Data from: Molecular and cytogenetic study of East African Highland Banana

East African highland bananas (EAHB) are staple food crop in Uganda, Tanzania, Burundi and other countries in the African Great Lakes region. Even though several morphologically different types exist, all EAHB are triploid and display minimal genetic variation. To provide more insights into the genetic variation within EAHB, genotyping using simple sequence repeat (SSR) markers, molecular analysis of ITS1-5.8S-ITS2 region of ribosomal DNA locus and the analysis of chromosomal distribution of ribosomal DNA sequences was done. A total of 40 triploid EAHB accessions available in the Musa germplasm collection (International Transit Centre, Leuven, Belgium) were characterized. Six diploid accessions of Musa acuminata ssp. zebrina, ssp. banksii and ssp. malaccensis representing putative parents of EAHB were included in the study. Flow cytometric estimation of 2C nuclear DNA content revealed small differences (max ~ 6.5 %) in genome size among the EAHB clones. While no differences in the number of 45S and 5S rDNA loci were found, genotyping using 19 SSR markers resulted in grouping the EAHB accessions into four clusters. DNA sequence analysis of the ITS region indicated a relation of EAHB clones with M. acuminata and, surprisingly, also with M. schizocarpa. The results suggest that EAHB cultivars originated from a single hybrid clone with M. acuminata ssp. zebrina and ssp. banksii being its most probable parents. However, M. schizocarpa seems to have contributed to the formation of this group of banana.

东非高地香蕉（East African Highland Bananas, EAHB）是乌干达、坦桑尼亚、布隆迪及非洲大湖地区其他国家的主粮作物。尽管存在多种形态学特征各异的类群，但所有东非高地香蕉均为三倍体，且遗传变异程度极低。为深入解析东非高地香蕉的遗传变异，本研究采用简单序列重复（simple sequence repeat, SSR）标记进行基因分型，对核糖体DNA位点的ITS1-5.8S-ITS2区域开展分子分析，并对核糖体DNA序列的染色体分布进行了检测。本研究对保存在比利时鲁汶国际中转中心香蕉种质资源库的40份三倍体东非高地香蕉种质材料进行了特征分析。本研究同时纳入了6份二倍体尖叶芭蕉（Musa acuminata）的zebrina亚种、banksii亚种和malaccensis亚种材料，这些材料被认为是东非高地香蕉的推定亲本。通过流式细胞术估算2C核DNA含量，结果显示东非高地香蕉克隆间的基因组大小仅存在微小差异（最大差异约为6.5%）。尽管未发现45S与5S核糖体DNA位点的数量存在差异，但利用19个SSR标记进行的基因分型分析将东非高地香蕉种质划分为4个类群。ITS区域的DNA序列分析显示，东非高地香蕉克隆与尖叶芭蕉（Musa acuminata）存在亲缘关系，令人意外的是，其与裂果芭蕉（Musa schizocarpa）也存在关联。研究结果表明，东非高地香蕉栽培品种起源于单一杂交克隆，其中尖叶芭蕉的zebrina亚种和banksii亚种是其最可能的亲本。不过，裂果芭蕉（Musa schizocarpa）似乎也参与了该类香蕉的形成过程。