hey phicac
not quite sure what you mean by "will they still be better than the mother" but from my experience less sunlight has not had an effect on the genetics of my seeds.
however plants grown in less than optimum conditions dont have the chance to show their full potential. this makes breeding pot luck!(no pun intended)
this is why when i choose to breed i like to grow at least 10 plants of the same strain under the same conditions so i can choose the best male and female to be the mummy and daddy.
it does get a lot more complicated and i have had to study genes, stabilisation and crossing procedures so far but i am still far from being a master like stitch, mossy and cres
what exactly were you thinking of breeding? if you give us a bit more detail we will be able to give much better help