A manually annotated Actinidia chinensis var. chinensis (kiwifruit) genome highlights the challenges associated with draft genomes and gene prediction in plants

Most published genome sequences are drafts, and most are dominated by computational gene prediction. Draft genomes typically incorporate considerable sequence data that are not assigned to chromosomes, and predicted genes without quality confidence measures. The current Actinidia chinensis (kiwifruit) 'Hongyang' draft genome has 164\ua0Mb of sequences unassigned to pseudo-chromosomes, and omissions have been identified in the gene models

Apple, from genome to breeding

Genome resources for apple (Malus  7 domestica Borkh), the main fruit crop of temperate regions, have been developed over the past 10 years, culminating in the sequencing of the \u2018Golden Delicious\u2019 genome. The apple genome sequence anchored to a high-density linkage map provides the apple community with new tools to identify genes and other functional elements that will enable the study of the evolution of plant genome structure, as well as facilitating genomic-assisted breeding. Transcriptomics, proteomics and metabolomics studies are greatly benefiting from the availability of an annotated genome. In this review, we report on the status of the apple genome and on current molecular and genetic tools available in apple that will improve the efficiency of the process of cultivar development; we discuss how an integrative \u2018omics\u2019 approach could greatly enhance the understanding of biological processes that determine agronomically and economically favorable phenotypes; we review the databases and bioinformatics tools that are available to manage and exploit the large amounts of biological data generated for apple and other plant genomes

Austropuccinia psidii, causing myrtle rust, has a gigabase-sized genome shaped by transposable elements

Austropuccinia psidii, originating in South America, is a globally invasive fungal plant pathogen that causes rust disease on Myrtaceae. Several biotypes are recognized, with the most widely distributed pandemic biotype spreading throughout the Asia-Pacific and Oceania regions over the last decade. Austropuccinia psidii has a broad host range with more than 480 myrtaceous species. Since first detected in Australia in 2010, the pathogen has caused the near extinction of at least three species and negatively affected commercial production of several Myrtaceae. To enable molecular and evolutionary studies into A. psidii pathogenicity, we assembled a highly contiguous genome for the pandemic biotype. With an estimated haploid genome size of just over 1?Gb (gigabases), it is the largest assembled fungal genome to date. The genome has undergone massive expansion via distinct transposable element (TE) bursts. Over 90% of the genome is covered by TEs predominantly belonging to the Gypsy superfamily. These TE bursts have likely been followed by deamination events of methylated cytosines to silence the repetitive elements. This in turn led to the depletion of CpG sites in TEs and a very low overall GC content of 33.8%. Compared to other Pucciniales, the intergenic distances are increased by an order of magnitude indicating a general insertion of TEs between genes. Overall, we show how TEs shaped the genome evolution of A. psidii and provide a greatly needed resource for strategic approaches to combat disease spread