应用流式细胞术测定药用植物黄芩基因组大小

为了探讨和优化应用流式细胞术(FCM)测定药用植物的基因组大小（或称C值）的方法，本文分别以新鲜、幼嫩和硅胶干燥的叶片为材料，采用Otto和LB01两种细胞核提取液，利用流式细胞术对黄芩C值进行测定。结果表明，选用豌豆为内标植物时，相比LB01一步法，Otto两步法在低温提取、离心和保存条件下，碘化丙啶染色浓度为0.02 mg/mL，得到的细胞核散点图相对集中，碎片较少，容易准确取门，CV较小。不同提取材料表明，幼嫩叶片和新鲜叶片利用Otto二步法均能到高质量的细胞核悬液，细胞核数量多且散点图集中，有利于取门和测定的C值更准确。而干燥叶片提取的细胞核得到的散点图分散，无法准确取门和测定C值。最终，以黄芩为例系统地优化了利用流式细胞术测定药用植物基因组大小的方法，并首次成功测定黄芩1C值为0.58 pg，基因组大小约为562 Mbp，从而为了解物种的遗传背景和基因组值在系统演化中的变化规律，以及黄芩属药用植物资源的遗传评价和保护利用等方面的研究提供理论基础。

Estimating genome size of medicinal plant Scutellaria baicalensis Georgi by flow cytometry

To discuss and optimize the methods of estimating nuclear DNA content of medicinal plants by flow cytometry （FCM）, fresh leaves, younger leaves and dry leaves by silica were taken as samples and Otto＇ s buffer and LB01 buffer were used to estimate the C-value of Scutellaria baicalensis Georgi by FCM. The results showed that better results were easily and accurately gotten with relatively concentrated scatterplot, less debris, more simplicity to take gates and lower CVwhen using Otto＇s buffer with two-steps method to extract, prepare and store under low temperature with the concentration of propidium iodide （PI） at 0.02 mg/mL, compared to that by using LB01 buffer. The results of different materials demonstrated that both fresh leaves and younger leaves could get better quality suspension of nuclei by Otto＇ s and generated a larger amount of nuclei and more concentrated particles in scatterplots, which would help take gates and estimate C-value more accurately. On the contrary, younger leaves would lead to a large number of centralized nuclei, which was unable to take gates and estimate C-value accurately. At last, the method of estimating nuclear DNA content of the medicinal plant S. baicalensis was systematically optimized, and the C-value of S. baicalensis was first estimated successfullyas 1 C=0.58 pg, and the genome size was 562 Mbp by FCM. These results will provide references for recognizing the genome size of S. baicalensis and the estimation of other medicinal plants by FCM, and thus lay foundation for the genetic evaluation and conservation of medicinal plants of Seutellaga.