old seeds and 'blind' seedlings - any correlation?

[Ruth_10]

it would have to be an abberation of the same gene, or a similar gene that causes a blind seedling

It could be several genes are necessary for the process, start to finish, of divesting the seed coat, and loss of functionality of one or more would lead to varying degrees of blindness. It could be signaling factors that act up- or downstream from gene induction itself, as well.

Not sure if the seed coat gets harder with seed age - I always assumed that it is the embryo that gets weaker (as it slowly consumes nutrients that are stored in the seed over time), and that's why it gets harder for the seedling to shake off the coat.

Loss of vitality of the embryo sounds right to me. A seed that is kept frozen for many years (metabolic processes slowed to almost nothing) is both old and has a dry seed coat, yet is able to germinate and shake off its seed coat. A seed that is kept at room temperature (metabolic processes continuing at a good pace) for many years is old and its seed coat is at ambient moisture; success here will be variable.

Dice, would be interested in the reference on triploids, or even a rough time frame for when it was published.