% (P <0 .0 5 )、- 12 .82 %和 3.33% ;A/P分别提高 4 .0 9%、7.73%和 0 .4 5 % ;NH3 -N含量分别提高 13.98%(P <0 .0 5 )、5 .38%和 - 9.6 8% ;AAN含量分别提高 1.2 8%、- 32 .6 9% (P <0 .0 5 )、8.33%。MCP在整个过程中没有显著变化。血液中NH3 -N在第二、第三、第四阶段分别升高 - 19.70 % (P <0 .0 5 )、6 7.4 2 % (P <0 .0 1)、- 9.85 % ;AAN分别提高 0 .4 0 %、37.6 5 % (P <0 .0 1)、8.37% ;SUN分别下降 3.4 4 %、6 .0 5 %、15 .4 8%。阶段性相继饲喂CS87、F89和CIM在一定程度上提高瘤胃发酵和氮代谢 ,促进体内对氮的吸收和利用     

Effects of powdery mildew and weather on winter wheat yield. 1. Variation of weather between years

A vital question to upgrade disease management systems is whether damage functions, established in years with specific weather conditions, can be applied also in other years. A simulation approach was used to explore effects of weather on yield and damage. Two existing models of wheat and a third, a combination of both, were used to compute yield, first in absence of mildew. In a second paper, effects of mildew will be reported. Yields simulated for different years were not significantly correlated with yields harvested, adjusted for their increase over years, in the Netherlands. Differences in performance between the models could be attributed to the method of simulating development and growth early in the cropping season.Samenvatting Om systemen voor geleide bestrijding van ziekten te verbeteren, werd de vraag gesteld of schaderelaties, vastgesteld in jaren met specifieke weersomstandigheden, ook gebruikt kunnen worden in andere jaren. Twee bestaande modellen van tarwe en een combinatie van beide, werden gebruikt om het effect van weer op opbrengst te berekenen, eerst bij afwezigheid van meeldauw. De berekende opbrengsten in verschillende jaren toonden geen samenhang met de behaalde opbrengsten, gecorrigeerd voor een jaarlijkse toename, in Nederland. Verschillen tussen de modellen konden worden toegeschreven aan de wijze waarop de groei en ontwikkeling van tarwe vroeg in het seizoen wordt berekend.     

烤烟新品种云烟85在安徽烟区的主要性状表现

于1999年对皖北烟区5个市(县)种植的烤烟新品种云烟85的产量、质量和抗病性进行了调查,并与当地的当家品种NC89进行了比较.2001年又调查了不同饼肥用量对云烟85的产量和质量的影响.结果显示:云烟85的产量与NC89相当,产值比NC89增加1069.95～4080.00元/hm2,均价和上等烟比例也都高于NC89,均价增幅为0.48～1.20元/kg,上等烟比例增幅为2.0～17.0个百分点,其原烟外观质量、化学成分和评吸鉴定结果均优于NC89;增加饼肥用量能够进一步改善云烟85的烟叶质量.云烟85抗黑胫病能力比NC89强,但对气斑病和烟草脉斑病的抗性较差,在生长前期有畸型株发生.因此,在生产中应增施磷钾肥以减轻气斑病的危害,并适当增加饼肥的用量以提高烟叶质量,同时要加强烟草脉斑病的预防和蚜虫防治工作.     

追肥时间对云烟97生长发育·产量及经济效益的影响

[目的]研究不同追肥时间对云烟97生长发育、产量和质量的影响。[方法]试验设4个处理,分别为不追肥及栽后20、30、40 d追肥。[结果]适当追肥可以提高烟叶产量和质量;栽后20、30 d追肥,烟叶各项农艺性状、植物学性状和经济性状均优于全部使用基肥和栽后40 d追肥处理。[结论]该研究可为确定云烟97合理的追肥时间提供理论依据。     

