Hi There

I'm trying to germinate Musa Velutina, but I still do not succeed..
I do so:
I put the seeds in the water for 48 hours and change the water once in the day.
Then I plant them in a container and add in the container universal ground PH 5.5-6.5. and I plant the seeds half-in-ground, and half over. and cover the container with a zip lock bag, I opened the ziplock and sprayed every day.
I was happy because I noticed that started to germinate some seeds
then in a few days they went black.
the container had morning sun up to 12:00
is now at the window
some seeds have not yet germinated, but I think they will begin germination. the seeds are fresh.
why have they gone black? the root had to be formed.
maybe I should not have opened ziplock every day?
but fortunately I still have eight seeds and put them in the water today. and I will try to plant them deeper.
Thank you in advance