Google phenotype.

I also see this when the roots get tangled.

Seed gets planted wrong end up.
Root tip emerges, makes it's U-turn, sees daylight, heads back down and loses the fulcrum needed to shed it's husk.
That uses up all the energy stored in the seed and the plant stress-flowers with a tangled rootball.

Attachment 296772Attachment 296773

Or. it could be something else.

Aloha,
Weezard