Variability of duration of pre-anthesis phases as a strategy for increasing wheat grain yield     

Guillermo A. García  Román A. SerragoMaría L. Appendino  Lucio A. Lombardo  Leonardo S. VanzettiMarcelo Helguera  Daniel J. Miralles 《Field Crops Research》2011,124(3):408-416

In wheat, stem elongation phase (SEP) duration is critical for grain number (GN) per unit of area determination, as it is the phase in which the spikes grow. Lengthening SEP, for instance by photoperiodic sensitivity, without altering the cycle to anthesis (AT) has been proposed as an alternative way to increase spike dry weight, and in turn GN. As most works supporting this idea have modified only SEP by artificial manipulation (e.g. photoperiod extensions), it is relevant to evaluate this hypothesis in populations segregating for this attribute in natural conditions. The aim of this work was to analyse the variability in SEP duration relative to AT in two F4 populations; in order to select contrasting phenotypes to evaluate the impact of this attribute on grain yield components and to analyse the selection response of this attribute. These segregating populations (Las Rosas INTA × Triguero 230 (A) and Klein Estrella × ProINTA B. Alazán (B)) were derived from parental lines with similar flowering time but different relative duration of their pre-anthesis phases. Two field experiments with previous vernalization treatment in cool chamber were carried out. In 2006, F4 populations were characterized and from one of them (population B, which presented higher variability) four groups were selected, which presented contrasting phenotypes in the attribute under study. Progenies of these groups (F5), together with remnant F4 full-sib of each one, were studied during 2007. Grain yield per plant was higher, due to GN increases, when duration of the SEP was lengthened. However, selection response to longer SEP with similar cycle to AT could not be found, possibly as the result of a high environmental influence on this attribute. The phenotypic variability evidenced in this attribute was not clearly associated with major adaptation genes evaluated (i.e. Ppd and/or Vrn), suggesting that other minor genes could be associated.  相似文献   

Effect of dihydrotestosterone on mouse embryonic stem cells exposed to H2O2-induced oxidative stress     

Mi Na Lee  Sang Hun Lee  Min Young Lee  Yun Hee Kim  Jae Hong Park  Jung Min Ryu  Seung Pil Yun  Yu Jin Lee  Mi Ok Kim  Kwangsung Park  Ho Jae Han 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(3):247-256

Oxidative stresses induced by reactive oxygen species (ROS) have been shown to be involved in several physiological and pathophysiological processes, such as cell proliferation and differentiation. Steroid hormones can protect cells against apoptosis or induce cell proliferation by several mechanisms. Among androgenic hormones, dihydrotestosterone (DHT) is generated by a 5α-reduction of testosterone. Unlike testosterone, DHT cannot be aromatized to estradiol, therefore DHT is considered a pure androgenic steroid. This study was conducted to examine the effect of DHT (10^-7 M) on H₂O₂ (10^-3 M) -induced injuries in mouse embryonic stem (ES) cells. H₂O₂ induced ROS generation and increased lipid peroxide formation and DNA fragmentation. These effects of H₂O₂ were inhibited by pretreatment with DHT. H₂O₂ also increased the phosphorylation of p38 MAPK, SAPK/JNK and nuclear factor kappa B (NF-κB), but DHT blocked these effects. Moreover, H₂O₂ decreased DNA synthesis and the levels of cell cycle regulatory proteins [cyclin D1, cyclin E, cyclin-dependent kinase (CDK) 2, and CDK 4]. These effects of H₂O₂ were inhibited by pretreatment with DHT. In conclusion, DHT may partially prevent H₂O₂-induced cell injury through inhibition of ROS and ROS-induced activation of p38 MAPK, SAPK/JNK and NF-κB in mouse ES cells.  相似文献   

