What is the DNA Sequence for an apple?
https://www.rosaceae.org/species/malus/malus_x_domestica/genome_v1.0

You can see the data in the URL above. The details are described in this article.

As others said, NCBI seems useful.
Go to this site.
Chose chromosome you want to see and click genebank or refsequence corresponding to the chromosome in the table (Assembly Unit: Primary Assembly). 
You can see overview of the sequence.
Find FASTA in the page showing the overview and click FASTA. Then the sequence data will be downloaded.