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以甘薯(Ipomoea batatas)品种‘徐薯18’(2n=6x=90)及其近缘野生种I.lacunosa(K61,2n=2x=30)的种间体细胞杂种XL1为材料,利用形态学与细胞学分析、酯酶同工酶、重金属离子胁迫的离体鉴定、扩增片段长度多态性(AFLP)、甲基化敏感扩增多态性(MSAP)等技术对XL1的特性和遗传组成进行了分析。结果表明,XL1对铝和铬的耐受性显著高于‘徐薯18’,胁迫条件下,XL1的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性显著高于‘徐薯18’,而丙二醛(MDA)含量显著低于‘徐薯18’。XL1的基因组含有双亲的特异条带和改变的条带,XL1的胞嘧啶甲基化位点由双亲的特异位点和改变的位点组成,XL1中‘徐薯18’特异的基因组条带和甲基化位点比例显著高于I.lacunosa的比例。XL1具有与‘徐薯18’相同的叶绿体和线粒体基因组组成。本研究进一步证明了体细胞杂交在甘薯遗传改良上的重要作用,同时,本研究结果将有助于甘薯近缘野生种中的有益基因发掘,也有助于进一步理解甘薯栽培种的进化和系统发育。
The interspecific somatic hybrid XL1 of Ipomoea batatas (’Xushu 18’ (2n = 6x = 90) and its relative wild I.lacunosa (K61,2n = 2x = 30) The characteristics and inheritance of XL1 were studied with cytological analysis, esterase isozyme, in vitro identification of heavy metal ions, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP) The composition was analyzed. The results showed that the tolerance of XL1 to aluminum and chromium was significantly higher than that of ’Xushu 18’. Under the stress conditions, the activities of superoxide dismutase (SOD) and catalase (CAT) of XL1 were significantly higher than those of ’ 18 ’, while the content of malondialdehyde (MDA) was significantly lower than that of’ Xushu 18 ’. The XL1 genome contains specific bands and altered bands of the parents. The cytosine methylation site of XL1 is composed of the specific sites of the parents and the altered sites. The XU-SHU 18-specific genomic band in XL1 and The proportion of methylation sites was significantly higher than that of I. lacunosa. XL1 has the same chloroplast and mitochondrial genome composition as that of ’Xushu 18’. This study further demonstrated the important role of somatic hybridization in sweet potato genetic improvement. At the same time, the results of this study will be helpful for the exploration of beneficial genes in the wild relatives of sweet potato and also help to further understand the evolution and phylogeny of sweet potato cultivars .