烤烟叶数株高突变株的生长特征及DNA初步鉴定

The growing characteristics and preliminary gene DNA identification of the flue-cured tobacco mutant

把2 0 0 1年烤烟大田自然条件下出现的多叶数、超株高的突变株,采用组织培养获得的再生苗,2 0 0 2年在3个不同生态地点栽植进行生长观察,同时从细胞学、生理生化和遗传物质DNA的鉴定方面,以原品种株做对照。结果发现,在植株形态生长方面,突变株较对照株叶数仍表现出多叶数、超株高和晚花发育的特征性状;在叶细胞结构方面,突变株叶片气孔保卫细胞叶绿体个数极显著多于对照株;在生理生化特性指标方面,突变株叶绿素a、b和总量及可溶性蛋白质含量均较对照株高,且突变株和对照株的COD、POD同工酶及可溶性蛋白质SDS PAGE电泳有酶谱带差异;提取叶细胞DNA的RAPD分析和开花期叶片mRNA差异显示的电泳图谱中,突变株与对照株对所选用的随机引物扩增产物条带数存在着数量差别。初步证明该变异株应是晚花或多叶数基因的突变体,为克隆烤烟叶数或晚花基因提供了依据。

The mutant of flue-cured tobacco variety K346 leaf number and trunk height had been discovered in the tobacco leaf production fields in 2001, and it was studied by comparing with the original variety after tissue culture regenerated plant in 2002. Results are follows: (a) The mutant was grown bigger and its flowering time was late just as the same characters when it was discovered. The mutant's leaf number was higher than CK on the plant shape development side; (b) The chloroplast's number of the stoma guard cells in mutant leaf were extremely higher than CK on the cytologic structured character side markedly; (c) The content of chlorophyll a, b and total chlorophyll, or the soluble protein in the mutant were higher than in the check variety. Electrophoretic analysis of peroxidase isozyme and cytochrome-oxidase isozyme indicated that there were certain difference between them, and were alike in the soluble protein electrophoresis of SDS-PAGE on this plant physiological and biochemical side. Ultimately as (d), the mutant band's number on electrophoresis gel of RAPD analysis and mRNA differentiation displayed by DDRT-PCR method were distinct from CK, through the use of relatively short primer sequences that, by chance, or the position set was different. It proved that DNA of the body cell and the gene expression at the flowering stage was different between the mutant and the check variety, and the mutant's gene about the leaf number or the flower budding date might be changed in the molecular level of DNA. This is very important to the tobacco breeding and planting, and give primary identification of mutant genes for the crop.