Tropical roses for Australian rose breeding

Thought this might be a good opportunity to let people know of some special seedlings that I have coming through at the moment. 6 months(ish) ago Viru sent me a packet of seed from India of Rosa clinophylla. This rose is also known as the Swamp Rose because it grows for at least part of the year submerged by monsoonal rains. They thrive in hot humid conditions such as like we get in many parts of Australia. They started germinating a little while back and I now have over 80 Rosa clinophylla seedlings here growing in my little greenhouse. This is is a photo of some of them yesterday.


Closeup of the leaves:

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Their leaves are quite different looking.

The seed began germinating without any cold stratification like normal roses require. It is hoped that these can be incorporated into breeding roses more suited to life in Australia. Seeing as I have a lot of these I would like to make them freely available to people interested in using them for breeding.

There is a catch!

This species concerns me a little bit. The seeds germinated without any stratification and I have had an excellent germination rate. Feedback from others indicates that very hot weather seems to retard germination but once the weather starts cooling down they begin to germinate. I think it has potential to become a weed species here in Australia. I contacted AQIS about it and their opinion was that it was on the allowable imports list and that's the end of it as far as they were concerned. I asked them if a weediness assessment had been done on it and they replied saying there hadn't been one done because seed had been allowed into the country before rules and regs. tightened and now they haven't got a legal leg to stand on. So it will come down to us to be responsible with it. I do not want to go down in the history books as the person who brought another major weed into the country! So I'm going to be very selective as to what goes where and anything that gets sent out will go with conditions, or strings attached and I would like to discuss here best practice procedures for it. For instance, when these seedlings are larger and I have sent ones out to interested people I will be destroying all but five of them for me to keep as breeders. Once I'm finished using them in hybridising I will be destroying all but one them to keep here as a specimen plant (they are VERY large roses). They bloom continuously and are evergreen, in a warmer climate they will flower all year around, so any OP pollinated hips will be removed and destroyed and any prunings will be put through the chipper and mulched or burnt. Those are the kinds of strings that I think should be attached to keeping this plant. I think the winters down here will keep it in check but it worries me how it might respond to conditions in say northern NSW into QLD. I'm not sure it will survive outdoors here so if it doesn't I will be asking for pollen from to use from others to whom I have sent plants. I won't be sending any plants out until at least mid-spring, 2010. ANother thing might be not to, under any circumstances, use it as a rootstock. Then we could never keep track of where it is.

Anyway... don't let this stop you from requesting one if you would like to use it in breeding. I won't be sending them out to people who just want to grow on for their garden, unfortunately, so please do not ask if this is what you want it for. I might be being overly cautious but until such time as we know things like whether seedlings can germinate in the environment etc I think we should be cautious. If we can demonstrate that it poses no risk then that would be awesome (if the seeds have been here for a while and they haven't become a weed yet maybe it's ok... it's super large so not an ideal garden specimen so maybe we have this working in its favour). Let me know what you think should be added to this list of conditions.. basically mine are going to be grow under quarantine conditions here... just in case.

Here is the HMF link to the clinophylla page: [You must be registered and logged in to see this link.]

There are lots of other tropical and subtropical roses that we should be using too, such as R. roxburghii (but this has some strange breeding behaviour), gigantea, laevigata, banksiae, and bracteata.

Interesting and wise planning Simon. Don't need any more weeds around here - even roses lol. But are they feral in India - or anywhere else I wonder? You should see the dog rose in NZ - pretty thing, but no thanks.

No... interestingly clinophylla is critically endangered in its natural habitat (another reason why I don't REALLY want to destroy all the plants. They represent a significant gene pool). The problem is you can never really predict how a plant from somewhere else will behave in a different situation. We may not have the same development pressures, climate pressures, herbivory or disease pressures, and it might be able to spread unchecked. Development/habitat destruction was listed as the main cause of its decline in India. So, I guess I just want people to be aware that what they are in possession of is largely untested in terms of weediness potential and that there may be potential for it to become a major weed and that we should be mindful of this when we grow it.

The foliage on your seedlings is very attractive Simon...to me they scream of health!