论文部分内容阅读
用非放射性的Ｄｉｇｏｘｉｇｅｎｉｎ标记的１１－ｄＵＴＰ取代３２Ｐ标记的ｄＡＴＰ或ｄＣＴＰ，标记克隆的ＢＢＴＶｃＤＮＡ－１０．５ｋｂｃＤＮＡ，制备成探针．通过核酸斑点杂交对粗提取的ＢＢＴＶ，ＢＢＴＶ－ＤＮＡ，感染ＢＢＴＶ的香蕉植物的拟茎，球茎处的组织，新生叶片以及成熟后的叶片进行了检测．结果表明：ＢＢＴＶｃＤＮＡ－１ｃＤＮＡ探针特异性强，不与ＣＭＶ—ＲＮＡ、无毒香蕉组培苗提取的核酸发生杂交反应；仅与粗提ＢＢＴＶ、ＢＢＴＶ－ＤＮＡ、ＢＢＴＶ侵染的香蕉组织的核酸提取物发生杂交反应．此探针灵敏度高，可检出含有ＢＢＴＶｃＤＮＡ－１０．５ｋｂ的质粒ＤＮＡ的最小量为１０ｐｇ；测定感病香蕉植株的拟茎汁液的最高稀释度可达１∶１２８，相当于０．４ｍｇ病蕉组织中的病毒含量．测定同一病株不同部位的结果表明，ＢＢＴＶ在植物体内的分布不均匀，拟茎处组织中病毒含量最高，球茎处的组织以及新生叶片中的病毒含量次之，成熟后的叶片中的病毒含量最低
The probe was prepared by substituting non-radioactive Digoxigenin-labeled 11-dUTP for 32P-labeled dATP or dCTP and labeling the cloned BBTV cDNA-10.5 kb cDNA. BBTV, BBTV-DNA, BBTV-infected banana plants were planted in the stems, corms, tissue of newborn leaves and mature leaves by dot blot hybridization. The results showed that the BBTVcDNA-1cDNA probe was highly specific and did not hybridize with the nucleic acids extracted from CMV-RNA and non-toxic banana plantlets. Nucleic acid extracted only from BBTV, BBTV-DNA and BBTV infected banana tissues Hybridization occurs. This probe is highly sensitive and can detect a minimum of 10 pg plasmid DNA containing BBTVcDNA - 10.5 kb. The highest dilution of the pseudostem juice of diseased banana plants is up to 1:128, equivalent to 0.4 mg diseased banana The amount of virus in the tissue. The results of different parts of the same strain showed that the distribution of BBTV in plants was not uniform, the content of virus in the tissues of the stems was the highest, the content of the virus in the tissues of the corms and the new leaves was the second, and the virus content in the mature leaves lowest