保存方法和保存时间对竹子核DNA含量 （2C-值） 检测的影响

竹子核DNA含量（2C 值）的检测对竹资源的科学研究具有重要意义，而大部分野外采集的样本，通过不同方法保存后，均使用流式细胞仪技术进行核DNA含量检测。本文选取麻竹（Dendrocalamus latiflorus）、筇竹（Chimonobambusa tumidissinoda）和毛花酸竹（Acidosasa purpurea）三种竹子样本，使用硅胶保存法和Sample protector试剂保存法分别保存4d、8d、12d、16d后，采用流式细胞术检测样品2C 值。CV值可以用来反映数据检测结果质量，是对检测结果准确性以及精确性的评价标准，我们通过样品CV值的大小和2C 值的变异率来评价保存方法和保存时间对竹子2C 值检测的影响。方差分析显示，保存时间对CV值具有显著性影响（P < 0001），随着保存时间增大，CV值增大；保存方法对2C 值变异率有显著性影响(P < 0001)。硅胶保存法保存后的样品，测量值比新鲜材料大；Sample protector试剂保存法保存后，测量值比新鲜材料小。因此，随着保存时间的增加，样品CV值增大，引起检测结果质量降低。研究发现，硅胶保存法和Sample protector试剂保存法会影响竹子样本2C 值大小，但2C 值大小的变化小于10%。

The Effects of Preservation Methods and Storage Time on Estimating the Nuclear DNA Content(2C-value) of Bamboos

Measurement of nuclear DNA content of bamboos (2C value) is important for scientific research. Sample preservations were required for nuclear DNA content estimate using flow cytometry method, when plants tissues were collected from remote areas. Three bamboo species (Dendrocalamus latiflorus, Chimonobambusa tumidissinoda and Acidosasa purpurea) were selected in this study. Samples were treated with two preservation methods and nuclear DNA contents were estimated by flow cytometry after four days, eight days, twelve days and sixteen days, respectively. Coefficient of variation (CV) was an indicator of sample quality which affects the accuracy and precision of DNA content estimates. Differences in nuclear DNA content (2C value) and variations in CVs were analyzed to evaluating the effects of two preservation methods and storage time. Univariate ANOVA analysis revealed that CVs were influenced by storage time significantly (P < 0001). Besides, differences of 2C values between preserved tissues and fresh tissues were influenced by preservation methods significantly (P < 0001). CVs were increasing when time elapsed. After short time preservation, nuclear DNA contents generated from dried tissues were higher than those from fresh tissues, while nuclear DNA contents generated from fixed tissues were lower than those from fresh tissues. We concluded that data quality decreases along with the preservation time increases, expressed as higher CVs. Silica gel desiccant treatment and sample protector treatment could contribute to variations in 2C values of bamboos and the changes of 2C values were lower than 10%.