James575,

The cross is possible, and was accomplished a century ago in California, by Luther Burbank.

It was not an easy cross, according to Burbank, and I don't know that anyone has duplicated it. The plants were perenniel and could be grown from cuttings.

Karl

I tried this and got small empty seedpods. I tried both as the seed/pollinater parent.
I also crossed Nicotiana sylvestris with N. tabaccum and got many seeds. They weren't fully developed and not one grew.
Andy Reed

Was it a particular Nicotiana and Petunia species that Burbank used?

In the Genus Datura some species cross readily and some are imcompatible. However, D. leichhardtii can be crossed to all, but D. ceratocaula and serve as a bridge between incompatible species crosses.

For eksample, its next to impossible to get viable seeds from D. discolor x D. meteloides, but if you start to make D. leichhardtii x D. discolor and D. leichhardtii x D. meteloides then it will be possible to get viable seeds by making (D. leichhardtii x D. discolor) x (D. leichhardtii x D. meteloides) or D. discolor x (D. leichhardtii x D. meteloides) etc.

That is why I wonder, which specific plants Burbank used to obtain viable seeds :)

Thanks

Tonny in Denmark

I don't know if it would be possible to find out what species Burbank used. Sometimes he would make thousands of attempts at a cross and use whatever pollen was available without regard to which species it it came from.

I read a 4 volume biography published by the Luther Burbank Society and it actually had a picture of what he called a "Nicotunia". It was much like a sprawling Nicotiana with stunted, creeping growth, so he jokingly referred to it as a "petunia with a nicotine habit".

I've often wondered about this cross, and after a lot of research, found that a small wild species which has been collected from along railroad tracks in the Florida panhandle, Petunia parviflora, is the only one on record with the same haploid chromosone count as most Nicotiana species. Maybe someone can find one and give it a shot.

Academic types sometimes slandered Burbank because he was so often successful where they failed. If they tried at all. For some years it was doubted (by academics) that Logan and Burbank actually crossed Raspberries with Blackberries. Logan's Loganberry was a chance seedling, but there were no other parents available. Burbank's Primus and Phenomenal were deliberate crosses.

Luther Burbank: His Methods and Discoveries (12 volumes) is not hard to find. Check your public or university library. There is also an 8 volume set with much the same information, and maybe somewhat less misinformation. Burbank did not have editorial control of the 12 volumes.

From there it is useful to read what Burbank read: Herbert's Amaryllidaceae (with much about other hybrids he raised) and Darwin's Variations. All are fascinating sources of inspiration. And if you can find Ivan Michurin's works (e.g., Selected Writings) you can learn even more.

Karl King

Quotation from Luther Burbank: His Methods and Discoveries (II, 275-280)

"One of the most curious hybridizing experiments I ever performed consisted of crossing the common garden petunia with a variety of tobacco, known as Nicotiana Wigandiodes rubra.

In this cross the petunia pollen was used to fertilize the pistil of the tobacco plant. The seed thus produced was planted in the summer, as soon as it ripened, and possibly two hundred plants were raised.

When about a foot high the plants were placed in boxes in the greenhouse to keep over winter. They revealed no inclination to bloom, nor did they vary greatly from the parent tobacco plant, except in the matter of growth, which was very uneven, some of the hybrids being two or three times as large as others. The foliage was somewhat unusual; yet its resemblance to the tobacco was so great that a casual observer would have doubted whether the cross had really been made.

In a word, the characteristics of the tobacco plant seemed to preponderate.

But towards spring, when the plants were set again out of doors, they soon began to show the influence of their mixed heritage. Some of them turned crimson, and others pink; yet others remaining green. Moreover, the plants themselves developed a great diversity of habit. Even during the winter some of them had begun to fall over and show a tendency to trail like vines. As the second season advanced, some of these became genuine trailers like the petunia, and produced blossoms altogether different in color from the red flowers of the tobacco plant.

These plants did not bloom very abundantly, but their great diversity of form and peculiarity of foliage and flower made them a very striking lot of plants.

Some of them grew four or more feet in heithg with large tobacco-like leaves, and others were trailing dwarfs that to all appearances might have belonged to an entirely distinct race.

The plants that closely resembled the tobacco parent were, for the most part, weeded out. The ones that gave evidence of their hybrid origin were carefully nurtured. But it was noticed towards fall that although the tops grew splendidly, there seemed to be an unusual lack of roots. The plants would come to a certain size, and then take on what could perhaps best be described as a "pinched" appearance, from lack of vitality incident to their defective roots. There was, however, a great difference among the individual plants, some of them remaining strong throughout the season.

When the plants were taken up, it appeared that the sickly ones had produced only a few long, frail, wiry roots. It appeared to have been impossible for them to develop a thoroughly good root system. Evidently most of the new plants had inherited the rank-growing tops of the giant tobacco and the smaller, less efficient roots of the petunia."

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The plants were not sufficiently interesting to Burbank, so he left them out without protection in the winter and they died.

If anyone wants to repeat this experiment, I'd suggest keeping some of the Nicotiana seedlings to use as rootstocks. That way when the hybrid seedlings turned out too weak they could be grafted. And then?

Karl

Back when protoplast fusion was all the rage, petunia-nicotiana was one such thing that grew to maturity.
For those who don't renmember or are too young to remeber, protoplast fusion was done by disolving the cell walls of cells, getting naked protoplasts. These are living cells without cell walls. Protoplansts from different species were fused, and cell walls were allowed to re-form. Sometimes plants grew from the fused protoplasts. These were different from sexually produced hybrids in several ways.
1. The fused protoplasts had complete sets of chromosomes from each "parent". If both had been diploid, the reuslt was often a tetraploid. I say often, as somoetimes more than 2 protoplasts fused.
2. The plant that resulted could have more than 2 parents.
3. The resulting plants had the cytoplasm from both (all) parents.
They likely differed in other ways too.
As I remember, the petunia-nicotiana fusion derived plant made seeds. But my memory lies sometimes.
Plant protoplasts were also fused with mammal sperm. The resulting things metabolised for hours before it quit metabolising. That may mean it lived for some hours. There were no cell divissions.
This work was done just before gene splicing was successful. With gene splicing, the desire to fuse protoplasts gave way to just taking genes from on species to another.
Walter

The correct spelling of the tobacco species Burbank used is Nicotiana wigandioides.

Protoplast fusion is a fascinating subject. I read a book about it in the late 70s. In one line of research a mouse cell-line lacking a critical gene/enzyme was fused to a human cell. After several divisions all the human chromosomes had been discarded -- except for the one carrying the gene missing from the mouse line.

Something like this seems to be happening in some partial hybrids. The tendency is to discard most or all of the chromosomes from one parent, but a deficiency in the other parent allows at least part of the other's chromosome to remain, to fix the problem. For example, Lilium martagon album was pollinated by L. Hansoni. Several hundred of the seedlings looked like ordinary purple Martagons -- none had white flowers.

This suggests that it may be a good idea to keep the seed parent stressed, increasing the probability that paternal "genes" which can help the embryo survive in the weakened seed parent will be selectively retained.

Karl

Here is a link that might be useful: Hybrids of bulbous plants

In this DNA based classification, tobacco is closer to potatoes than to Petunias.
Go to Solanaceae_IV.pdf on linked page

Here is a link that might be useful: Olmstead publications