转座子在不同柑橘品种中的多态性显示

发布时间：2018-03-09 21:30

本文选题：柑橘　切入点：TD　出处：《华中农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：芽变是柑橘等果树作物育种的重要变异来源之一,也是果树体细胞变异的重要类型。柑橘杂种类型多,枸橼、柚和宽皮橘等基本种之间可相互杂交而产生各种杂柑。芽变和杂交事件是柑橘进化和新品种选育的重要基础。芽变的分子机制还不太清楚,一般认为芽变在分子水平差异极小。探究转座子在不同芽变品种中的多态性,找到鉴别芽变品种的标记,有助于推进芽变机理的认识,为柑橘芽变育种提供理论依据。柑橘遗传背景高度杂合,研究转座子在杂种柑橘形成过程中的变化,有助于理解柑橘杂种材料基因组变异和种间进化关系。本课题在甜橙基因组的基础上,利用TD(transposon display)技术,先研究33个转座子在柑橘芽变品种中的多态性,后挑出20个来研究转座子在杂种柑橘及其亲本中的多态性,主要结果如下:1.筛选了33个高丰度的转座子用于芽变鉴别。18个DNA转座子中有5个(DTM63、DTM58、Helitron1、Spem和mPing2),15个反转录转座子有4个(Line1、LTR-Gypsy3、LTR-Gypsy5和Tcs2)能较好地鉴别柑橘成熟期、色泽、育性等性状变异的芽变品种。DNA转座子DTH3,在甜橙芽变品种中多态性高,表现活跃,但在供试温州蜜柑芽变品种中没有明显的多态性。2.罗伯逊脐橙及其早熟芽变罗脐35号中检测到较多转座子差异,能被DTM63,Spem和mPing2这些转座子鉴别开来。mPing2在柑橘芽变中表现活跃,能鉴别罗伯逊脐橙及罗脐35号、暗柳及红暗柳、普通i*柑及黔阳无核i*柑,以及红肉t/溪蜜柚与橙皮t/溪蜜柚这些芽变品种对。3.转座子作为标记不同程度地支持了柚和橘杂交产生酸橙,酸橙和枸橼杂交产生柠檬,柚和甜橙杂交产生葡萄柚以及橘和甜橙杂交产生克里曼丁橘这4个事件。20个转座子中有10个支持柚和橘杂交产生酸橙,支持率最高。4.柚、橘和酸橙以及柚、甜橙和葡萄柚这2个组合中,均检测到3个活跃的转座子,分别为:LTR-Copia1、Helitron1、MUDR2和DTM53、DTM63、MUDR2;MUDR2在这2个组合中都表现活跃。5.柚、甜橙和葡萄柚组合中,转座子表现各异:Spem片段丢失严重,Harbinger2和LTR-Gypsy1未丢失片段也没有发生转座,而MUDR2表现活跃,发生了新的转座。
[Abstract]:Budding is one of the important sources of variation in citrus and other fruit tree crop breeding, and is also an important type of somatic variation in fruit trees. Basic species, such as pummelo and tangerine, can cross with each other and produce a variety of hybrids. Sprouts and cross events are the important basis for citrus evolution and breeding of new varieties. The molecular mechanism of sprouting is not well understood. It is generally believed that there is very little difference in sprouts at the molecular level. To explore the polymorphism of transposons in different varieties of sprouts and to find markers to identify them will help to promote the understanding of the mechanism of sprouting. The genetic background of citrus was highly heterozygous, and the variation of transposon during the formation of hybrid citrus was studied. It is helpful to understand the genetic variation and interspecific evolution of citrus hybrids. Based on the genome of sweet orange, we studied the polymorphism of 33 transposons in citrus germinated varieties by using TD(transposon display-technique. Then 20 were selected to study the polymorphism of transposons in hybrid citrus and its parents. The main results are as follows: 1. 33 transposons with high abundance were screened for bud differentiation. 5 of 18 DNA transposons were identified as maturing stage. 5 of 18 DNA transposons were identified with Helitron1Spem and mPing2s, and 15 retrotransposons with 4 Line1t LTR-Gypsy3LTR-Gypsy5 and Tcs2) were used to identify citrus maturity, color and color. DNA transposon DTH3, a mutant variety with fertility and other traits, was highly polymorphic and active in sweet orange germinated varieties. However, there was no significant polymorphism in bergamot germinated varieties. 2. More transposon differences were detected in Robertson navel orange and its early maturing roxum 35, which could be identified by transposons DTM63- Spem and mPing2. MPing2 was active in citrus sprout. It can distinguish Robertson navel orange from Luo navel 35, dark willow and red willow, ordinary iquat and Qianyang seedless ivy orange. And the budding varieties of red meat t / stream pomelo and orange peel t / stream grapefruit. 3. Transposon as a marker to support the hybrid of pomelo and orange to produce lime, lime and citron to produce lemon, Grapefruit and orange hybrids produce grapefruit, and orange and orange hybrids produce Creman blueberries. Ten out of 20 transposons support pomelo and orange hybrids to produce lime, with the highest approval rating of .4.Pomelo, orange and lime, and grapefruit, In both combinations of sweet orange and grapefruit, three active transposons were detected. They were: 1: LTR-Copia1 Helitron1 (MUDR2) and DTM53 (DTM63) MUDR2MUDR2 were active in both combinations. Pummelo, orange and grapefruit were active. Transposons show different types of loss of MUDR2 fragments, such as serious loss of MUDR2 fragments, serious loss of MUDR2 fragments and no transposes, while MUDR2 is active and new transposers occur.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S666

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