满天星试管玻璃化苗与正常苗的比较研究   总被引：2，自引：0，他引：2  

曹天旭  朴炫春  廉美兰  李美兰 《黑龙江农业科学》2009,(5):86-88

以满天星组培正常苗和玻璃苗为材料,通过生理生化特性、同工酶分析,探讨了满天星试管苗玻璃化发生原因。结果表明：玻璃苗组织含水量较高,为95.8%,而正常苗为91.7%。玻璃苗的各种叶绿素平均含量及可溶性糖和还原糖含量分别为正常苗的14.0%,63.8%和86.9%;而玻璃苗的过氧化物酶（POD）的活性增加,是正常苗的2.6倍。采用聚丙烯酰胺凝胶电泳法对酯酶同工酶进行分析结果表明,玻璃苗的酯酶同工酶电泳谱带出现缺失的异常现象,同时其谱带颜色较浅;过氧化物同工酶电泳结果表明玻璃苗与正常苗相比活性增加且谱带增多。  相似文献   

猪囊尾蚴排泄分泌抗原M13h基因的真核表达质粒的构建及表达分析     

赵光辉  鲁琨  张改平  宁长申  王选年  张龙现  菅复春  宋海涛 《河南农业大学学报》2009,43(2)

根据GenBank中的参考序列设计并合成引物序列,从pMDM13h中扩增带酶切位点和His-tag的基因序列;用HindⅢ和Xho Ⅰ双酶切PCR扩增产物和pcDNA3.0栽体,连接构建真核表达重组质粒Pc3M13h,利用PCR,双酶切和测序鉴定其正确性;重组质粒pe3M13h转染COS-7细胞,瞬时表达的转染细胞(96孔板)在转染36～48 h后,应用双抗体夹心酶联免疫吸附试验和免疫细胞化学,分别检测pc3M13h在COS-7细胞培养上清液和细胞内的表达.结果表明,设计合成的引物成功扩增了带有酶切位点和His-tag的基因序列;成功构建了真核表达重组质粒pe3M13,双抗体夹心酶联免疫吸附试验和免疫细胞化学检测显示,pc3M13h重组质粒不但能够在COS-7细胞中进行表达,而且能够进行微量的分泌表达.  相似文献   

Abomasal bacteria produce an inhibitor of gastrin secretion in vitro     

Simcock DC  Lawton DE  Scott I  Simpson HV 《Research in veterinary science》2006,81(1):152-157

Previously, proliferating microflora transferred with abomasal nematodes, were suspected to be the source of the gastrin inhibitor in some parasite excretory/secretory products. Aerobic cultures in HBSS of abomasal fluid from uninfected sheep became inhibitory during the static growth phase, unless antibiotics were present. Basal gastrin secretion was reduced by up to 90%. Rumen fluid and incubates and medium in which Streptococcus bovis and ovine rumen Actinomycete spp. had been grown also contained the inhibitor. Unlike abomasal cultures, rumen fluid and incubates also reduced the measurement of gastrin standards. Rumen incubates were less potent after exposure to pH 2-3, suggesting that inactivation normally occurs in the unparasitised abomasum. Contaminating bacteria which generate the gastrin inhibitor in parasite ES products are probably rumen organisms which survive in the abomasum and proliferate during subsequent incubation. Significantly, rumen bacteria have been shown to be capable of affecting the secretory activity of the gastric mucosa.  相似文献   

BRL-CM在昆白小鼠胚胎干细胞分离培养中的应用   总被引：1，自引：0，他引：1  

李三华  曹斌云  牟玉莲  张莉  冯书堂 《安徽农业科学》2006,34(13):3025-3026

目的:探讨Buffalo大鼠肝细胞条件培养基(BRL-CM)在昆白小鼠胚胎干细胞(ES)分离培养中的应用。方法:用BRL-CM培养生长在STO(一种小鼠成纤维细胞)饲养层上的昆白小鼠的桑椹胚和囊胚,然后由囊胚内细胞团(ICM)得到ES细胞集落,在有饲养层和无饲养层时用BRL-CM培养分离得到的ES集落。结果:桑椹胚在上述培养条件下能发育成囊胚,然后囊胚在饲养层上长出ICM;用0.1%Trypsin-0.016%EDTA离散ICM,接种到饲养层上培养得到ES集落,ES集落能维持早期传代。结论:在分离培养昆白小鼠的ES细胞时,BRL-CM结合STO饲养层可以用来培养桑椹胚和囊胚,桑椹胚可以发育为囊胚并孵出内细胞团;同时,这种培养条件也能维持昆白小鼠ES细胞的增殖和早期传代。  相似文献   

