The morphological characteristics of diatoms are useful for studying their taxonomy. However, the distinction between closely related diatom taxa can be very difficult, especially when the morphological characters are modified by environmental constraints. In the present study, 13 fresh water diatoms were identified morphologically and cultured under axenic conditions. To check this, PCR primers specific for multilocus genes were designed to amplify and screen 13 fresh water diatom monocultures. Multilocus PCR primers (DRR3, scfcpA, Lhcf11, SIT1, SIT3, SIT4, LOC101218388, COI-5P, rbcL, rbcL-3P, LSU D2/D3, UPA, psaA, and 18S rRNA) were tested. It was found that psaA gene, a plant pigment chlorophyll-based PCR marker, amplified in all the diatoms. Out of 13 diatom amplicons, only two fresh water diatoms DNA were sequenced. This included Cyclotella meneghiniana and Sellaphora pupula. The Sanger sequencing results thus established that morphologically identified diatom, Sellaphora pupula, exhibited close phylogeny to Sellaphora whereas fresh water Cyclotella meneghiniana has close lineage to marine diatom Thallosiosira.

中文翻译：

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光系统 I P700 叶绿素 a 载脂蛋白 A1 作为 PCR 标记物来识别硅藻及其相关谱系

硅藻的形态特征有助于研究它们的分类。然而，密切相关的硅藻类群之间的区分可能非常困难，尤其是当形态特征因环境限制而改变时。在本研究中，对 13 种淡水硅藻进行形态学鉴定并在无菌条件下进行培养。为了检查这一点，设计了多位点基因特异性的 PCR 引物来扩增和筛选 13 种淡水硅藻单一培养物。多位点 PCR 引物（DRR3、scfcpA、Lhcf11、SIT1、SIT3、SIT4、LOC101218388、COI - 5P、rbcL、rbcL- 测试了3P、LSU D2 / D3、UPA、psaA和18S rRNA )。发现psaA基因（一种基于植物色素叶绿素的 PCR 标记物）在所有硅藻中扩增。在 13 个硅藻扩增子中，只有两个淡水硅藻 DNA 被测序。这包括Cyclotella meneghiniana和Sellaphora pupula。因此，Sanger 测序结果确定，形态学上鉴定的硅藻Sellaphora pupula与Sellaphora表现出接近的系统发育，而淡水Cyclotella meneghiniana与海洋硅藻具有密切的谱系海藻。