Tuesday, January 16, 2007

Intergeneric Crossing

We have a special entry for you today!!! When I got the new issue of African Violet, I happened to turn to Dr. Smith's column about breeding new violets. The first question on the page is one that I've wondered about since I got interested in violets. Can you cross a Saintpaulia with any of the other gesneriads??? His answer is informative and interesting (page 6 of the new Jan/Feb AV) but made to fit the limited space of the Q&A format. I had more questions. I kept wondering about trying to cross a violet with streptocarpus or a sinningia and then I got a bit of inspiration..... ask some people who would know!

I wrote to Dale Martens who has made some fantastic intergeneric crosses! (Click on the link.) She is the co-author of Crosswords, a publication for hybridizers, and she was the featured speaker at a half-day seminar put on by the AGGSTC, the local gesneriad club, in September of 2005. In addition, Dale is one of the nicest people you could want to meet! When I wrote to her with my questions for the blog she immediately took the time to answer... Here is her reply!
"For those new to intergenerics, streptocarpus is a genus and Saintpaulia is a genus (with a common name of African violets). If you cross two different genera (plural for genus) you have an intergeneric. Which gesneriads make the best candidates for hybridizing: Ones that have the same number of chromosomes so they match. How do you find out the number of chromosomes? Research! I believe sinningia is aroudn 26 and streptocarpus is 32, but could be wrong. One must put an "x" in front of the intergeneric's name which is a combination of both genera. I have crossed achimenes x smithiantha to get xAchimenantha, and Phinaea x Diastema to get xPhinastema, and smithiantha x eucodonia to get xSmithicodonia. The closest genera to Saintpaulia is streptocarpus, but genetically not just any streptocarpus. Studies seem to indicate that the evolution of Saintpaulia is from the Streptocarpus subgenus Streptocarpella.

Streptocarpellas are stemmed and branching streptocarpus with fuzzy leaves. A common one is Streptocarpella 'Blueberries and Cream'. Some of us have tried crossing streptocarpella x saintpaulia. The most likely person to succeed probably needs to cross a species AV with a species streptocarpella that lives near it (within miles) in Africa in nature. Therefore, it'd take some research to find which ones live close to each other. I have tried crossing species AVs with all sorts of other gesneriads including Petrocosmea since to me it's most similar. But Petrocosmeas live in Asia, so it's quite unlikely to cross with an AV."

Again, a special "Thank You!" to Dale for taking the time to reply! Hopefully, even more will follow about the intergeneric hybridizing of gesneriads and more specifics on the Saintpaulia genus.

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