南五味子和北五味子藤茎中五味子素类化合物含量的HPLC法测定及差异比较分析

为了测定与比较我国南北地区五味子藤茎中的五味子素的含量和差异,探究五味子藤茎的可开发利用度。以五味子酯甲与五味子乙素含量作为考察五味子素类化合物的指标,采用超声-乙醇法提取五味子素类化合物,高效液相色谱法测定,测定条件：Kromasil-C18(4.6 mm×200 mm, 5 mm)色谱柱,柱温30℃,检测波长220 nm,流动相：甲醇-水(体积比75∶25),进样量5μL,流速0.8 mL/min。结果显示五味子乙素含量在0.026 4～0.132 mg/mL范围内线性关系良好,在南五味子藤茎中约0.028%,在北五味子藤茎中约0.147%,平均回收率为98.73%,RSD为1.33%。五味子酯甲含量在0.032 4～0.162 mg/mL范围内线性关系良好,在南五味子藤茎中约0.237%,在北五味子藤茎中约0.100%,平均回收率为103.64%,RSD为2.60%。表明了南五味子藤茎和北五味子藤茎中均含有丰富的五味子素类化合物,本研究中的两种五味子素类化合物在南北地区五味子藤茎中的分布差异具有统计学意义,五味子藤茎的开发利用具有广阔的前景。     

玉米光合色素含量快速测定

叶片中光合色素的含量是植物光合生理生态研究中的一项重要指标.本文旨在介绍:(1)玉米叶片光合色素含量的快速测定方法;(2)叶片中叶绿素a、叶绿素b和类胡萝卜素含量的计算公式.     

马杜霉素在鸡组织中残留检测方法的研究 Ⅰ酶联免疫吸附测定(ELISA)

本文用混合酸酐法和活化酯法合成４种马杜霉素结合抗原。用其中一种作免疫原,免疫家兔产生抗体;用其余三种作包被原,探讨不同包被原用于ＥＬＩＳＡ检测马杜霉素残留时,对其灵敏度（Ｉ５０）和方法回收率的影响。试验结果表明,马杜霉素结合抗原免疫家兔制备的抗体对马杜霉素具有很高的特异性、亲合性和选择性。在间接竞争ＥＬＩＳＡ中,使用Ｍ－Ｃ６－ＯＶＡ（ＡＥ）、Ｍ－ＯＶＡ（ＭＡ）和Ｍ－ＯＶＡ（ＡＥ）作包被原时,马杜霉素标准工作曲线的Ｉ５０值分别为３２３、９７５和８８０ｎｇ／ｍｌ,这证明Ｍ－Ｃ６－ＯＶＡ（ＡＥ）作包被原能大大提高ＥＬＩＳＡ检测的灵敏度。添加回收率试验测得鸡各组织样本回收率为７７７％～１０４３％,变异系数为３８％～１８０％,检测极限为３０～８０μｇ／ｋｇ。     

mgr-mir-9 implicates Meloidogyne graminicola infection in rice by targeting the effector MgPDI

MicroRNAs (miRNAs), a class of small non-coding RNAs, are crucial endogenous gene regulators in a range of animals, including plant-parasitic nematodes. Meloidogyne graminicola is an obligate sedentary endoparasite of rice and causes significant yield losses. A number of studies focused on the roles of M. graminicola effectors during the parasitic process; however, how nematode miRNAs regulate its effectors needs elucidating. In this research, we analyzed a cluster of M. graminicola miRNAs obtained at the second-stage juveniles (J2s) stage that are closely linked to the regulation of M. graminicola effectors. There are 49 767 105 total clean reads obtained from three libraries. A total of 233 known miRNAs and 21 novel miRNAs were identified. Among the known miRNAs, mgr-lin-4, mgr-mir-1, mgr-mir-100, mgr-mir-86, mgr-mir-279, mgr-mir-87, mgr-mir-71, mgr-mir-9, mgr-mir-50, mgr-mir-72, and mgr-mir-34 are the most abundant 11 miRNAs families. Moreover, the expression levels of selected miRNAs were validated by real-time quantitative PCR. We hypothesized that these miRNAs might regulate the expression of secreted effectors during the J2s stage to facilitate its infection. Consistent with this, we found that mgr-mir-9 targets MgPDI, an important M. graminicola effector mRNA. In addition to that, J2s treated with mgr-mir-9 mimics showed down-regulation of MgPDI expression and reduced reproductive ability, alluding mgr-mir-9 is involved in nematode infection. These results provide novel insight into the regulatory functions of M. graminicola miRNAs during the infection and identify miRNAs and their effector targets as potential key management targets to limit parasite survival during the early stages of infection.