Hibiscus: Hibiscus acetosella - Red Sheild in particular, 1 by Michael_Ronayne

Michael_Ronayne wrote:
The following research paper has an abstract which lists the chromosome count for 12 species of African and North American Hibiscus.

Cytotaxonomy of Twelve Species of Hibiscus Section Furcaria
http://www.jstor.org/pss/2440020

Diploid (n = 18 or 2n = 36)
H. cannabinus
H. costatus
H. surattensis

Tetraploid (n = 36 or 2n = 72)
H. acetosella
H. aculeatus
H. bifurcates
H. furcellatus
H. meeusei
H. radiatus
H. rostellatus
H. sabdariffa

Octoploid (n = 72 or 2n = 144)
H. diversifolius

The hybrid fertility of the African Hibiscus acetosella and Hibiscus radiatus, with 72 chromosomes each, was discussed above. What is interesting is that North American native Hibiscus aculeatus is unusual in that it has 72 chromosomes compared to the typical count of 38 chromosomes for most North American natives.

Profile for Hibiscus aculeatus (comfortroot)
http://plants.usda.gov/java/profile?symbol=HIAC

This raises the intriguing possibility that Hibiscus aculeatus may be able to hybridize with Hibiscus acetosella and Hibiscus radiatus, without the resources of a fully equipped genetics laboratory.

While the chromosome counts are the same, we don’t know if the African chromosomes will pair-off with the North American chromosomes. Also the flowering times between the African and North American species are different and it may be difficult to cross pollinate the African and North American species. Obviously two ways crosses would yield the greatest potential. Hibiscus aculeatus flowers throughout the growing season which is not the case with Hibiscus acetosella. Unless you have access to heated greenhouse, such experiments would have to be conducted in Florida.

Assuming that hybrids can be produced and the 72 chromosomes pair-off the advantage to the gardening community would be the following.

1. The range of the African hybrids would be significantly expanded in North America.
2. Blooming times of the African hybrids may more closely match the North American growing season.
3. Potentially the hybrids could be prolific bloomers like their North American parent.
4. African hybrids could have greater vigor than the parent species.
5. New Hibiscus forms could be created.
6. If the hybrids are fertile, inbreeding and back-crosses to the parent species become possible.

I have been searching for any indication someone else has already done the cross with Hibiscus aculeatus but haven’t found any evidence that such a cross has been made. Remember that Hibiscus aculeatus is not a highly regarded Hibiscus and it may have been overlooked. Here is the Google search I was using:
http://www.google.com/search?hl=en&q=Hibiscus aculeatus hybr...

Attached is a photograph of Hibiscus aculeatus seedlings which I am growing. The prickly hairs are just starting to form but are still soft. The seeds were purchased from Georgia Vines (Zone 8b) which I highly recommend.
http://www.georgiavines.com/cart/index.php?main_page=index&c...

Nicking the seeds and using conventional sowing techniques I had modest success with the first batch of seeds. With nicking and using the Zip-Lock bag technique I had an almost a 100% success rate with the second batch of seeds. Attached is a photograph of one of my starter trays with two different batches of Hibiscus aculeatus seedlings.

So which DG member in Florida wants to try and create a new Hibiscus hybrid?

Mike



This message was edited Dec 21, 2009 7:10 AM