建兰ISSR-PCR反应体系的建立和优化（摘要）（英文）

目的]研究建兰Cymbidium ensifolium（Linn.） Sw]总基因组DNA的提取方法,并对建兰ISSR-PCR反应体系进行优化,建立更为完善的反应体系。方法]用改良的CTAB法提取叶片的基因组DNA,用1.0%琼脂糖电泳检测DNA质量;用分光光度计测定其纯度和浓度,DNA纯度以OD260/OD280的比值来估算,浓度估算法为：DNA浓度（ng/μl） =OD260×50×稀释倍数。计算DNA获得率（DNA量/所用叶片量×100%）。对建兰ISSR-PCR反应的4项影响因素（DNA模板、TaqDNA聚合酶、Mg2 ＋和dNTPs）逐个作5水平进行研究,以筛选最优的建兰ISSR-PCR反应体系。结果]获得高质量的建兰基因组DNA,以及优化了的建兰ISSR-PCR反应体系,即25μl PCR反应体积中,2.5μl 10×PCR buffer,2.5 mmol/LMgCl2,240 ng模板DNA,160μmol/LdNTPs,1.25 UTaqDNA聚合酶,0.4μmol/L引物,双蒸水15.78μl。最佳扩增程序为：94℃预变性5min,然后进行40个循环：94℃变性30 s,50 ～60℃退火（退火温度随引物不同而定） 30 s,72℃延伸50 s,72℃延伸7 min。结论]建立了建兰ISSR-PCR反应体系最适合的条件,为进一步利用ISSR分子标记技术进行建兰遗传多样性研究提供了基础。

Establishment and Optimization of ISSR-PCR Reaction System for Cymbidium ensifolium (Linn.) Sw

Objective] This research aimed to search a best method for extracting the genomic DNA of Cymbidium ensifolium and establish the optimized ISSR-PCR reaction system.Method] Genomic DNA was extracted from C.ensifolium leaves by modified CTAB method.ISSR-PCR reaction system for C.ensifolium was optimized.Result] High-quality genomic DNA was obtained from C.ensifolium.The 25 μl optimized ISSR-PCR reaction system for C.ensifolium contained 2.5 μl 10× PCR buffer,2.5 mmol/L MgCl2,240 ng template DNA,160 μmol/L dNTPs,1.25 U Taq DNA polymerase,0.4 μmol/L primer and 15.78 μl ddH2O.The optimal PCR procedures were：94 ℃ pre-denaturation for 5 min and then 40 cycles,94 ℃ denaturation for 30 s,50-60 ℃ annealing for 30 s （annealing temperature according to different primers）,72 ℃ extension for 50 s and a 72 ℃ extension for 7 min.Conclusion] An optimized ISSR-PCR reaction system for C.ensifolium was established,which provides a basis for further study on genetic diversity of C.ensifolium by using ISSR molecular marker technique.