Moreover, compared with DNA sample extracted from young true leaf, the DNA samples from cotyledons had more protein and were impure, the steps of purification with chloroform should be increased.

• 另外，与以真叶为材料提取的DNA样品相比较，子叶DNA样品中的蛋白质等杂质含量高，应增加氯仿抽提纯化次数。