基于ES的植被景观多样性评价模型研究     

林志垒 《中国农学通报》2006,22(7):543-546

介绍植被景观多样性评价模型的设计思想,然后进行构造其专家系统,该系统采用模块化程序设计技术,分为预处理、综合库、知识库、推理机、知识获取及知识管理和总菜单等6个模块,整个系统在主菜单控制下运行,各模块能独立运行。专家系统程序采用雄风专家系统开发平台VisualXF6.1,GIS由Arc/Info系统支撑。最后以永泰县为应用实例进行研究,创建永泰县植被景观多样性评价专家系统,对全县进行植被景观多样性评价,按景观多样性程度由高到低共评价5个等级,2243.4km2,评价结果与实际情况一致。  相似文献   

甘薯羧甲基淀粉钠性质的研究     

戴小阳  陈信波  罗泽民 《湖南农业大学学报(自然科学版)》1995,(2)

研究了甘薯淀粉与一氯醋酸进行醚化反应生成羧甲基淀粉钠（简称ＣＭＳ）的物理特性和结构特征．实验结果表明：羧甲基淀粉钠的糊化温度比原淀粉低，透明度比原淀粉高；膨胀度、粘度显著增大，冻融稳定性明显增强；在ｐＨ５～９范围内，耐酸耐碱稳定性好．抗剪切能力较弱．醚化反应在颗粒表面和颗粒结构内部都能发生，且对甘薯淀粉的晶体结构有所破坏．  相似文献   

LIF与心肌条件液在小鼠ES细胞分离中的差异比较     

刘俊平  曹鸿国  安志兴  张涌 《勤云标准版测试》2005,(3)

通过比较LIF和大鼠心肌条件液在小鼠ES细胞分离培养过程中的差异,从而选择较为合适的培养液用于小鼠ES细胞的分离培养与深入研究.取怀孕3.5 d小鼠囊胚,培养于小鼠胎儿成纤维细胞饲养层上,然后根据ES细胞培养液的不同分成2组,一组添加LIF的ES细胞培养液,另一组添加由大鼠心肌条件液组成的ES细胞培养液.结果显示,小鼠ICM的孵出率在心肌条件液中为76.30%,LIF条件液中为59.35%,两者差异极显著(p＜0.01);在LIF条件液中比心肌条件液中能较早地分离出ICM,时间差分别为11、11、12、10和12 h,平均为11.2 h;对传代的ES细胞集落,培养48 h时周边出现分化现象的ES细胞集落所占的比例在心肌条件液中为51.55%,LIF条件液中为31.69%,两者差异显著(p＜0.05),第五代小鼠ES细胞核型正常率在心肌细胞条件液中为78.6%,稍高于LIF条件液中的76%,差异不显著.  相似文献   

本地毛形线虫49 ku排泄分泌蛋白基因的克隆及序列分析     

郑宝亮  边传周  王秀荣  宋铭忻 《动物医学进展》2010,31(10)

为了获得本地毛形线虫(Trichinella nativa)49 ku ES蛋白的结构基因,用Trizol提取T.nativa肌幼虫的总RNA,用RT-PCR方法扩增出了编码T.nativa49 ku排泄分泌蛋白的结构基因。将PCR产物与T载体连接并经过大肠埃希菌增殖后送检测序。序列测定表明,目的基因TNPG长度为951bp,核苷酸序列同已发表的T.spiralis相应的序列P49同源性为98.63%,所推导的氨基酸序列同源性为99.05%。为T.nativa49 ku ES蛋白结构基因的进一步研究打下基础。  相似文献