# Genome

By [devona168](https://paragraph.com/@devona168) · 2021-10-29

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Apple is diploid (though triploid cultivars are not uncommon), has 17 chromosomes and an estimated [genome](https://en.wikipedia.org/wiki/Genome) size of approximately 650 Mb. Several whole genome sequences have been made available, the first one in 2010 was based on the diploid cultivar ‘[Golden Delicious](https://en.wikipedia.org/wiki/Golden_Delicious)’.[\[13\]](https://en.wikipedia.org/wiki/Apple#cite_note-auto-13) However, this first whole genome sequence turned out to contain several errors[\[14\]](https://en.wikipedia.org/wiki/Apple#cite_note-14) in part owing to the high degree of heterozygosity in diploid apples which, in combination with an ancient genome duplication, complicated the assembly. Recently, double- and trihaploid individuals have been sequenced, yielding whole genome sequences of higher quality.[\[15\]](https://en.wikipedia.org/wiki/Apple#cite_note-auto2-15)[\[16\]](https://en.wikipedia.org/wiki/Apple#cite_note-auto1-16) The first whole genome assembly was estimated to contain around 57,000 genes,[\[13\]](https://en.wikipedia.org/wiki/Apple#cite_note-auto-13) though the more recent genome sequences support more moderate estimates between 42,000 and 44,700 protein-coding genes.[\[15\]](https://en.wikipedia.org/wiki/Apple#cite_note-auto2-15)[\[16\]](https://en.wikipedia.org/wiki/Apple#cite_note-auto1-16) Among other things, the availability of whole genome sequences has provided evidence that the wild ancestor of the cultivated apple most likely is _Malus sieversii_. Re-sequencing of multiple accessions has supported this, while also suggesting extensive introgression from _Malus sylvestris_ following domestication.

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*Originally published on [devona168](https://paragraph.com/@devona168/genome)*