Germinating roses in the summer (forced to germinate by embryo culture) as a way to select out heat tolerant roses

General Discussion
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Discussion on another thread prompted me to develop this theme further.

I have, for the last several years forced summer germinations of some of my OP seedlings, mainly to experiment/optimise embryo culture methods/tricks.

As a result I have incidentally found that seedlings are more likely to die if forced to germinate in this hot season. Not only that, but my climate is notorious for being bad to grow roses in it during any season, period. So I guess it stands that most rose seedlings are at a higher risk of dying round here, whatever the season, but especially so in summer time, to be sure!!!

Now a thought just occurred to me…maybe if I continue to germinate seedlings in my summer (via embryo culture) this could be a way of selecting heat tolerant types, and gaining time in the process!

A case in point, two R.clinophylla XOP embryos(from Viru and Girija Viraraghavan/India) which were forced to germinate in the summer of 2009 by embryo culture, did very well. They flowered around six months of age.

I am currently using one of these Clinophylla which I kept, in a cycle of breeding.

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George you dont have to germinate in summer to see if they are heat tolerate or not.Down at Denilqiun in November we had 38c (100F) in the second month of spring, I lost a couple which could not tolerate the heat , but this does not phase me as it is a good culling tool. Most of the roses I have bred have been exposed to 48c (118F) and got through alright due to this culling process.

This is one of my aims to breed roses which can be grown in Australian conditions (heat and low humidity). At the moment I am working on some new types which will hopefully be more suited for the Eastern Seaboard of OZ up into the semi tropics. I have found because the breeding of these are different than what I normally breed, they are not so tolerate of the very high temperatures we have here in Deniliquin. They should be ok in the cooler coastal regions.

Warren