use strict;
use warnings;

$\ = "\n";
$, = ', ';


my %results = ();
my $line = 'HWUSI-EAS548:7:1:5:1527#0/1  + chr12  52084152 CGGAGC';

my @pieces = split /\s+/, $line;
my $id = $pieces[0];
my $seq = $pieces[-1];

$results{$id} = $seq;
foreach my $key (keys %results) {
    print "$key -----> $results{$key}";
}

--output:--
HWUSI-EAS548:7:1:5:1527#0/1 -----> CGGAGC