“A draft Musa balbisiana genome sequence for molecular genetics in polyploid, inter- and intra-specific Musa hybrids”

BMC Genomics

Research Article

Lee Wan Sin¹  Ranganath Gudimella¹  Norzulaani Khalid¹  Jennifer Ann Harikrishna¹  Mark W Davey²  Johan Keulemans² 

[1] Centre for Research in Biotechnology for Agriculture and Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia;Laboratory of Fruit Breeding and Biotechnology, Division of Crop Biotechnics, Department of Biosystems, Katholieke Universiteit Leuven, Willem de Croylaan 42, box, 2427B-3001, Heverlee, Leuven, Belgium;

关键词: (a)biotic stress;    Banana;    Fe’i;    Genetic diversity;    microRNA (miRNA);    Molecular breeding;    Musa acuminata;    Musa balbisiana;    Pisang Klutuk Wulung;    Plantain;    Polyploidy;    Wild banana;   

DOI  :  10.1186/1471-2164-14-683

 received in 2013-04-14, accepted in 2013-09-24,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundModern banana cultivars are primarily interspecific triploid hybrids of two species, Musa acuminata and Musa balbisiana, which respectively contribute the A- and B-genomes. The M. balbisiana genome has been associated with improved vigour and tolerance to biotic and abiotic stresses and is thus a target for Musa breeding programs. However, while a reference M. acuminata genome has recently been released (Nature 488:213–217, 2012), little sequence data is available for the corresponding B-genome.To address these problems we carried out Next Generation gDNA sequencing of the wild diploid M. balbisiana variety ‘Pisang Klutuk Wulung’ (PKW). Our strategy was to align PKW gDNA reads against the published A-genome and to extract the mapped consensus sequences for subsequent rounds of evaluation and gene annotation.ResultsThe resulting B-genome is 79% the size of the A-genome, and contains 36,638 predicted functional gene sequences which is nearly identical to the 36,542 of the A-genome. There is substantial sequence divergence from the A-genome at a frequency of 1 homozygous SNP per 23.1 bp, and a high degree of heterozygosity corresponding to one heterozygous SNP per 55.9 bp. Using expressed small RNA data, a similar number of microRNA sequences were predicted in both A- and B-genomes, but additional novel miRNAs were detected, including some that are unique to each genome. The usefulness of this B-genome sequence was evaluated by mapping RNA-seq data from a set of triploid AAA and AAB hybrids simultaneously to both genomes. Results for the plantains demonstrated the expected 2:1 distribution of reads across the A- and B-genomes, but for the AAA genomes, results show they contain regions of significant homology to the B-genome supporting proposals that there has been a history of interspecific recombination between homeologous A and B chromosomes in Musa hybrids.ConclusionsWe have generated and annotated a draft reference Musa B-genome and demonstrate that this can be used for molecular genetic mapping of gene transcripts and small RNA expression data from several allopolyploid banana cultivars. This draft therefore represents a valuable resource to support the study of metabolism in inter- and intraspecific triploid Musa hybrids and to help direct breeding programs.

【 授权许可】

CC BY   
© Davey et al.; licensee BioMed Central Ltd. 2013