[Arabidopsis] ap1 cal1 with petals

[bambusa from gmail.com]

Dear all,

I am growing ap1-1 cal1-1 double mutants from seeds ordered from ABRC
(CS6161), of which ap1-1 is homozygous and cal1-1 is heterozygous.
However, I saw some white petals from some of the plants. Could anyone
please help me to understand this, or give me some suggestions what I
should do with those plants having petals?

Thank you so much.

SL