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Original multidisciplinary research hereby clarifies the complex geodomestication pathways that generated the vast range of banana cultivars (cvs). Genetic analyses identify the wild ancestors of modern-day cvs and elucidate several key stages of domestication for different cv groups. Archaeology and linguistics shed light on the historical roles of people in the movement and cultivation of bananas from New Guinea to West Africa during the Holocene. The historical reconstruction of domestication processes is essential for breeding programs seeking to diversify and improve banana cvs for the future.

[...]Cavendish is susceptible to the new Foc Tropical Race 4 (Foc-TR4) strain, and could meet the same fate as Gros Michel if the fungus reaches Latin America, the world's leading banana exporter, says Rony Swennen of the Catholic University of Leuven in Belgium, and a banana breeder at the International Institute of Tropical Agriculture in Dar es Salaam. Planting of these variants, in combination with measures such as crop rotation, has allowed the cultivation of bananas on contaminated land.

Dessert and cooking bananas are vegetatively propagated crops of great importance for both the subsistence and the livelihood of people in developing countries. A wide diversity of diploid and triploid cultivars including AA, AB, AS, AT, AAA, AAB, ABB, AAS and AAT genomic constitutions exists. Within each of this genome groups, cultivars are classified into subgroups that are reported to correspond to varieties clonally derived from each other after a single sexual event. The number of those founding events at the basis of the diversity of bananas is a matter of debate. We analysed a large panel of 575 accessions, 94 wild relatives and 481 cultivated accessions belonging to the section Musa with a set of 498 DArT markers previously developed. DArT appeared successful and accurate to describe Musa diversity and help in the resolution of cultivated banana genome constitution and taxonomy, and highlighted discrepancies in the acknowledged classification of some accessions. This study also argues for at least two centres of domestication corresponding to South-East Asia and New Guinea, respectively. Banana domestication in New Guinea probably followed different schemes that those previously reported where hybridization underpins the emergence of edible banana. In addition, our results suggest that not all wild ancestors of bananas are known, especially in M. acuminata subspecies. We also estimate the extent of the two consecutive bottlenecks in edible bananas by evaluating the number of sexual founding events underlying our sets of edible diploids and triploids, respectively. The attribution of clone identity to each sample of the sets allowed the detection of subgroups represented by several sets of clones. Although morphological characterization of some of the accessions is needed to correct potentially erroneous classifications, some of the subgroups seem polyclonal.

Bananas, renowned for their delightful flavor, exceptional nutritional value, and digestibility, are among the most widely consumed fruits globally. The advent of advanced image processing, computer vision, and deep learning (DL) techniques has revolutionized agricultural diagnostics, offering innovative and automated solutions for detecting and classifying fruit varieties. Despite significant progress in DL, the accurate classification of banana varieties remains challenging, particularly due to the difficulty in identifying subtle features at early developmental stages. To address these challenges, this study presents a novel hybrid framework that integrates the Vision Transformer (ViT) model for global semantic feature representation with the robust classification capabilities of Support Vector Machines. The proposed framework was rigorously evaluated on two datasets: the four-class BananaImageBD and the six-class BananaSet. To mitigate data imbalance issues, a robust evaluation strategy was employed, resulting in a remarkable classification accuracy rate (CAR) of 99.86% 0.099 for BananaSet and 99.70% 0.17 for BananaImageBD, surpassing traditional methods by a margin of 1.77%. The ViT model, leveraging self-supervised and semi-supervised learning mechanisms, demonstrated exceptional promise in extracting nuanced features critical for agricultural applications. By combining ViT features with cutting-edge machine learning classifiers, the proposed system establishes a new benchmark in precision and reliability for the automated detection and classification of banana varieties. These findings underscore the potential of hybrid DL frameworks in advancing agricultural diagnostics and pave the way for future innovations in the domain.

Crop wild relatives are valuable resources for future genetic improvement. Here, we report the de novo genome assembly of Musa itinerans , a disease-resistant wild banana relative in subtropical China. The assembled genome size was 462.1 Mb, covering 75.2% of the genome (615.2Mb) and containing 32, 456 predicted protein-coding genes. Since the approximate divergence around 5.8 million years ago, the genomes of Musa itinerans and Musa acuminata have shown conserved collinearity. Gene family expansions and contractions enrichment analysis revealed that some pathways were associated with phenotypic or physiological innovations. These include a transition from wood to herbaceous in the ancestral Musaceae, intensification of cold and drought tolerances and reduced diseases resistance genes for subtropical marginally distributed Musa species. Prevalent purifying selection and transposed duplications were found to facilitate the diversification of NBS-encoding gene families for two Musa species. The population genome history analysis of M. itinerans revealed that the fluctuated population sizes were caused by the Pleistocene climate oscillations and that the formation of Qiongzhou Strait might facilitate the population downsizing on the isolated Hainan Island about 10.3 Kya. The qualified assembly of the M. itinerans genome provides deep insights into the lineage-specific diversification and also valuable resources for future banana breeding.

Identifying the molecular mechanisms underlying tolerance to abiotic stresses is important in crop breeding. A comprehensive understanding of the gene families associated with drought tolerance is therefore highly relevant. NAC transcription factors form a large plant-specific gene family involved in the regulation of tissue development and responses to biotic and abiotic stresses. The main goal of this study was to set up a framework of orthologous groups determined by an expert sequence comparison of NAC genes from both monocots and dicots. In order to clarify the orthologous relationships among NAC genes of different species, we performed an in-depth comparative study of four divergent taxa, in dicots and monocots, whose genomes have already been completely sequenced: Arabidopsis thaliana, Vitis vinifera, Musa acuminata and Oryza sativa. Due to independent evolution, NAC copy number is highly variable in these plant genomes. Based on an expert NAC sequence comparison, we propose forty orthologous groups of NAC sequences that were probably derived from an ancestor gene present in the most recent common ancestor of dicots and monocots. These orthologous groups provide a curated resource for large-scale protein sequence annotation of NAC transcription factors. The established orthology relationships also provide a useful reference for NAC function studies in newly sequenced genomes such as M. acuminata and other plant species.

