基于Survey分析的濒危植物四合木基因组研究

评价濒危植物四合木（Tetraenamongolica）基因组的大小及复杂程度，开展基因组研究可揭示四合木的超旱生机制，进一步挖掘其特色基因资源。为更好破解四合木的全基因组信息，采用第二代高通量测序技术的基因组Survey分析技术开展四合木基因组大小估测研究，并利用生物信息学方法估计了四合木杂合率、重复序列和GC含量等基因组信息。结果表明：四合木基因组大小为1 079.25 Mb，修正后的基因组大小为1 065.84 Mb，杂合率为0.76%，重复序列比例为75.25%，GC含量为33.57%。在经过四合木基因组初步组装后，获得3 502 126条contigs，总计682 Mb，其N50为187 bp，推测四合木基因组属于同源四倍体复杂基因组，全基因组测序组装难度较大。由于四合木的高杂合率，后续可采用第三代高通量测序技术（单分子测序）同时结合染色质区域捕获技术，有望最终获得高质量的四合木全基因图谱。

Genomic Survey Analysis of Endangered Plant Tetraena mongolica

To assess the size and complexity of the genome of the endangered plant Tetraenamongolica， and reveal the hyper-arid mechanism of T.mongolica and further explore its characteristic genetic resources， and to better decipher the whole genome information of T.mongolica， the second-generation high-throughput sequencing technology of genome survey analysis was used as the method， and bioinformatics method was used to estimate the genome information such as heterozygosity， repeat sequence and GC content of T.mongolica respectively. The results showed that the genome size of T. mongolica was 1 079.25 Mb， the corrected genome size was 1 065.84 Mb， and the heterozygosity rate was 0.76%， the percentage of repetitive sequences was 75.25%， and the GC content was 33.57% respectively. After the initial assembly of T. mongolica genome 3 502 126 contigs were obtained， totaling 682 Mb， with an N50 of 187 bp. It was hypothesized that T. mongolica genome belonged to a homo-tetraploid complex genome， which was difficult to assemble by whole-genome sequencing. Due to the high heterozygosity of T. mongolica， the third-generation high-throughput sequencing technology（single-molecule sequencing） combined with chromatin region capture technology could be used subsequently， which was expected to finally obtain a high-quality whole-genome map of T. mongolica.