Department of Botany, Annamalai University, Annamalainagar 608 002, Tamilnadu, India.
C R Biol. 2011 Jan;334(1):24-30. doi: 10.1016/j.crvi.2010.11.004. Epub 2010 Dec 28.
The aim of this study is to examine the effect of different doses (control, 5, 10, 15, 20 and 25 Kr) of gamma irradiation on seed germination, flowering, fruit and seed traits of Jatropha curcas and to identify DNA polymorphism among the mutants through a Randomly Amplified Polymorphic DNA (RAPD) marker analysis. The improved agronomic traits such as flowering, fruits and seeds were recorded in 5 Kr dose and seed germination percentage in 10 Kr dose treated plants, while corresponding parameters were reduced significantly (P>0.05) in 25 Kr dose gamma rays treated plants when compared to that of control. All the twenty-three random primers used except six primers, namely OPAW16, OPAK07, OPAK15, OPS01, OPAK20 and OPAL09 were showed polymorphic bands. The primers: OPAW16, OPAK07, OPAK15, OPS01, OPAK20 and OPAL09 produced only one band each across the six mutants, while the primers: OPU13, OPAB 15, OPF01 and OPAB11 were produced with maximum number of bands (8). The number of amplicons varied from 1 to 8 with an average of 3.9 bands, of which 2.3 were polymorphic. The percentage of polymorphism per primer ranged from 0 to 100 with an average of 55.16%. The Jaccard's coefficients of dissimilarity varied from 0.324 to 0.397, indicative of the level of genetic variation among the mutants studied. The maximum dissimilarity value (0.397) was observed in 5 Kr mutant while the minimum value (0.250) was observed in 20 Kr mutant when compared to that of control. In a dendrogram constructed based on genetic similarity coefficients, the mutants were grouped into three main clusters; (a) control, 10, 15 and 20 Kr dose mutants clustered together, (b) 25 Kr dose grouped alone, (c) 5 Kr dose also grouped alone. The mutants showing the differences in morphological traits showed DNA polymorphism in PCR profile amplified by RAPD marker. It is concluded that DNA polymorphism detected by RAPD analysis offered a useful molecular marker for the identification of mutants in gamma radiation treated plants.
本研究旨在探讨不同剂量（对照、5、10、15、20 和 25 Kr）γ射线辐射对麻疯树种子萌发、开花、果实和种子特性的影响，并通过随机扩增多态性 DNA（RAPD）标记分析鉴定突变体中的 DNA 多态性。在 5 Kr 剂量处理的植株中，记录到改良的农艺性状，如花、果实和种子，而在 25 Kr 剂量γ射线处理的植株中，种子萌发率显著降低（P>0.05）。除了 6 个引物（OPAW16、OPAK07、OPAK15、OPS01、OPAK20 和 OPAL09）之外，使用的 23 个随机引物均显示出多态性条带。引物：OPAW16、OPAK07、OPAK15、OPS01、OPAK20 和 OPAL09 在 6 个突变体中各产生一条带，而引物：OPU13、OPAB15、OPF01 和 OPAB11 产生的带数最多（8 个）。扩增子的数量从 1 到 8 个不等，平均为 3.9 个带，其中 2.3 个为多态性。每个引物的多态性百分比范围为 0 至 100%，平均为 55.16%。Jaccard 不相似系数从 0.324 到 0.397 不等，表明所研究的突变体之间存在遗传变异水平。在与对照相比时，5 Kr 突变体观察到最大的不相似值（0.397），而 20 Kr 突变体观察到最小的不相似值（0.250）。在基于遗传相似系数构建的系统发育树中，突变体分为三个主要类群；（a）对照、10、15 和 20 Kr 剂量突变体聚集在一起，（b）25 Kr 剂量单独聚集，（c）5 Kr 剂量也单独聚集。表现出形态特征差异的突变体在通过 RAPD 标记扩增的 PCR 图谱中显示出 DNA 多态性。因此，RAPD 分析检测到的 DNA 多态性为鉴定γ辐射处理植物中的突变体提供了有用的分子标记。