新疆石河子地区加工番茄里格尔87—5最适播期试验

以加工番茄里格尔87—5为材料,于2007年在石河子地区进行了分期播种试验,研究播期对加工番茄部分农艺性状、主要品质和产量的影响。结果表明,播期对番茄的株高和茎粗有着显著的影响,早播番茄的茎粗最粗,晚播番茄的株高最高,中播番茄株高和茎粗处于两者之间;播期对番茄主要品质成分的含量有很大影响,中播番茄果实中维生素C、可溶性糖、糖酸比最高,早播次之、晚播最低,随着播期的推迟,番茄中有机酸含量逐渐升高,播期对番茄果实中硝酸盐含量无明显影响;影响不同播期番茄产量的主要因子是单株果数,其次是单果重,番茄产量随播种期的延后呈先增后减的趋势。因此,里格尔87—5在新疆石河子地区最适播期为4月下旬。     

不同有机肥对烤烟云烟87生长发育及土壤肥力的影响

为探讨豫南烟区有机肥合理施用技术,利用田间试验研究了不同有机肥对烤烟云烟87生长发育及土壤肥力的影响。结果表明,移栽后30 d,与对照(只施用化肥)相比,施用有机肥+化肥处理烟株的株高、茎围、叶片数和叶面积均有一定提高;移栽后60 d,以芝麻饼肥+化肥处理各项农艺性状指标最好。与对照相比,施用有机肥处理产量和产值均显著增加,各施用有机肥+化肥处理间相比,以芝麻饼肥+化肥处理经济性状最佳,产量、产值、均价和上等烟比例分别为2 682 kg/hm2、69 677元/hm2、25.98元/kg和54.34%。施用有机肥+化肥处理烟叶的净光合速率、气孔导度和蒸腾速率均较对照显著提高。施用有机肥+化肥处理土壤中有机质含量在整个生育期均高于对照;不同有机肥+化肥处理间相比,以芝麻饼肥+化肥处理土壤碱解氮含量在移栽后45 d后较高,60 d之后下降较快;另外,芝麻饼肥+化肥处理的土壤有效磷和速效钾含量在整个生育期均较高。综合分析,对于豫南烟区主栽品种云烟87来讲,施用的有机肥以芝麻饼肥最佳。     

鸭疫里默氏杆菌AS87-01740基因生物信息学分析及其原核表达

[目的]了解鸭疫里默氏杆菌AS87-01740基因分子生物学特性,确定其编码蛋白抗原性,为鸭疫里默氏杆菌亚单位疫苗研发提供新的靶标抗原选择.[方法]采用PCR克隆鸭疫里默氏杆菌AS87-01740基因,以DNASTAR和NCBI数据库分别进行基因生物信息学分析;利用pCold-TF原核表达载体在大肠杆菌BL21感受态细胞中进行诱导表达,并分别以SDS-PAGE和Western blotting检测融合蛋白的表达形式及其抗原特异性.[结果]从鸭疫里默氏杆菌基因组扩增获得的AS87-01740基因编码框全长618 bp,编码205个氨基酸,理论分子量约21.87 kD,理论等电点(pI)8.2,正电荷氨基酸总数17个,负电荷氨基酸总数16个.AS87-01740蛋白序列在同种属分离株中,与2型血清型分离株(11845、YM、GD和CH-2)有很高的相似性(>99%),与1型血清型分离株(CH-1和CH-3)的相似性为92%;在不同种属中,与金黄杆菌(Chryseobacterium sp.)、动物溃疡伯格菌(Bergeyella zoohelcum)和脑膜炎败血伊丽莎白菌(Elizabeth-kingia meningosepticum)的相似性分别为61%、60%和57%.经异丙基硫代-β-D半乳糖苷(IPTG)诱导表达获得的融合蛋白分子量约77 kD,以可溶性表达形式为主.Western blotting检测结果表明,融合蛋白能与鸭疫里默氏杆菌阳性血清发生特异性免疫反应.[结论]AS87-01740基因编码蛋白在不同鸭疫里默氏杆菌分离株中具有很高的保守性,且能与其阳性血清发生特异性免疫反应,是研发鸭疫里默氏杆菌疫苗的潜在抗原.