I mentioned in an earlier thread under inground citrus that I had found one seed from a bag of minneola tangelos. Since most of the fruits were seedless, I figured that they had been the result of GA treatment with the single seed being the result of long distance pollination.

Anyway, I planted the seed and it has sprouted, but my minneola seed appears to be polyembryonic! I think there are three plants. That means that these should be clones of the mother plant correct? Also is it true that one of the plants could be a hybrid and the other 2 clones?

Skeet

Yes it could be. Also, they could all be clones. When you let them all grow until they are about 4", those that appear to be the same most likely are clones, while the single taller or shorter than the others would most likely be the hybrid. Look also into the leaves. Problem is that the others would die out soon, living only one or two.

Ok So I am trying to understand this as well. 2 of my Shikwasa seedlings have two sprouts coming from one seed. What does this mean exactly? Will both be exact clones of the parent tree or only one of them...

This whole monoembryonic versus polyembryonic thing have me confused.

My Ugli (Mono) Seedlings came up with one sprout so they will most likely be something "like" and Ugli fruit but not an exact clone.

I wasn't sure if Shikwasa Mandarins are Mono or polyembryonic.

Thanks for the reply Joe. I was under the impression that Minneola Tangelos seeds were not true to type which I thought meant that the seeds would be monoembryonic (and hybrid). I guess that would probably be the case if the seed had been the result of cross pollination, which is one way to get fruit from Minneolas.

When should I try to separate the seedlings?

Hi Marc,
I will try to explain what I know and leave the rest to the real experts. The fact that a single seed is monoembryonic (has only one embryo) does not mean that the mother plant is not capable of producing polyembryonic seeds, however, if a plant is capable of producing polyembryonic seeds (more than one embryo per seed) then at least one of the resulting plants will be a clone of the mother (all of them may be).
For plants that produce polyembryonic seeds it is also possible that one of the plants (embryos) will be a hybrid (product of sexual reproduction, ie pollen fertilizing the flower to produce a genetically different ofspring).

It is my understanding, experts correct me if I'm wrong, that those citrus plants that produce only monoembryonic seeds are generally not true to type (they are hybrids). Those plants that need pollination such as Minneola should fall into that category.

I think that the seed I found in this batch of Minneolas (which was seedless except for the one seed) was produced by the cloning process typical of many citrus. Seedless Minneolas are produced by spraying with gibberelic acid in lieu of pollination. Pollination produces a seedy fruit.

Skeet

The reason that Minneola contains very few seeds is because Minneola is sexually incompatible. Along with Minneola being sexually incompatible, it is also weakly parthenocarpic. Parthenocarpy is the ability to set fruit that contain little or no seeds. Therefore generally you have to eat five or six minneolas in order to obtain any seeds. in the case of polyembryonic seeds, more often then not, all of the embryos are nucellar embryos, therefore all of the seedlings are identical clones to the female parent. However, it is also possible that one of the embryos could by a zygote therefore one of the seedlings could be a hybrid. Three factors contribute to the development of only nucellar embryos at he EXPENSE of zygotic embryos. (1) nucellar embryos grow more rapidly within the seed, thereby getting a head start on the zygotic embryo, (2) the zygotic embryo is located unfavorably in the apex of the embryo sac and may receive fewer nutrients and is more subject to being crowded out, (3) zygotic embryos are usually genetically weaker than their nucellar counterparts. When a zygotic seedling is produced it is often recognized by differences in internode length, leaf size, leaf shape, leaf color, growth rate, foliage density, and branching. Such nonuniform or off type seedlings probably developed from zygotic embryos. Off type seedlings (zygotic) are generally avoided, but they may have potentially interesting characteristics, and worth growing on.. - Millet

Thanks Millet,
Am I correct in my thinking that if the Minneolas had been produced by cross pollination that the seeds would have been monoembryonic?

Skeet