Department of Plant Genetic Engineering, CINVESTAV-IPN, Campus Irapuato, Apdo. Postal 629, Km. 9.6, Libramiento Norte Carretera Irapuato-León, Zip Code 36821, Irapuato, Guanajuato, Mexico.
Plant Sci. 2012 Apr;185-186:321-30. doi: 10.1016/j.plantsci.2012.01.004. Epub 2012 Jan 13.
Genetic variation in three forms of asexually propagated Agave tequilana Weber var. 'Azul' plants namely offsets, bulbils and in vitro cultured individuals was studied by AFLP analysis. Low levels of variation were observed between mother plants and offsets and a higher level between mother plant and bulbils. Families obtained from commercial plantations showed lower levels of variation in comparison to families grown as ornamentals. No variation was observed between the original explant and four generations of in vitro cultured plants. Epigenetic variation was also studied by analyzing changes in methylation patterns between mother plants and offspring in each form of asexual reproduction. Offsets and bulbils showed an overall decrease in methylation whereas in vitro cultured plants showed patterns specific to each generation: Generations 1 and 4 showed overall demethylation whereas Generations 2 and 3 showed increased methylation. Analysis of ESTs associated with transposable elements revealed higher proportions of ESTs from Ty1-copia-like, Gypsy and CACTA transposable elements in cDNA libraries obtained from pluripotent tissue suggesting a possible correlation between methylation patterns, expression of transposable element associated genes and somaclonal variation.
通过 AFLP 分析研究了三种无性繁殖的龙舌兰 Weber 变种 'Azul' 植物，即分株、鳞茎和体外培养个体的遗传变异。在母株和分株之间以及母株和鳞茎之间观察到低水平的变异，而在商业种植园中获得的家系与作为观赏植物种植的家系相比，变异水平较低。在原始外植体和体外培养的四代植物之间未观察到变异。通过分析每种无性繁殖方式中母株和后代之间甲基化模式的变化，还研究了表观遗传变异。分株和鳞茎表现出整体甲基化减少，而体外培养的植物表现出每一代特有的模式：第 1 代和第 4 代表现出整体去甲基化，而第 2 代和第 3 代表现出甲基化增加。与转座元件相关的 ESTs 的分析表明，从多能组织获得的 cDNA 文库中 Ty1-copia 样、Gypsy 和 CACTA 转座元件的 ESTs 比例较高，这表明甲基化模式、转座元件相关基因的表达和体细胞变异之间可能存在相关性。
