Non-germinating seed (Maximoss)

[Kim K.]

Hello cucurbit fans,

I just germ tested the four lots of Maximoss (Maxima x. Moschata) seed I saved from my first grow out of seed from Joseph Lofthouse. The seed is two years old. Three lots were normal (78%-100%, with the statistical variation not meaningful because I only tested 10 or 11 seeds from each lot.) The other lot had zero germination.

Any idea what could cause this? I know Joseph cautioned me the cross wasn't completely stable and some seeds might be infertile, but is it normal for that to occur in every seed from a specific fruit?

My notes also mention this particular fruit experienced hard frost in the field before harvesting. (Missed it during the initial harvest.) That means I probably removed the seeds and cooked the flesh sooner than I otherwise would have, because frost can mean worse storage qualities. But the seeds all looked large and plump.

It's also possible that I did not ferment this batch of seeds in pulp and water like I normally do...but unfortunately if that's the the case, I didn't make a note of it.

Any educated guesses you guys have would be appreciated!

[Joseph Lofthouse]

It's common in the interspecies hybrids for particular fruits to be mostly infertile. One of the interspecies hybrids that I was most excited about last fall only had two viable looking seeds in it, and only one of them germinated. That's exciting!!!

You might try dissecting some of the seeds. Do they have endosperm and an embryo? Are they empty shells?

[Kim K.]

My daughters and I dissected the seeds and compared them with the viable ones. The infertile seeds had mold on the outside (the fertile ones did not.) The interiors of the infertile seeds had no sign of life, but looked full and plump. I do not know how to tell if a seed that hasn't germinated has an embryo. What should I look for?

[Kim K.]

And by the way, that is very exciting that you got a plant from that mostly infertile interspecies hybrid! Is it also a Max x. Moschata, or some other cross?

[Joseph Lofthouse]

I don't keep many records in my garden. Therefore right now, I don't remember which interspecies hybrid it was. I'll recognize it when it gets a little bigger.

Often times, the interspecies squash seeds are just empty shells, or the insides will be only partially developed.