Prediction of retrotransposons and assessment of genetic variability based on developed retrotransposon-based insertion polymorphism (RBIP) markers in Pyrus L
Prediction of retrotransposons and assessment of genetic variability based on developed retrotransposon-based insertion polymorphism (RBIP) markers in Pyrus L
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DOI：
10.1007/s00438-014-0914-5
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发表时间：
2015-02-01
影响因子：
3.1
通讯作者：
Cai, Danying
中科院分区：
文献类型：
--
作者：
Jiang, Shuang;Zong, Yu;Cai, Danying
种间杂交一直被认为是梨属植物进化的主要方式，因此，该属内的遗传关系尚未得到很好的记录。反转录转座子是植物基因组中普遍存在的组成部分，梨基因组中长末端重复序列（LTR）反转录转座子占42.4%，这表明反转录转座子在梨属植物的进化中可能具有重要意义。本研究共分离到1,836个全长LTR反转录转座子，设计了196个基于反转录转座子的插入多态性（RBIP）引物，利用其中24对Copia反转录转座子Ppcr 1亚家族引物对欧亚大陆110份梨种质资源进行遗传多样性分析。我们的研究结果表明，Ppcr 1复制多次在栽培亚洲梨的发展。遗传结构分析和UPGMA聚类分析结果表明，供试材料可分为东方和西方两大类群。在东方梨中，野生豌豆梨根据其形态分类单独聚为独立的类群。大青梨、砂梨和砂梨中国白色梨品种混杂在一起，推测亚洲梨栽培品种在发育过程中发生了杂交事件。在西方梨中，根据其地理分布在UPGMA树状图中得到两个分支;一个包含欧洲种，另一个包括来自北非和西亚的种。本研究的新发现对进一步认识梨的生殖发育和栽培梨的起源具有重要意义。
Interspecific hybridization has been considered the major mode of evolution in Pyrus (pear), and thus, the genetic relationships within this genus have not been well documented. Retrotransposons are ubiquitous components of plant genomes and 42.4 % of the pear genome was reported to be long terminal repeat (LTR) retrotransposons, implying that retrotransposons might be significant in the evolution of Pyrus. In this study, 1,836 putative full-length LTR retrotransposons were isolated and 196 retrotransposon-based insertion polymorphism (RBIP) primers were developed, of which 24 pairs to the Ppcr1 subfamily of copia retrotransposons were used to analyze genetic diversity among 110 Pyrus accessions from Eurasia. Our results showed that Ppcr1 replicated many times in the development of cultivated Asian pears. The genetic structure analysis and the unweighted pair group method with arithmetic mean (UPGMA) dendrogram indicated that all accessions could be divided into Oriental and Occidental groups. In Oriental pears, wild pea pears clustered separately into independent groups in accordance with their morphological classifications. Cultivars of P. ussuriensis Maxim, P. pyrifolia Nakai, and P. pyrifolia Chinese white pear were mingled together, which inferred that hybridization events occurred during the development of the cultivated Asian pears. In Occidental pears, two clades were obtained in the UPGMA dendrogram in accordance with their geographical distribution; one contained the European species and the other included species from North Africa and West Asia. New findings in this study will be important to further understand the phylogeny of Pyrus and origins of cultivated pears.