Comparative Study on Four Methods for Quick Extraction of Sorghum Genomic DNA

[Objective] This study was to find out a quick,simple,and low-cost method for the extraction of sorghum genomic DNA.[Method] Four plant genomic DNA extraction methods based on CTAB,including liquid nitrogen grinding method（method I）,buffer grinding method（method II）,drying grinding method（method III）and directly grinding method（method IV）,were used to extract the sorghum genomic DNA from leaves;further the quantity and quality of the yielded DNA were detected by gel electrophoresis,SSR-PCR and SRAP-PCR.[Result] These four methods performed no remarkable difference in DNA product.The method I and method II produced DNA with higher purity and better integrity,which,especially from method I,is effective for SRAP-PCR and SSR-PCR.While the DNA extracted via method III and method IV had less integrality and lower purity,and only effective in SSR-PCR.[Conclusion] Enough amount of sorghum genomic DNA to perform tens of PCR could be quickly extracted using all these four methods.The DNA obtained via method I and method II had a broader application spectrum（SRAP,RAPD,ISSR and SSR）than that via method III and method IV which is only proper for PCR targeting small DNA fragments（SSR）.

桉树ISSR-PCR反应体系的建立及优化

模板DNA、引物、dNTPs、Mg2+的浓度,Taq DNA聚合酶的用量以及退火温度是影响简单序列重复区间扩增(ISSR-PCR)结果的主要因素.以桉树叶片基因组DNA为试材,系统地测试了这6个因素对桉树ISSR反应结果的影响.结果表明:最优化的反应体系即20μL反应体系中,含20 ng模板DNA、0.4μmol.L-1随机引物、0.15 mmol.L-1dNTPs、2.0 mmol.L-1Mg2+、1.25 U TaqDNA聚合酶.最佳退火温度为55℃;PCR反应程序为94℃预变性5 min;94℃变性45 s,55℃退火45 s,72℃延伸1.5 min,35个循环;72℃再延伸7 min.

鹅掌楸ISSR-PCR反应体系的建立及优化

为建立鹅掌楸简单序列重复区间扩增ISSR的PCR优化反应体系,以鹅掌楸叶片基因组DNA为材料,系统地测试了模板DNA、引物、dNTPs、Mg2+浓度、TaqDNA聚合酶用量及退火温度对ISSR-PCR反应体系的影响。结果表明:优化的PCR反应体系为:20μL总体系中,含30 ng模板DNA,0.3μmol.L-1随机引物,0.2 mmol.L-1dNTPs,1.4 mmol.L-1Mg2+,0.8 UTaqDNA聚合酶;最佳退火温度为60℃;PCR反应程序为:94℃预变性5 min;94℃变性1 min,60℃退火45 s,72℃延伸2 min;45个循环;72℃再延伸7 min。