Sterile hybrid sweet peppers?

[Jang]

I’ve been growing a mix of different coloured sweet peppers marketed by Florian for a few years. Last autumn I saved seed separately from a red pepper, a yellow one and a black one.
I wasn't expecting the seed to come true but in fact, only the seed saved from the red pepper has germinated. The black and yellow seed has refused to germinate at all.
I suppose this must be a classic example of hybrid sterility implying that the black and yellow peppers are hybrids and the red not. I’m assuming (hoping) I didn’t mishandle the seed in some way.
I wonder how common hybrid sterility is. It seems possible to dehybridise tomatoes.

[Galina]

Hybridisation itself does not lead to sterility. Your red pepper can still be a hybrid.

But one of the processes of making commercial hybrids can lead to sterility in future generations. There is such a thing as using 'male sterility'. Where you have a plant that is made to be male sterile. This means it cannot transfer pollen to itself or to another variety, so pollen from another variety must be used. And this produces a guaranteed cross, because the variety's own pollen is prevented from playing a part. After all peppers can self pollinate as well as be cross pollinated by insects. The offspring, although fertilised itself by the pollen from another variety, probably has inherited the male sterility and the seed itself is not fertile or less than fully fertile. Certainly carrots are hybridised that way and landrace breeders, like Joseph Lofthouse has described in one of his podcasts how he had to overcome that. I am not sure about commercial pepper breeding, but this is potentially the culprit here.

First step, if you want to carry on with this experiment, would be to sow all seeds of the black and yellow and hope that a very small amount might be fertile. But be prepared for luck and for disappointment.

[Jang]

Thanks very much for this explanation. I’ve done a little further reading based on your pointer towards the inducing of male sterility for hybrid breeding purposes.
I have made further attempts to germinate both lots of seed using damp kitchen roll and still no sign of life. Perhaps for the moment the experiment has simply led me, with your help, to a little further understanding rather than to a fine line of interesting peppers!

[jayb]

Interesting topic, I didn't think male sterility was very widespread in sweet peppers, but they seem to meddle in most things so I shouldn't be surprised.
As Galina says and it was one thing I noticed growing hybrid male-sterile carrot varieties are the flowers produce no pollen, thereby they are unable to self which is the purpose to allow another variety to be grown alongside to cross-pollinate it. It's just weird and sad seeing the flowers without pollen. Male sterility is then carried forward to the next generation.

Did your pepper plants self or were they left for insects to mingle?

I don't think I've knowingly sown saved seeds from varieties with the terminator gene, although one or two f2 grow outs from F tomatoes have produced some poor growing plants. I remember reading a piece written by Tom Wagner discussing how it would be relatively easy to introduce this into tomato lines. (sorry no link back to it)

I was having a little read about,

https://www.tandfonline.com/doi/abs/....2014.11513108
https://www.sciencedirect.com/scienc...04423815302004
https://books.google.co.uk/books?id=...page&q&f=false

[Jang]

Taking up your comment that the male-sterile carrots you grew produced no pollen, I'm wondering whether that means that male sterility in a pepper should be obvious to the eye. I'm growing some more from fresh seed so will be more observant this season.

My plants were left to do their own thing amidst a lot of other varieties, mostly chilli.

[jayb]

I don't know, I fear plant sterility bred into plants is not so simple as one fits all. From the little understanding I have, different methods are used with different crops. Some hybrids have genes that render the seed they produce unable to germinate or die upon germination. Another example is carrot plants that are unable to produce pollen etc. To sidestep manual hybridising of crops there is the need to use one line to carry sterility with i think another line that carries a modifier/restorer to allow pollination.
Termination is a combination of breeding lines that produce productive hybrids but in combination prevent further generations surviving. Who in their right minds would follow this course?
With peppers, I think hot chillies work well with a restorer, sweet peppers not so much. But I guess this is a very poor grasp (and possibly an inaccurate one) of a very complex topic.

It will be interesting to hear if you get the same results.

[Jang]

Thanks for the references. The first one seems to suggest that induced male sterility in rappers is quite common but the second to suggest that a way of making it cost effective for production hasn't been found yet. So it's a bit difficult to know what to think.

Anyway, I can try to save seed from similar peppers this year in order to check out that I didn't just do something odd with the seed.

[Jang]

Rappers = peppers!
Must check more carefully.

[jayb]

Lol, sounds like your plants are partying!