Lee Sung-Il, Nguyen Truong Xuan, Kim Jong-Hwa, Kim Nam-Soo
Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea.
Institute of Agro-Biology, Vietnam National University of Agriculture, Hanoi, Vietnam.
Genes Genomics. 2019 Aug;41(8):941-950. doi: 10.1007/s13258-019-00825-7. Epub 2019 May 3.
B chromosomes are supernumerary chromosomes found in numerous plant species, including in the genus Lilium. Lilium amabile, an endemic Korean Lilium species, carries B chromosomes which are highly variable in terms of numbers and shape among the accessions collected throughout the Korea. Class 1 retrotransposons are highly abundant in the genome of Lilium species, but their biological functions are still obscure. Lilium species were known to hold high diversities derived from retrotransposons.
In this study, genetic diversities among the L. amabile accessions were analyzed to better understand relationships between genetic variations and cytological diversities.
Chromosomes were prepared from 95 L. amabile accessions for cytological identification. Genetic variations were analyzed by inter-retrotransposon amplified polymorphism (IRAP), and genetic differentiation was evaluated via Tajima's D neutrality and F analyses. Population structure and phylogenetic analyses were also carried out.
The L. amabile accessions were classified into 11 cytotypes by the chromosome constitutions. Genetic diversity measured by IRAP analysis revealed high genetic diversity among the accessions. In the joint analysis of cytological variation with genetical variation, IRAP diversity was not related to the cytological diversities of diploid and aneuploids among L. amabile accessions, and genetic differentiation was not obvious. Moreover, the geographical distribution of L. amabile was not related to either IRAP diversity or cytological diversity.
The B chromosome-carrying aneuploids occurred randomly among diploids throughout Korea, and IRAP diversification predated L. amabile dispersion in Korea without genetic differentiation.
B染色体是在众多植物物种中发现的超数染色体，包括百合属植物。朝鲜百合（Lilium amabile）是韩国特有的百合品种，携带B染色体，在从韩国各地收集的种质中，其数量和形状变化很大。1类逆转座子在百合属植物的基因组中高度丰富，但其生物学功能仍不清楚。已知百合属植物具有源自逆转座子的高度多样性。
在本研究中，分析了朝鲜百合种质之间的遗传多样性，以更好地了解遗传变异与细胞学多样性之间的关系。
从95份朝鲜百合种质中制备染色体用于细胞学鉴定。通过逆转座子间扩增多态性（IRAP）分析遗传变异，并通过 Tajima's D中性检验和F分析评估遗传分化。还进行了群体结构和系统发育分析。
根据染色体组成，朝鲜百合种质被分为11种细胞类型。通过IRAP分析测得的遗传多样性表明种质间存在高度遗传多样性。在细胞学变异与遗传变异的联合分析中，IRAP多样性与朝鲜百合种质中二倍体和非整倍体的细胞学多样性无关，遗传分化也不明显。此外，朝鲜百合的地理分布与IRAP多样性或细胞学多样性均无关。
携带B染色体的非整倍体在韩国的二倍体中随机出现，IRAP多样化早于朝鲜百合在韩国的扩散，且无遗传分化。