Background The banana ( Musa sp., AAA) genome is constantly increasing due to high-frequency of somaclonal variations. Due to its large diversity, a conventional numerical and morphological based taxonomic identification of banana cultivars is laborious, difficult and often leads to subject of disagreements. Results Hence, in the present study, we used universal DNA barcode ITS2 region to identify and to find the genetic relationship between the cultivars and varieties of banana. Herein, a total of 16 banana cultivars were PCR amplified using ITS2 primer pair. In addition, 321 sequences which were retrieved from GenBank, USA, were used in this study. The sequences were then aligned using Clustal W and genetic distances were computed using MEGA V5.1. The study showed significant divergence between the intra- and inter-specific genetic distances in ITS2 region. BLAST1 and Distance methods proved that ITS2 DNA barcode region successfully identified and distinguished the cultivar and varieties of banana. Conclusion Thus, from the results of the present study, it is clear that ITS2 is not only an efficient DNA barcode to identify the banana species but also a potential candidate for enumerating the phylogenetic relationships between the subspecies and cultivars. This is the first comprehensive study to categorically distinguish the economically important banana subspecies and varieties using DNA barcodes and to understand its evolutionary relationship.

Species delimitation is essential to study and conserve biological diversity. It is traditionally based on morphological trait variation observed in one or a few specimens. Nevertheless, such assessments may not sufficiently take intraspecific trait variation into account, misidentifying morphotypes as separate species. The use of high-throughput sequencing data alongside morphological data in taxonomic studies may substantially improve the accuracy of taxonomic assessments. The Musa genus, commonly known for comprising the wild relatives of banana varieties, consists of about seventy described species. However, the taxonomic status of multiple Musa species is uncertain due to typification errors and the lack of high-quality specimens. The species M . splendida and M . viridis from northern Viet Nam only substantially differ from each other in the color of their male flower bracts, which is red to pinkish-red in M . splendida and pink in M . viridis . Consequently, their taxonomic status as separate species has been debated. Here, we studied the genetic relationships between 121 M . splendida and M . viridis plants using high-throughput sequencing data (DArTseq) in which we identified 51,188 single nucleotide polymorphisms. We found that individuals genetically clustered in a principal component analysis (6 clusters), fastStructure analysis (four groups), and ASTRAL-III consensus phylogenetic tree (nine clades) based on their population origin rather than by their taxon identity. In addition, a strong signal for an isolation-by-distance pattern between populations was observed. Plants identified as M . viridis were more closely related to M . splendida plants from the same region than to M . viridis plants from other regions. Hence, we propose to treat M . viridis as a synonym of M . splendida .

Hybridization between wild Musa species and subspecies from Southeast Asia is at the origin of cultivated bananas. The genomes of these cultivars are complex mosaics involving nine genetic groups, including two previously unknown contributors. This study provides continuous genome assemblies for six wild genetic groups, one of which represents one of the unknown ancestor, identified as M. acuminata ssp. halabanensis. The second unknown ancestor partially present in a seventh assembly appears related to M. a. ssp. zebrina. These assemblies provide key resources for banana genetics and for improving cultivar assemblies, including that of the emblematic triploid Cavendish. Comparative and phylogenetic analyses reveal an ongoing speciation process within Musa, characterised by large chromosome rearrangements and centromere differentiation through the integration of different types of repeated sequences, including rDNA tandem repeats. This speciation process may have been favoured by reproductive isolation related to the particular context of climate and land connectivity fluctuations in the Southeast Asian region.

Many species are defined in the Musa section within its natural diversification area in Southeast Asia. However, their actual number remains debated as botanical characterisation, distribution and intraspecific variability are still poorly known, compromising their preservation and their exploitation as crop wild relatives of cultivated forms. To address the underexplored Musa diversity in mainland Southeast Asia, at the northern edge of the natural range, 208 specimens were collected in Vietnam, Laos and China, mainly belonging to Musa balbisiana , M . itinerans , M . acuminata and M . yunnanensis . Data on location, morphology, environment and local knowledge were recorded, and leaf samples collected for high-throughput genotyping. This study combines geographical, morphological, and genomic diversity to clarify the taxonomic classification. The collected species exhibit highly distinctive morphologies and genomes, just as they differ in ranges and life traits. Intraspecific genomic diversity was also observed, although not necessarily morphologically perceptible. Mainland Southeast Asia is confirmed as a primary diversification centre for the Musa section. The diversity observed is only partially represented in major international ex situ collections, calling for their urgent enrichment and the promotion of in situ management procedures, for the protection of these threatened species and to better harness their potential in breeding programmes. Although considered wild, the species studied are all affected to varying extents by human use. Musa yunnanensis and M . acuminata subsp. burmannica are the most strictly wild forms, with spontaneous interspecific hybrids first described in this study. Although gathered as fodder, they were only occasionally dispersed outside their endemic zones. Musa itinerans is not cultivated per se , but natural populations are widely exploited, leading to a geographically structured diversity. The diversity of M . balbisiana is widely distributed and geographically structured by human activities. This species should be regarded as domesticated. These various stages, from simple opportunistic gathering to true domestication, shed light on the evolutionary history of today’s cultivated varieties.