At least now I know the correct term for what I am studying.
I realize it is quite a leap for me, based on my limited findings, to deduce the existence of more than one highly polyploidy species that could be mistaken as one species, but on the other side of the coin, it would also be ridiculous to claim there is only one…I’m just intrigued at the possibility of finding a mulberry with Morus nigra fruit quality that will prosper well in the southeast.
I am also intrigued with my latest find. As you know, I have been in pursuit of finding real Morus nigra seeds that others could order and grow. To date, I have bought eleven orders of seeds that seemed promising on Ebay and over the internet…mainly concentrating my efforts on foreign suppliers in countries that Morus nigras are found. All except one had small nuclei. This one from Greece is especially interesting. First of all, the seeds sprouted in six days (I have never had mulberry seeds sprout in less than two weeks). When I examined a seedling root it showed large nuclei consistent of Morus nigra. Now it is not uncommon for mulberry to have some polyploid nuclei, especially in the root cells, but ALL the nuclei in the roots were of Morus nigra size. But, two weeks later, I examined the first true leaves and was surprised to find a totally different story. These nuclei are Morus alba size (~ 6 um) and the cells are multinucleated. I have observed “binucleated” cells often in albas and rubras, but never more than two nuclei per cell.
I will examine the leaves in a few more weeks to see if there is any consolidation of nuclei into one large nuclei, or anything of that nature. The seeds were a little larger than alba/rubra seeds, but not the size of true nigra seeds. The person selling the seeds insists that they are Morus nigra and claims that the photos of the plant that the seeds came from are his photos (although I have seen these photos on other sites). The photos have some Morus nigra characteristics (What do you think?) Seeing that these seedlings also share the “jigsaw puzzle” cells, if it turns out that they grow up without turning into typical Morus nigras (nucleus size and all), I wonder if this may be the mulberry species that derived Morus nigra…Just a thought.
I need to edit this image (remove the “Morus nigra” title) because now I don’t know what to call it
Note the multinuceated cells.
Morus nigra??? No (see below)
It appears that only the seedling root tips have large 15 um nuclei typical of Morus nigra
…the leaves produced from these seedlings did not have large nuclei. I was not aware at the time that endopolyploidy is common in mulberry root tips. The seedlings from Greece are very intriguing though…The leaves have a majority of cells that are multinucleate, with some cells having as many as six nuclei. I frequently see cells that are binucleate in several cultivars of mulberry but never six nuclei. I am growing several of these plants to see what they become.